Search

The present study aimed to determine the effects of egg type (nest clean or floor eggs) on eggshell microbiological, hatching performance, chick quality, yolk sac microbiology, and the interaction between egg type and post-hatch use of ceftiofur on broiler performance at 7, 14, 21, 28 and 35 days. A total of 2500 fertile eggs were obtained from a commercial flock of Cobb Slow® broiler breeders. Half of the eggs were collected directly from the floor, and the other half were collected from the nests. Microbiological evaluation of eggshells was performed before and after sanitization. After hatching, 420 male chicks were randomly selected and distributed in a completely randomized design in a 2 × 2 factorial scheme, separated by the type of egg (clean nest or floor) and the inclusion or not of subcutaneous ceftiofur, totaling four treatments. Egg type did not influence hatchability although the contamination level was 1.3% higher. The body weight and body weight gain of chicks at seven days were greater for chicks from nest eggs that received ceftiofur than chicks from floor eggs that also received ceftiofur. There was no interaction between the studied factors or individual effects for performance at 14, 21, 28, and 35 days. It is concluded that incubation of floor eggs, after standard sanitization, does not influence the hatch results and chick quality. Furthermore, it has been proven that the use of ceftiofur is unnecessary when there is correct management during broiler rearing.

CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico Este trabalho foi conduzido com a finalidade de avaliar os efeitos dos níveis reduzidos de vitamina D3 (colecalciferol) sobre o desempenho e qualidade óssea de frangos de corte até os 35 de idade. Foram utilizadas, ad libidum, dietas para a fase inicial (1 a 14 dias) e crescimento (15 a 35 dias). As dietas eram isonutritivas e o suplemento vitamínico forneceu quantidades adequadas de todas as vitaminas, exceto vitamina D3. Os níveis de vitamina D3 utilizados foram: Grupo A, 0 UI/Kg em ambas as fases; Grupo B, 625 UI/Kg na fase inicial e 500 UI/Kg na fase de crescimento representando 25% da inclusão utilizada comercialmente; Grupo C, 1.250 UI/Kg na fase inicial e 1.000 UI/Kg na fase de crescimento representando 50% da inclusão utilizada comercialmente; Grupo D, 1.875 UI/Kg na fase inicial e 1.500 UI/Kg na fase de crescimento 75% da inclusão utilizada comercialmente; Grupo E, 2.500 UI/Kg na fase inicial e 2.000 UI/Kg na fase de crescimento representando 100% da inclusão utilizada comercialmente. O delineamento experimental foi inteiramente casualizado com 5 tratamentos de 6 repetições cada. 360 pintos machos Cobb® de um dia foram distribuidos em 30 gaiolas contendo 12 aves cada. Semanalmente as aves foram avaliadas quanto ao consumo de ração (CR), peso corporal (PC), conversão alimentar (CA) e viabilidade (V). Aos 21 e 35 dias de idade, um frango por repetição foi abatido e as tíbias e fêmures retirados e dissecados. Os ossos foram avaliados quanto à percenutal matéria seca, matéria mineral, cálcio, fósforo, força de resistência à quebra e densidade óssea. Aos 35 dias de idade os ossos passaram por avaliação histopatológica para avaliação morfológica macro e microscópica. Ao final do experimento as aves foram avaliadas quanto à deformidades varus e valgus. Para as variáveis de desempenho, percentual de cálcio, fósforo, matéria mineral, densidade e resistência óssea houve efeito linear crescente até os níveis de suplementação de aproximadamente 25% de inclusão. Na avaliação histomorfológica, apenas o grupo que recebeu dieta com 75% da inclusão comercial de vitamina D3 aprensentou tecido ósseo dentro da normalidade, os demais grupos apresentaram alterações compatíveis com quadros de osteopenia e osteopetrose. Os resultados observados demonstraram que para dietas isonutritivas não se torna necessário utilizar os níveis comerciais praticados atualmente, uma vez que a redução em até 75% e 25% garantiram, respectivamente, o desempenho zootécnico e qualidade óssea durante o período avaliado. This work was conducted with the purpose of evaluating the effects of reduced levels of vitamin D3 (cholecalciferol) on the performance and bone quality of broilers up to 35 days of age. Diets for the initial phase (1 to 14 days) and growth (15 to 35 days) were used ad libidum. The diets were isonutritive and the vitamin supplement provided adequate amounts of all vitamins, except vitamin D3. The levels of vitamin D3 used were: A group, 0 IU / Kg in both phases; B group, 625 IU / Kg of in the initial phase and 500 IU / Kg in the growth phase, representing 25% of the inclusion used commercially; C group, 1.250 IU / Kg in the initial phase and 1.000 IU / Kg in the growth phase, representing 50% of the inclusion used commercially; D group, 1.875 IU / Kg in the initial phase and 1.500 IU / Kg in the growth phase representing 75% of the inclusion used commercially; E group, 2.500 IU / Kg in the initial phase and 2.000 IU / Kg in the growth phase, representing 100% of the inclusion used commercially. The experimental design was completely randomized with 5 treatments of 6 repetitions each. 360 one-day-old Cobb® chicks were distributed in 30 cages containing 12 birds each. The birds were weekly evaluated for feed intake (CR), body weight (BW), conversion (WC) and viability (V). At 21 and 35 days of age, a repetitive chicken was euthanized and the tibiae and femurs removed and dissected. The bones were evaluated for the percentage of dry matter, mineral matter, calcium, phosphorus, bone strength and density. At 35 days of age, the bones underwent histopathological evaluation for macro and microscopic morphological evaluation. At the end of the experiment, the birds were evaluated for varus and valgus deformities. For the performance variables, percentage of calcium, phosphorus, mineral matter, dry matter and bone strength, there was a linear effect increasing up to the supplementation levels of approximately 25% of inclusion. In the histopathological evaluation, only the group that received a diet with 75% of the inclusion of vitamin D3 presented bone tissue within the normal range, the other groups showed alterations compatible with osteopenia and osteopetrosis. The observed results showed that for isonutritive diets it is not necessary to use the commercial levels currently practiced, since the reduction by up to 75% and 25% guaranteed, respectively, the zootechnical performance and bone quality during the evaluated period.