The effect of non-genetic factors on the early body weights of Tunisian local goats

Abstract

-It was evaluated in this study the environmental effects on body weights of goat kids from birth to 150 days of age of Tunisian local goat population, on the basis of 1,656 records obtained from the Arid Areas Institute of Médenine, Tunisia, during 2001-2005. Except for birth weight, individual records were adjusted for standard ages (30, 60, 90, 120 and 150 days) using either extrapolation or interpolation on field data. Data were analyzed by GLM procedure and SNK (α = 0.05) means comparison test. The kidding year (2001)(2002)(2003)(2004)(2005), kidding month (December, January, February, and March), birth type (single and twins), sex (male and female), coat colour of kid and age of dam (2-10 years) were definied as non-genetic factors. Results showed that mean values and standard deviation (SD) of body weight at birth (0), 30, 60, 90, 120 and 150 days of age were 2.57 ± 0.52 kg, 4.06 ± 1.16 kg, 6.99 ± 1.87 kg, 8.90 ± 2.46 kg, 11.48 ± 3.35 kg and 13.53 ± 4.80 kg for male and 2.29 ± 0.44 kg, 4.76 ± 1.13 kg, 3.09 ± 1.33 kg, 8.08 ± 2.02 kg, 10.24 ± 2.36 kg and 12.15 ± 6.54 kg for female. The kidding year, birth type and sex had effect on body weights of Tunisian local kids at all ages. The single and male was always heavier than the twins and the females. The birth month had effect on all body weights except for weight at 30 days of age. The age of dam had effect on body weights from 60 to 150 days of age. However, the coat color had no significant effect on all body weights. Environmental effects estimated in this study are important and need to be taken into account for Tunisian local goat management and breeding improvement under harsh conditions.

Early growth and survival rates of crossbred lambs (Dorper x indigenous) under semi-intensive management at Areka, Southern Ethiopia: Effects of non-genetic factors

“…Hormonal differences between sexes and their resultant effects on growth may also be implicated. The difference in sex hormones, sexual dimorphism, affects feed intake, growth rate and feed efficiency (Mabrouk et al, 2010). In our study the general trend of sex variation was evident at later ages of lambs, which agrees with the findings of Hassen et al (2002) who reported the importance of sex as lambs get older in the cool highlands of Ethiopia.…”

Early Growth of Adilo Kids under Smallholder Management Systems, Southern Ethiopia: Influences of non-Genetic Factors

“…These results agree with the previous reports (Annor et al, 2012;Baneh et al, 2012;Bedhane et al, 2013) while others reported the significant effect of sex on birth weight (Mabrouk et al, 2010) and subsequent body weights (Dadi et al, 2008). The superiority of males over females may be explained by the precocity, the sexual dimorphism in favour of body growth in males than females (Mabrouk et al, 2010).…”

“…This may also be explained when kids stop suckling, weaning shock might contribute for further slow growth. Similar finding has been reported by Mabrouk et al (2010) who found stagnant growth of kids in heavy rain season at age of 120 or 150 days. In contrast, Annor et al (2012) reported higher body weights and faster gain of kids born during heavy and light rain seasons.…”

“…Similar to our findings, Zahraddeen et al (2008) reported that winter kids had heavier birth weight than spring or summer births. Hailu et al (2004), Dadi et al (2008) and Mabrouk et al (2010) also shown that kids born during dry season had higher pre-weaning growth performance than wet season. The superiority of birth weight in dry season is attributed to free feed selection and feeding upon quality feeds and less tethering pressure.…”

“…Indigenous goats are resistant to diseases and parasites, tolerant to adverse climatic conditions, have endurance to sustain droughts and low and fluctuating nutrient availability. However, extreme climatic stresses and poor quality feeds limit the potential expression of genetic merits in goat flock (Mabrouk et al, 2010;Baneh et al, 2012). Knowledge of non-genetic factors on production traits allows a more accurate assessment of breeding values (Dadi et al, 2008).…”