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%. A total of 160 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) breeders 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 3 and 15%, to meet the same BW goals as their control fed 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 wk 27 and 40, 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 wk 27 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 d until 35 d 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 wk 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.

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Studies on mammals and poultry showed that maternal dietary treatments can alter the offspring performance. However, in contrast to rodent studies, little is known about multigenerational dietary manipulations in broiler breeders. The presented research aimed to investigate the effects of a reduction of 25% in the dietary crude protein (CP) level in the F0 generation on the body composition and reproductive performance of F1 broiler breeders. In the F0 generation, breeders were fed either a control (C) or reduced balanced protein (RP) diet, 25% reduction in crude protein and amino acids. Female F0-progeny of each treatment were fed a C or RP diet, resulting in 4 treatments in the F1 breeder generation: C/C, C/RP, RP/C, and RP/RP. The reproductive performance of breeders fed RP diets was negatively influenced by the dietary CP reduction in the F1 generation (P < 0.001). Moreover, breeders descending from hens that received RP diets in the F0 generation showed a significantly reduced reproductive capacity compared to their control fed counterparts (P < 0.001). Breeders fed RP diets in the F1 generation were characterized by higher plasma T3 concentrations (P < 0.001), an increased proportional abdominal fat pad (P < 0.001) and proportional liver weight (P < 0.001). During the rearing phase, the RP fed breeders needed a higher feed allowance, whereas no differences could be observed between the C/C and RP/C or the C/RP and RP/RP breeders. However, breeders originating from birds fed RP diets in the F0 generation needed lower feed allocations in the laying phase to maintain a similar body weight. Egg weight was reduced for the C/RP and RP/RP breeders. At 34 wk of age, eggs from C/RP and RP/RP breeders showed a reduced proportional albumen weight, whereas no effects on egg composition were found at 42 wk of age. It was concluded that prenatal protein undernutrition triggered hens to relocate more energy towards growth and maintenance and less towards reproductive capacity.

Protein content reduction in broiler breeder diets has been increasingly investigated. However, broiler breeders reared on low protein diets are characterized by a deterioration of the feather condition. Furthermore, polydipsia induced by controlled feed intake increases litter moisture and as a consequence pododermatitis. This project aimed to study the litter moisture, pododermatitis and feather condition of breeders fed with a 25% reduced balanced protein (RP) diet during the rearing and laying period over three successive generations. The experiment started with two treatments for the F0 generation: control (C) group fed with standard C diets and RP group fed with RP diets. The female F0-progeny of each treatment was divided into the two dietary treatments as well, resulting in four treatments for the F1 generation: C/C, C/RP, RP/C and RP/RP (breeder feed in F0/F1 generation). The RP diet fed breeders received on average 10% more feed than C diet fed breeders to achieve the same target BW. The female F1-progeny of each treatment were all fed with C diets which resulted in four treatments for the F2 generation: C/C/C, C/RP/C, RP/C/C and RP/RP/C (breeder feed in F0/F1/F2 generation). Litter moisture, footpad and hock dermatitis were recorded at regular intervals throughout the experimental period in all three generations. For the F0 and F1 generation, the pens of breeders receiving C diets had significantly higher litter moisture than the RP diets fed groups (P<0.05), resulting in an elevated footpad dermatitis occurrence (FDO) (P<0.05). No difference was found in the F2 generation. The feather condition was scored during the laying period for each generation. F0 and F1 breeders reared on the RP diets had poorer feather condition than those receiving the C diets (P<0.05). The C/RP breeders had a significantly poorer feather condition than RP/RP breeders (P<0.05). For the F2 generation, RP/RP/C breeders had a significantly better feather condition compared with the other three groups (P<0.05). The RP/C/C breeders were significantly better feathered than C/C/C breeders (P<0.05). In conclusion, providing RP diets to broiler breeders improved litter condition and hence reduced FDO whereas impaired feather condition. Furthermore, positive transgenerational effects of the maternal RP diets on the feather condition may be inferred, hence potentially altering the welfare status.

Several studies in mammals focused on the maternal programming of the metabolism by epigenetic mechanisms, while currently, the consequences of a maternal dietary treatment on the offspring performance of farm animals are of particular interest for commercial purpose. In the present study, we investigated if the zootechnical performance of the progeny was altered by a maternal dietary treatment, being a lower dietary crude protein (CP) of the grandparent and/or parent generation. The multigenerational effects of a reduced maternal CP content were investigated by reducing the dietary CP level by 25% in rearing and laying diets of pure line A breeders. The F0 generation breeders were fed either control (C) or reduced balanced protein (RP) diets. The F1 breeder generation was constructed by dividing the F0 female progeny again over a C or RP diet, resulting in 4 dietary treatments in the F1 generation: C/C, C/RP, RP/C, and RP/RP (letters indicating the diets in, respectively, F0 and F1 generations). The offspring performance was evaluated by a zootechnical and nitrogen retention trial on C and low-protein (LP) broiler diets. For the C broiler diet, the C/RP and RP/RP offspring were characterized by a higher BW from d 35 until d 42 compared to the C/C progeny, whereas the RP/C offspring had an intermediate BW that did not differ from the other groups. A tendency (P = 0.067) towards a better nitrogen retention was observed for the offspring of breeders that received the RP diets in F0 and/or F1 generation compared to the C/C progeny. For the LP broiler diet, the C/RP (P = 0.021) and RP/C (P = 0.001) offspring had a higher BW compared to the C/C progeny during the entire grow-out period. In addition, the C/RP offspring were characterized by a lower FCR from d 28 onwards (P = 0.021). In conclusion, dietary treatments imposed on mother hens can have direct effects on the next generation, as well as indirect effects on multiple generations.