Equine chorionic gonadotropin improves the efficacy of a timed artificial insemination protocol in buffalo during the nonbreeding season

Abstract

Two experiments were conducted to evaluate the effects of equine chorionic gonadotropin (eCG) treatment on ovarian follicular response, luteal function, and pregnancy in buffaloes subjected to a timed artificial insemination (TAI) protocol during the nonbreeding season. In experiment 1, 59 buffalo cows were randomly assigned to two groups (with and without eCG). On the first day of the synchronization protocol (Day 0), cows received an intravaginal progesterone (P4) device plus 2.0 mg estradiol benzoate im. On Day 9, the P4 device was removed, all cows were given 0.150 mg PGF(2α) im, and half were given 400 IU eCG im. On Day 11, all cows were given 10 μg of buserelin acetate im (GnRH). Transrectal ultrasonography of the ovaries was performed on Days 0 and 9 to determine the presence and diameter of the largest follicle; between Days 11 and 14 (12 hours apart), to evaluate the dominant follicle diameter and the interval from device removal to ovulation; and on Days 16, 20, and 24 to measure CL diameter. Blood samples were collected on Days 16, 20, and 24 to measure serum P4. In experiment 2, 256 buffaloes were assigned to the same treatments described in experiment 1, and TAI was performed 16 hours after GnRH treatment. Pregnancy diagnosis was performed by ultrasonography 30 days after TAI. Treatment with eCG increased the maximum diameter of dominant follicles (P = 0.09), ovulation rate (P = 0.05), CL diameter (P = 0.03), and P4 concentrations (P = 0.01) 4 days after TAI, and pregnancy per AI (52.7%, 68/129 vs. 39.4%, 50/127; P = 0.03). Therefore, eCG improved ovarian follicular response, luteal function during the subsequent diestrus, and fertility for buffalo subjected to a TAI synchronization protocol during the nonbreeding season.

Ovsynch Plus protocol improves ovarian response in anovular Murrah buffaloes in low‐breeding season

“…Likewise, administration of eCG 72 hr prior to GnRH1 in Ovsynch Plus protocol accelerated the growth of ovarian follicles and DF diameter increased from 10.15 ± 0.26 mm to 12.23 ± 0.34 mm with better response for GnRH1 (96.6%) in Ovsynch Plus group than Ovsynch group (61.5%). This confirms that larger follicles are more responsive to ovulatory response of GnRH in buffaloes (Carvalho et al., , ; Karuppanasamy et al., ). Apart from higher ovulatory response, majority of eCG treated anovular buffaloes ovulated earlier as compared to those in Ovsynch group.…”

“…Hence, inclusion of eCG prior to GnRH1 may be a good strategy to synchronize all buffaloes to have a responsive DF. Studies wherein progesterone implants along with eCG have been used for inducing oestrus in anoestrous buffaloes during low‐breeding season with a pregnancy rates close to 30% (Barile, ; Carvalho et al., ; De Rensis & López Gatius, ; Neglia et al., ). In addition, combining PRID with Ovsynch protocol resulted in similar conception rate (30%) in anovular buffaloes (De Rensis et al., ).…”

“…Studies have shown that follicles size >9 mm is necessary to respond to Ovsynch protocol in anovular buffalos at the time of first GnRH injection (Baruselli, Madureira, Barnabe, Barnabe, & Berber, ; Karuppanasamy et al., ; Rohilla et al., ). In addition, it is reported that incorporation of eCG in synchronization protocol has either improved ovarian follicular response and fertility in Bos taurus (Mussard, Burke, Behlke, Gasser, & Day, ; Perry, Smith, Roberts, MacNeil, & Geary, ), Bos indicus (Sá Filho et al., , ) and buffaloes (Carvalho et al., , , ; Murugavel, Antoine, Raju, & López‐Gatius, ) during low‐breeding season or had no effect on follicular response and pregnancy rate in cattle (Souza et al., ) and buffalo (Neglia et al., ). Thus, it is evident that enhancing follicular growth prior to GnRH injection may be an important determinant to ovulate a large DF, thereby forming a robust corpus luteum (CL) necessary for progesterone priming.…”

Chemometric evaluation of binary mixtures of alginate and polysaccharide biopolymers as carriers for microencapsulation of green tea polyphenols

“…An ANN is a non-linear computing system consisting of a large number of interconnected processing units (neurons), which simulates the human brain learning. [30] Based on the ANN computed from the data obtained in the present study, the most suitable network was selected based on training and validation preferences and errors, as previously stated by Di Scala et al [31] and Carvalho et al [32] The selected network had a Tanh hidden activation function and identity output function, with the lowest validation error of 0.072 achieved in the training period, and was selected for analysis of the formulated binary mixtures.…”

Ovarian responses of dairy buffalo cows to timed artificial insemination protocol, using new or used progesterone devices, during the breeding season (autumn–winter)

“…The beneficial effect of eCG has also been described in grazing dairy buffalo (Carvalho et al . ). That study found that eCG‐treated females presented larger dominant follicle diameters and greater ovulatory and pregnancy responses compared with No‐eCG‐treated females.…”