Abstract
The goal of this study was to evaluate the effects of variable dietary metabolizable energy and crude protein concentrations on the performance, behaviour, expression of growth related genes and economic impact of broiler chickens. A total of 250 Cobb broiler chicks were divided randomly into five groups of ten replicates (10 chicks/replicate). Five diets with five different combinations of calories and protein were formulated as the following; normal energy and normal protein (NENP), low energy and high protein (LEHP), high energy and low protein (HELP), normal energy and low protein (NELP), low energy and normal protein (LENP) during starter and finisher period. The results revealed that the highest body weight and body weight gain were observed in the HELP and NELP groups which were similar in improvement of feed utilization and protein efficiency ratio. The total feed intake was increased with decreased dietary energy as in NENP group. Nutrient digestibility was improved with increasing diet energy density as in HELP and NELP groups. The expression of IGF-1 and growth hormone genes were markedly higher in HELP and NELP groups, while the myogenin expression significantly increased in HELP, NELP and LEHP groups. Moreover, the final weight greatly correlated with the gene expression related to growth. Eating and drinking frequencies were highest in LENP and LEHP groups. Birds reared in HELP diet were more active, as expressed by greater walking, wing shaking, leg stretch, preening and flying. Briefly, our results suggested that the energy of diets greatly affected the broiler performance, behaviour and digestibility. Additionally, inclusion of low protein diet with addition of critical amino acids had a positive effect on economic efficiency of broilers. Thus, NELP and HELP diets are recommending for growth of Cobb broiler and could have a significant economic impact.
Highlights
In a commercial poultry production, nutrient density is the most critical nutritional aspect, because it has a significant impact on performance and health of poultry, which in turn influence the cost-effectiveness [1,2]
The highest body weight (BW) in the starter period was detected in groups fed on low energy and high protein (LEHP), high energy and low protein (HELP) and normal energy and low protein (NELP), while the feed intake didn’t affect by dietary treatment
In spite of the dry matter digestibility values were similar among the groups, but the highest value was reported in the group fed HELP, NELP and low energy and normal protein (LENP), while it tended to be lower for those fed normal energy and normal protein (NENP) and LEHP (Table 2)
Summary
In a commercial poultry production, nutrient density is the most critical nutritional aspect, because it has a significant impact on performance and health of poultry, which in turn influence the cost-effectiveness [1,2]. Dietary crude protein (CP) requirements are high in modern broiler strains due to the fast growth rates which increasing the overall cost of finished product [3]. The carcass characteristics can be altered through manipulation of dietary protein and/or energy in broilers [4]. Synergy between protein and energy specified the importance of a well-adjusted calorie: protein (C:P) ratio to attain optimum performance and carcass characters of broilers. There are two important aspects controlling production; firstly, increasing the energy:protein ratio ensuring that all the protein will be utilized for fast growth, secondly, decrease energy amount to produce leaner carcasses. A correct level of protein with high biological value in the ration is importance for optimum economic performance [8].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
