The aim of experiment was to evaluate whether biostimulation by mature intact bull to anoestrus buffalo alters breeding performance associated with CIDR based oestrus synchronization protocol during low breeding season. Anoestrus buffalo that had calved 170.0+-10.6 (132 to 208) days before the start of the trial, were either exposed to bull (n=30, BE) or not exposed to bull (n=10, BN) for 12 days after CIDR placement (day 0). Animals received PGF 2 alpha on day 9, CIDR was removed on day 10 and Timed AI (TAI) was performed with frozen thawed semen at 48 and 60 h after CIDR removal. Buffalo were observed for oestrus detection twice daily for three days after CIDR removal. Blood sampling was done on day 9, 12 and 20 of the experiment to monitor the progesterone and cortisol levels (5 per group). Pregnancy test was done 60 days after insemination. Oestrus expression was noted in 68.97 percent (BE) and 60 percent (BN) animals (P GT 0.05). Progesterone rise above 1 ng/ml on day 20 was recorded in 4/5 (80 percent) in BE group and 2/5 (40 percent) in BN group (P GT 0.05). Conception rate was 37.9 percent (11/29) and 30 percent, (3/10) in BE and BN groups respectively (P GT 0.05). It is concluded that CIDR and fixed time artificial insemination can be used to overcome partially the problem of anoestrus and seasonality in buffalo. However, biostimulation in CIDR treated anoestrus buffalo did not increase the number of ovulating/oestrus buffalo during low breeding season probably due to a shorter exposure period (only 12 days) to bull.

The present study evaluated the impact of once-used intravaginal progesterone inserts (TRIU-B) from day 4 to day 10 post-ovulation on luteal profile (corpus luteum diameter, CL; plasma progesterone) and conception rate in buffalo (n=80) during summer season. The buffaloes were estrus synchronized by Cloprostenol (500 micro g, i.m.) administered 11 days apart, followed by AI during standing estrus. All the buffaloes were equally categorized into control (without TRIU-B) or treatment (pervaginally inserted with once-used TRIU-B) group. From each group, 15 buffaloes were subjected to ovarian ultrasonography for CL diameter measurements on day 4 and day 10 postovulation followed by jugular vein blood collection for plasma progesterone analysis. On day 10 postovulation, the control group buffalo had larger (P LT 0.05) CL diameter (15.2+-0.5 vs. 14.0+-0.3 mm), whereas, plasma progesterone was higher (P LT 0.05) in treatment group (3.4+-0.2 vs. 1.7+-0.1 ng/ml). Conception rates were 55.0 and 37.5 percent in treatment and control groups, respectively (χ2=2.46, P GT 0.05). Moreover, pregnant and non-pregnant buffalo of treatment group exhibited higher (P LT 0.05) plasma progesterone on day 10 post-ovulation compared to their control counterparts. In conclusion, pervaginal insertion of once-used TRIU-B enhanced post-ovulation plasma progesterone but failed to improve conception rate in buffalo.

During the last years buffalo reproductive researchers have been tried to develop and apply fixed timed artificial insemination protocols to increase pregnancy rates to maximize improvement. The objective of this paper is to evaluate the pregnancy rates of different protocols of synchronization (Ovsynch and progesterone implants) and resynchronization of ovulation in a meat water buffalo herd during reproductive season of 2016. 194 mature Mediterranean females, were randomly assigned to four different protocols, ultrasound evaluation were used to determine cyclicity (presence of corpus luteum or follicles GT= 7 mm de diameter). 18 days after insemination all females were resynchronized and at day 25 ultrasound were performed, those nonpregnant females were inseminated 28 days after first insemination. All inseminations were performed by the same technician and only one bull was used. InfoStat software was used, statistical significance was considered when p value was lower than α of the 5 percent. No statistical significance were found within the protocols. Early embryonic dead 50 days after IA was 3.4 percent. Pregnancy rate was 47.9 percent and 53.5 percent for insemination and reinsemination respectively and the final pregnancy rate after the adjust for early pregnancy loss 73.2 percent, during the 28 days of the breeding period. The results obtained allow breeders to choose the best pharmacological option to use FTAI in their herds based on their own needs to improve production without affecting pregnancy rates.