Resumo em Inglês:

ABSTRACT This study aimed to determine production cycles based on the stocking period and the influence of the cycles on productive performance indices, production costs, and profitability. The present study was carried out on a fish farm located in Palmital - SP, Brazil, which consists of 2706 m3 of net cages with an annual production of 400 tons of tilapia and regular harvests throughout the year. Production data, investment and expenditures were obtained by using a semi-structured questionnaire to calculate the total operational costs and profit indices. All monetary values of invested items have been corrected by the General Price Index (GPI) for December 2014. Three rearing phases were identified and characterized as the nursery, pre-finishing, and finishing phases. The production cycle is between 195 and 270 days and the profitability index is between 15.08 to 26.09%, in which the best production scenario is found when carrying out all of the rearing stages (nursery, pre-finishing, and finishing) in high temperatures. The stocking fish in low temperatures increases the production time by 38.46%. The extend production time allow the producer to regularly offer the product and have more flexibility on the decisions of the production

Resumo em Inglês:

ABSTRACT By using informetric tools, we evaluated the contribution and impact of the open source computer-assisted sperm analysis (CASA) software on sperm studies, especially pertaining to fish. The article was cited 125 times between 2007 and 2014 in four publication types (articles, doctoral dissertations, master’s theses, and books). Among articles, the number of citations increased at rate of three citations per year and the calculated h-index was 17. Of the studies that cited Wilson-Leedy and Ingermann (2007), fish were the main group of organisms studied (61 articles); of these, 34 articles used the open source CASA, covering 23 marine or freshwater species. Studies conducted in 12 countries were published in 21 journals. Four ways of knowledge sharing were identified: by direct partnership with the system developers; by knowledge multipliers, who worked directly with the system developers; by groups that adopted the system by their own initiative; and through expansion of cooperation networks with autodidacts. In regard to specific analytical procedures, motility, curvilinear velocity, average path velocity, and straight-line velocity were the main CASA parameters used to describe sperm movements. As expected, the usage of this tool has been increasing over the years, being a reliable and versatile alternative to more costly similar platforms. However, the potential of the CASA system has not been completely explored and it is our assessment that some results produced by CASA are poorly understood or even misunderstood.

Resumo em Inglês:

ABSTRACT This study investigated the effect of dietary amino acid composition from proteins alternative to fishmeal on the growth performance of the common snook, Centropomus undecimalis. Fish of 10.79±0.71 g (n = 150) were stocked in 15 shaded outdoor tanks of 1 m3. The basal diet contained 643.4 g kg−1 salmon byproduct meal (SML) and 200.0 g kg−1 soy protein concentrate (SPC). Two other diets replaced 39 and 29% of the SML with poultry byproduct meal (PBM, 170.1 g kg−1) and SPC (334.9 g kg−1), respectively. Fish were fed twice daily for 84 days under 32±1 g L−1 water salinity and 27.3±0.9 °C temperature. Final survival (99.5±2.6%) was unaffected by dietary treatment. Snook grew slower (0.24±0.03 and 0.27±0.04 vs 0.35±0.06 g day−1) and achieved the lowest body weight (31.1±6.62 and 33.3±10.20 vs 40.4±13.18 g) and the highest feed conversion ratio (3.69±0.29 and 3.11±0.51 vs 2.33±0.34) when fed SPC and basal diets compared with PBM, respectively. Retention of dietary crude protein varied from 36 to 38% for fish fed the basal and SPC diets, but exceeded 51% in fish fed PBM. Results indicate a greater ability of the common snook to gain weight and increase retention of nutrients when dietary protein is of terrestrial animal origin. Dietary protein from PBM yields a more balanced dietary amino acid composition relative to fish muscle, but possibly in excess of the species requirements.

Resumo em Inglês:

ABSTRACT The objective of this study was to evaluate the oxidative stability of cashew nut meal (CNM) at 180 days of storage and the effects of its use in the feed of meat quails. A total of 280 animals at seven days of age, of both sexes, were distributed in a completely randomized design with five treatments, in a 2 × 2 + 1 factorial arrangement, and seven replicates of eight birds each. The treatments were a control diet without CNM and diets containing levels of 12.5 or 25% of new CNM (NCNM) or stored for 180 days (SCNM). The lipid oxidation of the brans was evaluated by determining the acidity index and peroxide index. The parameters evaluated were the quail performance, metabolizable coefficients and energy of diets, carcass characteristics, relative weights of the liver and pancreas, and bone parameters. The acidity of cashew nut meal was 4.66% and 6.16 (% in oleic acid) for NCNM and SCNM, respectively. Independent of the storage, inclusion of CNM resulted in higher metabolizable energy values in the diet, reduced intake, and, because weight gain did not vary, feed conversion improved compared with the control treatment. Carcass traits, relative weights of liver and pancreas, as well as bone growth and quality were not affected by dietary treatments. Despite the hydrolytic rancidity, CNM can be used in the diets for meat quails at up to 25% of inclusion.

Resumo em Inglês:

ABSTRACT The objective of this study was to determine the nutritional value of glycerin for pigs using different inclusion levels of this test ingredient and the methodologies of total collection and chromium oxide marker. Eight barrows were distributed individually into metabolic cages, in a randomized-block experimental design, and fed diets containing 0, 50, 100, and 150 g kg−1 plant-derived crude glycerin. The feed digestibility methodologies of total feces and urine collection and chromium oxide marker were analyzed. Inclusion of up to 150 g kg−1 crude glycerin improved the digestibility coefficients of organic matter and energy of the diets. The collection method based on the use of chromium oxide marker underestimates the digestibility coefficient of ash and the energy values of glycerin in relation to the total collection method, but yields similar results to those obtained with the total collection method for the dry matter, organic matter, crude protein, ether extract, and neutral detergent fiber assessed.

Resumo em Inglês:

ABSTRACT The objective was to evaluate the effects of corn silage supplemented with 1-propanol or inoculated with L. buchneri on the ruminal fermentation profile, digestibility, and production traits of lactating Holstein cows. Whole-corn plants were harvested at 350 g/kg dry matter (DM) and packed in nine bag silos (13 t/silo). At ensiling, two treatments were applied: control (no additive; six silos) and L. buchneri inoculation with 1 × 105 cfu/g (three silos). Feeding started after 247 days of storage; one L. buchneri and two control silos were opened in each experimental period. Twenty-one multiparous Holstein cows (~33 kg/day of milk) were allocated to seven balanced 3 × 3 Latin squares with 21-day periods (14 days of adaptation). The experimental diets contained (DM basis): 80 g/kg cottonseed, 95 g/kg citrus pulp, 180 g/kg soybean meal, 90 g/kg corn grain (ground), 25 g/kg minerals and vitamins premix, and 530 g/kg of corn silage. Source of corn silage was the only difference between experimental treatments: control, L. buchneri, or control silage supplemented with 1-propanol (10 g/kg of diet DM). The 1-propanol was dissolved in water (1:1) and sprinkled onto the ration during mixing, immediately before each feeding. Dry matter intake, nutrient digestibility, milk yield, and composition were not affected by treatments. Cows fed 1-propanol had greater concentrations of 1-propanol in the rumen fluid, higher concentration of glucose, and lower concentration of non-esterified fatty acids in blood plasma. Corn silage inoculated with L. buchneri at 1 × 105 cfu/g does not affect silage fermentation, ruminal fermentation profile, or milk production. Supplementation of 1-propanol at 10 g/kg affects the ruminal fermentation profile without affecting feed intake and milk production of mid-lactating dairy cows.

Resumo em Inglês:

ABSTRACT The addition of levels of ethanol extract of brown propolis was evaluated by assessing diet degradation in rumen fluid and predicting cumulative in vitro gas production by nonlinear (dual pool logistic and exponential) models. A total of 35 g of crude propolis were extracted in 65 mL of cereal alcohol (95% ethanol). In a completely randomized factorial design, the experimental diets combined four concentrations of extracted propolis diluted in cereal alcohol (0, 50, 70, and 100% of propolis extract) and supplementation doses (4, 8, 12, 16, and 20 mL/kg dry matter), tested in triplicate. Diet (400 g/kg Tifton hay and 600 g/kg concentrate) was incubated for 96 h carried out three times in three different weeks. There was significant interaction between extract concentration and dose on the dry matter (DM) degradability. Dry matter degradability of diet decreased exponentially as a function of the increase in dose (y = 678.55×dose–0.271). Pure alcohol treatment showed a negative exponential effect, with degradability of 303.61 g/kg when administered at a dose of 20 mL/kg DM. Treatment 100% ethanol extract reached the greatest degradability, estimated at 18.93 mL/kg DM. The treatment with 70% extract showed 6.35 mL/kg DM and the 50% extract, 7.65 mL/kg DM of minimum degradability. The reduction potential of pure ethanol was –0.32 mL gas/mL. Estimates of maximum gas production by dual pool logistic and exponential models were 13.10 mL and 12.07 mL for 100% extract, respectively. The 100% extract produced the highest gas production estimates, above 30 mL gas/100 mg DM of fermented diet. The degradation and fermentation of ruminant diet can be improved using 13 mL/DM kg of ethanol extract of propolis.

Resumo em Inglês:

ABSTRACT Herbivores face the dilemma that the level of feed intake is negatively related to factors that determine digestive efficiency, such as thoroughness of ingesta comminution by chewing, and retention of digesta in the digestive tract. Ruminants have evolved particular adaptations to solve this dilemma. Most ruminants share the characteristic of “digesta washing”: fluid moves through their digestive tract faster than particles, thus effectively washing very fine particles, such as bacteria, out of the digesta plug. As the forestomach is followed by auto-enzymatic digestion, this allows a continuous, increased harvest of microbes from the forestomach. True rumination only evolved twice, in the camelids and the true ruminants. These both evolved a density-dependent sorting mechanism based on physical separation of the digesta by the process of flotation and sedimentation, ensuring that the process of rumination is applied to large particles. Differences in this sorting mechanism might facilitate a faster digesta processing in true ruminants as compared with camelids. The hallmark of ruminant digestive anatomy is the omasum, in which the fluid required for both digesta washing and the reticular separation mechanism is re-absorbed. In ruminants of the tribe Bovini, the omasum has reached the largest size and this group has a particularly great forestomach fluid throughput. Increasing the degree of digesta washing even more should increase microbial harvest from the forestomach and reduce the susceptibility to acidosis. At the same time, it should result in a metabolic state of the microbiome more tuned towards biomass production and less towards methanogenesis. Enhancing the forestomach fluid throughput by selective breeding could represent a promising way to further advance the productivity of the ruminant digestive tract.

Resumo em Inglês:

ABSTRACT Studies on B-vitamin requirements of cattle, conducted more than 60 years ago, concluded that mature ruminants do not require B-vitamin supplements because the amounts of vitamins provided by the diet and synthesized by the ruminal microflora were sufficient to prevent emergence of deficiency symptoms. As a result, the impact of subclinical deficiency on maintenance of normal and efficient metabolism has been disregarded and very little research effort has been devoted at defining dairy cow requirements for B vitamins. However, emergence of deficiency symptoms is the last stage of the deficiency; deficiency appears as soon as the supply is inferior to the needs, leading to a loss of metabolic efficiency. As B vitamins play critical roles in carbohydrate, protein, and lipid metabolism, it is likely that the demand for these cofactors increases with milk yield. Reports over the last two decades of beneficial effects of B-vitamin supplementation, such as thiamin, niacin, biotin, folic acid, and vitamin B12, suggested that, under some conditions, the need for B vitamins exceeds the supply from the diet and the synthesis by rumen microbes, leading to sub-optimal milk production and metabolic efficiency. However, responses to B-vitamin supplementation are highly variable. The major challenge faced by studies on B-vitamin requirements of dairy cows is the very limited knowledge on dietary factors driving the fate of B vitamins in rumen. This knowledge is essential to identify the conditions under which the dairy cow could benefit from B-vitamin supplements. The present review aims to describe the present state of knowledge on B-vitamin requirements of dairy cows as well as some of the major problems that need to be overcome to progress in this research field.

Resumo em Inglês:

ABSTRACT Precise body composition measurements are essential in animal nutrition studies because the impact of treatments is evaluated based on changes in body weight and composition. Various indirect techniques for animal compositional evaluation have been developed and evaluated for applicability in animal nutrition studies. A fast, accurate, minimally invasive method that requires little input is considered the ideal for providing information about the animal. Measurements obtained by dual-energy x-ray absorptiometry (DXA) are highly correlated with those obtained by chemical analysis and dissection. The algorithms of DXA software partition the six chemical components of the body (lipids, water, proteins, carbohydrates, non-bone mineral, and bone mineral) into three compartments (total body mineral content, fat mass, and lean mass). Questions have been raised about how this partitioning affects the precision of the DXA method. In addition, the relationship between the DXA measurements and dissected carcass tissues is nonrepresentational of the relationship between DXA and chemical analysis. Furthermore, since DXA devices and their software were developed primarily for human medicine, they may not be fully adequate for animal evaluation. Calibration is required to obtain true values. The DXA method has some advantages and disadvantages that should be identified and controlled before calibration. Nonetheless, DXA is a valuable tool that provides precise, repeatable body composition measurements of live monogastric animals and their carcasses.