Effect of Superovulation Prior to Mating on Milk Production Performance During Lactation in Ewes

Abstract

Thirty lactating ewes were used to evaluate the effect of superovulation on milk production. Twelve ewes had been injected, prior to mating, with 700 IU of pregnant mare serum gonadotropin; 18 ewes were injected with saline as a control. Thirteen ewes (nine control and four superovulated ewes) were fed at low plane of nutrition; the other ewes (nine control and eight superovulated ewes) were fed at high plane of nutrition. Superovulated ewes, fed at both low and high planes of nutrition, had dramatically higher milk yields (59%), and their milk composition was not changed. Plane of nutrition increased milk lactose and P contents without significant effect on milk production. The increased milk yields in the superovulated ewes were accompanied by increases in dry matter, gross energy intakes, and gross efficiency of milk synthesis. At the end of lactation, superovulated ewes had higher mammary dry fat-free tissue, total DNA, and total RNA. The results demonstrated that superovulation prior to mating dramatically increased milk production and efficiency regardless of plane of nutrition. Increased milk production and efficiency in the superovulated ewes were due to the increased mammary secretory cell numbers and their synthetic activities presumably through the increased endogenous hormonal stimulation of mammary growth and development during pregnancy.

Progesterone administration reduces the behavioural and physiological responses of ewes to abrupt weaning of lambs

“…This confirms and expands results from a study by Smith and Inskeep (1970), who reported that treatment with progestagens (medroxiprogesterone and flurogestone acetate) had no effect on ewes' milk production. The few published studies relating P4 to ewes' milk production were carried out in superovulated ewes (Manalu et al, 2000), or under supraphysiological P4 concentrations provoked by treating ewes that had a corpus luteum with exogenous P4 (McKusick et al, 2002). In our experiment, all ewes were non-cyclic and the P4 concentrations provoked by our treatment were similar to those observed in a normal luteal phase.…”

Non-nutritional factors affecting lactation persistency in dairy ewes: a review

“…This is because superovulation prior to mating increases corpora lutea number and mean serum progesterone concentration during pregnancy (Manalu et al, 1998). Analysis of the mammary glands at the end of lactation showed that superovulated ewes had 79% higher total DNA and 56% higher total RNA than non-superovulated ewes (Manalu et al, 2000), indicating a higher number of secretory cells and higher synthetic activity per cell.…”

“…(Butler et al, 1981;Schoknecht et al, 1991). Higher average serum progesterone levels during pregnancy are related to well developed mammary glands at parturition, which show a high number of mammary cells and increased synthetic activity (Manalu et al, 1998(Manalu et al, , 2000. In addition, since the mammary glands are suckled more frequently by twins than by singles, the local inhibitors of milk secretion, such as the FIL, are removed.…”

Sonometri fetus kambing kacang usia 7 minggu hasil superovulasi menggunakan hormon PMSG

“…Induk kambing yang disuperovulasi memiliki produksi susu lebih optimum sehingga dapat menunjang kehidupan anaknya (Manalu et al 2000). Anak yang dihasilkan dari induk yang disuperovulasi juga memiliki bobot lahir yang lebih besar, tingkat kematian yang lebih rendah, dan bobot sapih yang lebih besar (Manalu dan Sumaryadi 1998).…”

“…Salah satu manfaat lain superovulasi adalah efek stimulasi ovarium berupa peningkatan sekresi endogen hormon kebuntingan. Superovulasi pada Kambing Kacang memberikan pengaruh berupa peningkatan jumlah dan ukuran folikel dominan serta korpus luteum yang terbentuk yang pada akhirnya meningkatkan konsentrasi serum progesteron dan esterogen induk (Andriyanto et al 2017).Induk kambing yang disuperovulasi memiliki produksi susu lebih optimum sehingga dapat menunjang kehidupan anaknya (Manalu et al 2000). Anak yang dihasilkan dari induk yang disuperovulasi juga memiliki bobot lahir yang lebih besar, tingkat kematian yang lebih rendah, dan bobot sapih yang lebih besar (Manalu dan Sumaryadi 1998).…”