PRODUCTIVE AND PHYSIOLOGICAL PERFORMANCE OF NILI-RAVI BUFFALOES UNDER VARIOUS HOUSING MANAGEMENT PRACTICES DURING SUMMER

Abstract

Heat stress is a challenging issue for the dairy farmers of Pakistan since the geographical location of Pakistan is sub-tropic. The study was conducted to evaluate the effect of housing strategies on the production performance of Nili-Ravi buffaloes during period of early (March and April), mid (hot-dry: May and June; hot-humid: July and August) and late summer (September and October). The study was carried out at Buffalo Research Institute (BRI), Livestock Experiment Station (LES), Bhunike, Distt. Kasur, Punjab. Mature lactating multiparous (3rd, 4th, 5th and 6th parity) Nili-Ravi buffaloes (n=20) with similar level of milk production and stage of lactation were selected from the herds maintained at LES, Pattoki. Buffaloes were divided into four different treatment groups with 5 buffaloes in each group. Animals were re-randomized after each experiment to balance for milk production and stage of lactation. Group A was kept under roof shade only; B was given anti-stress product (dry yeast powder; saccharomyces cerevisiae); C under fans and group D buffaloes kept under showers and fans, provided with roof shades. During early-summer (Experiment-1) temperature humidity index (THI) value was recorded as 73.1 and 81.0 during months of March and April, respectively. Significant (P<0.01) higher milk production (MP; liter) was achieved in shower group (D; 8.37±0.08) as compared to A (7.97±0.10), B (8.07±0.08) and C group (8.14±0.09). Similarly, dry matter intake (DMI; kg) value was noted high as 15.8±0.11 (P<0.05) for shower group (D) as compared to 14.3±0.11, 14.5±0.12 and 15.6±0.09 for group A, B and C, respectively. Cost per liter of milk was higher for group C and B and were lower than the margins achieved with increased milk production. During hot-dry summer (May-June; Experiment-2), milk production (MP; liter) was significantly (P<0.01) high in shower group (D; 7.33±0.10) as compared to A (6.39±0.13), B (6.52±0.09) and C group (6.95±0.11) whereas, THI value were 85.6 and 87.6 for May and June, respectively. Dry matter intake (DMI; Kg) was significantly (P<0.05) high (15.4±0.16 kg) for Shower group (D). However, cost of production (cost/liter of milk) was lower for shower group (D) buffaloes. In the hot-humid climatic conditions (July-August; Experiment-3) daily milk production (MP; liter) was noted and values were found as 4.61±0.06, 5.00±0.08, 5.12±0.08 and 5.80±0.09 for the treatment groups A, B, C and D during hot-humid summer (Significantly higher in group D; P<0.05). Similarly, the value for DMI (Kg) was found as 13.02±0.09, 14.11±0.08, 14.32±0.13 and 15.21±0.16 for the treatment groups A, B, C and D, respectively (Significantly higher in group D; P<0.05). Respiration rate (RR), rectal temperature (RT) and pulse rate (PR) were significantly (P<0.01) lower for group D during hot-dry and hot-humid summer, as compared to other groups. In the late summer, Milk production (MP; liter) and DMI (Kg) were significantly (P<0.01) lower for control group (A) as compared to other treatment groups (B, C and D) whereas, cost per liter of milk was more during mid. and late summer. The findings from these studies strongly imply the application of cooling measures especially during mid-summer (hot-dry and hot-humid) and late summer. While increased milk production was also seen in early summer, the additional costs of feed and cooling netted lower margins than shade alone. Keywords: Nili-Ravi, milk production, heat stress, dry matter intake