Effect of dietary supplementation of organic chromium on performance, carcass traits, oxidative parameters, and immune responses in commercial broiler chickens.

An experiment was conducted to study effect of supplementing graded concentrations (0, 100, 200, 300, or 400 µg/kg diet) of organic chromium (Cr) on performance, carcass traits, oxidative stress, and immune responses in commercial broiler chickens reared in open-sided poultry house under tropical climatic conditions. Each diet was fed ad libitum to eight replicates consisting of six birds in each pen from 1 to 42 days of age. Body mass gain and feed efficiency at 21 and 42 days of age and relative mass of liver, abdominal fat, and ready to cook yields at 42 days of age were not affected (P > 0.05) by supplementing organic Cr in broiler diet. Body mass loss during pre-slaughter holding period (12 h) reduced and relative breast mass increased nonlinearly (P < 0.01) with concentration of Cr in diet. Lipid peroxidation decreased, while activities of glutathione peroxidase and glutathione reductase in plasma increased nonlinearly with Cr supplementation. The ratio between heterophyl and lymphocyte was not affected (P > 0.05) with Cr supplementation in broiler diet. Relative mass of lymphoid organs (bursa, spleen, and thymus) and antibody production to Newcastle disease vaccination were not affected (P > 0.05) by the treatments employed. The cell-mediated immunity (lymphocyte proliferation ratio) increased nonlinearly with dietary Cr concentration. The results of the present study indicated that supplementation of organic Cr did not influence body mass and feed efficiency. However, supplementation of the Cr reduced pre-slaughter holding losses, increased the relative mass of breast, and increased antioxidant status and lymphocyte proliferation in broilers reared in tropics.

Nutritional evaluation and utilisation of quality protein maize, Nityashree hybrid maize, and normal maize in broiler chickens.

Three experiments were conducted to determine the apparent metabolisable energy, apparent digestible amino acid values, and utilisation of three maize varities in chickens: quality protein maize (QPM), hybrid maize Nityashree (HMN) and normal maize (NM). There was no significant difference in the apparent metabolisable energy (AME) content amongst the three varieties of maize. Lysine and threonine digestibilities were significantly higher in QPM compared to either HMN or NM. No difference in the digestibilities of other amino acids occurred among the three different maize varieties. There was no difference between diets containing NM or HMN for body weight gain (21 and 40 d of age) and overall feed conversion ratio (0-40 d), but values were significantly higher for QPM (and Lys-supplemented NM) diets. The relative weights of dressed meat yield and giblets were unaffected by dietary replacement of NM with QPM, HMN, or Lys supplementation of the NM diet. However, abdominal fat content decreased and breast meat yield increased with both dietary replacement of NM with QPM and Lys supplementation of the NM diet. The concentration of protein in serum was significantly increased by dietary replacement of NM with QPM. Adding Lys to the NM based diet significantly increased the Ca concentration in serum compared with NM or HMN diets. However, the highest concentration of Ca in serum was found in the QPM diet. The concentration of total cholesterol in serum significantly decreased by either replacing NM with QPM or adding Lys to the NM based diet, compared with the NM diet. These results suggested that the feeding value of quality protein maize was superior to normal maize, while the feeding value of hybrid maize Nityashree was similar to that of normal maize.

Rice bran lysolecithin as a source of energy in broiler chicken diet.

1. Rice bran lysolecithin (RBL) was evaluated in broiler chicken diets. In the first experiment, RBL was included in diet at 0, 0·5, 2, 8 and 32 g/kg and fed to 250 broiler chickens from 0 to 42 d of age. In the second experiment, RBL was fed at 0, 25 and 50 g/kg diet to 405 day-old broiler chickens until 21 d of age, while during the finisher phase (22-35 d of age) chickens receiving each concentration of RBL were given all three concentrations of RBL in a 3 × 3 factorial manner. The diets were isocaloric. 2. Body weight, food consumption and food conversion efficiency were unaffected by feeding RBL, while the weight of pancreas increased at ≥2 g/kg of RBL in diet (experiment 1). In experiment 2, body weight was greater in the chickens receiving RBL at either 25 or 50 g/kg (21 d) and 50 g/kg (35 d of age). At 21 d of age, food consumption was greater at 25 or 50 g RBL/kg diet, while food conversion efficiency improved with 50 g RBL/kg diet. 3. Fat digestibility increased with RBL at 32 g/kg (experiment 1) and ≤25 g/kg (experiment 2). Rice bran lysolecithin increased ready to cook weight at 50 g/kg during starter phase and decreased abdominal fat at 25 and 50 g/kg during finisher phase (experiment 2). Liver and meat fat content were not affected. 4. It is concluded that lysolecithin from rice bran oil could be used as energy supplement in broiler chicken diet.

Response of naked neck (Nana) and normal (nana) broiler chickens to dietary energy levels in a subtropical climate.

1. The comparative response of naked neck (Nana) broiler chickens and their normally feathered (nana) full sibs to varied dietary energy levels was assessed under natural ambient conditions in a subtropical climate in two separate trials, one in winter (19.0 to 26.0 degrees C) and the other in summer (28.1 to 37.4 degrees C). 2. The chickens were fed on diets with 10.9, 11.5 or 12.1 MJ ME/kg and with a constant protein content of 200 g/kg from 1 to 42 d of age. 3. Both genotypes showed similar body weight, food intake and food conversion efficiency at 42 d of age. Body weight and food conversion efficiency improved on the diet with the highest energy content. 4. Apparent retention (AR) of crude protein (CP) was higher in nana chickens than in their Nana sibs in the winter trial, while no differences were observed for AR of dry matter (DM), crude fibre (CF), ether extract (EE) or calcium. In the summer trial, no difference in nutrient retention was seen between the genotypes. Increasing dietary energy had a positive influence on AR of DM, CP and EE. 5. The relative weights of feathers and skin were lower in Nana chickens than in their normal counterparts. Ready-to-cook yields were greater at the high dietary energy content, while abdominal fat increased with increasing energy content. Nana chickens had more skin protein and less fat in breast muscle and skin than their normal sibs in the summer trial. 6. It was concluded that the Nana broiler chickens showed similar performance and did not differ in dietary energy requirements in comparison to their nana sibs under natural ambient conditions in a subtropical climate.