Effects of dietary fat type and level on broiler breeder performance

The effects of added dietary fat type and level on broiler breeder performa nce were evaluated in two trials. Ln Trial 1, diets included no added fat ( NAF) or 3.0% added poultry fat (PF) for individual bird energy intakes of 4 30 and 467 kcal/d at peak production (PCD), or 1.5% PF or 3.0% corn oil (CO ) at 449 PCD. in Trial 2, diets contained NAF, 1.5 or 3.0% added CQ or PF, or 3.0% lard (LA) for peak energy intakes of 463 PCD. All diets in Trial 2 were isocaloric and isonitrogenous. Feeding of experimental diets was initi ated when breeders were 22 wk old in both trials, and hen BW was measured a t various weeks between 22 and 47 wk in Trial 1 and between 27 and 65 wk in Trial 2. Egg production, egg weight (EW), eggshell quality, and hatchabili ty were recorded at various weeks between 24 and 48 wk in Trial 1 and betwe en 27 and 64 wk in Trial 2. Body weights and EW increased progressively, an d eggshell quality fluctuated variably with age. Egg production peaked betw een Weeks 32 and 35, and hatchability was significantly depressed at Week 6 3. Egg weight and hatchability were not affected by dietary treatment, howe ver, BW increased with energy level in the diet between Weeks 27 and 47. Bo dy weight was also higher in birds fed 1.5 or 3.0% added fat compared with NAF and was higher in birds fed LA compared with CO at the 3.0% level. Egg specific gravity and shell weight per unit of surface area at Week 41 were increased by feeding low or high energy compared with moderate energy, and relative eggshell conductance was increased by using moderate compared with high energy diets and by feeding 1.5% PF compared with 3.0% PF. Egg specif ic gravity was increased by PF when compared with CO across fat level at We eks 26 and 47 and by LA when compared with PF across fat level and breeder age. These data suggest that certain dietary energy and fat regimens may af fect BW and eggshell quality without associated effects on EW and hatchabil ity at various breeder ages.