Effects of different sources and levels of dietary chromium supplementation on performance of broiler chicks.

The current experiment was carried out to evaluate the effect of different dietary chromium supplementation sources, chromium oxide (Cr2 O3 ), chromium methionine (Cr-Met), or chromium yeast (Cr-yeast), at different levels each (500 or 1,000 ppb) on growth performance, physiological traits, and carcass characteristics of broiler chicks. A total of 490 seven-day-old Arbor Acres chicks were randomly distributed into 7 experimental groups each in 10 replicates of 7 birds each. The groups were control, 500 ppb Cr2 O3 , 1,000 ppb Cr2 O3 , 500 ppb Cr-Met, 1,000 ppb Cr-Met, 500 ppb Cr-yeast, and 1,000 ppb Cr-yeast. The results showed significant superiority of the organic chromium sources (Cr-Met or Cr-yeast) concerning body weight and weight gain, the group supplemented with 1,000 ppb Cr-yeast consumed the lowest feed (3,185 g) and had the best feed conversion ratio (1.60) compared to the control (1.73). The chromium treatments recorded significantly better protein and lipid profile, antioxidant status, and immunological parameters than the control group. Similarly, dietary chromium supplementation increased carcass yield and decreased intestinal pathogenic bacteria. In conclusion, supplementing broiler diets with organic chromium sources at 1,000 ppb promotes growth performance, physiological traits, and carcass characteristics; such chromium treatments enhanced the antioxidant status and immunity levels of broilers.

Effect of dietary inclusion of Leucaena leucocephala or Moringa oleifera leaf meal on performance of growing rabbits.

This experiment was carried out to evaluate the effect of including either Leucaena leucocephala (LLM) or Moringa oleifera leaf meal (MOLM) as tropical feed resources at two levels (30 or 40 %) on growth performance, carcass traits, and economical efficiency of growing rabbits. A total of 60 California growing rabbits were randomly distributed into five experimental groups, each consisting of 12 rabbits and were allocated individually; the groups were control, 30 % LLM, 40 % LLM, 30 % MOLM, and 40 % MOLM. The experimental period lasted from 6 to 12 weeks of age. The results showed that rabbits fed control and 30 % MOLM diets had significantly the highest final body weight and daily weight gain being 2,040 and 2,000 g and 31.6 and 30.6 g/day, respectively. Similarly, the best feed conversion ratio was associated with 30 % MOLM and control groups (3.2 and 3.4), while the worst value was for 40 % LLM group (5.2). MOLM treatments recorded significantly the highest dressing percentage along with control group. The inclusion of MOLM by 30 and 40 % improved the economical efficiency (2 and 1.5) in comparison with the control group (1.1). The results suggest that MOLM can be included in growing rabbit diets up to 40 % without any adverse effect on growth performance or carcass traits with higher economical efficiency of growing rabbits.