Increasing levels of concentrate digestibility, performance and ingestive behavior in lambs

SUMMARY The objectives of this research were to determine the effects increasing levels of concentrate on nutrients digestibility, performance, economic viability of diets and ingestive behavior of lambs. Fifteen crossbred lambs were used in a randomized complete block design according to initial body weight and age. Lambs were penned individually during 55 days, being 10 days for adaptation of diets and 45 days for data collection. The treatments consisted in three isonitrogenous diets with increasing levels of concentrate: 40, 60, or 80%, in dry matter basis. No effect (P>0.05) were observed on dry matter intake, crude protein intake, crude protein digestibility and neutral detergent fiber digestibility, whereas the dry matter digestibility was lower (P<0.01) for lambs fed diets with 40% of concentrate. The addition of 80% concentrate decreased (P<0.05) neutral detergent fiber intake, however this treatment provided higher average daily gain, followed by 60 and 40% of concentrate. In relation to feeding behavior, the animals fed80% concentrate spent more time with feeding (P<0.05) compared to the other treatments. It is concluded that supplementation of concentrate between 60 to 80% improves dry matter digestibility and performance of crossbred lambs without relevant affect dry matter intake and ingestive behavior. A diet with 80% concentrate provides positive gross margin of profit.