Timed artificial insemination in the reproductive management of buffalo(Bubalus bubalis) herds.
Creators: name: Rossi, Pasquale
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2013

description: The aims of the present study were to ascertain, in Mediterranean environment:
a) the influence of season on successful of AI in different years;
b) the relationships between CL vascularization, CL function, and pregnancy outcome to AI in buffaloes, are consistent across the breeding season and the transition period to the non-breeding season. The study was organized in two experiment. The first experiment was conducted between 2009 to 2012 on 1088 Italian Mediterranean buffaloes underwent AI throughout. Starting from 40 Days after calving buffaloes were synchronized by the Ovsynch with timed-AI (OVSINCH-TAI).Throughout the trial overall fertility rate was meanly 75.5% with an intercalving period of 4162.4, without differences among the years. The conception rate significantly decreased progressively from the second to the seventh service. Around 66% of mated buffaloes were pregnant within the second service and these represent the 87.4% of the total conceptions. A total of 3429 buffaloes were synchronized during the study. Interestingly, 28.3% animals did not have a functional CL (NCL) after the first GnRH and 21.5% were excluded on the day of AI (NMAI) because did not show signs of estrus. Therefore, 49.8% of buffaloes were not inseminated. The incidence of LEM registered in Period 1 was significantly higher than that in other periods. The second experiment, was performed to further evaluate the effect of the season on CL function and pregnancy rate. A total of 256 animals were selected and were mated by AI after synchronization of ovulation by the Ovsynch-TAI. Pregnancy was further assessed on day 45 after AI by ultrasonography: buffaloes with embryonic development on Day 25, but not pregnant on Day 45, were considered to have undergone late embryonic mortality. Morphology of the CL and function were assessed by ovarian ultrasonography on 39 buffaloes in each of Periods 1 and 2. Features of the CL (dimensions and blood flow parameters) were recorded on Days 10 and 20 after AI. In Period 1 (breeding season), 62.6% of buffaloes had embryonic development on Day 25 after AI and 58.0% were pregnant on Day 45, which represented a late embryonic mortality of 7.3%. In Period 2 (transition period), 59.2% of buffaloes had embryonic development on Day 25 after AI and 45.6% were pregnant on Day 45, which represented a late embryonic mortality of 23. For the 78 buffaloes that were intensively observed (39 in each period), 56.4% and 53.8% showed embryonic development on Day 25 after AI during the breeding season and the transition period, respectively. Pregnancy rates decreased to 53.8% during the breeding season and 43.6% during the transition period on Day 45 after AI, which reflected late embryonic mortality of 4.5% and 19.0%, respectively. Buffaloes pregnant on Day 45 after AI had greater concentrations of P4 on Days 10 and 20 after AI in Period 1 than in Period 2. The Time Average Medium Velocity (TAMV) on Day 10 after AI was greater for buffaloes in Period 1 than in Period 2. The following data are combined for Period 1 and Period 2.  The dimensions of the CL on Day 10 and Day 20 after AI were greater (P &lt; 0.01) for buffaloes that were pregnant on Day 45 after AI compared with buffaloes that were not pregnant.  Buffaloes pregnant on Day 45 also had a greater (P &lt; 0.01) CL area on Day 20 after AI .  Concentrations of P4 on Day 10 and Day 20 after AI were greater (P &lt; 0.01) for buffaloes that were pregnant on Day 45 after AI compared with buffaloes that were not pregnant. The CL time average medium velocity (TAMV) on Day 10 after AI was greater (P &lt; 0.05) for buffaloes pregnant on Day 45 after AI compared with buffaloes that were not pregnant.