RESUMO
The cellulose present in the cell wall of vegetables prevents the greater release of nutrients to the animal. Therefore, the use of the cellulase enzyme is a viable strategy as it is capable of breaking cellulose bonds, releasing nutrients such as glucose, increasing dietary energy, and thus improving the productive performance of birds. Trichoderma reesei is efficient in the production of cellulase, which is produced via submerged fermentation followed by purification, formulation, and drying. Therefore, an experiment was carried out using 240 male broilers of the Cobb-500® lineage to verify the effects resulting from the addition of powdered (500 g/t and 1000 g/t) and liquid (500 mL/t) cellulase over a period of 1 to 21 days. A completely randomized experimental design was used, consisting of four treatments with six replications and ten birds per replication that were housed in an experimental cage. It was observed that performance and digestibility results were significantly different with cellulase supplementation. Also, the relative weight of the large intestine in the period between one and seven days increased when cellulase was added at 1000 g/t. In the period of between eight and 14 days of life, the birds that consumed only the basal diet obtained higher levels of liver protein than those that received the treatments with the addition of the enzyme. However, 15 and 21 days, the consumed feed effect did not occur between thus, it is not conclusive whether hepatotoxicity occurs with the addition of cellulase. For the blood parameters, at 21 days, the diets with added cellulase were not significantly different regarding electrolytes. It was concluded that this cellulase produced by Trichoderma reesei can be included in the animals' diet.
RESUMO
The objective of this experiment was to evaluate the effects of a diet containing canthaxanthin and 25-hydroxycholecalciferol (25-OH-D3) on the production and reproductive performances of Cobb 500 broiler breeders aged 53 to 61 weeks. The study included 36,000 Cobb 500 female and 3,600 male broiler breeders aging 51 weeks. The birds were housed in three poultry houses divided into four plots, totaling 12 experimental units each containing 3,000 females and 300 males. The birds received the following treatments: control diet (without the studied additives) or the control diet with the addition of 60mg kg-1feed of 25-(OH)-D3 and canthaxanthin feed (6mg of canthaxanthin and 2,760,000IU of 25-(OH)-D3 per kg of feed) per the supplier's recommendations. The experimental design used was a randomized complete block design with two treatments and six replicates. The results were subjected to analysis of variance followed by the F-test. The treatments had no effect on egg production, usability of eggs and number of incubatable eggs per bird housed. The inclusion of canthaxanthin and 25-(OH)-D3 in the diet reduced embryonic mortality while increasing egg yolk pigmentation, hatching percentage, and number of viable chicks produced per bird. Therefore, the use of 60mg kg-1of 25-(OH)-D3 plus canthaxanthin is recommended in the diet of Cobb 500 broiler breeders aging 53 to 61 weeks to improve important reproductive traits that have great economic impacts on poultry farms.
O objetivo deste experimento foi avaliar dietas contendo Cantaxantina e 25-hidroxicolecalciferol (25-OH-D3) sobre o desempenho produtivo e reprodutivo de matrizes de corte da linhagem Cobb 500, de 53 até 61 semanas de idade. Foram utilizadas 36.000 fêmeas e 3.600 machos com 51 semanas de idade, reprodutores de corte Cobb 500. As aves foram alojadas em três aviários divididos em 4 parcelas, totalizando 12 unidades experimentais, cada uma contendo 3.000 fêmeas e 300 machos. As aves foram submetidas aos seguintes tratamentos: dieta controle (sem os aditivos em estudo) ou dieta com adição de 60mg kg-1de ração de 25-(OH)-D3 e Cantaxantina (6mg de cantaxantina e 2.760.000UI de 25-(OH)-D3 por kg de ração), conforme recomendações do fornecedor. O delineamento experimental utilizado foi em blocos casualizados, com dois tratamentos e seis repetições. Os resultados foram submetidos à análise de variância e posteriormente aplicou-se o teste F. Não houve efeito dos tratamentos sobre as variáveis produção de ovos, aproveitamento de ovos e número de ovos incubáveis por ave alojada. A inclusão de Cantaxantina e de 25-(OH)-D3 na dieta reduziu a mortalidade embrionária e aumentou a pigmentação da gema dos ovos, o percentual de eclosão e o número de pintos viáveis produzidos por ave. Portanto, recomenda-se a utilização de 60mg kg-1de 25-(OH)-D3 mais Cantaxantina na dieta de matrizes de corte da linhagem Cobb 500, de 53 a 61 semanas de idade, para melhorar importantes características reprodutivas que têm grande impacto econômico para as empresas avícolas.
