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ThesisItem Open Access Studies on hormonal induction of lactation in cows(Department of Animal Sciences, College of Veterinary and Animal Sciences, Mannuthy, 1977) Joseph, P M; KAU; Pavithran, KA trial to induce lactation in cows and heifers using the hormones oestradiol dipropionate or stilboestrol dipropionate in combination with progesterone was conducted. The experimental animals comprised of six each of heifers and cows divided into three groups of two each of cows and heifers. Natural oestrogen and progesterone were given to animals in the first group at the rate of 0.05 mg and 0.125 mg per kg body weight respectively at 12 hour intervals consecutively for seven days. The animals in the second group received synthetic oestrogen and progesterone at the same dose and for the same duration. The Animals in the third group were given synthetic oestrogen and progesterone at the rate of 0.10 mg and 0.25 mg per kg body weight respectively, on alternate days, during a period of 14 days. There was considerable udder development in all the animals. The development was more in the animals of group I and III in comparison to those of group II. The heifers exhibited pronounced udder development than the cows. Lactation commenced within a period of 13-21 days after the first injection in all the animals. The milk yield reached the peak with in period of four to ten weeks. The peak yield varied from 140 ml to 4300 ml. The average milk yield per day in the three groups during the period of the first 60 days was 1766,942 and 1638 ml for group I, II and III respectively. The yield obtained for group I and III was significantly higher than that of group II. The heifers gave better yield than the cows. The composition and properties of the milk obtained from the induced lactation was compared with those of the milk from normal cows. It was found that on the eighth day onwards there was no significant difference in the composition and properties of milk obtained from the experimental animals as compared to those milk from postpartum cows. In general the milk from the animals of induced lactation had similar qualities to that of the milk from postpartum cows. The erythrocyte count, haemoglobin concentration and packed cell volume decreased and the plasma protein increased during the treatment as well as the post-treatment periods in comparison to the pre-treatment period. During the treatment period the animals exhibited symptoms of heat. Normal oestrus was observed in six animals with in 42-57 days from the commencement of lactation. Four of them were inseminated and all of them conceived. The body weight remained unchanged in the cows but the heifers showed a slight decline in body weight. Both natural and synthetic oestrogen along with progesterone were effective in inducing lactation. Natural oestrogen in combination with progesterone was more effective in short duration treatment. When the synthetic oestrogen along with progesterone was given for a longer period better results were obtained than short duration. The induction was more successful in heifers than in cows. Regaining of the reproductive efficiency in some fo the problem breeders was an added advantages of the technique adopted.ThesisItem Open Access Studies on the whey proteins of cows` milk in induced lactation(Department of Dairy Science, College of Veterinary and Animal Sciences, Mannuthy, 1985) Sadananda, Talukdar; KAU; Pavithran, KA comparative study on the milk proteins in general and the whey proteins in particular was conducted between cows of first lactation and inferitile heifers brought into lactation by hormonal treatment. It was intended to study the differences, if any, between the two sets of cows in respect of the milk proteins and the possible secretory process involved therein . An exhaustive review of literature has been presented on the levels of various components of whey proteins and other related aspects. The methods of analysis of various components of milk have been detailed. The cows used in the study were crossbred ones, randomly selected from the University Livestock Farm, Mannuthy and maintained under similar farm conditions. The experimental group of animals, the heifers, were given estrogen (0.1 mg/kg body weight) and progesterone (0.25 mg/kg body weight) together in a single injection daily for 7 days consecutively. Gradual development of the udder during the course of treatment was noticed. Between the termination of the treatment and first milking, the development was more conspicuous. Regular milking, twice in a day, was started from the 21st day after the first injection. Secretion was initially colostral, and gradually within a period of 5 days, it resembled normal milk in appearance. The minimum yield from one animal in a day was 200 ml whereas the maximum reached was 4, 500 ml. From the 16th day of first milking, chemical analysis was started with in the case of experimental group. Animals in the control group began with the 3rd month of their lactation when the sample collection was started for analysis. Milk samples from both the groups were collected every 6th day and thus 6 samples from each animal were used for analysis. Both chemical analysis and electrophoresis were used to study the milk components. Estimation of nitrogen was done by the kjeldahl method. Average contents (in percentage) of albumin, globulin, total whey protein and other whey proteins were 0.383, 0.1786, 0.64 and 0.10 respectively in the milk of normal lactation; the values in the induced lactation being 0.603, 0.284, 1.045 and 0.158 respectively. Out of the total nitrogen in milk, the total whey nitrogen and the non protein nitrogen were 26.526 and 6.376 per cent respectively, in normal lactation, the values were 31.524 and 5.432 per cent respectively. Average total protein, casein and crude protein contents in normal milk were 2.97, 2.33 and 3.17 per cent respectively. But in induced milk, the values were 3.79, 2.773 and 4.007 per cent respectively. The ratio of whey protein :casein was 22:78 in normal lactation whereas in induced lactation it was 27;73. The contribution of whey protein to the higher total protein content of induced milk is more than that of casein. Differences between the whey components between the two groups were noticed. On statistical analysis, albumin, globulin, non – protein nitrogen and the other whey proteins together (whey proteins excluding albumin plus globulin) did not have significant difference between the two groups. So also was the casein. There was, however, significant difference between the two groups in respect of total whey nitrogen, total whey protein and total protein. Individual differences were highly significant in respect of albumin, globulin, total whey protein, total protein and crude protein. The last one had highly significant difference between the groups also. Globulin, non – protein nitrogen and other whey proteins, on the other hand, did not indicate any significant difference neither between groups or between individuals. The whey protein was subjected to electrophoretic separation in Acrylamide gel system with Borate buffer. In this attempt, it could be fractionated into six different bands in each case. But the mode of fractionation between groups in particular was found different from each other. A general trend for an increase in the protein content was thus seen in the milk of induced lactation that was mostly brought about by whey proteins. This may be a reflection of the secretory pattern involved with the normal and the induced lactation. Further investigations in detail may elucidate this in future.