The present study was designed to see the effect of different rations on the milk production as well as milk fat percentage. For this purpose 20 Nili-Ravi early lactating buffaloes were selected from the existing herd and randomly divided in to five groups A, B, C, D and E. The animals were selected on the basis of their age and stage of lactation. The group A was treated with conventional ration (control group) while group B and C were supplemented with oil @ 3 % and oil + niacin @ 15 g / day / animal respectively. While group D and E were supplemented with megalac @ 3 % and megalac + niacin (1 5g/day/animal). Green fodder was given for the maintenance requirement of the animals, while the production requirements were met through experimental rations. The research trial was continued for three months at BRI, Patokki.

Milk production was recorded daily. Milk composition was analyzed on weekly basis. The milk production among the different groups was 7.13 ± 0.59, 7.70 ± 1.30, 7.31 ± 1.02, 7.31 ± 0.81 and 7.46 ± 0.61 liters. Statistical analysis showed that the milk production in groups was similar and not significant between the groups but significant among the weeks.

Milk composition in terms of fat and its fractions (Solid Non Fat, Total Solids) protein and lactose percentage will be determined on weekly basis. The economics of milk production on various rations was estimated. The milk fat contents of groups were 5.29 ± 0.35%, 6.23 ± 0.37%, 6.31 ± 0.21%, 6.67 ± 0.33% and 7.41 ± 0.3 1%, for control (A), vegetable oil (B), vegetable oil + niacin (C), megalac (D) (rumen bypass fat), and megalac + niacin (E) groups respectively. The SNF contents of milk were 9.31±0.23, 9.27±0.10, 9.20±0.14, 9.50±0.30 and 9.24±0.16 for groups A, B, C, D and E respectively, while the TS contents were 13.81 ± 0.49, 14.78 ± 0.34, 14.88 ± 0.15, 15.49 ± 0.59 and 15.84 ± 0.40for groups A, B, C, D and E respectively. The milk protein contents of different groups were 3.24 ± 0.07, 3.27 ± 0.07, 3.32 ± 0.08, 3.27 ± 0.10 and 3.32 ± 0.19 respectively for control, vegetable oil, vegetable oil + niacin, megalac (rumen bypass fat), and megalac + niacin groups respectively. The lactose contents of milk were 4.20 ± 0.05, 4.30 ± 0.08, 4.39 ± 0.12, 4.32 ± 0.08 and 4.46 ± 0.14 for groups A, B, C, D and E respectively

Blood samples were collected on fortnightly basis. The blood samples were analyzed for the total proteins, urea, cholesterol and glucose level. Blood samples were collected from all animals of the groups. The serum total protein for different groups were 3.41±26.4, 3.14±42.47, 3.71±39.05, 3.36±35.02 and 3.17±38.07 g/l in buffaloes in groups A, B, C, D and E. The blood urea contents were 15.47±1.62, 22.03±2.26, 18.71±2.19, 19.65±1.34 and 16.60±4.59 mg/dl in buffaloes in groups A, B, C, D and E. The blood cholesterol contents were 139.79±41.47, 180.21±8.52, 164.77±7.79, 168.45±4.89 and 137.90±9.88 mg/dl in buffaloes in groups A, B, C, D and E, while the blood glucose contents were 44.96±2.66, 35.18±9.65, 43.57±3.24, 37.66±18.94 and 35.73±1.12 mg/dl in buffaloes in groups A, B, C, D and E.
Body weight gain of the animals was recorded on fortnightly basis. The weight of the animals was recorded early in the morning.

CONCLUSION
Dairy animals of high genetic merit require nutrients in addition to those produced from ruminal fermentation to achieve their potential and maintain milk quality. Fat and proteinaceous feed supplements should be designed to achieve optimal microbial efficiency in the rumen and to maximize digestibility and absorption fats and proteins from the small intestine. The degree of protection of fat supplements from ruminal metabolism should be as high as possible in order to minimize their deleterious impact on microbial metabolic activities. Fat supplements should also contain a fatty acid profile that allows the composition of milk fat to satisfy the nutritional demands of consumers and to provide the special physicochemical properties that are required for manufacturing

Buffaloes would be expected to exceed cattie in fat test by 1 to 3%, depending on breed and environmental conditions, but fat percentage of buffaloes appears to be influenced by environmental factors such as age and season of calving in about the same proportions as for cattle. The buffalo is less efficient as a milk producer, slower in reaching maturity, and subject to longer calving intervals than Sahiwal cattle in Pakistan. The high fat content of buffalo milk, coupled with larger fat globules, results in buffalo milk having higher utility on small farms than cattle milk because of ease in removal of the fat.

It is concluded that as the animals were fed concentrate ration, there is milk fat depression in the milk of dairy animals. So to maintain the milk fat for most dairy producers, the most effective method of maintaining an adequate milk fat percentage in the milk is:
o ensure that adequate fiber is in the ration, and
o include buffers in the concentrate mix or total mixed ration of the dairy animal.