Improvement of Fertility Rate Using Ovsynch and Biostimulation Protocols with Timed Artificial Insemination in Thari Cattle

Forty Thari cattle of 1st to 4th parity maintained on semi intensive management conditions at Thari Cattle Farm Nabisir Road, Distt. Umerkot and its surroundings were used in the study. Before the start of experiment rectal palpation was done to confirm non-pregnant females. The feeding and drinking was done according to routine practices of the farm.

The females were grouped into four groups each of 10: (i) Group-A (non-treated without biostimulation) in which animals received 2ml sodium chloride (Nacl) on 0, 7 and 9th of the experiment and were not exposed to bull. (ii) Group-B (Ovsynch without biostimulation n=10) in which animals were administered with 2ml of GnRH (Dalmarelin, Fatro-Italy) on day 0, on day 7 5ml PGF2α (Lutalyse®, Pfizer-USA) and 2nd injection of 2ml GnRH (Dalmarelin, Fatro-Italy) on day 9. Females were not exposed to bull. (iii) Group-C (non-treated with biostimulation) in which females were injected 2ml of normal saline on day 0, 7 and 9 of the synchronization and females were exposed to biostimulation for half an hour daily (6 am and 6 pm) from day 0 of synchronization to artificial. (iv) Group–D (Ovsynch with biostimulation) in which females were injected with Ovsynch protocol which involves administration of 2ml GnRH (Dalmarelin, Fatro-Italy) on day 0, injection of 5ml PGF2α (Lutalyse® , Pfizer-USA) on day 7 and a 2nd injection of 2ml GnRH (Dalmarelin, Fatro-Italy) at day 9. Females were also exposed to biostimulation for half an hour, daily (6 am and 6 pm) from day 0 of synchronization to AI.

Females of all groups were watched daily for heat from the start of the treatment (day 0). All females were inseminated after the last injection (day 9) following protocols of injection at 12 and 24 h after onset of estrus with semen received from Directorate of Animal Breeding (DAB), The following parameters were recorded in all groups. (i) Onset of estrus were watched closely (in females of all groups) after 2nd injection of PGF2α for behavioral signs of heat. The major bevioral signs were observed including mounting, bellowing, sniffing, restlessness and micturition. The animals were inseminated artificially at 12 and 24 h, after third injection of GnRH in group D and B. However, females of A and C group were artificially inseminated twice 72 and 96 h after the PGF2α injection. (ii) Duration of estrus was recorded by observing estrus signs visually from onset of estrus signs till cessation of estrus signs. (iii) Fertility/ Pregnancy rate was determined by per rectum palpation at 2 months post AI.

Statistical package Graph pad instate 3.05 versions of was used to analysis the data. Analysis of variance (ANOVA). To determine significant Difference between means of groups’ chi square test was used. Significant level was considered at P<0.05.

The effect of ovsynch protocol with or without biostimulation on estrus response, onset of estrus, estrus duration and fertility rate of Thari cattle is shown in Table I. Estrus response was significantly different among the groups (P<0.05). Ovsynch bull-exposed group showed higher estrus response as compared to other groups. In addition to that multiparous animals significantly showed better estrus response as compared to primiparous Thari cattle in all groups (Table I). The onset of estrus was earlier with ovsynch biostimulated group than non-treated non-exposed, and control group. Similarly onset of estrus was lower in than ovsynch bostimulated group (54.89± 1.20) and higher in control group (60 ± 0.00), respectively (Table I). Moreover, onset of estrus differ significantly among bull (exposed and non-exposed) group (P<0.05) and primiparous animals showed earlier onset of estrus as compare to multiparous animals (Table I). The estrus duration did not differ significantly among ovsynch bull exposed and non-exposed the group (P<0.05). While duration of estrus was higher with ovsynch bostimulated group than non-treated non-exposed, and control groups. However, primiparous animals showed longer estrus duration as compare to multiparous animals (Table I). Pregnancy rate significantly differed among the groups (P<0.05). Ovsynch bull-exposed group showed higher pregnancy rate as compare to other treated and control groups (Table I). In addition to that multiparous animals showed significantly higher pregnancy rate as compare to primiparous Thari cattle in all groups (Table I).

ES technique is applied to reduce the problems of silent heat and anestrus probloms in cattle. Hormones like gonadotropin releasing hormone prostaglandin F2α and analogues are being used for ES (Khumran et al., 2012). The ovsynch synchronization protocol is the most popular ES protocol which consists of series of GnRH -PGF2α-GnRH injection treatments since last decade and provides satisfactory fertilization to timed AI (Jabeen et al.,2012).

Table I. The effect of ovsynch protocol with or without biostimulation on estrus response, onset of estrus, estrus duration and on number of pregnancies in Thari cattle.

Different superscripts within the column shows significant difference p<0.05

This protocol is being used in buffaloes with satisfactory pregnancy rates (Chaikhun et al., 2010). Biostimulation or effect of a male via genital stimulation, olfactory pheromones, or other less defined external sign such as tactile, visual and auditory have been used to induce estrus (Chenoweth, 1983). In the current study response of estrus was significant in the cattle with ovsynch and biostimulated group than non-treated non-exposed, and control groups. Roy and Prakash (2009) reported 18% reduction in anestrous rate with synchronization and biostimulation. Estrus response was higher with ovsynch with biotimulation (60%) than ovsynch non-exposed to biostimuation (50%). However, difference was non-significant among groups (P>0.05). These results are in agreement with the findings of Berardinelli et al. (2001). They reported that the response of estrus was more in postpartum cattle exposed to biostimuation during synchronization of estrus than non biostimulated. Ahmed et al. (2011) reported 90% of estrus response in cattle exposed to biostimulation than 65% females without biostimulation. Similarly, Alberio et al. (1987) also reported 67.9% estrus response with biostimulation than 32.7% without biostimulation.

In the current study multiparous animals showed significantly higher estrus response as compared to primiparous Thari Cattle in all groups. All multiparous animals showed significantly better estrus responses as compared to primiparous animals among the groups (P<0.05). Contrary to this, Khanh et al. (2012) observed non-significant difference among the primiparous and multiparous cattle, however, estrus response was higher in multiparous than primiparous animals. Similarly, Ghosh et al. (2012) reported lower estrus response in primiparous (38.9%) than in multiparous (77.7%) cattle. Number of factors could be affecting this outcome such as synchronization protocols may have induced difference in physiological response and played a major role in variation among observations. In the present study ovsynch method of ES were used whereas Khanh et al. (2012) used progesterone supplementation in the form of controlled internal drug releasing device (CIDR) for ES. In this study estrus duration was higher with ovsynch biostimualtion than non-treated without biostimualtion, and control groups. This finding lies in range with Khanh et al. (2012). However, Flores et al. (2006) observed higher duration of estrus (P<0.05) in multiparous than primiparous cattle. The difference observed between present study and above two studies may be due different breeds and environmental condition which induce variation response among synchronization treatments. In the current study the duration of estrus were 23 and 22 h in primiparous and multiparous animals, respectively. This was higher than results by Roelofs et al. (2005). They reported 13.6 and 10.8 h duration of estrus in primiparous and multiparous females, respectively. The difference in results may be due to difference in housing, handling and environmental condition.

In this current study pregnancy rate was significantly higher in ovsynch with biostimualations group 50% as compared to ovsynch without bio-stimualations group (40%). Tauck and Berardinelli (2007) found 59% and 37% fertility rate with biostimulation and without biostimulation in cattle, respectively. These findings support the result of current study. In the present study 50% and 40% pregnancy rate were recorded with biostimulation and without biostimulation. These findings are lower than those reported by Purabi et al. (2011). Ahmed et al. (2011) found 81.82%, 66.7% and 40.0%, 33.7% conception rate with biostimulation and without biostimulation group, respectively. The difference in the results may be due to difference in environment, breed and ES protocol.

In the current study 60% conception rate was observed in multiparous cattle in ovsynch with bio-stimualation and ovsynch without biostimulations, while in primiparious these values were 40% and 20%, respectively with ovsynch with biostimualations and ovsynch without biostimualation. The present results are in line with those of Khanh et al. (2012) who observed higher pregnancy rate in multiparous animals compared to primiparious animals. However, the differences were non-significant. Murugavel et al. (2009) observed 57.6% conception rate in multiparous cattle and 40.6% in primiparous cattle with progesterone based ES protocol.

It can be concluded from the present study that: The estrus response and pregnancy rate was higher in bull exposed (with biostimulation) groups as compare to non-bull exposed (without biostimulation) groups.

The authors have declared no conflict of interest.