Effect of Concentrate Feed Supplementation on The Growth Performance of Crossbred Sheep

Abstract: Sheep grazing on poor pastures may not meet the nutritional needs of sheep especially during the dry season, and concentrated supplementation can be an effective strategy to optimize rumen microbial activity through a balanced supply of energy and protein. Therefore, the experiment was conducted to optimize the concentrate feed supplementation of crossbred sheep in the southwestern region of Bangladesh. Fifteen female sheep were divided into five treatment groups and randomly allowed to five levels of concentrate feeds. The experimental design was based on randomized complete block design (RCBD). Sheep were initially weighed and grouped by keeping the average weight of the five treatment groups approximately the same. The concentrate mix allocated to the five treatment groups was 0, 100, 150, 200 and 250 g per sheep per day respectively. The energy and crude protein contents of the concentrate mixture were 12.00MJ and 219.0g per kg DM. All groups of sheep were allowed to graze for 10 hours daily from 8 am to 6 pm. The allocated concentrate feed was given twice a day in the morning and evening in equal proportion. All relevant data like body weight, date of onset of estrus, date of insemination, deworming, vaccination and medication were recorded in a registrar regularly. Empty body weight data were taken fortnightly in the morning before allowing them to concentrate feed and grazing. The data were analyzed using the GLM procedure of SAS version 9.1.3. Results revealed that the body weight increased with the increasing concentrate supplementation but the mean differences were not varied significantly (p>0.05). In most of the cases the numerically highest body weight was observed in sheep fed concentrate @ 250g sheep^-1. In case of fourth weight, highest body weight was observed in sheep fed 250g concentrate per day (15.73±1.46) followed by 200g (14.04±1.63), 150g (14.62±4.23), 100g (13.63±2.83) and non-supplemented (12.43±2.43) group. In case of sixth weight, body weight ranged from 13.28±2.37 to 18.11±1.53 being highest in 250g concentrate supplemented group and lowest in no supplemented group. Growth rate (g day^-1) of crossbred lambs increased with increasing concentrate supplementation. Mean differences in crossbred sheep differed significantly between supplemented and non-supplemented groups but did not differ among supplemented groups. This indicates that minimum concentrate supplementation (100 g sheep^-1 day^-1) is sufficient for crossbred sheep to ensure optimal growth. Keywords: Body weight, concentrate feed, crossbred sheep, growth rate, performance

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