Assessing carcass and meat characteristics of Damara, Dorper and Australian Merino lambs under restricted feeding

Abstract

Seasonal weight loss (SWL) is the most pressing constraint in ruminant production systems in tropical climates. SWL is controlled using supplementation, which is costly and difficult to implement in extensive systems, or using breeds adapted to tropical hot dry climates, like the Damara and Dorper. Albeit 15 years in Australia, little is known on how these sheep compare to Australian Merino. Here, the responses of the Damara, Dorper and Merino breeds to nutritional stress were compared. Seventy-two 6-month-old ram lambs, 24 from each breed, were allocated to growth (gaining 100 g/day) or restricted diets (losing 100 g/day, 85% of maintenance needs). Animals were weighed and carcass and meat characteristics determined. Results point out to the existence of important differences between the three genotypes, in particular between the Merino and the Southern African breeds. Additionally, Merino ram lambs seem to have been more influenced by SWL than the other two, with consequences on meat characteristics.

The hepatic and skeletal muscle ovine metabolomes as affected by weight loss: a study in three sheep breeds using NMR-metabolomics

“…Dorper and Damara breeds seem to be more tolerant to feed restriction. Previous studies on these animals713 (Supplementary Table S8) already suggested this tendency. Variations in the carcass weight and yields and in the dimensions of eye muscle were similar in Dorper and Damara breed, and both different of what was observed in Merino.…”

“…Animal production in the tropics and the Mediterranean is strongly affected by pasture scarcity and quality during the dry summer and autumn months, leading to Seasonal Weight Loss (SWL), as we have demonstrated in South Africa34, Western Africa56, Western Australia7 and the Canary Islands89. To counter the effects of SWL, farmers use supplementation to balance the nutritional needs of the animals.…”

“…The Merino has a long history in Australia after being introduced in 17972, but in the last two decades, market changes and animal welfare policies have led to an increased interest for breeds with other characteristics, particularly regarding the absence of wool (shedding hair sheep), heat tolerance and a natural adaptation to SWL7. Recently, two breeds from South Africa, the Damara and the Dorper, have been introduced to Australia.…”

“…We have studied SWL effect on live weight10, carcass and meat characteristics711, in gene expression of regulatory enzymes in the liver12, and more recently on the skeletal muscle proteome13, and fatty acid composition of muscle14 and the Damara fat tail adipose tissue15. However, no broad characterization of the muscle and liver metabolomes of these three breeds has ever been conducted.…”

Facilities, breed and experience affect ease of sheep handling: the livestock transporter’s perspective

“…Le Neindre et al (1993) reported variation between breeds in ease of movement through facilities, and differences in reaction style to stressors have also been described (Boissy et al, 2005). Shedding 'hair' breeds such as the Dorper and Damara have grown in popularity over the last 15 years due to reduced labour requirements compared with more traditional breeds such as the Merino (Almeida et al, 2013;Alemseged and Hacker, 2014), and quantitative differences in avoidance behaviours between Dorpers and Merinos have been found (Njisane and Muchenje, 2013). Consequently, breed differences in behaviour are likely to become more apparent and more important for efficient handling of sheep as the balance of breeds changes.…”