Feeding broiler breeders a reduced balanced protein diet during the rearing and laying period impairs reproductive performance but enhances broiler offspring performance

Mammalian studies have shown that nutritional constraints during the perinatal period are able to program the progeny (metabolism, performance). The presented research aimed to investigate if broiler breeders and their offspring performance could be influenced by reducing the dietary crude protein (CP) level with 25% level in the feed of breeders. A total of 160 one-day old pure line A breeder females were randomly divided over 2 dietary treatments. The control group was fed commercial diets, whereas the reduced balanced protein (RP) birds received an isoenergetic diet that was decreased with 25% in dietary CP and amino acid during their entire lifespan. The RP birds required an increased feed allowance, varying between 15 and 3%, to meet the same BW goals as their control counterparts. The difference in feed allocations and reduction of the dietary CP level resulted in a net protein reduction varying between 14 and 23%. At 27 and 40 weeks, the body composition of the breeders was changed as a result of the dietary treatment. At both ages the proportional abdominal fat pad weight of the RP breeders was increased (P < 0.001), whereas the proportional breast muscle weight was only higher at 27 weeks in the control group compared to the RP group (P < 0.001). Egg weight (P < 0.001) and egg production (P < 0.001) was decreased for the RP fed birds. The lower dietary CP level reduced the proportional albumen weight of the RP eggs (P = 0.006). Male offspring from RP breeders were characterized by an increase in BW from 28 days until 35 days of age (P= 0.015). Moreover, female progeny of RP breeders showed a reduced FCR (P = 0.025), whereas male progeny showed a tendency (P = 0.052) towards a lower FCR at 5 weeks of age. In conclusion lowering dietary CP levels in rearing and laying phase of breeders had a negative effect on breeder performance but enhanced live performance of the offspring.status: publishe