Reproductive performance of layer chickens reared on deep litter system with or without access to grass or legume pasture.

Abstract

Despite several studies carried out to investigate the effects of access to pasture on poultry performance, there is a dearth of information on the comparative benefit of grass and legumes. This study investigated the effects of rearing systems [deep litter system (DL), deep litter with access to legumes (LP) or grass (GP) pastures] on the performance of ISA Brown layers. Two hundred and forty 12-week-old pullets were housed for this study. They were reared until 60weeks of age. Eighty birds were assigned to each treatment; each treatment had four replicates of 20 birds each. Two birds per replicate were slaughtered at weeks 20, 35 and 58 for determination of the weights of liver, ovary, oviduct and the number of follicles. Daily egg production records were kept from the day of first egg to 42weeks in lay. Body weights were recorded weekly. Results indicated that at 20weeks of age, the hens kept in the LP had higher (p<0.05) ovary weight (g) (34.98±1.4), oviduct weight (52.55±2.28) and oviduct length (cm) (49.73±11.34), and higher number of large yellow follicles (3.75±1.31) and small yellow follicles (12.75±5.17) than those in the GP (0.83±0.02, 1.68±0.19, 16.38±1.14, 0.00 and 0.00), and DL (1.03±0.11, 1.48±0.48, 14.43±0.58, 0.00 and 0.00) respectively. The age (days) at first oviposition was earlier (p<0.05) in the LP (139.25±0.85) than that in the GP (146.75±0.48) and DL (146.75±0.48). The hen-day egg production was lower (p<0.05) in GP (74.19±1.25) than that in the DL (78.82±0.78) and LP (79.93±1.13) at mid-laying phase. Concentrate feed intake was lower (p<0.05) in LP and GP than DL suggesting economic benefit. It was concluded that access to LP enhanced the performance of layers than DL and GP as indicated by the parameters measured.