Effects of dietary protein levels during rearing and dietary energy levels during lay on body composition and reproduction in broiler breeder females

Abstract

A study with a 2 × 3 × 2 factorial arrangement was conducted to determine the effects of 2 dietary protein levels (high = CPh and low = CPl) during rearing, 3 dietary energy levels (3,000, MEh1; 2,800, MEs1; and 2,600, MEl1, kcal/kg AMEn, respectively) during the first phase of lay, and 2 dietary energy levels (2,800, MEs2; and 3,000, MEh2, kcal/kg AMEn, respectively) during the second phase of lay on body composition and reproduction in broiler breeders. No meaningful interactions for energy and protein treatments within the different phases of the study were found and, therefore, this paper focusses on the main effects. Pullets fed the CPl diet had a 12.8% higher feed intake, 14% lower breast muscle, and 97% higher abdominal fat pad portion at 22 wk age. The increased abdominal fat pad and decreased breast muscle of the CPl compared to the CPh birds increased hatchability during the first phase of lay, due to a decreased embryonic mortality between d 10 to 21 of incubation, and increased egg production during the second phase of lay. Feeding birds the MEh1 and MEl1 diets slightly decreased egg production compared to the MEs1 birds. Birds fed the MEh1 diet showed a higher mortality compared to the birds fed the MEs1 and MEl1 diets. Feeding birds the MEh2 diet did not affect egg production, increased hatchability of fertile eggs, decreased embryonic mortality between d 3 to 21 of incubation, and increased the number of first-grade chicks. It was concluded that a low-protein diet during rearing changed body composition with positive effects on incubation traits during the first phase of lay and improved egg production during the second phase of lay in broiler breeders. A high-energy or low-energy diet compared to a standard diet during the first phase of lay slightly decreased total and settable egg numbers while a high-energy diet during the second phase of lay increased hatchability and number of saleable chicks.

Direct and maternal reduced balanced protein diet influences the liver transcriptome in chickens

“…In addition, C/RP and RP/RP chickens had more abdominal fat compared to C/C and RP/C chickens, and proportional liver weights were the highest in the C/RP chickens, and were significantly higher when compared to the RP/C chickens. These changes are in accordance with other studies where low and high protein diets were administered while maintaining similar body weights in broiler breeders (27,28) .…”

Effects of different dietary protein levels during rearing and different dietary energy levels during lay on behaviour and feather cover in broiler breeder females

“…Body weight, uniformity, mortality, feed intake, and egg production traits were previously reported by Van Emous et al (2015).…”

Growth curve and diet density affect eating motivation, behavior, and body composition of broiler breeders during rearing

“…The body fat composition that was reduced with diluted diets is increased when breeder pullets are grown to HBW. This is an important finding, as the body fat content at rearing is related to the egg persistency in the second half of the production phase (van Emous et al., 2015 ). The fact that the feed allowance of the treatment DIL-HBW was 28% higher compared to CON-RBW makes us expect higher differences than observed in eating time and behavior.…”