Growth Performance of Pigs as Affected by Seasonal Stress in Relation to Energy Levels in Rations

The experiment was conducted on 18 weaned (56 days) Hampshire and cross bred (50% Hampshire × 50% Local) pigs of average body weight 10.55 kg under the agro-climatic conditions of Assam, India to find out the effects of seasonal thermal stress on their growth performance given different levels of energy (110, 100 and 90% energy of NRC, 1998) in the diet. The metabolizable energy values were 3260, 2936.5 and 3585.8 kcal/kg in grower ration and 3260.2, 2936.6 and 3587 kcal/kg in finisher ration for normal energy (NE), low energy (LE) and high energy (HE), respectively. The temperature humidity index (THI) during the study period was found to be indicative of thermal stress to the experimental animals during summer (79.55–82.56) as compared to the winter seasons (67.21–73.81). Higher total feed intake and better feed conversion ratio was recorded in winter season. Lower feed intake and better FCR was recorded in HE group. The average body weight was higher (P<0.01) in winter and Hampshire pigs attained higher body wt. (81.80 kg). The energy level of diet had significant (P<0.01) influence on the body weight gain and minimized the production losses in terms of body wt. gain during summer. Data indicated that growth performance varied with the seasons and during the warm season feed intake was a major limiting factor to growth rate but increasing energy density of diet could help to minimize the effect.