ABSTRACT: The objective was to evaluate the animal production and ingestive behavior of the steers fed different supplements during the growth phase in Aruana grass, and the influence of this supplementation on production performance in feedlot phase. The treatments consisted of three supplements during the growing phase: mineral salt (0.12 g/kg of body weight - BW), low intake energy-protein supplement (1.26 g/kg of BW), and medium intake (3.76 g/kg of BW). Forage canopy characteristics, animal production, and animal behavior on pasture were evaluated in a completely randomized design with three replicates (paddocks). The titanium dioxide marker was used to determine the intake and apparent digestibility during the pasture phase. The production performance in feedlot was evaluated in a completely randomized design with eight replicates (animals). Twenty-four Aberdeen Angus steers (15 ± 1.5 months old; 364.8 ± 21.7 kg BW) were used. At the end of the growth phase the animals were confined and fed a single diet. Dry matter, crude protein, and neutral detergent fiber (NDF) contents of forage and intake were not influenced by the treatments. The average daily gain was higher for the medium intake supplement in pasture phase. The apparent digestibility of NDF (P = and chewing rate were higher for the medium intake supplement. The average daily gain and fat thickness of carcasses were higher for the medium intake supplement in the feedlot phase. The supplements of medium intake increase animal productivity during the growing phase on pastures and cattle’s finishing performance in intensive production systems.

RESUMO: O objetivo deste trabalho foi avaliar a produção animal e o comportamento ingestivo de novilhos alimentados com diferentes suplementos durante a fase de crescimento em capim Aruana, e a influência desta suplementação sobre o desempenho produtivo durante a fase de terminação em confinamento. Os tratamentos consistiram de três suplementos durante a fase de crescimento: sal mineral (0,12 g/kg do peso corporal - PC), suplemento energético-proteico de baixo consumo (1,26 g/kg do PC) e suplemento energético-proteico de médio consumo (3,76 g/kg do PC). As características do dossel forrageiro, a produção animal e o comportamento ingestivo em pastos de capim Aruana foram avaliados utilizando um delineamento inteiramente ao acaso com três repetições (piquetes). O marcador externo dióxido de titânio foi utilizado para determinar o consumo e digestibilidade aparente dos nutrientes na fase de pastagem. O desempenho em confinamento foi avaliado utilizando-se um delineamento inteiramente ao acaso com oito repetições (animais). Vinte e quatro novilhos Aberdeen Angus (15 ± 1,5 meses de idade; 364,8 ± 21,7 kg de peso corporal médio inicial) foram utilizados. Ao final da fase de recria, os animais experimentais foram confinados e alimentados com uma dieta única. Os teores de matéria seca, proteína bruta e fibra de detergente neutro (FDN) da forragem, bem como o consumo destas frações não foram alterados pelos tratamentos. O ganho médio diário foi superior para o suplemento de ingestão média na fase de pastagem. A digestibilidade da FDN e a taxa de ruminação na fase pastagem foram mais elevadas para o suplemento de média ingestão. O ganho médio diário e a espessura de gordura das carcaças foram mais elevados para o suplemento de ingestão média na fase de acabamento em confinamento. Suplementos de ingestão média aumentam a produtividade animal durante a fase de crescimento em pastagens e o desempenho em confinamento de bovinos provenientes de sistemas intensivos de produção.

ABSTRACT The objective of our study was to evaluate the effect of the use of legume (Arachis pintoi) or nitrogen fertilization on animal performance, characteristics of carcass and meat, and fatty acids profile of crossbred steers on Megathyrsus maximus cv. Aruana pasture, overseeded with temperate grasses. The experimental design was completely randomized, with three treatments and three replicates. The experiment was carried out from June to October (127 d). The treatments were: Low-N: 100 kg of N/ha; Medium-N: 200 kg of N/ha; and Legume: Arachis pintoi + 100 kg of N/ha. The pasture with higher nitrogen fertilization (N200) showed a more significant forage mass yield. The mixed grass with legumes presented a higher concentration of saturated fatty acids and saturated:unsaturated ratio in the meat. However, the grass pastures resulted in a higher content of unsaturated fatty acids in the meat. The other pasture variables, and characteristics of carcass and meat were not influenced by the treatments. The increase in nitrogen fertilization, from 100 to 200 kg/ha, and Arachis pintoi mixed with Aruana grass pasture overseeded with black oat and ryegrass does not affect the daily weight gain and the carcass and meat characteristics of the steers. The grass-legume mixture decreases the total concentration of unsaturated fatty acids in meat without influencing the concentration of polyunsaturated fatty acids.

ABSTRACT The purpose of this study was to evaluate the performance of beef cattle with two levels of energy-protein supplementation of low-consumption on African Bermudagrass pasture, overseeded in winter with oat and ryegrass, with or without irrigation. Twenty-four castrated Angus steers (11 months old and had an initial average of 220 kg body weight (BW)) were used in experimental area of 3.6 ha. The experiment was completely randomized in a 2×2 factorial design, with three replicates. The evaluation period was 249 days (July/2019 to March/2020). The treatments were: irrigated pasture with supplementation of 1 g/kg BW or 2.7 g/kg BW and non-irrigated pasture with 1 g/kg BW of supplement or 2.7 g/kg BW. The grazing method was continuous with a variable stocking rate. Irrigation provided pastures with better chemical composition in winter and spring. Irrigation increased the daily accumulation rate in winter (84.6 vs. 45.9 kg DM/ha/day), providing a greater stocking rate (1,702 vs. 1,385 kg/ha) and, consequently, body weight gain per hectare. Supplementation of 2.7 g/kg BW provided a greater stocking rate in winter (1,652 vs. 1,435 kg/ha) and spring (3,096 vs. 2,811 kg/ha), not changing in summer. The association of irrigation and supplementation of 2.7 vs. 1.0 g/kg BW improves the intake pattern by the animal in summer without changing productivity parameters. Irrigation increases productivity and the nutritional value of pasture with higher livestock production per area in periods of water deficit. The supply of 2.7 vs. 1.0 g/kg BW provides a greater stocking rate and body weight gain per hectare.

ABSTRACT The objective of this study was to evaluate the growth performance and meat quality of feedlot Aberdeen Angus steers fed high-concentrate diets with or without a natural feed additive composed of a mixture of yeasts and essential oils (EO). A completely randomized design with two diets (with or without natural feed additive) and 12 replicates was used. Twenty-four steers with initial shrunk body weight of 402.62±48.2 kg and average age of 18±2.0 months were used. Steers were fed ad libitum a diet containing 777.3 g of concentrate/kg dry matter (DM) and 222.7 g of corn silage/kg DM for 74 days. The mixture of yeast and EO was supplied at the rate of 10.0 and 0.117 g/animal/day, respectively. Average daily weight gain and feed efficiency in the adaptation period was greater in animals fed natural feed additive; however, there was no difference for the total experimental period. Dry matter intake, carcass weight, carcass yield, proportion of carcass bone, carcass muscle + fat:bone ratio, round thickness, and arm length were not altered by treatments. The inclusion of a natural feed additive in the diet increased the cooling loss (0.98 vs. 1.25%), proportion of carcass muscle (51.32 vs. 54.56%), carcass muscle:fat ratio (1.70 vs. 2.11%), leg length (68.79 vs. 70.71 cm), and arm perimeter (36.70 vs. 37.88 cm) and reduced the proportion of carcass fat (30.17 vs. 25.92%). Carcass length was greater in animals fed the diet with a natural feed additive. Meat color, texture, and marbling were not altered by treatments. The addition of natural feed additive to high concentrate diets does not alter the productive performance of feedlot Aberdeen Angus steers, although it can increase the proportion of lean meat of carcasses.

ABSTRACT The objective of this study was to investigate the effects of slaughter body weight (SW) on the performance, carcass characteristics, and meat quality of Jersey bulls in feedlots from weaning to slaughter. Eighteen Jersey bulls (125.7±15.9 kg; 5±0.6 months old) were used in the study. The treatments corresponded to three slaughter-weights: L360 – light weight, SW of 360 kg, M390 – medium weight, SW of 390 kg, and H420 – heavy weight, SW of 420 kg (n = 6/treatment); the animals were slaughtered at 368, 392, and 422 kg, respectively. The average daily gain was not influenced by SW. The M390 and H420 groups remained in feedlot, on average, 6 and 51 d longer, respectively, to reach a similar SW in relation to the L360 group. The increase in SW did not influence dry matter intake. However, the L360 group exhibited greater dry matter intake relative to body weight compared with the other two groups (29 vs. 26 g/kg). The increase in SW resulted in heavier and longer carcasses, with higher hot carcass yields. However, animals with greater SW had lower fat thickness. In addition, the increase in SW led to greater pistol cut, bone, and muscle weight for the carcasses. Although the meat color of Jersey bulls was darker in the H420 group, the meat was considered softer and more palatable by the consumer panel compared with the meat from the L360 group. The L360 group exhibited less fluid loss during thawing and cooking. Shear force measured by Warner Blatzer Shear was lower for H420. Animals slaughtered in the L390 group had an intermediate carcass weight, similar carcass yield, better cover fat and meat quality (color and shear) than animals slaughtered in the H420. Combining these factors with a shorter feedlot time compared with that of heavier animals, the SW of feedlot Jersey bulls is recommended at 390 kg.

RESUMO: Os efeitos da suplementação energética e da ervilhaca (Vica sativa L.) foram estudados para avaliar o perfil de ácidos graxos intramusculares de novilhos terminados em pastagens de aveia (Avena sativa L.). Foram avaliados 18 novilhos mestiços com 21 meses de idade. O experimento foi realizado em três tratamentos e seis repetições: pastagem de aveia (OA), pastagem de aveia + ervilhaca (OA + VET) e pastagem de aveia + suplementação (OA + SUP). A suplementação compreendeu a adição de fubá na dose diária de 1% do peso corporal dos animais. Os novilhos que receberam suplementação apresentaram maior teor lipídico no Longissimus lombar do que aqueles alimentados com OA + VET (1,25 contra 1,02%), enquanto aqueles alimentados com AO (1,15%) apresentaram valores intermediários. Os níveis de ácido linoléico conjugado foram maiores em novilhos alimentados com AO (0,57%) e OA + SUP (0,59%), enquanto a maior quantidade de ácidos graxos ômega-3 foi observada em animais alimentados com OA + VET (3,32%). Animais terminados em pastagens sem suplementação apresentaram menor proporção de n-6: n-3 (3,14). Novilhos terminados em pastagem de aveia com ervilhaca apresentaram gordura intramuscular mais saudável do que aqueles terminados com suplementação de milho moído, uma vez que apresentaram maior quantidade de PUFAs e melhor a relação n-6: n-3.

ABSTRACT: The effects of energetic supplementation and mixture vetch (Vica sativa L.) were studied to evaluate the intramuscular fatty acid profile of steers finished on oat (Avena sativa L.) pastures. Eighteen 21-month-old crossbred steers were evaluated. The experiment was carried out in three treatments and six repetitions: oat pasture (OA), oat pasture + vetch (OA + VET), and oat pasture + supplementation (OA + SUP). Supplementation comprised the addition of corn meal at a daily dose of 1% of the animals’ body weight. Steers receiving supplementation had higher lipid content in Longissimus lumborum than did those fed with OA + VET (1.25 vs 1.02%), whereas those fed with OA (1.15%) showed intermediate values. Conjugated linoleic acid levels were higher in steers fed OA (0.57%) and OA + SUP (0.59%), whereas the highest amount of omega-3 fatty acids was observed in animals fed OA + VET (3.32%). Pasture-finishing without supplementation resulted in a lower ratio of n-6:n-3 (3.14). Steers finished in oat mixture with vetch showed healthier intramuscular fat than did those finished with cornmeal supplementation; importantly, the higher the amount of PUFAs, the better n-6:n-3 ratio.

ABSTRACT This study was performed to determine and quantify the inherent auction factors that affect the selling price of beef calves (weanlings - from six to nine months old). Data on the selling price, location and month of the auction, genetic group, lot size live weight, and sex of animals were collected in 148 auctions from January 2004 to December 2014. A total of 4,312 lots corresponding to 48,588 calves were classified into seven genetic groups according to their phenotypic characteristics. The values were deflated using the General Price index (IGP-DI) inflation index and met the parametric assumptions. The selling price was standardized by the yearly median, assuming that its value corresponds to 100%, and the other values varied in their function. Path analysis quantified the direct and indirect effects of the variables taken as explanatory of the selling price, followed by regression analysis and Tukey test. Overall, the direct effect of the average weight was the highest (0.7), followed by sex (0.38). The smallest direct effect was the genetic group (−0.075). There was a growing exponential relationship between average weight of the lot and selling price and a decreasing ratio between price per kilo and the average weight of the lot (−0.0003 percentage points per kilogram). Males were generally 15.7% more valued than females. The British × Zebuine crossbreed was the most valued breed, followed by the British breed (8.9 and 3.6%, respectively). The highest premium was in November, followed by February (9.57 and 8.84%, respectively, compared with median year). The selling price increases linearly by 0.3284 percentage points for each additional animal in the lot. The average weight of the lot was found to be the most important variable in the formation of the selling price, followed by the sex of the animals.

ABSTRACT Our objective was to evaluate performance and fatty acid contents of the meat of Holstein veal fed in feedlots and slaughtered at four different pre-determined live weights (140, 180, 220, and 260 kg). Twenty-three non-castrated calves with initial average ages of 58 days and 57 kg live weight were used in this study. Average daily gain, dry matter intake, nutrient intake, cold carcass weight, cold carcass yield, scraps, and fat thickness improved with increasing slaughter weight. However, C18:0, C22:0, C18:2Trans10Cis12, C18:1n9Cis acids, sum of unsaturated fatty acids, and lipid content decreased with the increase in slaughter weight. Raising the slaughter weight of Holstein calves from 144 to 260 kg improves the performance of animals, mainly due to the increase in their intake capacity. However, this increase in slaughter weight does not result in significant changes in the fatty acid composition of the meat.

ABSTRACT The use of animals from dairy farms is an alternative to meat production since it provides an increment of total income for farmers. This study aims to evaluate the performance of Holstein calves finished in two feeding systems (feedlot or pasture). Forty-three animals with 58 days old and 57 kg were divided in two treatments: 23 animals finished in feedlot with corn silage plus concentrate based on corn and soybean meal (40:60); 20 animals kept in cultivated pastures according to the period of the year: Italian ryegrass (Lolium multiflorum) and pearl millet (Pennisetum americanum) with supplementation with the same feedlot-concentrate at 1% body weight. Animals were slaughtered with 200 kg. Dry matter and nutrient intake were determined, with the use of chromium oxide for estimating pasture intake. Feedlot animals had greater total intake and total digestible nutrients, resulting in higher average daily gain (0.949 vs 0.694 kg day-1). Crude protein intake, neutral detergent fiber and feed conversion did not show significant differences. Holstein calves have improved performance when finished in feedlot.

RESUMO. O manejo da pastagem com níveis de lâminas foliares pode favorecer incrementos significativos na produção, sendo que as folhas representa um papel importante na relação planta-animal, sendo responsável pela eficiência fotossintessintética e substrato de melhor qualidade na dieta animal. Com o intuito de avaliar as massas foliares da estrela africana (Cynodon nlemfuensis var. Nlemfuensis), o presente trabalho teve como objetivo identificar qual massa de lâmina foliar proporciona melhor produtividade e qualidade nutricional. Os tratamentos avaliados foram as diferentes massas de lâmina foliar: 800, 1.200, 1.600 e 2.000 kg de matéria seca ha-1. O delineamento experimental utilizado foi inteiramente casualizado, com quatro tratamentos e três repetições, totalizando 12 parcelas de 100 m2 cada. Os resultados indicaram elevação na produção de colmo, na relação folha: colmo e nos dias de descanso de acordo com o aumento das massas de lâminas foliares. A taxa de acumulo diário de laminas foi semelhante para os tratamentos. Além disso ocorreu decréscimo nos teores de proteína bruta e elevação nos teores de fibra em detergente neutro e ácido. No entanto, as maiores produções de forragem foram observadas nos tratamentos 1.200 e 1.600 kg ha-1 de massa de lâminas foliares.

ABSTRACT. Pasture management with levels of leaf blades may favor significant increase in production, and the leaves indicated an important role in plant-animal relationship, caused by photosynthesis efficiency and better quality in animal diet. Current study identifies which leaf blade mass of the African star (Cynodon nlemfuensis var. Nlemfuensis) provides better productivity and nutritional value. Treatments comprised different leaf blade masses: 800, 1200, 1600 and 2000 kg of dry matter ha-1. The experimental design was completely randomized, with four treatments and three repetitions, totaling 12 plots with 100 m2 each. Results indicated increase in production, in the leaf/stem ratio and in the interval days according to increase in leaf blade mass. Daily accumulation rate was similar to treatments. Crude protein decreased and fiber increased with rise in leaf blade mass and the highest forage productions were reported in the treatments 1200 and 1600 kg ha-1 leaf blade mass.

ResumoObjetivou-se com esta pesquisa avaliar os efeitos do estádio fenológico, o tamanho de partícula e o pré-murchamento sobre as características de fermentação e valor nutritivo da silagem de aveia preta (Avena strigosa). O experimento foi conduzido durante o período hibernal de 2011, em “latossolo vermelho” de textura argilosa localizado em Renascença, sudoeste do Paraná, Brasil. O delineamento experimental foi inteiramente casualizado em esquema trifatorial (3x2x2) com quatro repetições, sendo os fatores tamanhos médios de partícula: 5; 13 e 22mm; estádios de ensilagem: início do florescimento e florescimento pleno; e manejos: com e sem pré-murchamento. O tamanho de partícula alterou apenas o pH do material ensilado, com melhores resultados com 22mm, sem efeitos na composição bromatológica da silagem produzida. A operação de pré-murchamento é eficiente em restringir a emissão de efluentes no início do florescimento e, também, confere à silagem melhores condições de fermentação, com redução da capacidade tampão de 87,68 para 53,20 meq NaOH 100g MS-1 e do pH de 3,64 para 3,15, os quais garantem melhor preservação do valor nutritivo da forragem, possuindo menores teores de fibra em detergente neutro (FDN) e fibra em detergente acido (FDA), com maior proteína bruta (PB), digestibilidade in vitro da matéria seca (DIVMS) e nutrientes digestíveis totais (NDT). Com o avanço da maturidade, verifica-se elevação nos teores de FDN e FDA e redução nos teores de PB, DIVMS e NDT. A ensilagem em início de florescimento, seguida de pré-murchamento, possui condições adequadas para fermentação e apresenta melhor valor nutritivo

AbstractThe objective was evaluate the effect of growth stage, particle size and pre-wilting on fermentation characteristics and nutritional value of the black oat silage (Avena strigosa S.). The experiment was conducted during the winter of 2011, in the city of Renascença, Southwest region of Paraná State, Brazil. The experimental design was completely randomized distributed in a factorial (3x2x2) with four replications. The factors evaluated were particle sizes: 5, 13 and 22mm; ensilage stages: early flowering and full flowering; and management: with and without pre-wilting. The particle size changes only the silage pH, with better results under 22mm, without any effects on the chemical composition of the silage produced. The management of pre-wilting is efficient to restrict effluents emission at early flowering, also gives better silage fermentationconditions, with reduced buffering capacity of 87.68 to 53.20meq 100g NaOH DM-1 and of pH from 3.64 to 3.15, which ensure a better preservation of the forage nutritional value, having lower levels of neutral detergent fiber (NDF) and acid detergent fiber (ADF) with greater crude protein (CP), in vitro dry matter digestibility (IVDMD) and total digestible nutrients (TDN). With the advancement of maturity it is observed increases in NDF and ADF and decreases in the values of CP, IVDMD and TDN. The ensilage in the early flowering stage followed by pre-wilting has suitable conditions for fermentation and has better nutritional value.

O objetivo da pesquisa foi avaliar o valor nutritivo de pastagens de Coastcross-1 e Tifton 85 consorciadas com amendoim forrageiro (0, 25, 50 e 75% da área implantada), submetidas a cortes ao longo de dois anos de estudo, em área localizada no Sudoeste do Paraná. O delineamento experimental foi o fatorial (três fatores), distribuídos em blocos ao acaso com três repetições. Os fatores foram as cultivares (2), o percentual de área implantada com o amendoim forrageiro (4) e as estações do ano que apresentaram condições de corte (5). Avaliaram-se os percentuais de proteína bruta, fibra em detergente neutro e digestibilidade in vitro da massa seca das lâminas foliares, colmo + bainha das gramíneas e da massa de forragem disponível das pastagens. Os valores de proteína bruta variaram de 17,0 a 20,4% e 16,8 a 19,3 % para a massa de forragem disponível de Coastcross-1 e Tifton 85, respectivamente. Maiores valores de digestibilidade foram verificados no início das avaliações. Em média, a cv. Coastcross-1 apresentou melhor valor nutritivo quando comparada ao capim Tifton 85, e, a maior contribuição de amendoim forrageiro elevou os teores de proteína bruta nas lâminas foliares das gramíneas estudadas, a partir do segundo ano de estabelecimento.

This study evaluated the nutritive value of pastures of Coastcross-1 and Tifton 85 mixed with increasing inclusion of forage peanut (0, 25, 50, 75% occupancy area), subjected to cuts, over two study years in Southwestern Paraná State. The experimental design was factorial (three factors) distributed in randomized block. The factors were cultivars (2), the occupancy area of forage peanut (4) and seasons of cuts (5), with three replications. It was evaluated the percentage of crude protein, neutral detergent fiber and in vitro digestibility of dry matter of leaf blades, stem + sheath of grasses and available forage mass of pastures. Values of crude protein ranged from 17.0 to 20.4% and from 16.8 to 19.3% for the forage mass available of Coastcross-1 and Tifton 85, respectively. Higher digestibility values were found at the beginning of evaluations. On average, the Coastcross-1 showed better nutritive value compared to Tifton 85, and, the inclusion of forage peanut increased crude protein content in leaf blades of grasses studied, in the second year after planted.

O objetivo deste experimento foi avaliar as características da carcaça de bezerros holandeses terminados em confinamento ou em pastagem com suplementação e abatidos com diferentes pesos de abate. Os animais confinados foram alimentados com volumoso e concentrado comercial, na proporção de 40:60, sendo a silagem de milho utilizada como volumoso. O delineamento experimental foi o inteiramente casualizado, em arranjo fatorial 2x4 (dois sistemas de terminação x quatro pesos de abate). Os animais foram abatidos à medida que atingiam os pesos de abate pré-determinados (140, 180, 220 e 260kg). O sistema de acabamento não teve influência sobre o peso e rendimento de carcaça quente e fria e as perdas de carcaça, mas os animais confinados apresentaram maior espessura de gordura. Animais confinados apresentaram melhor conformação, comparados com os terminados em pastagem. À medida que aumentou o peso de abate, houve crescimento linear para peso de carcaça quente e fria, rendimento de carcaça quente e fria, conformação, medidas métricas e peso dos cortes comerciais da carcaça. O percentual do corte traseiro decresceu com o aumento do peso de abate, enquanto que a espessura de gordura apresentou resposta quadrática. Os sistemas de abate apresentaram rendimento de carcaça semelhante. As características da carcaça melhoram com o aumento do peso de abate, mas, em percentagem, são semelhantes

A produção alternativa de forragens em períodos de escassez, especialmente durante o inverno, é muito importante para o pastejo de bovinos de corte e leite no Brasil. O presente trabalho teve como objetivo avaliar a influencia da fertilização nitrogenada na produção e o valor nutritivo da forragem de azevém (cv. Barjumbo). O experimento foi conduzido durante os invernos de 2009 e 2010, sendo implantado na área experimental da UTFPR, Dois Vizinhos - PR, Brasil. O delineamento foi de blocos ao acaso, com quatro doses de N (0; 40; 80 e 120 kg de N ha-1) e três repetições. As parcelas experimentais foram de 5x5 m, com espaçamento de 20 cm entre linhas e 2,5 cm entre plantas, totalizando 20 kg ha-1 de sementes viáveis. Foram determinadas a produção de massa seca, o teor de proteína bruta, o total acumulado de proteína bruta e o teor de fibra em detergente neutro, durante todo o ciclo de crescimento do azevém em dois ciclos de cultivo. A adubação nitrogenada promove um aumento significativo e linear na produção de matéria seca e acúmulo de proteína bruta, com os melhores resultados com a maior dose avaliada (120 kg N ha-1). Maiores níveis de nitrogênio não são capazes de promover efeitos significativos no teor de FDN da forragem.

Alternative production of forages in periods of scarcity, especially during the winter, is expressively important for grazing of beef and dairy cattle in Brazil. The current work aimed to evaluate the influence of nitrogen fertilization on the production and nutritional value of ryegrass forage (cv. Barjumbo). The experiment was carried out on the winter seasons of 2009 and 2010, at the experimental area of UTFPR, Dois Vizinhos - PR, Brazil. The design consisted of randomized blocks with four N rates (0; 40; 80 and 120 kg ha-1) and three replicates. Each plot measured 5x5 m, with 20 cm row spacing and 2.5 cm between plants, totaling 20 kg ha-1 of viable seeds. It was determined the dry matter production, crude protein level, total accumulation of crude protein and neutral detergent fiber, during the whole growth cycle of ryegrass in two crop seasons. Nitrogen fertilization promotes a significant and linear increase in dry matter yield and in accumulation of crude protein, with the best results with the highest rate evaluated (120 kg N ha-1). Nitrogen levels are not capable to promote significant effects in forage neutral detergent fiber content.

O Brasil sacrifica muitos bezerros de origem leiteira ao nascer, o que pode se tornar um problema mercadológico bastante sério. O objetivo deste experimento foi avaliar a composição física da carcaça e as características qualitativas da carne de bezerros holandeses terminados em confinamento ou em pastagem com suplementação, abatidos aos 140; 180; 220 ou 260 kg de peso corporal. No início da terminação, os bezerros apresentavam em média 57 kg e 58 dias de idade. Os animais confinados foram alimentados com volumoso (silagem de milho) e concentrado, na proporção de 40:60 e os da pastagem suplementados com concentrado a 1% do peso corporal. O delineamento experimental foi o inteiramente casualizado, em arranjo fatorial 2 x 4 (dois sistemas de terminação x quatro pesos de abate). Foi observada interação significativa entre peso de abate e sistema de terminação somente para a textura da carne. Os animais terminados em pastagem apresentaram melhor textura com o aumento do peso, enquanto que os animais confinados o peso não influenciou. Animais terminados a pasto apresentaram maior percentagem de músculo (69,48% contra 66,57%), menor percentagem e quantidade de gordura (9,58% e 9,75 kg contra 13,20% e 13,08 kg respectivamente) em relação aos animais do confinamento. Houve crescimento linear para a quantidade total de músculo, osso e gordura, relação músculo/osso, relação porção comestível/osso, palatabilidade e suculência quando se elevou o peso de abate. O percentual de osso e a cor da carne decresceram linearmente com o aumento do peso de abate. A percentagem de músculo e gordura apresentaram comportamento quadrático. Os animais de raças leiteiras são excelentes produtores de carne magra, com boa maciez, palatabilidade e suculência.

The Brazil sacrifices many dairy calves at birth, which can become a very serious problem merchandising. The objective of this experiment was to evaluate the physical carcass composition and meat quality characteristics of Holstein calves in feedlot or pasture with supplementation, slaughtered at 140, 180, 220 or 260 kg body weight. In the early termination calves had on average 57 kg and 58 days of age. The confined animals were fed forage (corn) and concentrated, in the ratio of 40:60 and concentrated pasture supplemented with 1% body weight. The experimental design was completely randomized in a factorial 2 x 4 (two feeding systems x four slaughter weights). It was observed a significant interaction between slaughter weight and finishing system only for the texture of the meat. The finished animals on pasture showed improved texture with increased weight, whereas the confined animals did not affect the weight. Animals finished on pasture had higher muscle percentage (69.48% vs 66.57%), and lower fat percentage (9.58% and 9.75 kg vs 13.20% and 13.08 kg) compared to confined animals. There was a linear increase in the total amount of muscle, bone and fat, muscle / bone ratio, compared edible portion / bone, palatability and juiciness when increased slaughter weight. The percentage of bone and meat coloring decreased linearly with the increase of slaughter weight. The proportion of muscle and fat, showed quadratic behavior. The animals of dairy breeds are excellent producers of lean meat, with good smoothness, flavor and juiciness.