EFFECT OF DIETARY LIVE YEAST (SACCHAROMYCES CEREVISIAE) SUPPLEMENTATION ON SOME PRODUCTIVE TRAITS AND METHANE PRODUCTION OF LACTATING BUFFALOES UNDER HEAT STRESS

SUMMARY he aim of the present study was to investigate the effect of yeast supplementation (Saccharomyces cerevisiae MUCL 39885, Probio-Sacc®, Biochem, Lohne, Germany) on performance and methane production of dairy buffaloes under heat stress. Ten Egyptian lactating buffaloes with an average live body weight 585 ±30 kg, in their 3 rd or 4 th lactation seasons and at 90±10 days in milk were randomly assigned into two nutritional groups each of 5 animals. The first group served as a control (G1), while the second group (G2) was individually supplemented with 5 g probiotics per head per day. Each 1 g of Probio-Sacc® contained 1.5 x 10 10 CFU live Saccharomyces cerevisiae MUCL 39885.The experimental period lasted for 90 days. Experimental animals were housed in semi-opened pens under an ambient temperature and relative humidity ranged from 23.3 - 34.4 o C and 21.1 - 69.3 %, respectively and offered their daily requirements according to NRC (2001). Total milk yield (TMY), Milk fat content (MF), milk protein content (MP), Milk total solids (TS), Solids not fat (SNF), Lactose content (ML) and 7% fat corrected milk yield (FCMY) were measured in each group. Temperature humidity index (THI) values ranged from 77.31 to 80.41, indicating that experimental animals were under moderate to severe heat stress during the experimental period. Average total milk yield, (FCMY) and (MF) were higher ( P ≤0.05) in yeast group than the control. milk protein, milk ash, (ML), (TS) and (SNF) tended to be higher insignificantly in yeast supplemented group, but the effect was not significant. Meanwhile, somatic cell count was insignificantly lower in LY treated group than in the control group. Live yeast treatment had no significant effect on total methane production per day but reduced the methane production per kg milk production as compared with the control group. It can be concluded that live yeast supplementation ameliorated the effect of heat stress on buffalo milk production and composition, although it tended to increase methane production due to the increase in dietary dry matter intake. It improved buffaloes milk production, net revenue and animals feed efficiency through different climate changes, by reducing methane production per kg milk production.