EFFECT OF GRAZING ACTIVITY AND SUPPLEMENTARY FEEDING ON ENERGY UTILIZATION BY GOATS

Document Type : Original Article

Authors

Animal and Poultry Nutrition Department, Desert Research Center, P.O. Box 11753, El-Matareya, Cairo, Egypt

Abstract

hirty non-productive female Shami goats were employed in a 60-day experiment to study the effect of grazing activity and supplementary feeding on energy expenditure (EE) and balance (EB). Goats were divided into three treatments, 10 per each. Animals were grazing a limited area of alfalfa with (GS) or without (G) a limited concentrate supplement, while animals in control treatment were in confinement (in-door, I) in which the same amount of supplement was given with alfalfa hay depending on their recommended requirements. The concentrate feed mixture, as supplementary feeding, was given to cover approximately 50% of the metabolisable energy used for maintenance requirements (MEm). Total EE was estimated by a heart rate (HR) monitor for 48h after individual calibration by oxygen consumption with a face mask open-circuit respiratory system. The internal marker technique was used to estimate the individual intake and digestibility for 6 animals per each treatment in which bags was used for total fecal collection. Animals in control group were consumed significantly less roughage (g/kg BW0.75) in comparison with those in grazing treatments. Digestible energy was affected by grazing activity and supplementary feeding. Total EE was greater for grazing vs. in-door and reduced with supplementary feeding. As a result, the EB was positive and similar between animals in control (I) and GS groups, while a negative EB associated with body weight loss were observed when animals grazing without supplementation (G). In conclusion, grazing activity has a significant effect on the EE and consequently the MEm and supplementary feeding is essential to maintain grazing animals without deterioration.

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