Forced Mating an Efficient Tool in Camel Production to Reduce the Age at Puberty and Calving Interval in Dromedary She-Camel (Camelus dromedarius)

Camel rearing is confronted with low numerical productivity due to its specific physiology of reproduction. First, a seasonal breeder, the reproduction cycle of camel is constrained by this limited time when the animals are available for mating. Indeed, the male is rutting only during the breeding season (4-5 months/year) and the female is ovulating only in case of mating (Tibary and Anouassi, 1997). In addition to such restricted breeding season, longer gestation period (up to 13 months), delayed age at puberty (up to 5 years) and longer calving interval (2 years on average) are the natural constraints in reproduction of camels. Some pastoral camel herders of Pakistan and Africa use forced mating as a tool to get pregnant she-camels whenever a rutting bull is available to them. Camel herders believe that when forced mating is practiced then either she-camel will conceive or comes in heat after few days or within week. So, it could be used as reproductive management tool to shorten the age at puberty and calving interval in the seasonal breeder camels. Hence, the current study was conducted to observe the effects of forced mating in the female young stock and parturient females.

The present study was conducted at Camel Breeding and Research Station (CBRS) Rakh Mahni. The area of this farm lies in the deserted plain of Thal. The location of this farm is in Thal area between 31° 10’ and 32° 22’ North Latitude and 70° 47’ and 72° East Longitude. The sandy desert area included in the Agro-Ecological Zone-III A and B has slight strips of sand points and sand dunes (Figure 1). Arid to semi-arid subtropical continental climatic conditions and the mean value of monthly highest temperature is up to 45.6 ºC, while during the winter season, it ranges from 5.5 to 1.3 ºC. The mean value of annual rainfall in that area is from 150-350 mm, which may increase from South to North (Rahim et al., 2011). The CBRS is camel farm made in 2005 keeping in view the camel’s production and breeding. For this purpose the Marecha camel from Cholistan desert was imported to the farm, almost more than hundred in strength. The livestock present there consume mostly tree browsing, shrubs and herbs grazing.

Marecha camel breed has been used for the current study and those are reared for reproductive and dairy production purposes (Figure 2). Available rutting bull forced three female young stock (FYS) and ten parturient females, one month after parturition for mating. The animals were kept in semi-open sheds during the whole trial period. The animals were sent in the field for 8 hours from 08:00AM to 16:00PM for grazing/browsing (Figure 3). After that the animals were manger fed with concentrate approximately 3 kg per day along with 3 kg missa bhoosa (Gram crop residues + Guar crop residues). Lucerne fodder was provided as cut and carry system approximately 20 kg/h/day. Crude Protein (CP), Total Digestible Nutrient (TDN), Dry Matter (DM), Neutral Detergent Fiber (NDF), and Acid Detergent Fiber (ADF) of concentrate were 18, 66, 90.32, 29, 14.41 % respectively while Metabolic Energy (ME) noted was 2.41 Mcal/kg DM. Twice watering was provided. The animals were sprayed with Ecofleece solution for reducing the parasitic load. All the females were got conceived and delivered the calves next year successfully. The normal parameters of camels at CBRS (Camel Breeding and Research Station) Rakh Mahni are presented in Table 1. Figure 4 shows the research area visiting during study period (at CBRS Rakh Mahni).

Table 1: Normal parameters of camels at CBRS Rakh Mahni.

The age at puberty in FYS has been reduced to less than four years, age at first service is reduced to 38, 36.5 and 36 months in three FYS which resulted in reduction of age at first calving up to 1527, 1494 and 1478 days (Table 1) as compared to the normal age at first service in Marecha she-camel which is 4.5-5 years (1643-1825 days) (Faraz, 2016). While the parturient females delivered the calf in next year so considerably decrease the calving interval which is reduced up to 698, 690, 688, 624, 458, 440, 418, 406, 390 and 372 days in all ten she-camels, respectively (Table 2) as compared to the normal calving interval in Marecha she-camel which is 2-2.5 years (730-913 days) (Faraz, 2016; Faraz et al., 2019a, b). The observations of forced mating in ten parturient she-camels resulted in less calving interval at CBRS Rakh Mahni are shown in Table 3.

Table 2: Forced mating in three FYS resulted in less age at puberty at CBRS Rakh Mahni.

*FYS (Female young Stock).

Table 3: Forced mating in ten parturient she-camels resulted in less calving interval at CBRS Rakh Mahni.

¶She-Camel (Female Camel).

In the male, puberty appears when rut occurs. According to the study conducted by Yagil (1982), adequate food is available, particularly during cooler and wetter seasons, the rut is confined and when the calf is born. Rutting is partially affected by the level of nutrition and age of animal as reported by Yagil and Etzion (1980), Mukasa-Mugerwa (1981), Bedrak et al. (1983), and Deen (2008) but the main mechanism is linked to environmental and neuroendocrine control (Ainani et al., 2018). The age of puberty in male can be improved by the feeding system. Improving in the content of crude protein and energy in the diet, it is possible to increase the testicle size (Al-Saiady et al., 2013) and consequently to accelerate the maturity of reproduction organs especially since the richness of the diet could also modify the hormonal profile accelerating the puberty reported by Al-Saiady et al. (2015).

In female animals, the age at puberty could be also influenced by the diet by improving the blood estrogen level (Al-Saiady et al., 2012). Globally, a diet with balanced protein and energy improves the mating rate at an early age of the sexual activity or after parturition contributing to reduce calving interval (Hammadi et al., 1997).

The female animals remain fertile at the age of 25 years and they can produce 8-10 calves or maybe even more than during this period in the traditional management system. Breeding females reaching this proportion is in a small fraction of while most of stock gives around 6-7 calves (Schwartz and Walsh, 1992). The calving interval is long in the she-camels, e.g., 23-24 months in Somali camels as reported by Keskes et al. (2013b) and Ahmed et al. (2005), 24-25 months in Babile/Gursum (Sisay et al., 2015), 31 months in Afar reported by Keskes et al. (2013a), 25-26 months in Borana, Oromia (Megersa et al., 2008), 28-29 months in Somali, Rendile and Gabra camels of North Kenya (Kaufman, 2005).

Length of calving interval in dromedary camels could be extended due to different factors such as (i) limitation of the breeding season (ii) prolonged gestation period (iii) postpartum estrus may be late (1 year after parturition normally) (Mukasa-Mugerwa, 1981). Calving intervals were significantly prolonged as in the studies of Megersa et al. (2008) and the reason recorded was mating avoided intentionally camel herder because it had a negative effect on lactation length, milk yield, and calf survival rate. Indeed, pregnancy contributes to the shortening of lactation.

Lactation length was shorter as its mean value was 230 days and mean value of total lactation production was decreased by 1,532 liters in camel conceiving at 284 ± 21.5 days postpartum compared with non-pregnant camels (Nagy et al., 2015).

To decrease the calving interval, a first practice was the early separation. The separation of the young camel few days after birth, allows a rapid return of estrus and possibility of mating. Indeed, milking is the main mechanism to delay the return to estrus. In trials achieved in Tunisia, the mean calving interval decreased from 714 ±31 to 403 ± 8 days (Moslah, 1993). Associated to artificial milking for the young baby camel (Khorchani et al., 1991), a significant improvement of numerical productivity can be observed. In optimal conditions obtained in experimental station, it was possible to get 5 calving over 5 years, i.e., a numerical productivity comparable to that of bovine. In addition, such protocol could be completed by hormonal induction to overpass the natural seasonal reproductive physiology of camel. Even applied to females having missed the mating at the breeding season or after abortion, such hormonal treatment (PMSG + progesterone) could allow reducing calving interval by 3-4 months (Khorchani et al., 1997).

Mean values of calving interval and age at first calving were 2.82 and 5.17 years respectively among pastoral camel herds reported by Kalla et al. (2008) at the Komodugu-Yobe River basin in northeastern Nigeria. The age at first calving was reduced due to different veterinary services and the role of health care was shown its results as increasing sexual maturity and subsequent productivity (Megersa et al., 2008). Mukasa-Mugerwa (1981) reported that insufficient body weight was resulted due to a low plane of nutrition and it could be a possible cause of delaying in the age at first calving in camels. Megersa et al. (2008) reported the performance of camels in which two females were pregnant about a month post-calving due to accidental mating Borana, southern Ethiopia. Hammadi et al. (2001) studied the sexual activity return one month after calving in dromedary and reported that the first heat was 29.5 days from average postpartum intervals in traditionally managed camels. The results are in line as reported by Abdussamad et al. (2011) in dromedary camels of Nigeria. Williamson and Payne (1999) reported that postpartum estrus is delayed for about one year normally because a few females return to heat during one month after parturition.

In the female camel, lactation length differs from one region to other which ranges 8-24 months (Tibary and Anouassi, 2000). The lactation period depends on the climate, parturition, and feeding conditions (Eberlein 2007). However, the lactation period may last up to two years; the calf of the camel is usually weaned too earlier, during 3 and 18 months at any time because, under traditional pastoral systems, the average is 12 months (Mukasa-Mugerwa, 1981).

As seasonal breeder; camel is considered having longer calving interval and higher age at first mating. Forced mating in current experiment provided fruitful results. All the thirteen she-camels were successfully conceived and delivered the calves. Hence, this practice could be used as an indirect tool for reproductive management in camels. However, as there is low compatibility between dairy production and numerical productivity, the reduction of calving interval is only interesting in case of meat production. This study is the beginning and will be pioneer for this area of research, definitely further investigations should be done in this regard as relatively few information is available in literature data about this topic. The application for these procedures should be studied and discussed for future vogue in camel pastoral systems as well as in intensive farming.

The help extended by Camel Breeding and Research Station Rakh Mahni is gratefully acknowledged.

The authors have declared no conflict of interest.