Optimization of Grazing Hours for Crossbred Sheep of South-West Coastal Region of Bangladesh

Abstract: As small ruminants, sheep requires little feed and can thrive by grazing even on poor quality pasture in neighboring land, roadsides, and shrimp farm dykes. Therefore, the experiment was carried out to optimize the grazing hour of crossbred sheep in south-west area of Bangladesh. Crossbred sheep were developed by mating of indigenous female sheep with Garole male sheep. Twelve crossbred female sheep were randomly divided into four treatment groups and allowed four different grazing hours. The experiment was based on randomized complete block design (RCBD). Initially, the sheep were weighed and grouped in such a way that the average weight of the four treatment groups were nearly identical. The grazing hours allotted to the four treatment groups were 6, 8, 10, and 12 hours, respectively. From 6 a.m. to 6 p.m., all groups of sheep were allowed to graze. When the sheep in each treatment group had completed their allocated grazing period, they were housed. All relevant data, such as body weight, deworming, vaccination, and medication were regularly recorded in a registrar. Data of empty body weight were collected fortnightly in the morning before allowing them to graze. The results showed that as the grazing period increased, so did the body weight, but the mean differences were not significant (p>0.05). Sheep grazed 12 hours per day had the highest body weight in the majority of cases. The average growth rate of grazing sheep differed significantly between groups grazing for 6 to 8 hours and 10 to 12 hours. However, the growth rate of crossbred sheep did not differ significantly (p>0.05) between the 6 to 8-hour grazing group and the 10 to 12-hour grazing group. The growth rate (g day^-1) of crossbred sheep ranged from 22.44^b±4.75 to 92.00^a±11.95, with the 12-hour grazing group having the highest rate and the 6-hour group having the lowest. Since there is no significant difference between the growth of 10- and 12-hours grazing groups, 10 hours grazing period per day was optimum for crossbred sheep. Keywords: Body weight, Crossbred sheep, Grazing period, and Growth rate.

• Supervision