GROWTH PERFORMANCE, RUMEN FERMENTATION, AND NUTRIENT DIGESTIBILITY OF AWASSI LAMBS FED DIFFERENT LEVELS OF ORGANIC COPPER IN A BASAL DIET

his study investigated feed intake, growth performance, and rumen fermentation in Awassi lambs on diets supplemented with various levels of organic copper. A total of 24 eight-month-old male lambs weighing 25.5 ± 3.69 kg on average were studied over 90 days. The animals were divided randomly into four treatment groups of 6 lambs each, namely OCC (basal diet), OCF (basal diet + free of organic copper), OCC5 (basal diet + 0.5 g organic copper/kg DM), and OCC1 (basal diet + 1 g organic copper/kg DM). Samples of rumen fluid, feed intake, weight gain, and nutrient digestibility were collected during the trial and examined. The results showed that nutrient digestibility of organic matter and ether extract were higher (P < 0.01) in the OCC1 and OCC5 groups compared to the OCC. Similarly, there was a significant increase in concentration of acetic acid or/and NH3 of OCC1 compared to OCC. CH4 concentration was significantly lower in both OCC1 and OCC5 than the control group. The OCF treatment had a significant increase (P < 0.01) in pH compared to other treatments. No significant differences were found in daily weight gain, growth specific ratios, crude protein digestibility, crude fiber, and both isopropionic and propionic acids. The findings suggest that an Awassi lamb diet containing more than 0.5 g/kg copper feed over 90 days did not cause copper toxicity, improved rumen fermentation, and reduced methane emissions from the animals