Effect of Supplemental Manganese on Mineral Uptake by Tissues and Immune Response in Broiler Chickens

Two feeding trials were simultaneously conducted using 240 and 120 broiler chicks (Hubbard) for evaluating the mineral retention by tissues and immune competence, respectively as influenced by manganese (Mn) levels in feed. Mn was added at 0, 100, 400, 800, 1600 or 3200ppm levels to a corn-soya basal diet, using sulphate salt. In both trials, chicks were uniformly distributed into 6 experimental groups and housed in stainless steel battery brooders. From 8-28 days of age, each experimental diet was fed ad libitum to one test group. Results indicated that Mn supplementation from 0-800ppm did not influence body weight gain or feed consumption, but a significant depression in both parameters was noticed at 1600 and 3200ppm levels. The feed conversion efficiency was however, not affected by dietary Mn levels. Excess (1600ppm and above) or non - supplementation of Mn increased leg abnormality scores. Mn levels above 400ppm significantly decreased Ca, P and Zn retention in tibia, which was related to higher leg scores. A linear increase of Mn content in bone, kidney, liver and pancreas was noticed with the increase of Mn in feed. The antibody titers against inoculation of sheep red blood cells or cutaneous basophil hypersensitivity to phytohaemagglutinin-P were not influenced by the dietary increases of Mn up to 800 or 1600ppm levels, respectively. Both responses were negatively affected by increased Mn levels in feed. Heterophil to lymphocyte ratios, the indicators of stress were not altered by Mn supplementation up to 800ppm, but higher levels produced wider ratios. In conclusion, supplementation of Mn at 100ppm level was essential for leg health, better retention of Ca, P and Zn in bone besides optimum immune response. Mn supplementation at 100ppm level was as efficient as higher levels (upto 800ppm). Higher levels of Mn (1600ppm and above) had negative effect on all parameters studied in broilers up to 28 days of age

Effect of Surfeit Concentrations of Vitamin D3 on Performance, Bone Mineralization and Mineral Retention in Commercial Broiler Chicks

An experiment was conducted to see the effect of higher concentrations of vitamin D3 in diets containing sub optimal levels of calcium (Ca) and non-phytate phosphorus (NPP) in broiler chickens. Maize-soybean meal based starter and finisher reference diets (RD) prepared to contain 1.0% and 0.9% Ca, 0.45 and 0.35% NPP, respectively. The RD contained 1200ICU D3/kg. Another basal diet (BD) was prepared to contain 0.4% Ca and 0.2% NPP. The BD was supplemented with D3 at 4 different concentrations such as 1200, 2400, 4800 and 9600ICU/kg. Each diet was fed to 11 replicates of 5 chicks each during experimental period of 0 to 6 weeks of age. The body weight gain decreased significantly with reduction in levels of Ca and NPP in diet compared to those fed RD. Supplementation of vitamin D3 to the low Ca and NPP diet, though improved the weight gain significantly but not at per with RD. The feed efficiency was not affected by concentrations of Ca, NPP and D3 in diet at 36d of age. The relative weight of tibia, tibia breaking strength and tibia ash content decreased significantly with reduction in Ca and NPP levels in diet. Supplemental D3 replenished the tibia ash content and enhanced tibia weight and strength. Supplemental D3 non-linearly increased the serum Ca, P, acid and alkaline phosphatase contents in serum. Concentrations of Ca, P, Fe, Zn, Mn and Cu in excreta decrease non-linearly with increase vitamin D3 concentration in BD. It is concluded that higher levels of D3 supplementation to low Ca and NPP diet improved the performance partially but not at per with diet containing the recommended concentrations of Ca and NPP in broiler diet