Avaliação das Propriedades do Ácido Nicotínico no Desempenho e no Balanço Térmico de Frangos de Corte Durante Estresse por Calor

Foram oferecidas 4 doses de ácido nicotínico (AN) na água de beber de frangos de corte, a fim de estudar seu efeito no desempenho e na produção de calor em condições de estresse por calor (6 h de 35º C). As doses foram 15, 100, 330 e 1000 mg/L. Não houve efeito do AN nas doses usadas para ganho de peso, consumo de alimento, eficiência alimentar, consumo de água e temperatura retal. Foram observadas algumas alterações devido ao AN e estresse por calor nos parâmetros sangüíneos das aves. A produção de calor (kcal/h/peso metabólico) diminuiu com o uso de 100 e 1000 mg/L comparados com 15 mg/L. Nas dosagens usadas não foi observado efeito benéfico do AN no controle do estresse por calor

Determination of apparent metabolizable energy of crude glycerin in broilers chickens

The objective of the experiment was to determine the Apparent Metabolizable Energy corrected for nitrogen (AMEn) of a glycerin product derived from biodiesel production for broilers. A number of 35 male Ross 308 broilers, with 35 days of age was fed ad libitum diets containing 0, 5, 10, 15, or 20% glycerin. AMEn was determined using total excreta collection, with four days of adaptation and three days of collection. Increasing glycerin intakes resulted in increased water excretion. Glycerin AMEn varied as a function of dietary inclusion levels, and a cubic equation was identified by regression analysis. Maximum AMEn level- 4890 kcal/kg DM- was obtained with 15% glycerin inclusion. However, this level caused excessive water excretion, making its use unpractical

Influence of feeding time on sexual maturity and carcass composition in female broiler breeders

One thousand two hundred and ninety six Arbor Acres females and 144 males were used to study the influence of feeding time on sexual maturity and carcass composition. Treatments were: T1 = feeding at 6:30 am, T2 = 50% feeding at 6:30 am and 50% at 3:30 pm (dual), T3 = feeding at 11:00 am, T4 = feeding at 3:30 pm. Nutrition and management were as recommended to the commercial line. Variables studied were: sexual maturity at 5% production (SM), mean egg production percentage (PEP) body weight (BW), carcass composition, tibia weight (TIBW) and tibia calcium (Ca) and phosphorus (P) contents. Analysis of variance was used, and the means were compared using Student's t test. T2 females reached SM at 25.92 weeks, which was earlier (p<0.01) than the other treatments. PEP was greater (p<0.01) for T1 and T2 than for the other treatments. BW was greater in T1 and smaller in T4 (p<0.05) than in the other treatments. TIBW was greater in T3 than in T1 and T2 (p<0.05), with no effect (p>0.10) on carcass dry matter (DM), ether extract (EE), crude protein (CP) and ash (ASH). DM, EE, TIBW, Ca and P increased (p<0.05) whereas CP and ASH decreased with age. Time of feeding influenced body weight, but not carcass composition. Hens fed twice a day had earlier sexual maturity and similar egg production compared to those fed once at 6:30 am

Performance of female broiler breeders submitted to different feeding schedules

The performance of Arbor Acres broiler breeders (1,296 females; 144 roosters) was evaluated when submitted to the following treatments (T): T1 = feeding at 6:30 a.m. (control); T2 = 50% feeding at 6:30 a.m. and 50% at 3:30 p.m. (dual feeding); T3 = feeding at 11:00 a.m.; and T4 = feeding at 3:30 p.m. Treatments were randomly distributed in 48 pens. There were 27 females and 3 males in each pen and 12 repetitions per treatment. Nutrition and management were as recommended for the commercial strain. It was evaluated age at first egg (AFE), total egg production (TEP), number of days with production above 80% (DAP80), laying peak (P), female mortality (MOR), and gross profit margin (GM) per hen. Data were submitted to analysis of variance and means were compared by Student's t-Test. TEP of T1 (186.3±2.3) and T2 (186.5±1.5) were higher (p0.10) among treatments. GM per hen was better (p<0.05) in T1 and T2 hens. Control and dual treatments were more efficient than other treatments. It was concluded that it is possible to change conventional feeding management's by the dual feeding system