Effect of diet quality and shearing on feed and water intake, in vitro ruminal methane production, and blood parameters of Omani sheep

Effect of increasing doses of neem (Azadirachta indica) seed oil on feed intake, nutrients digestibility, ruminal fermentation and nitrogen utilization of Omani sheep

This study was conducted to examine the effects of neem (Azadirachta indica) seed oil (NSO) on feed intake, ruminal fermentability, feed digestibility, nitrogen balance, and blood parameters in Omani sheep. Nine Omani male sheep (BW; 54.44 ± 8 kg/sheep) were used in a replicated 3 × 3 Latin Square design with three dietary treatments and three periods, with each period lasting 21 days. The animals were randomly assigned into three treatment groups: basal diet without NSO (control); 20 mL/sheep per day NSO (low dose) or 40 mL/sheep per day NSO (high dose). Sheep fed with high dose presented lower (p < 0.05) intake, fiber digestibility, and excreted N in urine. However, diet supplemented with high NSO dose had a lower (p < 0.05) ruminal acetate proportion, while increased (p < 0.05) ruminal propionate compared to the control group. Moreover, sheep offered with NSO showed a linear decrease (p = 0.052) in ruminal ammonia nitrogen (NH₃-N) concentration. The high dose increased (p < 0.05) blood glucose and cholesterol, while decreased urea nitrogen concentrations. Emission of predicted methane (CH₄) reduced (p = 0.007) by 13% for high dose compared to the control group. In conclusion, these results suggested that NSO is a potential feed additive with up to 20 ml/kg of DM alters rumen fermentation profile, decreased CH₄ production, feed digestibility, and nitrogen metabolism for sheep.

Effect of dietary concentrate content on feed intake, feed efficiency, and meat quality of Holstein steers fattened in a hot environment

The objective of this study was to investigate the effect of feeding high and low concentrate diets on feed intake and feed efficiency, the morphological characteristics of the rumen papillae, and meat quality of Holstein steers fattened under hot climate conditions in Oman. Ten male Holstein calves, of 5 months of age, were selected for the experiment. The animals were fed concentrate and Rhodes grass hay and were divided into two groups of high concentrate (HC, n = 5) and low concentrate diets (LC, n = 5), in which their feed intake, weight gain, and feed efficiency were evaluated across three growing periods. Feed intake and efficiency and average daily gain (ADG) of the HC group were significantly greater than for the LC group and were affected by the diet (p < .01) and the period (p < .001). Across the fattening periods, ADG declined in both groups, with ADG improved by 35% for steers on the HC diet compared to steers on the LC diet. Carcass meat quality was not affected significantly by the dietary concentrate level. In conclusion, our results can be used to make improvements in feed efficiency of Holstein steers under hot climate conditions.