Resumo em Inglês:The objective of this study was to evaluate the methodology to establish the hemolytic activity of alternative complement pathway as an indicator of the innate immunity in Brazilian fish pacu (Piaractus mesopotamicus), in addition to verifying the influence of β-glucan as an immunostimulant. Fish were fed with diets containing 0, 0.1 and 1% β-glucan, during seven days, and then inoculated with Aeromonas hydrophila. Seven days after the challenge, they were bled for serum extraction. The methodology consisted of a kinetic assay that allows calculating the required time for serum proteins of the complement to promote 50% lysis of a rabbit red blood cell suspension. The method developed in mammals was successfully applied for pacu and determined that the hemolytic activity of the proteins of the complement system (alternative pathway) increased after the pathogen challenge, but was not influenced by the β-glucan treatment.
Resumo em Inglês:The objective of the present study was to evaluate the efficiency of the process of biodigestion of the protein concentrate resulting from the ultrafiltration of the effluent from a slaughterhouse freezer of Nile tilapia. Bench digesters were used with excrements and water (control) in comparison with a mixture of cattle manure and effluent from the stages of filleting and bleeding of tilapias. The effluent obtained in the continuous process (bleeding + filleting) was the one with highest accumulated population from the 37th day, as well as greatest daily production. Gases composition did not differ between the protein concentrates, but the gas obtained with the use of the effluent from the filleting stage presented highest methane gas average (78.05%) in comparison with those obtained in the bleeding stage (69.95%) and in the continuous process (70.02%) or by the control method (68.59%).
Resumo em Inglês:The objective of this research was to evaluate the effect of the addition of two Lactobacillus strains on the aerobic stability of the sugar cane (Saccharum spp.) silages. The experiment was carried out in a completely randomized design with three replicates in split-plot in time scheme, so that the treatments (silages without inoculant and with novel strain or commercial inoculants) were randomized on plot and in times of aerobic evaluation of the silages (zero, two, four, and six days after the opening of the silos) as subplots. The loss of stability of silages was continuous during the time of aerobic exposure. Inoculants influenced the changes in populations of lactic acid bacteria and yeasts and in the ammoniacal nitrogen, acetic acid and ethanol concentrations. The dry matter, crude protein, soluble carbohydrates contents and pH values showed similar changes in all three silages studied. A linear increase in crude protein content and pH values and decrease in the soluble carbohydrates content were observed. The dry matter contents increased to a maximum of 335 g/kg on fresh matter at four days, followed by reduction after six days. The results showed that the use of inoculants is recommended because it promoted higher production of acetic and propionic acids, reducing the population of yeast and, therefore, improving the aerobic stability of silages.
Resumo em Inglês:The objective of this study was to evaluate the effect of sugar cane ensilage with different Brix degrees, with or without the addition of 0.5% of calcium oxide (lime) on the chemical composition and fermentation losses of silages. A complete random design in a 9 × 2 factorial arrangement was used. Experimental silos were used, ensilage was done every 15 days with Brix measuring, and they were opened after 30 days of fermentation. As the Brix degree of the ensiled material increased, the contents of dry matter (DM) increased and contents of ash, crude protein (CP) and fibers (neutral and acid detergent fiber corrected for proteins - NDFap and ADFap) reduced. After fermentation, DM content of the silage presented a linear increase with the Brix degree content concentration, positively correlating with content of lime, but the contents of ash, CP, EE and NDFap were linearly reduced with the Brix increase. Content of ADFap suffered linear reduction for the treated silage whereas quadratic behavior was found in the untreated silage. Production of ethanol was presented in a quadratic manner for the silages without lime, and cubically in silages with lime, according to the Brix degree. The treated or untreated silages presented an average pH of 3.98 and 3.50, respectively. Contents of acetic acid and butyric acid were not affected by the lime content and Brix degree. Untreated silages presented reduction of contents of propionic acid as the Brix degree increased. The higher the Brix degree value, the higher the total losses of dry matter in the sugar cane silages with or without treatment. The treatment of the sugar cane with 0.5% calcium oxide on the natural matter basis is effective in reducing the undesired fermentation of the ensilage material.
Resumo em Inglês:The present experimental assay evaluated the effect of lab silo sealing methods on the ensilage of the sugarcane, with or without microbial additives (Lactobacillus plantarum and Propionibacterium acidipropionici). Twenty-liter plastic buckets were used as experimental silos, which were sealed with either a polyethylene sheet (silo cover with a mesh size of 200 µm) or an appropriate plastic lid equipped with Bunsen valve. Silos were stored for 30, 60, or 90 days. Fermentative losses, chemical composition, organic acids, ethanol and aerobic stability were evaluated. The sealing method employed did not influence most of evaluated variables, showing a small decrease of effluent production in silos covered with polyethylene sheet. The microbial additive did not avoid dry matter (DM) fermentative losses in sugarcane silages (216 g kg-1), nor affected aerobic stability (44.6 hours). The levels of neutral and acid detergent fiber of fresh sugarcane increased after ensiling due to DM losses as gases and effluent. The ethanol content of silages was not influenced by treatments (mean 146 g kg-1 of DM). The sealing methods of experimental silos were not affected by the evaluated variables; polyethylene sheet and plastic lid show the same performance on the fermentative model and both methods represent well the conditions of large scale farm silos.
Resumo em Português:Objetivou-se com este trabalho avaliar a disponibilidade de forragem, a composição morfológica e química do pasto, a capacidade de suporte do pasto e a produção de leite de vacas em três gramíneas forrageiras sob lotação contínua e taxa variável em solo de várzea. O delineamento experimental foi inteiramente casualizado com três tratamentos e três repetições. Os tratamentos constituíram-se das gramíneas Paspalum atratum cv. Pojuca, Brachiaria humidicola cv. Llanero e capim-tangola, híbrido natural de Brachiaria arrecta e Brachiaria mutica. A taxa de lotação foi ajustada para manter a forragem disponível entre 2.000 e 3.000 kg de massa seca por hectare. O período avaliado foi de novembro de 2003 a maio 2004. Não houve diferença significativa entre as espécies quanto à disponibilidade de massa seca de forragem verde, com valor médio de 2.902 kg/ha. O capim-pojuca apresentou 62% de lâminas foliares e 38% de colmo + bainha na massa seca de forragem verde, seguido pelo capim-humidícola com 49 e 51% e o capim-tangola com 18 e 82%, respectivamente. O capim-tangola apresentou teor mais alto de proteína bruta na lâmina foliar (15,41%) que os capins humidícola (9,98%) e pojuca (8,74%) e menores de fibra (FDN e FDA). A produção individual das vacas refletiu o melhor valor alimentício do capim-tangola, cuja média diária (10,27 kg/vaca) foi maior que no capim-pojuca (7,80 kg/vaca) e semelhante ao obtido com capim-humidícola (9,16 kg/vaca). A produção de leite por área não foi afetada pela gramínea forrageira, com média de 27,8 kg/ha × dia-1, uma vez que a taxa de lotação um pouco mais alta no capim-pojuca, apesar de não apresentar diferença significativa, compensou a menor produção individual das vacas.
Resumo em Inglês:The objective of this study was to evaluate the forage availability, pasture morphological and chemical composition, pasture carrying capacity and the milk production of cows on three forage grasses under continues stocking and the variable rate on lowland soil. The experimental design was completely randomized with three treatments and three replicates. The treatments were the Paspalum atratum cv Pojuca grass, Brachiaria humidicola cv Llanero grass and tangola grass (natural hybrid of Brachiaria arrecta and Brachiaria mutica). The stocking rate was adjusted to maintain the forage available between 2.000 and 3.000 kg dry matter per hectare. The period evaluated was from November 2003 to May 2004. There was no significant difference between the species when the dry matter availability of green forage was evaluated, with mean value of 2.902 kg/ha. The pojuca grass had 62% of leaf blade and 38% of stem + sheath in green forage dry mass, followed by humidícola grass with 49 and 51% and tangola grass with 18 and 22%, respectively. The tangola grass showed higher level of crude protein on the leaf blade (15.41%) than humidícola (9.98%) and pojuca (8.74%) grasses and lower levels of fiber (NDF and ADF). The individual production of cows was affected by the better nutritional value of the tangola grass. The average daily production of this grass was higher (10.27 kg/cow) than the pojuca grass (7.8 kg/cow) and had similar value to humidícola grass (9.16 kg/cow). The milk production per area, with had mean of 27.8 kg/ha × day-1, was not affected by the forage grasses because the more high stocking rate of pojuca grass, although not significant, compensated the lower individual production.
Resumo em Inglês:This study was carried out with the aim of assessing the efficacy of the fluazifop-p-butyl herbicide to control Brachiaria brizantha, cultivar Marandu, in the formation of Tifton 85 grazing. Treatments consisted of five doses of fluazifop-p-butyl herbicide (0.0, 62.5, 125.0, 187.5 and 250.0 g ha-1) plus controls with no herbicide, in a completely randomized layout, with four replications. Each plot consisted of a 10-L capacity pot, with two B. brizantha plants and two Tifton 85 plants. The herbicide application was conducted before the tillage of B. brizantha, when they were about 15 cm high. Visual assessments of control of B. brizantha and intoxication of Tifton 85 plants, at 07, 21 and 45 days after application were carried out. Sixty days after application, plants were harvested at ground level and oven-dried. Regrowth was assessed in the same manner, 60 days after cutting, to determine their dry weight. Control of B. brizantha was noted to be above 50%, from doses of 218.75 g ha-1 at 45 days after application. The fluazifop-p-butylherbicide did not show to be efficient in the control of B. brizantha in the doses assessed and caused intoxication to Tifton 85 plants.
Resumo em Inglês:This study evaluated the morphological development of two populations of tough lovegrass during 120 days of continuous growth (Experiment I), and the regrowth of one population under the combination of cutting height (5 cm and 10 cm) and phenological stage at the first cutting (vegetative and beginning of flowering; Experiment II). In Experiment I, plants were harvested at 30, 60, 90 and 120 days of growth; in Experiment II, three cuttings were carried out at every 30 days, and the plants were harvested four weeks after the previous one. In Experiment I, the populations did not differ for morphological development, showing a linear increase in height and tiller number, and a quadratic trend for root and shoot dry matter (DM). At 120 days of growth, plants presented 10 basal tillers and 80 leaves, strongly compressed at the base and no sign of senescence. In Experiment II, there was no significant cutting height × phenological stage interaction, but cuttings at 5 cm reduced plant size and yield. Cuttings started at the vegetative stage decreased the root (3.06 g DM/plant) and stubble dry matter (1.17 g DM/plant), compared with 6.84 g and 3.99 g DM/plant, respectively, with cuttings started at the flowering stage. Tough lovegrass shows basal architecture, basal bud renovation, leaves densely compressed in the tiller base, high belowground allocation, and elongation of internodes only in reproductive stage. Mechanical control is an alternative method to minimize its growth, especially if it is carried out early in the growing season and at low cutting height.
Resumo em Português:Este experimento foi conduzido com os objetivos de caracterizar e quantificar as frações que compõem os carboidratos e a proteína de diferentes silagens. Foi utilizado delineamento inteiramente casualizado com quatro tratamentos e cinco repetições: silagem de milho (AG 5011), silagem de sorgo-sudão, silagem de sorgo-forrageiro (BR 601) e silagem de girassol (Rumbsol 91). A silagem de girassol apresentou menor valor de carboidratos totais (CT) e da fração B2 (fração potencialmente degradável da fibra). As silagens de milho, sorgo-sudão e sorgo-forrageiro não apresentaram diferença quanto aos teores de carboidratos totais. A fração C (fração indigestível da parede celular) foi encontrada em maior proporção nas silagens de sorgo-sudão e girassol. Não houve diferenças na fração A da proteína (nitrogênio não-proteico) entre as silagens. A silagem de girassol apresentou maior valor de proteína bruta e nitrogênio total. Não foi observada diferença nos resultados entre as silagens de milho e sorgo, e a fração C foi menor para silagem de milho e sorgo forrageiro. As silagens de sorgo-sudão e sorgo-forrageiro apresentam menor valor nutritivo, devido à maior quantidade de parede celular e ao menor conteúdo de energia em comparação às silagens de milho e girassol.
Resumo em Inglês:This experiment was conducted to characterize and quantify the fractions that make up the carbohydrate and protein in silages. The design was completely randomized with four replications and five treatments: corn silage (AG 5011), sorghum-sudangrass silage, forage sorghum silage (BR 601) and sunflower silage (Rumbsol 91). Sunflower silage had the lowest value of total carbohydrates (TC) and B2 fraction (potentially degradable fraction of the fiber). Silages of corn, forage sorghum and sorghum-sudangrass showed no difference in cholesterol levels. Fraction C (indigestible cell wall fraction) was higher in silages of sunflower and sorghum-sudangrass. There was no effect on the protein fraction (non-protein nitrogen) between silages. Sunflower silage showed higher crude protein and total nitrogen. No differences were found between the silages of maize and sorghum, and fraction C was smaller for the corn silage and forage sorghum. Silages of corn, forage sorghum and sorghum-sudangrass presented lower nutritional value due to the greater amount of cell wall and less energy, when compared with silages of corn and sunflower.
Resumo em Inglês:The objectives of this study were to define breeding objectives and derive economic weights for production traits in family-based beef cattle systems, assess the sensitivity of these weights to changes in market and husbandry indicators and estimate the expected genetic changes in the selection criteria proposed. Based on data from the production systems, farms revenues and expenses, obtained from interviews and meetings with producers, a bioeconomic model was derived, relating biological traits of animals with the financial result of the production system based on calf-crop, selling male calves and culling cows for finishing. Traits considered in the model as breeding goals were weaning rate, weaning weight and cow weight. The economic weights, obtained by the partial derivative of the bioeconomic model with respect to the trait in question, assessed on the average value of the remaining traits, were R$ 73.21% for weaning rate, R$ 17.07/kg for weaning weight and R$ 4.75/kg for cow weight. An index for joint selection of these three criteria would allocate 89.5% of importance to weaning rate, 6.9% for weaning weight and 3.6% for cow weight. In this way, for every R$ 100.00 of genetic gain in this index, there would be an increase of 1.4% in weaning rate, but with reduction of 0.004 kg in weaning weight and 0.665 kg in cow weight due to negative genetic association between these traits. The proposed index and the relative importance identified for the economic traits can guide the selection decisions of smallholders, both in the choice of their animals and in the acquisition of bulls, cumulatively increasing the productivity of their herds.
Resumo em Inglês:The experiment was carried out to evaluate the performance and body development of beef heifers reared from 15 to 18 months of age on Pearl millet (Pennisetum americanum), Alexandergrass pasture (Urochloa plantaginea) or native pasture invaded by Annoni-2 grass (Eragrostis plana Nees). The experimental design was completely randomized following a repeated measure arrangement, with three treatments and two replications. The grazing method was continuous with variable stocking rate in order to maintain the sward height at 40 cm. Masses of leaf, stem and dead material, crude protein and neutral detergent fiber were similar between Pearl millet and Alexandergrass. Average daily gain, stocking rate, live weight gain per hectare, body weight, body condition score, weight-to-height ratio and reproductive tract score of the heifers kept on annual summer pastures (Pearl millet or Alexandergrass) were superior, compared with the heifers on Annoni-2 grass pasture.
Resumo em Inglês:The efficacy of estrus synchronization using short-term protocol was evaluated by ultrasound exams in Suffolk ewes during the pre-breeding season. The control Group (n = 12) was synchronized by treatment for 12 days with vaginal sponges impregnated with medroxyprogesterone acetate, and 400 IU eCG at sponge withdrawal. Experimental groups I, II and III kept the sponge in place for 4 days, and 100 µg of PGF2a was administered at sponge withdrawal. Additionally, Group I (n = 12) had 0.1 mg of estradiol benzoate (EB) administered during sponge placement and 50 µg of GnRH 48 hours after sponge removal. Group II (n = 6) had 35 mg of progesterone (P4) injected, and 0.1 mg of EB administered during sponge placement, 400 IU eCG at withdrawal and 48 hours after, 50 µg GnRH were administrated. Group III (n = 12) had 35 mg of P4 and 0.2 mg of EB administered at sponge placement, 400 IU eCG at withdrawal, and 50 µg of GnRH was administrated after 56 hours. Ovaries were monitored through ultrasound scanning. Concerning the first wave, no difference was detected between the control group and the experimental groups. However, the characteristics of ovulatory wave were significantly different between the groups. The duration of the follicular wave was shorter for Group III than for Group II. The follicle in Group I reached its maximum diameter before the Group II. The diameter of the follicle at the sponge withdrawal in the control group was larger than in Group I. After sponge withdrawal, the follicular growth rate was smaller in the control group than in Group III. The maximum diameter of the follicle in Group II was larger than in the other groups. The short-term protocol in which estrogen was used did not synchronize the emergence of the wave of follicular development.
Resumo em Português:Este estudo foi conduzido com o objetivo de determinar a exigência de fósforo digestível de suínos em crescimento. Foram utilizados 70 suínos mestiços (35 machos castrados e 35 fêmeas), com peso médio inicial de 29,72±1,52 kg, distribuídos em delineamento de blocos casualizados, com cinco tratamentos, sete repetições e dois animais (um macho e uma fêmea) por unidade experimental. O experimento teve duração de 21 dias. Os tratamentos consistiram de rações à base de milho e farelo de soja suplementadas com fosfato bicálcico, correspondendo a cinco níveis de fósforo digestível (0,19; 0,25; 0,30; 0,35 e 0,40%). Para cada nível de fósforo estudado, foi adicionado calcário buscando manter constante a relação cálcio:fósforo das dietas. O aumento dos níveis de fósforo digestível influenciou de maneira quadrática o consumo de ração e o ganho de peso, cujos valores máximos foram obtidos nos níveis de 0,32 e 0,31% de fósforo digestível, respectivamente. Não houve efeito dos níveis de fósforo digestível sobre a conversão alimentar. Os teores de cinzas e de cálcio analisados nos metatarsos não foram influenciados pelos níveis de fósforo digestível, enquanto o teor de fósforo apresentou resposta linear. A exigência de fósforo digestível para suínos alimentados com dietas à base de milho e farelo de soja é de 0,31%, que corresponde ao consumo diário de 5,87 g de fósforo digestível.
Resumo em Inglês:This study was carried out to determine the digestible phosphorus requirement for growing swine. Seventy crossbred swine (35 castrated males and 35 females), with initial weight of 29.72±1.52 kg were distributed in a completely randomized design with five treatments, seven replicates and two animals (one male and one female) per experimental unit. The experiment lasted 21 days. The treatments were composed of diets formulated with corn and soybean meal, supplemented with dicalcium phosphate, corresponding to five levels of digestible phosphorus (0.19; 0.25; 0.30; 0.35 and 0.40%). For each phosphorus level, limestone was added to maintain the calcium:phosphorus ratio constant. The increase in digestible phosphorus influenced feed intake and weigh gain quadratically, and the maximum values for those parameters were obtained with the levels of 0.32 and 0.31% digestible phosphorus, respectively. There was no effect of digestible phosphorus levels on the feed:gain ratio. The ashes and calcium contents analyzed in the metatarsi were not influenced by digestible phosphorus levels, while the phosphorus content in bone showed linear response. The requirement of digestible phosphorus for pigs fed diets based on corn and soybean meal is 0.31%, corresponding to a daily intake of 5.87 g digestible phosphorus.
Resumo em Português:Dois experimentos foram realizados com o objetivo de determinar as relações adequadas de arginina:lisina, isoleucina:lisina, valina:lisina e triptofano:lisina digestíveis para frangos machos nas fases inicial (7 a 21 dias) e de crescimento (28 a 40 dias de idade). Um total de 1.800 frangos no período inicial e de 1.440 no período de crescimento foi distribuído em delineamento inteiramente casualizado com 9 tratamentos e oito repetições de 25 e 20 aves por unidade experimental nos períodos inicial e de crescimento, respectivamente. As relações utilizadas no período inicial foram: 100, 105 e 110 arginina:lisina; 60, 65 e 70 isoleucina:lisina; 70, 75 e 80 valina:lisina; 15, 16 e 17 triptofano:lisina; e, no período de crescimento: 95, 105 e 115 arginina:lisina; 58, 67 e 76 isoleucina:lisina; 71,5, 77 e 82,5 valina:lisina; 14, 17 e 20 triptofano:lisina. As dietas experimentais foram formuladas atendendo às exigências mínimas de nutrientes, exceto lisina digestível (1.08% para o período inicial e 0.98% para o crescimento). No final dos experimentos, foram determinados o ganho de peso, o consumo de ração, a conversão alimentar, o peso e os rendimentos de peito e de filé de peito. No período inicial, não houve efeito das relações arginina:lisina e triptofano:lisina sobre os parâmetros avaliados, entretanto houve efeito linear das relações isoleucina:lisina e valina:lisina sobre o ganho de peso e a conversão alimentar das aves. No período de crescimento, as relações arginina:lisina influenciaram linearmente o ganho de peso e a conversão alimentar. Houve efeito quadrático das relações isoleucina:lisina, valina:lisina e triptofano:lisina sobre o ganho de peso. O aumento das relações isoleucina:lisina e valina:lisina resulta em melhor desempenho das aves no período de 7 a 21 dias de idade. As relações isoleucina:lisina, valina:lisina e triptofano:lisina indicadas para frangos de corte de 28 a 40 dias de idade são de 69, 76 e 18%, respectivamente.
Resumo em Inglês:Two experiments were carried out to evaluate digestible arginine:lysine, isoleucine:lysine, valine:lysine and tryptophan:lysine ratios for male broilers in two periods: 7 - 21 (starter) and 28 - 40 (finisher) days of age. A total of 1800 starter and 1440 finisher broilers were distributed in a completely randomized experimental design with 9 treatments, eight replicates of 25 and 20 birds per experimental unit in the starter and the finisher periods, respectively. The ratios used in the starter period were: 100, 105 and 110 arginine:lysine; 60, 65 and 70 isoleucine:lysine; 70, 75 and 80 valine:lysine; 15, 16 and 17 tryptophan:lysine, and in the finisher: 95, 105 and 115 arginine:lysine; 58, 67 and 76 isoleucine:lysine; 71,5, 77 and 82,5 valine:lysine; 14, 17 and 20 tryptophan:lysine. Diets were formulated to meet or exceed the nutritional requirements in both periods, except for digestible lysine (1.08% for the starter period and 0.98% for the finisher). At the end of each experiment, weight gain, feed intake, feed conversion and breast and breast fillet weight and yield were determined. In the starter period, the arginine:lysine and tryptophan:lysine ratios did not affect the evaluated parameters, but there were linear effects of isoleucine:lysine and valine:lysine ratios on birds weight gain and feed conversion. In the finisher period, the arginine:lysine ratios influenced linearlly weight gain and feed conversion. There was a quadratic effect of isoleucine:lysine, valine:lysine, and tryptophan:lysine on weight gain. The increase in the isoleucine:lysine and valine:lysine ratios results in better performance of the broilers from 7 to 21 days of age. The recommended isoleucine:lysine, valine:lysine and tryptophan:lysine ratios for broilers from 28 to 40 days of age are 69, 76 and 18%, respectively.
Resumo em Inglês:The objectives of this study were to determine the chemical composition of vegetable and mixed crude glycerin and digestible energy to and evaluate different inclusion levels in rabbit feeding. A total of 108 rabbits were used in the digestibility assay, assigned in a completely randomized design into nine treatments, one reference diet plus eight test diets, where the glycerin types were included at levels of 4, 8, 12 and 16%, replacing the reference diet roughage. In the performance assay, 180 rabbits were assigned to a completely randomized design into a 2 × 4 factorial arrangement (two types of glycerin and four levels of inclusion: 3, 6, 9 and 12%) plus a reference diet and ten replications. The vegetable and mixed crude glycerin showed digestible energy of 5,099 and 4,953 kcal/kg of dry matter, respectively. Although feed intake decreased linearly with the growing inclusion of both kinds of glycerin during both evaluated periods (from 32 to 50 and 32 to 70 days), performance losses occurred only with the inclusion of vegetable crude glycerin. The inclusion of mixed crude glycerin up to 12% allowed similar animal performance to the reference diet up to 50 days, unlike vegetable crude glycerin, for which inclusions over 6% in the diet resulted in poorer performance compared with that obtained with the reference diet. In the total period, differences were not observed for live weight or weight gain of the animals fed both glycerin types. Carcass weight decreased linearly with the inclusion of both glycerin types, with lower values compared with the reference diet only for the two highest levels of glycerin inclusion. Mixed crude glycerin can be included up to the maximum level studied (12%), while vegetable glycerin can be added up to 6% in the diet of growing rabbits.
Resumo em Inglês:This study aimed to evaluate the nutrient digestibility of roughages in horses with total feces collection and mobile bags. Two trials were carried out simultaneously. The first trial evaluated the digestibility of nutrients of coastcross hay (Cynodon dactylon cv. coastcross) with total feces collection. The second trial assessed the digestibility of nutrients of alfalfa hay (Medicago sativa), peanut (Arachis pintoi) and coastcross hay with mobile bags. This trial was conducted with gastric insertions of nylon bags every 12 hours, and each bag contained 663 mg of feed samples in a proportion of 17 mg DM/cm². Feces and bags were collected directly from the stall floor immediately after excretion. There was no difference between the digestibility of dry matter, crude protein, carbohydrates and hydrolysable carbohydrates of coastcross hay estimated with feces collection and mobile bags. Forage peanut showed high nutrients digestibility, with values close to those observed with alfalfa, indicating potential for use in diets for horses.
Resumo em Português:Avaliou-se o desempenho da progênie de matrizes de corte que consumiram aflatoxinas e glucomananos esterificados como adsorvente por quatro ou oito semanas. Foram conduzidos dois experimentos no período de 1 a 21 dias de idade. Em cada estudo foram utilizados 160 machos de 1 dia provenientes de matrizes alimentadas com dietas contendo aflatoxinas e adsorvente. Em ambos os ensaios, foi adotado um delineamento experimental inteiramente casualizado para avaliação de cinco dietas (tratamentos), cada uma avaliada com quatro repetições de oito aves. Nas dietas fornecidas às matrizes, as aflatoxinas foram adicionadas nos níveis 0; 0,500; ou 0,750 mg/kg de ração em combinação ou não a 0,10% de adsorvente. Os dois ensaios com frangos de corte foram conduzidos em baterias instaladas em unidade experimental climatizada, onde os pintos receberam uma dieta comprovadamente isenta de aflatoxinas durante todo o período experimental. Os parâmetros avaliados foram: peso corporal, ganho de peso, conversão alimentar pelo ganho de peso, proteínas plasmáticas totais, albumina sérica e pesos de fígado e bursa de Fabrícius ao primeiro dia de idade. A adição de até 0,750 mg aflatoxinas/kg e adsorvente durante oito semanas na dieta de matrizes de corte não influencia o desempenho zootécnico nem os parâmetros sanguíneos da progênie das matrizes.
Resumo em Inglês:The performance of the progeny from breeders hens fed diets containing aflatoxins and esterified glucomannans as a mycotoxins adsorbent during four and eight weeks was evaluated. Two experiments were carried out with broiler chickens from 1 to 21 days of age. In each study, one hundred and sixty 1-day old male chicks from broiler breeders fed diets with aflatoxins and mycotoxins adsorbent were used. The chicks were allocated in a completely randomized experimental design with five treatments and four replicates of eight birds each. In the diets supplied to the breeder chickens, aflatoxins were added at levels of 0, 0.500, or 0.750 mg/kg of the diet with or without 0.10% adsorbent. The two experiments were conducted in batteries installed in an environmental experimental controlled unit, where chicks received an aflatoxin-free diet during the entire trial period. The parameters studded were: body weight, weight gain, feed:gain ratio by weight gain, total plasmatic proteins, serum albumin, and liver and bursa weights at the first day of age. The addition of levels of up to 0.750 mg aflatoxins/kg and adsorbent in the breeders diets during eight weeks does not affect the performance or blood parameters of the broiler breeder progeny.
Resumo em Português:Avaliaram-se o consumo, o desempenho e a digestibilidade de dietas contendo diferentes grãos de oleaginosas em novilhos zebuínos em confinamento. Utilizaram-se 30 novilhos zebuínos com peso vivo inicial de 388,0±37,5 kg, distribuídos em delineamento inteiramente casualizado. As dietas foram formuladas com silagem de milho e quatro concentrados: um sem suplementação de lipídeos e três com a inclusão de grão de soja, caroço de algodão ou semente de linhaça. As rações, isonitrogenadas, apresentaram relação concentrado:volumoso 60:40 e foram fornecidas à vontade. Para determinação da digestibilidade aparente total, a produção fecal foi estimada utilizando-se fibra em detergente neutro indigestivel como indicador interno. O menor consumo de matéria seca (7,20 kg/dia) foi observado para a dieta contendo caroço de algodão, mas, entre as outras dietas, não houve diferenças nesta variável. O ganho médio diário foi menor quando se utilizou a dieta contendo caroço de algodão em relação à dieta sem lipídeo (0,93 vs. 1,16 kg/dia, respectivamente). No entanto, não houve diferença no ganho médio diário destas dietas em relação às demais. Houve redução da digestiblidade da fibra em detergente neutro na dieta contendo semente de linhaça. Adicionalmente, houve redução na digestibilidade dos carboidratos não-fibrosos nas dietas contendo caroço de algodão e semente de linhaça em relação à dieta com grão de soja, a qual não diferiu da dieta controle. A inclusão de caroço de algodão moído em dietas para bovinos em confinamento deve ser feita com cautela, pois pode provocar redução no consumo de matéria seca e no ganho médio diário. No entanto, a eficiência alimentar não é afetada pela adição de oleaginosas na dieta de bovinos de corte quando o nível máximo de extrato etéreo na matéria seca total da dieta não excede 6%.
Resumo em Inglês:This study was conducted to evaluate feed intake, performance and of digestibility diet containing different oilseeds to beef cattle finished in feedlot. Thirty zebu steers (388.0±37.5 kg of body weight) were used in a completed randomized design. The diets consisted of corn silage and four different concentrates: one without lipids and three with inclusion of soybeans, cottonseed and linseed. The diets, which were isonitrogenous, had roughage:concentrate ratio of 60:40 and were offered ad libitum. To determinate the total apparent digestibility of nutrients, the fecal output was estimated through internal marker indigestible neutral detergent fiber. The lowest dry matter intake was observed for cottonseed (7.20 kg/d), but among the other diets, the dry matter intake did not differ. The average daily gain was lower when cottonseed was used, in comparison with linseed (0.93 vs. 1.16 kg/d, respectively). However, there was no difference on average daily gain in relation to other diets. There was reduction in the digestibility of neutral detergent fiber in linseed diet. Additionally, there was a reduction in the neutral detergent fiber digestibility in diets with cottonseed and linseed compared with soybeans, which did not differ from the control diet. The inclusion of ground cottonseed in feedlot beef cattle diets should be realized with caution, since it can decrease dry matter intake and average daily gain. However, feed efficiency is not affected by the addition of oilseeds in beef cattle diets when the maximum ether extract level in total dry matter diet does not exceed 6%.
Resumo em Português:Objetivou-se avaliar o efeito do manejo para crescimento compensatório e da suplementação com ionóforo sobre o perfil metabólico e o crescimento da glândula mamária de novilhas leiteiras. Foram utilizadas 20 novilhas Pardo-Suíças puras, com peso inicial de 200 kg e 5 meses de idade. Os tratamentos foram arranjados em esquema fatorial 2 × 2 e os animais foram alocados aleatoriamente em cada uma das combinações. O fator 1 consistiu dos sistemas de alimentação (convencional e crescimento compensatório) e o fator 2, da utilização ou não de ionóforo (200 mg de monensina/animal/dia). Os animais do sistema convencional receberam alimentação ad libitum, enquanto os do sistema para crescimento compensatório foram submetidos a um manejo nutricional com dois períodos distintos: período de restrição energética (90 dias, P1) e período de realimentação (60 dias, P2). Novilhas submetidas ao sistema crescimento compensatório apresentaram maior concentração de nitrogênio ureico (N-ureico) plasmático e menor razão DNA:RNA no tecido mamário. Quando analisados dentro de período, os níveis de lipoproteínas de alta densidade (HDL) aumentaram no período de realimentação, enquanto os de N-ureico diminuíram. Além da alteração nos níveis de N-ureico, o balanço energético ao qual as novilhas em crescimento compensatório foram submetidas ocasionou aumento no teor dos ácidos graxos não-esterificados. Houve redução nos níveis de glicose sanguínea dos animais em crescimento compensatório no período de realimentação. A suplementação com ionóforo proporciona menor concentração de ácidos graxos não-esterificados durante o período de realimentação.
Resumo em Inglês:The objective of this trial was to compare the effect of compensatory growth regime on the metabolic profile and mammary gland development of dairy heifers. Twenty Brown-Swiss heifers averaging 200 kg of body weight and five months of age were used in a completely randomized design with a 2 × 2 factorial arrangement. The treatments were arranged in a factorial arrangement (2 × 2) and the animals were randomly allocated in each one of the combinations. The factor 1 consisted of the feeding regime (conventional and compensatory growth) and the factor 2, of the use or not of ionophore (200 mg of monensin/animal/day). The animals in the conventional regime received ad libitum feeding, while those in the compensatory growth regime were submitted to a nutritional management with two different periods: period of energy restriction (90 days) and realimentation period (60 days). Heifers submitted to the compensatory growth regime showed larger concentration of plasma urea nitrogen and lower DNA:RNA ratio in the mammary gland. When period was analyzed, the levels of high density lipoprotein (HDL) increased in the realimentation period, while the urea N decreased. In addition to the alteration in the levels of urea N, the energy balance to which the heifers in compensatory growth were submitted increased the non-esterified fatty acids. Blood glucose levels reduced in the animals in compensatory growth during the realimentation period. Supplementation with ionophore results in lower concentration of non-esterified fatty acids during the realimentation period.
Resumo em Inglês:The objective of this study was to evaluate the use of different mathematical models to describe growth of grazing beef cattle. Data of 20 Nellore bulls with initial weight of 129±28.1 kg and final weight of 405±62.0 kg were used. The animals were randomly divided into four plots and placed on B. decumbens Stapf pastures. Three plots received concentrate supplement with different protein profiles and the fourth plot received only mineral supplement. Animals were weighed every 28 days to design growth curve of full body weight. Five mathematical models were evaluated to describe animal growth: Multiphase, Linear, Logarithmic, Gompertz and Logistic models. Assessment of adequacy of the models was performed by using coefficient of determination, simultaneous F-test for identity of parameters, concordance correlation coefficient, root of the mean square error of prediction and partition of the mean square error of prediction. The analysis of the pairwise mean square error of prediction and the delta Akaike's information criterion were used to compare the models for accuracy and precision. Evaluation of all the tested models showed that all of them were able to predict variability among animals. However, Gompertz, Logarithmic and Logistic models created individual predictions that were not satisfactory. Models differed from each other concerning accuracy and precision; the best were in the following order: Multiphase, Linear, Gompertz, Logarithmic and Logistic. The Multiphase model was more efficient than the others for description of grazing beef cattle growth.
Resumo em Português:O objetivo neste estudo foi avaliar as condições nutricionais de tourinhos em aleitamento, a pasto, recebendo suplementação com concentrados proteicos durante a época de transição águas-seca. Foram utilizados 52 bezerros mestiços com idade média inicial de 130 dias. Os animais foram distribuídos em quatro lotes, alojados em piquetes de Brachiaria decumbens Stapf junto com suas mães, onde receberam uma das quatro estratégias de suplementação: três suplementos concentrados, ou sal mineral (controle). Os suplementos concentrados diferiram quanto ao nível de proteína. Após 45 dias, realizou-se a avaliação nutricional dos animais, que incluiu a estimação do consumo e da digestão de nutrientes e das características do metabolismo proteico. A estimação do consumo e da digestibilidade foi feita utilizando-se os indicadores: LIPE®, dióxido de titânio e fibra em detergente neutro indigestível. Realizou-se ainda coleta de amostras de urina e de sangue. O efeito de suplementação e os efeitos linear e quadrático do nível de proteína no concentrado foram avaliados pela decomposição da soma de quadrados em contrastes ortogonais, adotando-se α = 0,10. O consumo de concentrado substituiu parte do pasto ingerido pelos bezerros e aumentou a ingestão de proteína, a digestibilidade da matéria seca e matéria orgânica, o teor de nutrientes digestíveis totais e a excreção de nitrogênio na urina. O nível de proteína no suplemento tem efeito linear positivo sobre a ingestão diária de proteína, a digestibilidade de todos os nutrientes e o teor de nutrientes digestíveis totais e efeito quadrático sobre a excreção de nitrogênio na forma de ureia na urina.
Resumo em Inglês:The objective of this study was to evaluate the nutritional status of grazing nursing young bulls supplemented with concentrates with different protein levels during the rainy-dry season transition. Fifty two crossbred Nellore calves with initial mean age of 130 days were divided into four lots, housed in paddocks of Brachiaria decumbens Stapf and received one of the four different supplementation strategies: three different concentrate supplements, or mineral salt (control). The levels of protein in the concentrate supplements varied. After 45 days, the nutritional evaluation of animals, which included the prediction of intake and digestion of nutrients and characteristics of protein metabolism, was made. The prediction of intake and digestibility used the indicators LIPE®, titanium dioxide and neutral detergent fiber indigestible. Urine and blood samples were collected too. The supplementation effect, and the linear and quadratic effects of the level of protein in the concentrate were evaluated by the decomposition of the sum of squares into orthogonal contrasts, adopting α = 0.10. The concentrate intake replaced part of the pasture ingested by the calves and increased protein intake, the digestibility of dry and organic matter, the total digestible nutrients content, and the nitrogen excretion in urine. The level of protein in the supplement has a positive linear effect on the daily protein intake, the digestibility of all nutrients and the total digestible nutrients content, and quadratic effect on the excretion of nitrogen as urea in the urine.
Resumo em Inglês:This experiment was carried out to evaluate the carcass characteristics, chemical composition and fatty acid profile of the longissimus muscle of 32 young bulls from four genetic groups: Caracu; Canchin; Aberdeen Angus × Canchin; and Charolais × Caracu, finished in feedlot and slaughtered at 22 months old. Each group was composed of eight animals. There was no difference for moisture, ash, crude protein or total cholesterol between bulls from different genetic groups. However, total lipids percentage was higher for bulls from Caracu and Aberdeen Angus × Canchin and lower for Canchin and Charolais genetic groups. Polyunsaturated fattty acids and n-6 percentage was higher for Canchin and lower for Caracu, Aberdeen Angus × Canchin and Charolais genetic groups. Canchin and Charolais × Caracu genetic groups presented higher n-3 percentage than Caracu and Aberdeen Angus × Canchin. There was no difference for the n-6/n-3 ratio among the bulls from the four genetic groups.
Resumo em Inglês:The objective of this study was to determine requirements of calcium (Ca), phosphorus (P), magnesium (Mg), potassium (K) and sodium (Na) for grazing zebu bovines. The experiment area was composed of Brachiaria decumbens paddocks. Twenty-seven non-castrated animals, with initial live weight of 311.0 kg and at an average age of 14 months were used. Three animals were slaughtered, after adaptation period, so they were used as control for estimates of empty body weight and initial body composition of animals in the experiment. Out of the 24 remaining animals, four were sent to the maintenance group with restrict grazing time to limit energy intake close to the maintenance level. The other 20 animals were distributed in four treatments: mineral mixture, self-control intake and three-times-a-week-offer frequency (offered on Mondays, Wednesdays and Fridays) and daily. Concentrations of all studied macro elements in empty body and empty body gain decreased as live weight increased. The ratios obtained for g Ca/100 g of retained protein and g P/100 g of retained protein were 9.18 and 4.72, respectively. Total dietary requirement of calcium was lower than the one recommended by NRC (2000), but P requirement was very close to that.
Resumo em Inglês:The Cornel Net Carbohydrate and Protein System model version 5.0 was assessed as for its prediction of dry matter intake and milk production of grazing lactating Holstein × Zebu cows. Eight lactating cows grazing elephant grass (Pennisetum purpureum, Schum., cv. Napier) were used in two experiments of 30 days each. The experimental design was of randomized blocks (subplots). Dry matter intake was estimated using the chromium oxide and in vitro dry matter digestibility techniques. The estimated dry matter intake was compared with the values predicted by the model. Extrusa samples of the elephant grass pasture were obtained from a cow with esophageal fistula during nine days in each experimental period. Carbohydrate and nitrogenous fractions were analyzed and the degradation rate of carbohydrate was estimated by the gas production technique. The inputs referring to the animals (body weight, age, milk production, milk composition and breed type), to the environment (temperature, relative humidity of air and management condition) and to feeds chemical composition in each experimental period were inserted in the model. The model was accurate on the prediction of dry matter intake, considering that the mean values obtained by the chromium oxide technique and predicted by model (2.45 and 2.46% of body weight, respectively) did not differ significantly from each other. However, the model underestimated the observed milk production in 62.4%, where the metabolizable energy was the first limiting. These results demonstrate the need for studies that provide the development of a database for tropical foods (chemical composition and dynamics of rumen fermentation) and fitting of the model to the tropical conditions, for its appropriate application in formulation of diets and supplements in these regions.
Resumo em Inglês:The objective of this experiment was to estimate the requirements of energy, protein and macrominerals of grazing crossbreds calves, in Brachiaria decumbens Stapf pasture, castrated at different ages, with and without supplementation. Forty-seven young calves at initial age of 120±30.1 days and 115.3±1.97 kg of live weight were used. To estimate net energy requirements for weight gain, a regression equation between energy retained in the gain and empty body weight gain and metabolic empty body weight was obtained. For estimation of net protein requirements for weight gain, a regression equation was adjusted between protein retained in gain and empty body weight gain and energy content of this gain. Net requirements of Ca, P, Mg and Na for weight gain were determined by the equation Y' = a.b. Xb-1, in which a and b represent the intercept and the coefficient of the alometric equation of macromineral body content prediction, respectively. Neither castration nor concentrate supplementation affects body weight gain net requirements, except the ones of Ca, which were higher for non-castrated animals.
Resumo em Inglês:Two experiments were carried out with twenty-four male weaned Holstein calves to verify the influence of different dietary cation-anion concentrate and roughage proportions on calves metabolism. In the first experiment, calves were fed rations with -100, +200 and +400 mEq cation-anion balance/kg of dry matter, containing 60% of roughage and 40% of concentrate. In the second experiment, calves (117.6±20.8 kg average weight) received rations with similar dietary cation-anion balance but in diets of 40% roughage and 60% concentrate. As the dietary cation-anion balance became more positive, there was a quadratic response of blood pH in both diets with 60 and 40% roughage. A linear increase following increased dietary cation-anion balance was observed on bicarbonate concentration, carbon dioxide tension, carbon dioxide partial pressure and urine pH on both experiments, while anion gap decreased linearly. Blood urea nitrogen and base excess increased quadratically according to increased dietary cation-anion balance on 60% roughage, whereas those same parameters showed a linear increase on 40% roughage. Growing ruminant metabolism both in cationic and anionic diets was modified when the roughage:concentrate ratio was altered.
Resumo em Inglês:Performance, carcass, non-carcass and commercial cuts and components of Texel × Santa Inês crossbred lambs, managed in confinement and fed diets based on soybean oil, soybeans and a conventional diet, with or without the use of monensin (78 ppm dry matter basis) were evaluated. Thirty-six Texel × Santa Inês lambs (18 males and 18 females) were managed in intensive systems. Animals were slaughtered after 87 days of confinement, and performance, carcass characteristics, weight and percentages of carcass and non-carcass components were evaluated. The animals fed the control diet had heavier carcass and parts than animals fed soybean, while the oil diet did not differ from the controls in most parameters. The animals fed soybean showed lower intake kg dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF) and metabolizable energy (ME) compared with animals fed the control diet, increased ether extract (EE) intake in kg, % body weight (BW) and metabolic weight (MW) and did not differ from the soybean oil diet. Animals receiving monensin had lower DM intake, OM, CP, EE, NDF, gross energy (GE) regardless of the expression, % kg BW, or % PM, than the animals that did not receive the additive. Males produced better and had heavier cuts than the females; the latter deposited subcutaneous fat earlier. Animals that received oil or soybean showed greater body weight and small intestine percentage. Soybean oil intake did not improve performance, carcass weights or parts of Santa Ines × Texel lambs in confinement. Soybeans at 15% dry matter reduced energy intake and lamb performance. The use of monensin at 78 ppm on a dry matter basis is not recommended for lambs in confinement, especially if associated with oil or soybeans that may harm animal performance.
Resumo em Inglês:The objective of this study was to assess the tissue component yields and the physical, chemical and sensory characteristics of meat from Santa Inês sheep fed diets in which cactus pear partially or completely replaced corn. The study used 45 Santa Inês rams with initial live weight of 25±2.5 kg and final weight of 35±1.5 kg in a completely randomized design with five treatments (0, 25, 50, 75 and 100%) and nine replicates per treatment. The leg of the animal was used to analyze the tissue component yields, and the longissimus dorsi muscle was used for assessment of the sensory characteristics and the physical and chemical compositions. The inclusion of cactus pear in the diet increased the adipose tissue percentage quadratically, up to 50%, reducing the muscle/fat ratio. The lipid content of the meat decreased with the inclusion of cactus pear in the diet. The results indicate that cactus pear can replace 100% of the corn in the diets of Santa Inês sheep kept in confinement, resulting in a decreased lipid percentage and without compromising the physical and sensory characteristics of the meat.
Resumo em Português:O objetivo neste estudo foi avaliar o efeito do sistema de terminação em pastagem natural e do sexo sobre a qualidade de carcaça, o desenvolvimento regional e tecidual de cordeiros. Foram utilizados 45 machos não-castrados e 45 fêmeas, distribuídos inteiramente ao acaso em três sistemas de terminação: cordeiro com a mãe, mantido em pastagem; cordeiro desmamado mantido em pastagem; cordeiro desmamado mantido em pastagem e suplementado com casca do grão de soja a 1% peso corporal. O critério de abate foi a condição corporal, entre dois e três. As características da carcaça e componentes regionais foram influenciadas pelo sexo. O sistema de terminação com suplementação promoveu maior rendimento de carcaça e comprimento da perna. A composição tecidual foi afetada apenas pelo sexo, de modo que os machos apresentaram maior massa muscular em comparação às fêmeas. O crescimento alométrico da paleta dos animais que receberam suplementação e da paleta e da perna dos mantidos com a mãe foi precoce, enquanto o das costelas dos cordeiros sob suplementação e daqueles mantidos com a mãe foi tardio, embora os demais componentes tenham tido crescimento semelhante ao da meia-carcaça. Nas fêmeas, apenas a paleta daquelas terminadas no sistema com a mãe teve crescimento precoce, sendo isogônico para os demais cortes. Os sistemas de terminação avaliados comprovam que cordeiros Texel × Corriedale abatidos com condição corporal similar apresentam qualidade de carcaça semelhante. Houve influência do sexo sobre as características quali-quantitativas da carcaça. O desenvolvimento dos componentes regionais, nos machos, é influenciado pelo sistema de terminação, enquanto os componentes teciduais não são influenciados pelo sistema de terminação e sexo.
Resumo em Inglês:The objective of this study was to evaluate the effect of finishing systems on natural pasture and gender on the carcass quality, parts and tissue development of lambs. Forty-five non-castrated males and forty-five females were distributed in a completely randomized design into three treatments: lamb with mother kept on pasture; weaned lamb kept on pasture and weaned lamb kept on pasture with supplementation (soybean hulls at 1% of body weight). The criteria for slaughter was body condition score (2.0 - 3.0). The carcass characteristics and parts composition were influenced by the sex. The finishing system with supplementation promoted greater carcass yield and longer leg length. The tissue composition was different only for the sex, with the males presenting bigger amount of muscle mass. The allometric growth of shoulder of supplemented lambs and the shoulder and leg of the lambs with mother had been precocious, while the ribs of the supplemented lambs and lambs with the mother were late and the other components had growth similar to the half-carcass. For the females, only shoulder of lambs finished with mother presented precocious growth, being isogonic for the other cuts. The finished systems evaluated demonstrated that Texel × Corrierdale lambs slaughtered with similar body condition score present similar carcass quality. The development is influenced by the termination system and sex. The quali-quantitative characteristics of the carcass were influenced by the sex. The development of the regional components of the males are influenced by the finishing system. Nevertheless, the tissu components are not influenced by the finishing system or gender.
Resumo em Português:O objetivo neste trabalho foi avaliar o desempenho e o perfil metabólico da utilização de casca de soja associada a duas fontes de nitrogênio não-proteico (NNP) na terminação de cordeiros em confinamento. Foram utilizados 80 cordeiros mestiços Suffolk, machos não-castrados, com idade média inicial de 69±6 dias e peso corporal inicial de 23,11±1,78 kg. Os animais foram aleatoriamente separados em quatro grupos experimentais de acordo com a fonte de NNP: ureia convencional (1%); ureia protegida; 1% de ureia protegida + 0,5% de ureia convencional; e grupo controle, sem fornecimento de NNP. Amostras de sangue foram coletadas semanalmente para determinação das concentrações de ureia, albumina, γ-glutamiltransferase (GGT), cálcio e fósforo. O grupo controle apresentou maior ganho médio diário (GMD) e peso corporal final (PCF) em comparação aos grupos que receberam ureia protegida e ureia protegida e ureia protegida convencional, porém, não diferiu do grupo que recebeu ureia convencional. Não foram observadas diferenças no consumo de matéria seca, conversão alimentar e rendimento de carcaça quente e acabamento de carcaça entre os grupos. Em relação ao perfil proteico, o grupo alimentado com ureia convencional apresentou maior concentração de ureia plasmática em comparação àquele que recebeu ureia protegida + ureia convencional. O consumo de ureia protegida não melhora a eficiência no desempenho de cordeiros em confinamento alimentados com dietas com alta inclusão de casca de soja.
Resumo em Inglês:The aim of this study was to evaluate the metabolic profile of the use of soyabean hulls associated with two sources of non-protein nitrogen (NPN) on the finishing of feedlot lambs. Eighty crossbred Suffolk non-castrated lambs aging 69±6 days and weighing 23.11±1.78 kg were used. Lambs were randomly allocated into 4 experimental groups according to the NPN source: conventional urea (1%); protected urea; 1% protected urea + 0.5% conventional urea; and a control group, which did not receive urea supplementation. Blood samples were collected weekly to determine the plasma concentrations of urea, albumine, γ-glutamiltransferase (GGT), calcium and phosphorus. The control group had higher average daily gain and final weight than protected urea and protected urea + conventional urea groups; however, it did not differ from the conventional urea group. No differences between the groups were observed for dry matter intake, feed conversion or warm carcass yield and carcass finishing. Regarding the serum protein profile, the o group fed conventional urea had higher serum concentration of urea than that of protected + conventional urea. Urea supplementation did not improve the performance of feedlot lambs fed diets with high level of soybean hulls.
Resumo em Inglês:The objective of this study was to evaluate the effect of different levels of diet crude protein on the performance and stress resistance rate (Re) of Oreochromis niloticus larvae and fingerlings. In the first experiment, 5, 15 and 25 day-old animals were submitted to 1, 5, 7, 10, 15, 20, 30 and 40 minutes of air exposure on a sieve. In the second experiment, tilapia larvae were fed with 32, 40 and 55% crude protein (CP) diets. Animals after 15 and 30 days of feeding (21 and 36 days of life, respectively) were submitted to the air exposure test for 7 and 10 minutes. Re was estimated based on survival 24 hours after the tests. In the first experiment, it was observed that 5-day-old animals were more resistant than animals with 10 and 20 days of feeding (15 and 25 days of life, respectively), when Re starts to decrease for longer than 7 minutes. In the second experiment, the different diets affected survival, performance and Re, and, in general, the worst results observed were the ones for the animals which received the 55% CP diet. The air exposure tests were efficient to evaluate the effect of diet on the resistance rate of Nile tilapia.
Resumo em Inglês:The objective of the present study was to evaluate the apparent digestibility coefficients of dry matter (DM), crude protein (CP) and gross energy (GE) of the following agro-industrial byproducts: cassava leaf (Manihot esculenta), mesquite bean (Prosopis juliflora), cotton (Gossypium species), cocoa (Theobroma cacao), soursop (Annona squamata) and African oil palm cake (Elaeis guineensis) for Nile tilapia (Oreochromis niloticus). Fish from two weight classes (200±11 and 300±32 g) were stocked in tanks and fed a reference diet plus 30% of one tested byproduct with the addition of 0.1% chromic oxide. The fish were routinely moved to digestibility aquariums for feces collection, in a completely randomized design (n=3). The apparent digestibility coefficient (ADC) values between the two weight classes were similar, but differed between the byproducts for DM, CP and GE. The highest ADC DM, ADC CP and ADC GE for 200-g and 300-g tilapias were, respectively, 0.58 and 0.53; 0.77 and 0.78; 0.66 and 0.62 for the soursop bran and 0.52 and 0.51; 0.77 and 0.80; 0.66 and 0.60 for the palm cake, respectively. The cotton and cocoa bran had the worst results of ADC of DM in two weight ranges (means of 0.34 and 0.37 g/100 g, respectively) while the mesquite bean had the lowest ADC of CP and GE, with means of 0.28 and 0.14 g/100 g for 200-g and 300-g tilapias, respectively. The byproducts analyzed may be used in formulating diets for Nile tilapia adults, observing their contributions to the digestibility of nutrients and energy for the species.
Resumo em Inglês:This study analyzed associations between the occurrence of mastitis, metritis and retained placenta with the reproductive performance and milk production of four Holstein dairy herds of southern Brazil. Calving-to-conception intervals (CCI) and daily milk production were compared across herds, number of artificial inseminations and clinical occurrences and occurrence of mastitis, metritis and retained placenta. The CCI of cows with three or more clinical occurrences was longer than for those with no occurrences, but shorter for cows with retained placenta than for those without it. Cows with clinical mastitis up to 60 days post-partum had shorter CCI than those with mastitis after 60 days. Cows with retained placenta also had higher frequency of metritis. The daily milk production was higher for cows with three or more clinical occurrences than for those with one or none and for those without retained placenta than for those with retained placenta. A high number of clinical occurrences was related to prolonged CCI and increased daily milk production.