| Popis: |
Two broiler breeder trials were conducted through 73 and 69 weeks of age, respectively, using 720 hens divided among 24 pens in each trial. Half the pullets and hens (Hubbard × Hubbard) in each trial were fed simple rations and half were fed rations containing sources of unidentified hatchability factors and other nutrients and ingredients purported to improve hatchability. Feed intake was adjusted throughout Trial 1 to keep body weight close to that recommended in the breeder's guide. In Trial 2, during the laying period, eight breeder pens were fed at a level adjusted to keep body weights close to the breeder's recommendations, eight at a level adjusted to maintain body weights about 200 g heavier, and eight at a level adjusted to maintain weights about 500 g heavier than the first group. During both trials, eggs were incubated every 2 weeks during the production period. Performance by all parameters measured was essentially the same for both treatments in Trial 1. Fertility and hatchability held up well with the final hatch averaging 75.5% of eggs set. There was no advantage in feeding the complex ration. In Trial 2, there were no significant differences in the production parameters due to type of diet. Egg production, and weights of eggs, day-old chicks, and breeder hens were significantly (P |
