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.

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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.

RESUMOAvaliaram-se os efeitos da protease sobre o coeficiente de metabolizabilidade dos nutrientes em dietas contendo farinha de penas (2,0% na fase inicial e 3,0% na fase de crescimento) para frangos de corte machos, Cobb ® , de um a 32 dias de idade. Foram alojadas 336 aves em gaiolas metálicas equipadas com bandeja para coleta total de excretas. Foi utilizado delineamento inteiramente ao acaso, em arranjo fatorial 2x2 (com e sem adição da enzima protease 0,05% e duas valorizações da matriz nutricional da enzima), sendo sete repetições por tratamento, de 12 aves cada. Observou-se, na fase inicial, maior CMPB (P≤0,05) para as aves que, independentemente da adição de protease, consumiram ração com valorização da matriz nutricional da enzima. Não houve efeito dos tratamentos sobre o CMMS e o CMEE (P>0,05). Na fase de crescimento, houve interação entre os tratamentos para as variáveis CMPB e CMEE. Os frangos alimentados com dieta valorizada sem adição de enzima (controle negativo) apresentaram melhores resultados (P≤0,05) para CMPB e CMEE. Nos tratamentos com enzima, o melhor CMEE (P≤0,05) foi obtido com o tratamento sem valorização da matriz nutricional (over the top). Conclui-se que níveis reduzidos e enzima sem valorização melhoram os coeficientes de metabolizabilidade dos nutrientes na fase adulta de frangos de corte.Palavras-chave: coeficiente de metabolizabilidade, enzimas exógenas, frango de corte, protease (9-12-d-old) and growth (29-32-dold) ABSTRACT This experiment aimed to evaluate the effects of protease on metabolization coefficient of nutrients, performance and slaughter yield from male Cobb ® broilers fed diets with feather meal. Two experiments were carried out in a completely randomized design in a 2x2 factorial arrangement -with (0.05%) or without enzyme addition x considering or not the improvement of the nutritional value by protease, with seven replicates per treatment group. In experiment 1 the metabolization coefficient of dry matter (MCDM), crude protein (MCCP) and ether extract (MCEE) in initial