Effect of weaning age on growth performance of crossbred pigs reared up to 70 kg body weight under intensive system

This study investigated the effect of weaning age on growth performance of crossbred piglets reared up to 70 kg body weight (BW) under intensive system from May to November 2013. The experiment was conducted in a completely randomized design where weaner pigs were randomly allocated to three weaning ages (treatment) of 21, 28 and 35 days. Each treatment had 16 weaner pigs with four replicates (pen) each having four pigs of equal sex. The study was divided into three rearing periods: weaning phase (WP) (weaning to 70 days), grow to finish period (GFP) (70 days to 70 kg BW) and wean to finish period (WFP) (weaning to 70 kg BW). The growth parameters studied were BW, average daily gain (ADG), average daily feed intake (ADFI), feed conversion ratio (FCR) and days on test. Data were analysed using General Linear Model Procedures of Statistical Analysis System. The results showed that BW for piglets weaned at 21 days of age was significantly (P<0.05) lower (17.93 ± 0.69 kg) than that of piglets weaned at 28 days (21.57 ± 0.78 kg) but similar to piglets weaned at 35 days (19.34 ± 0.78 kg) which was intermediate during WP. Piglets weaned at 21 days of age had significantly lower ADG (0.267 ± 0.01 kg), ADFI (0.651 ± 0.01 kg) and higher FCR (2.56 ± 0.12) than piglets weaned at 28 and 35 days of age at the end of WP. Average daily gain (0.884 ± 0.02 kg), ADFI (2.31 ± 0.02 kg) and days on test (57 ± 2) significantly improved during GFP with respect to 21 day weaned group compared to 28 and 35 days groups. All the measured parameters did not significantly vary during WFP. Generally, weaning age had no effect on growth performance of piglets weaned at 21, 28 and 35 days of age suggesting that piglets can be weaned at these periods without adversely affecting growth performance. It is therefore recommended that further studies can be conducted to evaluate the effect of weaning age on the reproductive performance of the sows and profitability of the three weaning ages.