Variability Of The Ratio Between A.M. And P.M. Milk Yield In Bulgarian Murrah Buffaloes Under Two Different Farming Systems

The study assigned 65 buffaloes under intensive farming (FM-I) with 922 test day records, and 73 buffaloes in pasture system (FM-P) with 2505 records. The analyses of variance (LSMLMW and MIXMDL), including also year, season, parity and test day, showed significant effect of milking time on milk yield (P<0.001) and of test day and its co-effect with milker`s group on p.m./a.m. ratio in the herds from FM-P (P<0.001) and FM-I (P<0.05), respectively. The random factor individual was also highly significant on FM-P. On FM-I p.m. yield was averagely by 18.1% lower than a.m., the differences between a.m. and p.m. maintained practically constant throughout lactation. Atypical, contrary pattern was found.n FM-P -p.m. by 22.3% higher than a.m. yield, the difference becoming smaller until seventh month. The effect of lactation persistency on FM-P (P<0.05) is expressed in inverse proportion to the p.m./a.m. ratio. The substantial variability of a.m.-p.m. productivity, in particular its peculiarities in separate herds of buffaloes, should be taken into consideration in the development of prediction models.