PATTERNS OF LACTATION CURVE IN BULGARIAN MURRAH BUFFALOES FROM TWO FARMS

To assess the different patterns of lactation curve and their parameters, were assigned buffaloes from intensive and pasture farming with respectively 466 and 335 normal lactations. The effects of peak month on overall persistency (PI1), post-peak persistency (PIP) and peak yield ( PMY) were tested via LSMLMW and MIXMDL. The curves of lactations with first (LC1), second (LC2), third (LC3) and fourth-plus (LC4) peak month were shaped through conventional statistics. The results show mass deviation from the typical curve, the LC1 lactations being 60%, while LC2 are 1/4. Delaying the peak from 1st to 3rd month, PIP decreases from 88.2 to 86.4% (P< 0.05), but with highest value (90.4%) is LC4 (P< 0.01). Most productive are the lactations with typical pattern (LC2), while LC1 have lower milk yield, despite the higher peak yield, but because of the lower productivity and overall persistency (PI1) after it. It was demonstrated that for the economics of buffalo farming persistency by itself is not the only important parameter, but actually its combination with peak yield and the positioning of the peak.