Feed Efficiency, Genetics, and Dietary Factors in Sheep Production

The economic and ecological viability of sheep production hinges on two critical factors:

• feed costs
• carcass yields

The profitability and sustainability of this industry requires the careful selection of animals exhibiting superior feed efficiency and delivering high-quality meat. Recognizing that up to 70% of production costs are attributed to feed, farmers are increasingly seeking solutions that balance economic considerations with environmental sustainability.

Balancing Dietary Parameters for Optimized Production

Tailoring diets to promote optimal growth and development in sheep is a key strategy for achieving higher-quality meat. This involves ensuring ample protein intake and incorporating diets with higher intestinal absorption rates to maximize nutrient absorption in the gut. The delicate balance of dietary parameters is essential in crafting an optimized production system that enhances both economic and environmental sustainability.

Genetic Influences on Production Traits

A groundbreaking study explores the intricate interplay of dietary and genetic factors on crucial production traits, including feed efficiency, carcass quality, and meat quality. Specific genes such as Callipyge, Calpastatin, and Myostatin, along with identified causal mutations, emerge as influential factors affecting animal growth rates and meat fatty acid profiles. Moreover, potential markers for sheep selection are identified among variants of other reported genes, including PIGY, UCP1, MEF2B, underscoring the genetic complexity at play.

Heritability Estimates and Genetic Correlations

A comprehensive meta-analysis of heritability estimates unveils the genetic underpinnings of traits such as residual feed intake, hot carcass weight, dressing percentage, and intramuscular fat content. These traits exhibit moderate to high heritability, suggesting their potential enhancement through genetic selection. Positive genetic correlations observed, especially between body weight and key quality indicators, indicate the promising prospect of selecting for higher body weight to positively impact carcass and meat quality.

Conclusions

In the evolving landscape of sheep farming, the quest for sustainable and economically viable practices has led to a nuanced understanding of the interplay between feed efficiency, genetics, and dietary factors. As farmers strive to optimize production systems, the insights gleaned from this study pave the way for informed decision-making, promising a future where sheep production thrives economically while minimizing its ecological footprint.

Source: Chacko Kaitholil SR, Mooney MH, Aubry A, Rezwan F, Shirali M. Insights into the influence of diet and genetics on feed efficiency and meat production in sheep. Anim Genet. 2024 Feb;55(1):20-46. doi: 10.1111/age.13383. Epub 2023 Dec 19. PMID: 38112204.