Yordanka Ilieva, Pencho Penchev
Agricultural Institute – Shumen, 3 Simeon Veliki Blvd., 9700 Shumen, Bulgaria
Ilieva, Y., & Penchev, P. (2019). Breeding efficiency and related traits in buffalo cows under the conditions of Nature Park “Rusenski Lom”. Bulgarian Journal of Agricultural Science, 25(2), 380–384
A study was initiated with the objective to evaluate the efficiency of reproduction of Bulgarian Murrah buffaloes from two farms under the conditions of a Nature Park in Bulgaria, practicing tie-stall pasture system with natural mating. From farm 1 (Fm-1) it assigned 266 calvings (postpartum periods) of 65 buffalo cows and 37 heifers and from farm 2 (Fm-2) – respectively 240, 61 and 22. The studied traits were age of first calving (AFC), period from calving to first estrus/mating (CFE), number of matings per conception (NMC), calving interval (CI) and breeding efficiency (BE) by Wilcox et al. (1957) (BEW) and by Tomar (1965) (BET). The analysis of variance (LSMLMW and MIXMDL by Harvey, 1990) of BEW and CI established significant individual effect (P = 0.0077 и P = 0.0086). Also significant was the co-effect age × season of calving (P = 0.0039 and P = 0.0003), the conventional statistics showing that BEW, CI (P > 0.05) and CFE (P < 0.05; P < 0.01) improve with the advance in age, while conception rates worsens (P < 0.05; P < 0.001); and that after calving in winter the values are most unfavourable (P < 0.05; P < 0.01). BEW was not influenced by year of calving and month of conception. The buffaloes from the two farms demonstrate good BE, with non-significantly higher value on Fm-1 (95.5 versus 93.7%). The non-significantly shorter calving interval on Fm-1 (392.7 versus 402.6 days) compensates the difference of 3 months in AFC (1112.4 versus 1026.9 days) within BET, thus rendering the values of the two farms also close (93.2 versus 92.7%). This leads to the assumption that the method of Tomar is inappropriate for the conditions of Bulgaria, not taking into account the greater economic weight of AFC within the selection index developed previously by Peeva (2000); while the Wilcox coefficient is not suitable for buffaloes at all as it neglects this trait.