The effect of grazing saltbush with a barley supplement on the carcass and eating quality of sheepmeat

Influence of diets with silage from forage plants adapted to the semi-arid conditions on lamb quality and sensory attributes

Quality and sensory attributes of meat from 32 mixed-breed Santa Inês lambs fed diets composed of four silages with old man saltbush (Atriplex nummularia Lind), buffelgrass (Cenchrus ciliaris), Gliricidia (Gliricidia sepium), and Pornunça (Manihot sp.) were evaluated. Meat from lambs fed diet containing old man saltbush silage (P<0.05) showed greater values for cooking loss. Of the sensory attributes evaluated in the Longissimus lumborum muscle of the lambs, color and juiciness did not differ (P>0.05). However, the silages led to differences (P<0.05) in aroma, tenderness, and flavor values. The meat from animals fed the pornunça and Gliricidia silages was tenderer. Flavor scores were higher in meat from lambs that consumed old man saltbush silage and lower in the meat from those fed buffelgrass silage. Diets formulated with buffelgrass silage for sheep reduce meat production. Based on the results for carcass weight and meat quality, old man saltbush and pornunça are better silages for finishing sheep.

The Effect of Extensive Feeding Systems on Growth Rate, Carcass Traits, and Meat Quality of Finishing Lambs

This review aims to summarize the relevant published information about the effects of extensive feeding systems on the carcass and meat quality characteristics of lambs. Lambs finished in a feedlot or with supplementation under extensive systems exhibit faster growth rates, achieve target weights quicker, and produce heavier carcass weights when compared to grazing lambs. However, the literature also shows that finishing lambs on high-quality pasture can produce satisfactory growth rates without compromising carcass and meat quality traits. Lately, the consumer demand for products perceived as "healthy" and that are produced where animal welfare is optimal under systems which do not impact negatively on the environment, has heightened the interest in lamb production under extensive systems. Lambs raised on pasture can meet many of these specifications. Also, lambs fed higher quality green pasture can produce meat with greater amounts of health-claimable omega-3 fatty acids such as eicosapentaenoic acid plus docosahexaenoic acid than feeding systems based on feedlot pellets, grain, or dry pasture/straw. It is apparent that in some previous published research, the number of animals allocated for each treatment, and the lack of replicates, makes it difficult to formulate a correct understanding of the effect of forages on lamb carcass and meat quality. Future research should concentrate on the effect of legume, improved pasture, and specialized forage finishing systems on growth rate, carcass traits, and nutritional value of meat using well-designed experiments with an adequate number of lambs and appropriate paddock replicates per treatment.

Rendimentos de carcaça, cortes comerciais e não-componentes da carcaça de cordeiros Santa Inês alimentados com feno de erva-sal e concentrado

Objetivou-se com este trabalho avaliar os rendimentos de carcaça, cortes comerciais e não-componentes da carcaça de cordeiros Santa Inês alimentados com 30, 40, 50 e 60% de feno de erva-sal associado a concentrado. Foram utilizados 32 ovinos machos castrados, com 8 meses de idade e peso inicial de 22 + 1,97kg, confinados individualmente e abatidos após 60 dias de confinamento. Os pesos de carcaça quente e fria decresceram linearmente com o aumento de feno de erva-sal na dieta, no entanto, não houve efeito para o rendimento verdadeiro de carcaça (59,42%) e dos cortes: paleta (19,26%), pescoço (8,52%), costelas (26,57%) e perna (33,88%). Houve efeito linear decrescente para área de olho de lombo e espessura de gordura à medida que o nível de feno de erva-sal aumentou na dieta. Os pesos e os rendimentos de pele, fígado, coração, rins com gordura perirrenal e gorduras omental e mesentérica decresceram linearmente com a inclusão de feno de erva-sal na dieta, enquanto o conteúdo (%) do trato gastrintestinal aumentou. O aumento da proporção de feno de erva-sal na dieta de cordeiros proporciona adequados rendimentos verdadeiros de carcaça e dos cortes comerciais, no entanto, reduz a área de olho de lombo e a espessura de gordura subcutânea, medidas importantes na avaliação qualitativa da carcaça ovina.

Age and nutrition influence the concentrations of three branched chain fatty acids in sheep fat from Australian abattoirs

The characteristic mutton odour, associated with the cooked meat of older sheep, can be problematic for some consumers who find the odour disagreeable. Branch chain fatty acids (BCFAs) are considered to be the main determinants of mutton odour. In this study, the aim was to identify the factors influencing the BCFA content of animals at abattoirs in Australia. Samples of subcutaneous fat from over the chump (gluteus medius) were collected from 533 sheep carcasses at abattoirs in New South Wales, Victoria and Western Australia. The carcasses were from sheep differing in age, gender, breed and nutrition. The concentrations of three branched chain fatty acids (BCFAs); namely, 4-methyloctanoic (MOA), 4-ethyloctanoic (EOA) and 4-methylnonanoic acids (MNA), were determined. Statistical modelling showed that, with pre-slaughter nutrition in the model as a random term, BCFA concentrations could be used for discriminating the age of sheep. Fat samples from lamb carcasses had lower MOA and EOA concentrations and a higher concentration of MNA in comparison to hogget and mutton (P<0.05). When nutrition was excluded as a random effect from the statistical model, the MOA and MNA concentrations did not differentiate between lamb, hogget and mutton whereas, for EOA, lamb had a lower concentration than mutton (P<0.05) with hogget intermediate. An interaction existed between age and gender (P<0.05) where female lambs had lower EOA concentrations relative to the mutton but not for castrates.