COMPARATIVE STUDY ON AGE OF CONCEPTION OF BUFFALO HEIFERS IN DIFFERENT FARMING SYSTEMS

Kalin Hristov, Yordanka Ilieva, Pencho Penchev, Vladimir Planski

Abstract: With the aim to assess the effect of different farming systems on age of first conception, a comparative study was initiated on buffalo heifers from three farms for the period 2010-2015. All three farms (SIC, SIB and IMR) practice immediate separation of newborn from dam, 7-day colostrum and 3-month weaning period, live weight (LW) being monitored on Fm-3 only. Number of heifers assigned (n), farming system (FS), feeding in suckling period (SP) and use of natural-service bull (NS) were as follows: SIC – [n = 38, FS – free-stall plus pasture, SP – cow milk, NS – full time]; SIB – [n = 42, FS – tie-stall plus pasture, SP – buffalo milk, NS – by day]; IMR – [n = 69, FS – tie-stall plus yard, SP – milk replacer after first month, NS – by day, after heifers attain 380 kg LW]. The data were processed using the conventional statistical procedure. The results demonstrate the favourable effect of buffalo milk used in pre-weaning period, expressed in earlier age of conception in the heifers from SIB (729 days), as opposed to suckling cow milk on SIC – by 86 days (P < 0.05). Differences in farming system are implied by the considerably lower age of first conception established on SIB, in comparison to IMR (by 147 days, P < 0.001) where no pasture is used and breeding to bull is afforded after reaching a threshold live weight. The study found pronounced seasonality of reproduction, expressed in large percentage of heifers (75%) breeding in the period August-December. A tendency was also observed the heifers born in spring to conceive youngest.

Keywords: age of first conception; breeding season; buffalo heifers

Date published: 2018-06-01