English abstract
Sheep farming systems in the Sultanate of Oman similar to others in arid and semi-arid areas are facing challenges toward improving their performance. The major challenges are feeds availability, feed prices, and the high year-round ambient temperature. Furthermore, livestock environmental aspects remain a global and local challenge. The general goal of this work was to evaluate strategies for improving performance of Omani sheep. The specific objectives of this work were: 1) to evaluate the impact of diet concentrate and energy levels and animal shearing on feed and nutrient intakes and ruminal methane production of Omani sheep, 2) to measure the variations in feed intake, water intake, rectal temperature, and blood parameters between different groups of sheared and fleeced rams fed high- or low-quality diets. Two experiments were conducted to evaluate the effect of diet and shearing on nutrient and feed intake, water intake, rectal temperature, digestibility and ruminal methane production in Omani yearling rams. Our results showed that the dietary increase in concentrate level (60%:40%, concentrate to roughage ratio) has increased organic matter and nutrients intake of the total diet, water intake, and has reduced ruminal methane production compared to the low concentrate fed diets with (80%:20%, roughage to concentrate ratio). Furthermore, shearing has a significant effect on increasing organic matter intake, water intake and reducing the rectal temperature of animals. Most of the variation in water intake and ruminal methane production is driven by the diet effect.
Partial substitution of low-quality Rhodes grass by high quality concentrate has improved the total diet organic matter digestibility and nutrients digestibility and had no observed effects on biochemical blood parameters or animal health.
This study suggests that shearing of animals under shade and supplementing greater amounts of high energy feeds would lead to improving Omani sheep subsistence under hot climate conditions and mitigate their methane production.
