Interaction of dietary vitamin D-3 and sunlight exposure on B. indicus cattle: Animal performance, carcass traits, and meat quality

Attempts to improve beef tenderness through supplementation with dietary vitamin D-3 have been challenged by null results and negative impacts on animal performance and carcass traits. Because vitamin D-3 is also synthesised by the animal via ultraviolet radiation from sunlight, the effectiveness of supplementation with dietary vitamin D-3 may be modulated by the degree of exposure of the animal to sunlight. Hence, this work aimed to verify whether dietary vitamin D-3 modifies meat quality without negatively affecting animal performance and carcass traits in B. indicus beef cattle that were either exposed to or protected from natural sunlight. Forty-two (411 +/- 38 kg) Nellore-type castrated males were fed a high-concentrate diet for 45 days after assignment to a treatment group. The treatments comprised combinations of three levels of vitamin D3 [ViTD - none (V0) or 2 x 10(6) IU of vitamin D-3 administered for either 2 (V2) or 8 (V8) consecutive days pre-slaughter] and two shading conditions (SHADE - unshaded or shaded). The post-mortem (pm) measurements were taken in the Longissimus thoracis et lumborum muscle. The animal performance and carcass traits were unaffected by ViTD or SHADE The V2 treatment increased the Myofibrillar Fragmentation Index in shaded animals compared to unshaded ones. Animals under shade had higher muscle calcium concentration. There was no effect of either ViTD or SHADE on the shear force. The L* values were higher at 24 h pm than at 0 and 1 h pm, with no differences among the animals in the ViTD or SHADE groups. Higher a* values were observed among animals in the V8 group than in the V0 group, and higher b* values were observed among animals in the V8 group than in the V2 or V0 groups, which were not different. In conclusion, ViTD and SHADE did not affect animal performance, carcass traits or shear force, whereas animals receiving a lower ViTD dosage and SHADE exhibited altered myofibrillar fragmentation. ViTD affected the colour parameters, and changes in the lightness of the beef related to the time pm were found in meat from animals under SHADE. (c) 2012 Elsevier B.V. All rights reserved.

Genetic associations between flight speed and growth traits in Nellore cattle

The aim of the present study was to estimate genetic parameters for flight speed and its association with growth traits in Nellore beef cattle. The flight speed (FS) of 7,402 yearling animals was measured, using a device composed of a pair of photoelectric cells. Time interval data (s) were converted to speed (m/s) and faster animals were regarded as more reactive. The growth traits analyzed were weaning weight (WW), ADG from weaning to yearling age, and yearling scrotal circumference (SC). The (co)variance components were estimated using REML in a multitrait analysis applying an animal model. The model included random direct additive genetic and residual effects, fixed effects of contemporary groups, age of dam (classes), and age of animal as covariable. For WW, the model also included maternal genetic and permanent environmental random effects. The direct heritability estimate for FS was 0.26 +/- 0.05 and direct heritability estimates for WW, SC, and ADG were 0.30 +/- 0.01, 0.48 +/- 0.02, and 0.19 +/- 0.01, respectively. Estimates of the genetic correlation between FS and the growth traits were -0.12 +/- 0.07 (WW), -0.13 +/- 0.08 (ADG), and -0.11 +/- 0.07 (SC). Although the values were low, these correlations showed that animals with better temperaments (slower FS) tended to present better performance. It is possible to infer that long-term selection for weight and scrotal circumference can promote a positive genetic response in the temperament of animals. Nevertheless, to obtain faster genetic progress in temperament, it would be necessary to perform direct selection for such trait. Flight speed is an easily measured indicator of temperament and can be included as a selection criterion in breeding programs for Nellore cattle.

Estratégias de sinalização da qualidade da carne suína ao consumidor final

A suinocultura destaca-se na economia brasileira. Contudo, avaliando-se o consumo interno da carne suína in natura, observa-se uma estagnação em patamares baixos. O artigo tem como objetivo analisar as principais iniciativas adotadas pelo Sistema Agroindustrial (SAG) da carne suína no Brasil visando sinalizar qualidade aos consumidores. Devido à marcante assimetria de informações, ressalta-se a importância da organização da cadeia produtiva, melhor direcionando esforços para a expansão do mercado interno. Este trabalho sugere ações visando aprimorar a coordenação deste SAG com vistas à melhoria na qualidade da carne ao consumidor e à redução da informalidade.

Lipid and selenium sources on fatty acid composition of intramuscular fat and muscle selenium concentration of Nellore steers

The objective of this study was to evaluate the effect of lipid and selenium sources in diets for finishing Nellore steers on the fatty acid composition and selenium concentration of the longissimus muscle. Fifty Nellore steers (body weight = 458 +/- 39 kg) were assigned to one of six dietary treatments: 1) diet containing sunflower seed and inorganic selenium; 2) sunflower seed and organic selenium; 3) whole cottonseed and inorganic selenium; 4) whole cottonseed and organic selenium; 5) soybeans and inorganic selenium; and 6) soybeans and organic selenium. Diets were formulated with the same amount of nitrogen and calories and supplied once daily to steers in collective pens, with three animals per pen, for 120 d. At the end of the trial, steers were slaughtered and samples of the longissimus muscle were collected for fatty acid and selenium analysis. Effect of selenium sources was detected for selenium concentration in the longissimus muscle. Organic selenium had higher concentrations in the meat compared with inorganic selenium. The total saturated, monounsaturated and polyunsaturated fatty acids did not differ between the sources of lipids and selenium. For selenium sources, no differences were observed between the concentrations of polyunsaturated fat. Also, no differences in C18:2 cis-9 trans-11 concentrations were noted; however, steers fed sunflower seed presented greater proportions of this fatty acid in the meat. The results indicated that the use of sunflower seed, cottonseed or soybeans and organic or inorganic selenium in feedlot diets to Nellore cattle does not alter the great part of the fatty acid profile of the longissimus muscle. However, the inclusion of sunflower seed in the diet increases the meat CLA cis-9, trans-11, which is desirable and beneficial for the health of consumers.

Growth curve in Santa Ines sheep

The objective of this research was to use non-linear models to describe the growth pattern in Santa Ines sheep and to study the influence of environmental effects on curve parameters with the best-fit model. The models included the Brody, Richards, Von Bertalanffy, Gompertz, and Logistic models. We used 773 field reports on 162 animals ranging in age from 120 to 774 days, including 46 males and 116 females. The statistics used to evaluate the quality of fit included RMS (residual mean square), C% (percentage of convergence), R-2 (adjusted determination coefficient) and MAD (mean absolute deviation). Of the fixed effects studied, the only significant relationship was the effect of sex on parameter A. The Richards model was problematic during the process of convergence. Considering all studied criteria, the Logistic model presented the best fit in describing the growth pattern in Santa Ines sheep. (C) 2011 Elsevier B.V. All rights reserved.

Contribution to economic evaluation of systems that value animal welfare at farm

The demand for "welfare friendly" products increases as public conscience and perception on livestock production systems grow. The public and policy-makers demand scientific information for education and to guide decision processes. This paper describes some of the last decade contributions made by scientists on the technical, economical and market areas of farm animal welfare. Articles on animal welfare were compiled on the following themes: 1) consumer behavior, 2) technical and economical viability, 3) public regulation, and 4) private certification policies. Most studies on the economic evaluation of systems that promote animal welfare involved species destined to produce export items, such as eggs, beef and pork. Few studies were found on broilers, dairy cows and fish, and data regarding other species, such as horses, sheep and goats were not found. Scientists understand that farm animal welfare is not only a matter of ethics, but also an essential tool to gain and maintain markets. However, it is unfortunate that little attention is paid to species that are not economically important for exports. Studies that emphasize on more humane ways to raise animals and that provide economic incentives to the producer are needed. An integrated multidisciplinary approach is necessary to highlight the benefits of introducing animal welfare techniques to existing production systems.