Thirty Staphylococcus aureus isolates used in the study obtained from cattle (20) and goat (10) were haemolytic on blood agar. Twenty one of the isolates (14 from cattle, 7 from goats) produced a-haemolysis, 3 produced b-haemolysis (2 from cattle and 1 from goats), and 6 isolates (4 from cattle and 2 from goats) produced both a- and b-haemolysis. The haemolysins tested against erythrocytes from rabbit, cattle and horse in order to demonstrate a-, b- and d-toxins, respectively revealed that a- and b-toxins were produced by all the isolates but b toxin was produced by only 7 isolates from cattle and by 3 from goats. On titration it was recorded that highest titre was recorded for a-toxins (for cattle, 1:2560 and for goat, 1:1280) whereas the highest titres for b and d-toxins was similar (1:160) for cattle as well as goat isolates. The result obtained for qualitative and quantitative haemolysin assays correlated well with the haemolysis pattern seen on the blood agar plates.

The study found out the chemical and microbial quality of various milk samples collected from different sources of milk procured from rural areas of Tirupati. Thefat, SNF and protein percentages of milk samples collected from Dairy Experimental Station were higher than the other milk samples collected from commercial dairies of Sangam, Balaji and Heritage and local vendors. The milk samples collected from local vendors showed lower fat, SNF and protein percentages. No significant difference was observed in the milk samples collected from commercial dairies of Sangam, Balaji and Heritage with regard to fat, SNF and protein percentages. None of the milk samples collected from Dairy Experimental Station were found to be adulterated with water, whereas higher percentage of water was observed in the milk samples of local vendors. The Standard Plate Count of milk from local vendors is higher followed by Dairy Experimental Station. Presence of E.coli organisms in the milk samples collected from local vendors and Dairy Experimental Station indicated the extraneous contamination and unhygienic conditions of milking barn.

First lactation milk yield per day of lactation length of 379 Sahiwal cows, collected from cattle breeding farm, Chak Ganjaria, Lucknow were utilized for the present study. The optimum number of progeny size to achieve the accuracy attained by different methods of sire evaluation (Daughter's average (DA), contemporary comparison (CC), Least-squares (LS), Simple Regressed Least-squares (SRLS) and Best linear unbiased prediction (BLUP» ranged from 47.615 (CC) to 161.069 (BLUP). Similar results were also obtained in the ratio ofoptimum progeny size estimated by different methods with that of actual progeny size per sire available ranging from 5.270 (CC) to 17.828 (BLUP). Present findings revealed that BLUP method showed highest increase in accuracy of 207.72% among all the methods studied.