Effect of feed form and nutrient density on growth performance, blood parameters, and intestinal traits in broiler breeder pullets.

This study was conducted to evaluate the effect of feed form and nutrient density on growth performance, blood parameters, and intestinal traits of broiler breeder pullets during grower (7-19 wk) and pre-breeder (19 weeks to 5% production) periods. A total of 450 female broiler breeder pullets were used in a completely randomized design with a 3 × 2 factorial arrangement including 3 feed forms (mash, crumble, and pellet) and 2 nutrient densities (standard diet with the nutrient requirement of Ross 308 parent stock nutrition specification, and diluted diet by using sunflower hull to have 10% lower nutrient than the standard diet). Five replicates with 15 pullets per replicate were allocated to each of the 6 treatments. Blood samples were collected at 19 wk of age. Egg production reached 5% in the mid of 25 wk. Results showed that pullets fed crumble or pellet diets had greater body weight gain and a lower feed to gain ratio (F:G; P < 0.001). Diet dilution led to a decrease in body weight gain while increasing the F:G (P < 0.05). Pullets fed the pellet diets had shorter eating times than those fed crumble diets, whereas the longest eating time belonged to pullets fed mash diets (P < 0.001). Pullets fed pellet diet had a greater heterophil to lymphocyte (H/L) ratio than those fed crumble or mash diets (P = 0.007). Diluting the diet led to a decrease in the H/L ratio (P = 0.026). Neither feed form nor nutrient density had a significant effect on body weight uniformity, blood glucose and lipid concentrations, liver enzyme activities, and intestinal traits (P > 0.05). It can be concluded that pelleted or crumbled diets with lower nutrient density can be considered in broiler breeder's pullets feeding with no detrimental effect on their performance or health state.

Effect of dietary nutrient density and vitamin premix withdrawal on performance and meat quality of broiler chickens.

BACKGROUND: The objective of this study was to evaluate the effects of feeding high- and low nutrient density diets, and three different vitamin premix withdrawal regimes on broiler performance and meat quality. Male broiler chicks (480 days old) were reared on the floor in a 2 × 3 factorial arrangement for 42 days. Chickens were slaughtered at 42 days of age and meat samples kept at -20 ± 1°C and analysed after 1, 90 and 180 days of storage. RESULTS: Broiler performance was significantly affected by dietary nutrient density. Vitamin premix withdrawal had no significant effect on body weight. The results showed no significant differences between nutrient density and vitamin premix withdrawal on lightness (L*), redness (a*) and yellowness (b*). Oxidative stability of thigh muscle lipids during frozen storage was significantly affected by nutrient density, while vitamin premix withdrawal had no significant impact on lipid oxidation. High nutrient density diet led to a significantly (P < 0.05) decreased pH compared with the low nutrient density diet. CONCLUSION: Increasing dietary nutrient density improved broiler performance but impaired meat quality while vitamin premix withdrawal during finisher periods had no negative effect on broiler performance and meat quality.