Detection of estrous behavior in buffalo heifers by radiotelemetry following PGF2α administration during the early or late luteal phase

Reproductive management in buffalo by artificial insemination

Artificial insemination (AI) is important for genetic improvement and to control the period of breeding in buffalo and has increased significantly over the past 20 years. AI is more difficult in buffalo compared with cattle due to variable estrous cycles, reduced estrous behavior, and reproductive seasonality. The latter is associated with a higher incidence of anestrus and increased embryonic mortality during the nonbreeding season. Protocols to control the stage of the estrous cycle have undergone recent development in buffalo. These protocols are based on the control of both the luteal phase of the cycle, mainly by prostaglandins and progesterone, and follicle development and ovulation, by prostaglandins, progesterone, GnRH, hCG, eCG and estradiol. Protocols that synchronize the time of ovulation enable fixed timed AI, avoiding estrous detection. Factors to consider when selecting an AI protocol include animal category (heifers, primiparous or pluriparous), reproductive status (cyclic or anestrus), and season. This review looks at the current status of estrus synchronization and AI in buffalo and provides some practical suggestions for application of AI in the field.

Effect of season on dairy buffalo reproductive performance when using P4/E2/eCG-based fixed-time artificial insemination management

This study aimed to compare the reproductive efficiency of dairy buffaloes subjected to TAI protocols based on progesterone, estrogen, and equine chorionic gonadotrophin (P4/E2+eCG) during the fall/winter (n = 168) and spring/summer (n = 183). Buffaloes received an intravaginal P4 device (1.0 g) plus estradiol benzoate (EB; 2.0 mg im) at a random stage of the estrous cycle (D-12). Nine days later (D-3), the P4 device was removed and buffaloes were given PGF_2α (0.53 mg im sodium cloprostenol) plus eCG (400 IU im). GnRH (10 μg im buserelin acetate) was administered 48 h after P4 device removal (D-1). All animals were subjected to TAI 16 h after GnRH administration (D0). Frozen-thawed semen from one bull was used for all TAI, which were all performed by the same technician. Ultrasound examinations were performed on D-12 and D-3 to ascertain cyclicity (presence of CL), D-3 and D0 to measure the diameter of the dominant follicle (ØDF), D+10 to verify the ovulation rate and diameter of the corpus luteum (ØCL), and D+30 and D+45 to detect pregnancy rate (P/AI 30d and 45d, respectively) and embryonic mortality (EM). Fetal mortality (FM) was established between 45 days and birth, and pregnancy loss between 30 days and birth. There were significant differences between fall/winter and spring/summer only for cyclicity rate [76.2% (128/168) vs. 42.6% (78/183); P = 0.02]. The others variables did not differ between the seasons: ØDF on D-3 (9.6 ± 0.2 mm vs. 9.8 ± 0.2 mm; P = 0.35); ØDF on D0 (13.1 ± 0.2 mm vs. 13.2 ± 0.2 mm; P = 0.47); ovulation rate [86.9% (146/168) vs. 82.9% (152/182); P = 0.19]; ØCL on D+10 (19.0 ± 0.3 mm vs. 18.4 ± 0.3 mm, P = 0.20); P/AI on D+30 [66.7% (112/168) vs. 62.7% (111/177); P = 0.31]; P/AI on D+45 [64.8%% (107/165) vs. 60.2% (106/176); P = 0.37]; EM [1.8% (2/111) vs. 3.6% (4/110); P = 0.95]; FM [21.9% (18/82) vs. 8.0% (7/87); P = 0.13]; and PL [23.8% (20/84) vs. 12.1% (11/91); P = 0.13]. In conclusion, dairy buffaloes present similar reproductive efficiency in fall/winter and spring/summer when subjected to P4/E2/eCG-based protocol for TAI.

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

This study evaluated the effect of new or used P4 devices on the ovarian responses of dairy buffalo that were administered an estradiol (E2) plus progesterone (P4)-based timed artificial insemination (TAI) protocol during the breeding season. On the first day of the TAI protocol, 142 cows were randomly assigned to receive one of the following: a new device (New; 1.0 g of P4; n = 48); a device that had previously been used for 9 days (Used1x, n = 47); or a device that had previously been used for 18 days (Used2x, n = 47). Ultrasound was used to evaluate the following: the presence of a corpus luteum (CL); the diameter of the dominant follicle (ØDF) during protocol; ovulatory response; and pregnancies per AI (P/AI). Despite similar responses among the treatments, there was a significant positive association of the ØDF during TAI protocol with ovulatory responses and number of pregnancies. In conclusion, satisfactory ovarian responses and a satisfactory pregnancy rate were achieved when grazing dairy buffalo were subjected to the TAI protocol in breeding season, independent of whether a new or used P4 device was used. Furthermore, the presence of the larger follicle was associated with a higher ovulation rate and higher P/AI following TAI.

A correlation of fecal volatiles and steroid hormone profiles with behavioral expression during estrous cycle of goat, Capra hircus

Chemical signals (both volatile and non-volatile) form the major communication channels in animals. These signals are transferred mainly through excretory sources to facilitate inter-individual communication. In particular, the reproductive cycle of female mammals, including goats, exhibits significant changes in the constituents of their excretory products, and female mammals also express different behavioral patterns. We propose that feces is one of the important sources of chemo-signals in goats. However, the behavioral patterns and analysis of excretory sources based on chemical communication have not yet been studied in the Indian goat, Capra hircus. To validate our hypothesis, we analyzed the behavioral patterns and the volatiles and steroid hormone profiles in the feces samples of female goats during the estrous cycle. Here, we synchronized the estrous cycle in six female goats and obtained feces samples. The samples were extracted with dichloromethane and analyzed using gas chromatography-mass spectrometry. A portion of the sample was used for hormone assay to confirm the phases in the estrous cycle. Induction of she-goats into estrus was detected from the vaginal swelling, mucus discharge, restlessness, reduced milk secretion, bellowing, bleating, frequent urination, standing heat, allowing the male to mount, mounting on other females and teasing of males. The repeated male behaviors viz., flehmen, mounting, penile protrusion, body rubbing, dominance over other males and finally coitus with estrus female by male goats were observed. Analysis of volatiles revealed a total of twenty-four compounds combining all the phases in the estrous cycle. Among those, some of the volatile compounds and two antioxidants (ascorbic acid and vitamin E) were estrus-specific. Based on the fecal steroid analysis, higher level of estradiol during estrus and higher level of progesterone during post-estrus were observed. The behavioral patterns of female and male goats combined with qualitative differences in the volatile compounds and the two antioxidants rendered the estrus identifiable. Furthermore, the fecal steroid analysis also supported the detection of hormonal status during the estrous cycle. To the best of our knowledge, this is the first report correlating the behavior with volatiles and hormones in the feces samples from female Indian goats. It is concluded that the volatile pattern and hormone profile in feces, supported by specific behavioral patterns, should be considered a better modality of non-invasive estrus detection in goats.