Effect of a Calcium Soap of Fatty Acids on Reproductive Characteristics and Lactation Performance of Fat-Tailed Sheep

Abstract

Experiments were carried out to study the effect of feeding Megalac, calcium soaps of fatty acids (protected fat), on reproduction and lactation of sheep. In the first experiment, 20 Ghezel and 20 Mehraban cyclic fertile ewes (4-5 years old) were randomly allotted to 4 groups. The control group was fed with a balanced ration and the other groups received the same diet as well as a daily allowance of 40 g non-protected fat (NP), 40 g protected fat (LP), or 80 g (HP) protected fat. The ewes were fed with their respective rations for one cycle length. Blood samples were collected and analyzed for progesterone (P4), cholesterol (CHOL), High Density Lipoproteins (HDL), Low Density Lipoproteins (LDL) and triacylglycerols (TG). The ewes were slaughtered on their next estrous period and the size and number of follicles in ovaries were recorded. There were no significant effects of feeding fat on ovarian weights, cycle length and follicular numbers in each class, or on the size of the largest follicle. Serum concentrations of P4, CHOL, TG and HDL were greater for HP ewes as compared with the control ewes (p<0.05). In the second experiment, effects on lactation and lamb performance of feeding protected fat during mating, late gestation and early lactation were studied in Mehraban ewes. Milk and fat yields on day 25 of lactation were significantly increased by feeding protected fat. Protected fat resulted in lower weight loss in ewes and a higher lamb birth weight. Average daily weight gain of lambs from birth to day 60 and the weaning weight of lambs were increased by feeding protected fat (p<0.05). In conclusion, calcium soaps of fatty acids increased serum P4 between days 10 to 14 of the cycle which may be beneficial to early pregnancy maintenance. Protected fat seemed to have a beneficial effect on milk yield, fat yield, lamb daily gain, lamb birth weight and ewe weight loss.

Effect of Calcium Soap of Fatty Acids Supplementation on Serum Biochemical Parameters and Ovarian Activity during Out-of-the-Breeding Season in Crossbred Ewes

“…While the ultrasonographic examination of the ovaries of control ewes showed presence of smooth small ovaries in four ewes (66%) and presence of small follicles in two ewes (34%), the obtained results are similar with that obtained of Ghoreishi et al [9]; El-Shahat and Abo-El Maaty [30] and Liel et al [8]. A positive effect of CSFA on ovarian activity of Barki ewes as indicated by increasing the number of medium and large sized follicles on day zero of the second estrus cycle, and by increasing the number and size of corpora lutea 7 days later in the same cycle was recorded by Liel et al [8].…”

“…Elevation of triglycerides levels in CSFA-treated ewes was reported by Ghoreishi et al [9] and Liel et al [8]. This increase might be due to the depression in lipogenic enzyme activity by the liver and adipose tissues associated with feeding supplementary fat [27] or may be due to production of lipoproteins in the intestine by fat [28].…”

“…This increment might be due to increased availability of cholesterol which would provide increased sterol precursors for progesterone biosynthesis by the corpus lutea [37]. This reflects the beneficial effect of dietary treatment of protected fat on the ovulation and corpus lutea formation and also to early pregnancy maintenance [9]. Moreover, the increase in serum concentration of lipids was associated with an increase in the intracellular lipid droplets within the small and large steroidogenic cell types that constitute the bovine corpus luteum and provide an increased precursor for P4 biosynthesis [38].…”

“…Calcium soaps of fatty acids supplementation increase the number and size of ovarian follicles in estrous cyclic ewes and increase the circulating progesterone concentration [8]. In ewes fed supplemental fat, there are reports of increased plasma concentrations of cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and progesterone [9, 10]. The first author recorded that increased consumption of fats by cows resulted in increases in the number of ovarian follicles, increase in the number and size of corpora lutea, stimulation of postpartum ovarian activity, and improved pregnancy rate in goats [11, 12].…”

Aminoácidos protegidos em ração para borregas mestiças

“…Como os níveis das lipoproteínas mantiveram-se baixos as relações LDL HDL -1 e CT HTL -1 também apresentaram o mesmo padrão de resposta (Tabela 7). ); MG -Média geral; CV -Coeficiente de variação; VR -Valor de referência segundo Kaneko et al, (2008); ** Valor de referência segundo Ghoreishi, et al, (2007).…”