Effect of extended colostrum feeding on the plasma profile of insulin, thyroid hormones and blood glucose of crossbred pre-ruminant calves.

In the present study, the effect of extended colostrum feeding on certain physiological and endocrinological parameters of pre-ruminant crossbred calves from birth to one month of age was investigated. Estimation of blood glucose level, plasma concentration of anabolic hormones as thyroid hormones and insulin were performed and compared with control calves (G-I) which were fed with colostrum for the first three days of age and thereafter with the whole milk, till 30 days of age. There was steady increase in the blood glucose level (BGL) from birth to one month of age in both groups of calves, with the rise being slightly higher in the calves of G-II group, which is attributed to the action of glucagon by gluconeogenesis especially in the neonates. Intake and absorption of increased amounts of dietary proteins and amino acids in colostrum stimulated a significant increase in the plasma insulin concentration in GII calves compared to G-I calves, over and above the accelerated tissue development of pancreas. Fluctuating levels of thyroid hormones in plasma of calves of both the groups suggested that the concentration of thyroid hormones were not influenced either by extended colostrum or whole milk feeding in calves, but rather followed a diurnal rhythm.

Serum profile of calcium, phosphorus and magnesium in crossbred heifers as influenced by gestation and early lactation.

The serum profile of certain macroelements such as calcium, inorganic phosphorus and magnesium of healthy crossbred heifers in Kerala were estimated before and after conception, at different stages of pregnancy and early lactation. The serum concentration of calcium showed a decreasing trend during second trimester of pregnancy which attained significantly lower (P < 0.01) value (5.57 mg/dl) when compared to controls. By the ninth month of pregnancy calcium level was elevated. The serum phosphorus level was significantly higher (P < 0.01) during the fifth month of pregnancy (8.29 mg/dl) when compared to controls and then it was decreased by the 9th month of pregnancy. The serum magnesium level showed an increasing tendency to attain a peak value (2.55 mg/dl) by the 9th month of pregnancy which was significantly higher (P < 0.01) when compared to the control. During the period of study no production diseases were encountered in the animals screened which indicated that the serum calcium, phosphorus and magnesium profile of these animals were at the optimum level.

Assessment of physiological stress in periparturient cows and neonatal calves.

Pregnancy is considered to be one of the physiological stressors. The stress hormone, cortisol is significantly involved in various events during periparturient period including initiation of parturition. The study was conducted to estimate the serum cortisol concentration in cows and the neonatal calves in order to correlate the effect of cortisol on certain haematological and biochemical parameters such as blood glucose level (BGL), total plasma protein (TPP), lymphocyte:neutrophil ratio and mitogen induced lymphocyte proliferative response. Blood samples were collected from six cows in four periods, namely., 3 days prior to parturition, on the day of parturition, and 7 days after parturition. Blood samples were also collected from neonatal calves in the period 0, 7 and 14 days of age. Calves above two months of age and non-pregnant dry cows were considered as the controls. The serum cortisol concentration in cows on the day of parturition was significantly higher (P < 0.01) than controls and the value in calves was also significantly higher (P < 0.01) at 0 day than their controls. On the day of parturition BGL level of the dam and calves were significantly higher (P < 0.01), whereas the proliferative response of lymphocytes to mitogen was significantly lower (P < 0.01) than controls. However TPP levels did not differ significantly. This confirmed that the dam at the time of parturition and neonatal calf before taking colostrum are under a high risk of infection because of the low profile of immune status. The lymphocyte:neutrophil ratio also justified the above suggestion.