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

Abstract

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.

The effect of feed restriction on the fat profile of Santa Inês lamb meat

“…The lambs that are usually reared under intensive farming and are fed concentrates and cereal straw until slaughter, within 90 days of age, produce meat with high n-6 concentrations (Brito, Ponnampalam, & Hopkins, 2016). The same authors cited that the PUFA of lamb meat are affected by the dietary concentrate ratio, and according to Mushi et al (2010), different dietary concentrate levels affect the fatty acid profile of the adipose tissue and increase the ratio of the desirable fatty acids (DFA) in the meat.…”

Effect of finishing diet and duration on the sensory quality and volatile profile of lamb meat

“…219 There was no difference in muscle fat content among dietary treatments or finishing 220 periods (Table 1). Other authors have reported that lambs receiving concentrate diets 221 generally have higher growth rates (Fraser & Rowarth, 1996) and IMF than lambs receiving 222 pasture-based diets (De Brito et al, 2017). However, Crouse et al (1978) found no difference 223 in fat thickness or percentage carcass fat of lambs fed low, medium or high energy diets and 224 slaughtered at constant weights.…”

Livestock Performance for Sheep and Cattle Grazing Lowland Permanent Pasture: Benchmarking Potential of Forage-Based Systems

“…Even though finishing lambs at pasture is the conventional production system for lowland grasslands, some alternative feeding options may be included to finish lambs indoor or for specialist early lambing flocks which aim to market lambs in spring when prices are traditionally high, for example silage, concentrate, total mixed rations or by products [45], reaching growth rates above 300 g/d [46,47]. However, whether this alternative is economically convenient will depend upon the feed conversion efficiency and the prices of feed and meat.…”