Carcass traits of Rambouillet and Merino × Rambouillet lambs and fatty acid profiles of muscle and subcutaneous adipose tissues as affected by new sheep production system

Desempenho e características de carcaça de cordeiros Santa Inês e suas cruzas com Dorper terminados em confinamento

RESUMO Objetivou-se avaliar o desempenho e características de cordeiros Santa Inês e suas cruzas desmamados aos 75 dias de vida e terminados em confinamento. Foram utilizados 30 cordeiros não castrados, 10 Santa Inês, 10 ½Dorper × ½Santa Inês e 10 ¾Dorper × ¼Santa Inês, com idade e peso vivo médio no início do experimento de 82 dias e 19,40 kg, respectivamente. Foi utilizada dieta única contendo 169,0 g/kg de proteína bruta e 2,80 Mcal/kg MS. Não houve efeito do genótipo sobre o desempenho dos cordeiros, exceto para escore corporal final, em que os mestiços Dorper alcançaram os maiores escores. As carcaças dos cordeiros ½Dorper × ½Santa Inês e ¾Dorper × ¼Santa Inês apresentaram maior largura da garupa, área de olho de lombo e percentual de lombo do que as carcaças dos cordeiros Santa Inês. As carcaças dos cordeiros ¾Dorper × ¼Santa Inês alcançaram maior largura do tórax e do anterior quando comparadas com as carcaças dos cordeiros Santa Inês, tendo obtido também melhor conformação e acabamento de carcaça quando comparadas com as carcaças dos demais genótipos. Entretanto, as carcaças dos cordeiros Santa Inês e ½Dorper × ½Santa Inês apresentaram maior percentual de pescoço em relação às carcaças dos cordeiros ¾Dorper × ¼Santa Inês.

Effect of concentrate level and slaughter body weight on growth performances, carcass traits and meat quality of Barbarine lambs fed oat hay based diet

This study was conducted to evaluate concentrate level (CL) and slaughter body weight (SW) effects on growth performances, carcass traits and meat quality of Barbarine lambs. Twenty-four weaned male lambs (23.1 kg), receiving an oat-hay based diet, were allotted into two groups. The LCL group received low concentrate level (300 g) and the HCL group received high concentrate level (600 g). Lambs were slaughtered at two prefixed weights (35 and 42 kg). For each group and each weight, six lambs were slaughtered. Lambs from HCL group had higher ADG, carcass yields, carcass compactness and subcutaneous fat thickness, and lower carcass meat proportion. CL increase did not affect meat pH, meat and fat color, chemical and fatty acid composition. Late slaughtering improved carcass yields and increased carcass adiposity. However, it did not affect carcass meat proportion and shoulder tissue composition. SW had effect on meat color and fatty acid composition.

Fatty acid and vitamin E composition of intramuscular fat in cattle reared in different production systems

The aim of this study was to evaluate the fatty acid composition of intramuscular fat and the vitamin E content of beef from different production systems. Four cattle production systems were used: cattle reared under intensive conditions and fed concentrate (INT1) from Spain, cattle raised at pasture and supplemented with concentrate (SUP1) from the United Kingdom, cattle raised at pasture and on corn silage (SUP2) from Germany and cattle reared under extensive conditions slaughtered at two and three years old (EXT2 and EXT3) from Uruguay. The highest proportion and content (mg per 100g of muscle) of linoleic acid (C18:2n-6) and arachidonic acid (C20:4n-6) and the lowest saturated fatty acids (SFA) was found in INT1 beef. In contrast, beef reared under extensive conditions showed the highest proportion and content of linolenic acid (C18:3n-3), docosapentaenoic acid (DPA, C22:5n-3) and eicosapentaenoic acid (EPA, C20:5n-3), and SUP1 and SUP2 beef showed the highest level of palmitic acid (C16:0) and SFA. Beef from intensive system (INT1) had the lowest P/S (PUFA/SFA) ratio, whereas beef from extensive system (EXT2 and EXT3) had the lowest n-6/n-3 ratio. The results of the PCA (principal components analysis) of fatty acid composition showed that beef from intensive system (INT1) was clearly differentiated from the other meats and was located with the C18:2n-6 and C20:4n-6 and the n-6/n-3 ratio. EXT2 and EXT3 beef were located with C18:3n-3 and long chain fatty acids. Beef from extensive systems had the highest concentration of vitamin E (3.91mg α-tocopherol/kg muscle).

Productive performance and meat quality of Mouflon×Sarda and Sarda×Sarda suckling lambs

The objective of this study was to compare slaughtering performance, carcass characteristics, and meat quality in lambs of two different genotypes. Sixteen crossbred Mouflon×Sarda (M×S) and sixteen pure Sarda breed (S×S) suckling lambs were analysed. Chemical and fatty acid composition were determined on semitendinosus and longissimus dorsi muscles and perirenal and pelvic fats. Dressing percentage was higher (P<0.01) in M×S group and after histological dissection M×S carcasses had more muscle tissue (P<0.01) and less separable fat (P<0.05). Muscles of M×S had less cholesterol than the S×S lambs (P<0.01). Polyunsaturated/saturated and n-6/n-3 fatty acids ratios of the intramuscular lipids were optimal in both groups. Indexes of atherogenicity and of thrombogenicity in muscles varied between 0.9 and 1.1. The results indicated several good qualities in both the genotypes, but M×S lambs have some traits which could provide a higher market price.

Plant bioactives for ruminant health and productivity

Plants have been used throughout history for their medicinal properties. This use has often focused on human health but plants have also been, and still are, applied in ethnoveterinary practice and animal health management. In recent times, the use of synthetic chemicals has become prevalent. Public awareness of the potential environmental and health risks associated with heavy chemical use has also increased. This has put pressure on regulatory bodies to reduce the use of chemicals in agriculture. The most striking example is the 2006 banning of antibiotics in animal feed by the European Union. Moves such as this have increased the drive to find alternatives to synthetic chemicals and research has again turned to the use of plant bioactives as a means of improving animal health. Current scientific evidence suggests there is significant potential to use plants to enhance animal health in general and that of ruminants (cattle, deer, sheep, etc.) in particular. Active areas of research for plant bioactives (particularly saponin and tannin containing plants) include reproductive efficiency, milk and meat quality improvement, foam production/bloat control and methane production. Nematode control is also a significant area of research and the evidence suggests a much broader range of phytochemicals may be effective. This review presents a summary of the literature and examines international research efforts towards the development of plant bioactives for animal health.