At 59 weeks of age, breast weight was 74 g lower in fast feed decrease treatment but was unaffected by body weight group. At 45 weeks of age, fat pad weight was decreased by the fast feed decrease treatment. At 59 weeks of age, ovaries were heavier in the high body weight group and the slow feed decrease treatment. At this time, ovary weight, large yellow follicle number and oviduct weight were lowest in the low feed decrease treatment while egg production level was the greatest. These results indicate that more rapid decreases in post-peak feed allotments than are typically implemented in the commercial industry may decrease or limit increases in body component weights without having marked negative effects on egg production.
P is available to monogastric animals.
Because P is one of the two major macro-minerals involved in skeletal formation, additional inorganic P is supplied in the feed to meet P requirements of chickens. However, environmental concerns about excretion of undigested P are increasing. Identification of methods to increase the use of phytate P by poultry is now a major focus in the industry. Phytase is an enzyme which can hydrolyze phytate releasing P so that it is available for absorption. Phytase can increase P retention and subsequently decrease P excretion.