Maternal, Postnatal, and Management-Related Factors Involved in Daily Weight Gain and Survivability of Suckling Zaraibi Goat Kids in Egypt.

Abstract

Simple SummaryA pre-weaned Zaraibi goat kid’s body weight gain and survival are complex traits affected by the maternal ability of the doe and the kid’s capability for rapid growth and survival, in addition to the management tactics and environmental variables during the postnatal period. In this study, we investigate the effect of some potential maternal, postnatal, and management-related factors, including sex, litter size, birth weight, daily milk yield, parity, kidding year, and kidding season. The effects of these factors on both the daily body weight (ADG) gain and survivability of Zaraibi (Nubian) kids during the suckling period are studied. The body weight gain for kids was influenced significantly by all the aforementioned factors, except for the kidding season. The framework of the survival analysis revealed that the male kids experienced a greater risk of death compared with the female kids. The single-born kids were at a lower risk of death compared with two or more kids born in a litter. Survival rates increased steadily along with the increase in the mother’s daily milk yield and the dam’s parity number. There was a decrease in the probability of mortality with each passing year. In practice, monitoring traits that indicate an imbalance in milk and that could lower the body weight of the kid could promote the identification of kids with a higher risk of death and the inability to achieve the required body weight gain.During the early period of an animal’s life, rapid growth and higher survival rates can provide more profits to producers by minimizing the rearing and replacement costs. The present study aimed to investigate the effect of some maternal, postnatal, and management-related factors (sex, the litter size [LS], the kid’s birth weight [KBW], the daily milk yield [DMY], and the parity order), as well as the kidding year and season on both the average daily weight gain (ADG) and survivability of suckling Zaraibi goat kids during the postnatal period. A total of 3005 kidding events were available from the herd of Zaraibi goats raised at El-Serw Experimental Station from 2008 to 2014, which belongs to the Animal Production Research Institute. Data revealed that the overall ADG was 131.14 ± 2.34, 94.22 ± 2.21, and 85.63 ± 2.33 g/day, whereas the survival rates were 94.68%, 91.81%, and 90.62% during the periods from birth to 1, 2, and 3 months, respectively. During all periods considered, the aforementioned maternal, postnatal, and management-related factors significantly affected the ADG. In males, the ADG increased compared with females. Singletons had a higher ADG compared with kids born to a litter of two or more. A higher KBW and DMY were associated with an increase in the ADG. Additionally, increasing the parity order was associated with an increased ADG. The kidding season did not have a significant effect on the ADG, whereas the kidding year showed a significant effect on the ADG. During the pre-weaning period, the hazard of death increased by 23.1% (hazard ratio (HR) = 1.231; 95% CI = 0.972–2.057) in males compared with females in terms of survival rates. A higher LS was associated with an increase in the incidence of mortality, increasing by 51.6% (HR = 1.516; 95% CI = 1.363–1.719) with each unit increase in the LS. Additionally, the KBW was an extremely important determinant of survivability, as the risk of death decreased by 62.8% (HR = 0.372; 95% CI = 0.229–0.504) with the increase in the KBW. Likewise, survival rates increased steadily along with an increase in both the DMY and parity number. The risk of death decreased by 52.7% (HR = 0.473; 95% CI = 0.376–0.808) and 38.2% (HR = 0.618; 95% CI = 0.512–1.724) with the increase in the DMY and parity number, respectively. The kidding season did not significantly affect the kid’s survivability, but with each passing year, there was a decrease of 2.8% (HR = 0.972; 95% CI = 0.952–0.991) in the probability of mortality. In conclusion, better growth and survival rates can be achieved by controlling the maternal, postnatal, and management-related factors, as well as upgrading management plans.