Background: Pig rearing is well imbibed in the people of north eastern states of India and offers a source of income to rural tribal masses. However, change in climatic parameters especially the increase in temperature due to global warming causes significant production losses thereby affecting the poor farmers. Methods: Two genetic groups, Hampshire and Hampshire × Local, were studied in this agro-climatic study in Assam State, India, to determine the influence of temperature stress on productive metrics. Two distinct seasons of the year were used to measure the pigs’ cortisol levels. Thermal stress in the experimental animals was measured using the Temperature Humidity Index (THI). Result: During summer (79.55 - 82.56) both the groups showed higher (P less than 0.01) concentration of serum cortisol compared to the winter season. The THI was found to negatively affect the food conversion efficiency , body weight gain and linear body measurements in both the genetic groups. Subsequently, to overcome the effect of THI, different feed formulations varying in energy content were fed to the pigs during summer and winter season. The diet contained 3260, 2936.5 and 3585.8 kcal/kg of metabolisable energy in the grower ration and 3260.2, 2936.6 and 3587 kcal/kg in the finisher ration for the normal energy (NE), low energy (LE) and high energy (HE) rations, respectively. The results indicated that the energy level included in the diet had a significant impact on the body weight gain (P less than 0.01) and reduced the average daily body weight gain during the summer time. Incorporating HE resulted in a decrease in feed intake and an increase in FCE. Data showed that the growth performance of pigs in Assam varied with the season. Although reduced feed intake during the summer season was a major limiting factor to growth rate. Modification of diet with increasing the energy density might be helpful to minimize the production losses due to thermal stress.

Twenty-four healthy and uniform crossbred (Hampshire × Assam Local) pigs, 4 months of age, were selected to study the effect of 500 ppm Zn supplementation on certain serum biochemical parameters for a period of four months. The animals were divided into three groups (n=8/group): group C (basal diet), group T ₁ (basal diet + 100 ppm Zn + calcium carbonate @ 1.5% DM) and group T ₂ (basal diet + 500 ppm Zn). Serum samples were collected at 15-day intervals and analysed for serum Zn, copper, total serum protein, albumin, globulin, and glucose cholesterol. The serum Zn concentration in the T ₁ group decreased significantly (P<0.01) from day 30 until day 120 of treatment, whereas in the T ₂ group, the level increased significantly (P<0.01) from day 15 onwards. The serum copper concentration did not change groups. The total protein concentration in the serum showed a significant (P<0.01) increasing trend in the T ₂ group from day 45 of treatment, and a significant (P<0.01) decreasing trend was observed in the T ₁ group compared to the C group. The serum globulin concentration decreased significantly (P< 0.05) in the T ₁ group compared with the C and T ₂ groups during the treatment period. An increasing trend in glucose and cholesterol levels was recorded at T ₂ during the treatment period. However, decrease, (P<0.01) in glucose and cholesterol levels was recorded in the T ₁ group from day 30 to day 120 of treatment. The haemoglobin concentration showed a significant (p<0.01) decreasing trend in the T ₁ group from day 45 onwards.