Relationship of some metabolic Hormones with Increased Live Body Weight of Male and Female of Karakul and Awassi Lambs

Abstract

This study was conducted in the animal field of the Al-Kafeel Company from November 2019 till May 2020 to investigate the possible association between growth hormone (GH) and thyroxine (T4) with the growth traits in Awassi and Karakul sheep. The total number of animals which used in the study was 60 lambs, 28 (13 males and 15 females) from Karakul and 32 (18 males and 14 females) from Awassi. Blood samples were collected at birth, weaning, and six months of age, and both GH and T4 concentrations were measured. Results showed higher values of T4 for Karakul as compared with Awassi at birth and weaning. Karakul breed was also exhibited significantly higher values of GH over Awassi breed only at weaning, while, no significant differences were observed at birth and six months of age. Karakul lambs showed higher weights as compared with Awassi lambs at all studied periods. A highly significant (p < 0.01) positive correlation was observed between T4 concentration and the weight of lambs at most studied periods. Whereas, GH did not exhibit any correlation with growth traits measured in both breeds. The elevated T4 might be one of the reasons for superiority of Karakul over Awassi breed in live body weights. This high correlation between T4 and growth traits could be used in the early selection of lambs to improve the weights of sheep at marketing.

Seasonal variation of thyroxine concentration in Karagouniko and Chios rams in temperate environmental conditions

“…This hypothesis is strengthened because PHOTO remained practically unchanged for the two experimental periods (in average terms), combined with the statistically different values of AIRT and SUNS between these periods. Also, the negligible fluctuations of the body weight of the experimental rams (Matsoukis et al 2022b) support the hypothesis mentioned above, bearing in mind that a positive relation has been reported between thyroxine concentration and body weight in sheep (Hashem 2014;Veena et al 2018;Aljubouri et al 2021). The thyroxine pattern concerning the direction of day length change in our experiment is in agreement with the results of other researchers for Karagouniko ewes (Kantas et al 2008a;Menegatos et al 1994), Chios ewes (Kantas et al 2008b) as well as Karagouniko × Mytilene ewes (Menegatos et al 2006).…”

Effect of Breed and some Non-Genetic Factors on Productive Performance in Two Sheep Breeds

“…(58.06, 61.76, and 62.39 cm) for male lambs compared to female lambs (56.75, 60.68, and 61.38 cm), respectively, and highly significant (P<0.01) at six months of age for male lambs compared to female lambs in all body measurements for both breeds. The results of the current study agree with [12], in the Egyptian Chios and Rahmani sheep, [13], in Awassi sheep in Turkey and [14], in the Iraqi Karadi breed as well as [15], in the Iranian Zandi sheep breed, and [16], in Karakul sheep breed in Turkey and [17], also for Iranian Baluchi breed and [18], in Corriedale sheep and Iraqi Hamdani sheep [19], as they indicated the presence of a significant effect of lambs sex on body weights from birth to six months of age, weight increases and most of the body measurements. Whereas, no significant effect of lamb sex on living weights.…”

“…In addition, the number of cotyledons increases with the age of the dam, and this increase leads to an increase in the size of the placenta and thus an increase in the surface area The nutritional exchange between the dam and the fetus, which is reflected positively on the weight of the lambs, or this may be attributed to the fact that young ewes generally produce less milk to feed the lambs [32][33][34]. The results of the current study differed with [12], on the Egyptian Chios and Rahmani sheep, as there was no effect of dams on the weights of the lambs and their weight increases, and with, [13,35], in their study on sheep Turkish Karman and Awassi, in addition, [16] in Karakul sheep.…”