A higher proportion of female lambs in Kurdish × Romanov ewes fed a diet rich in n-۳ fatty acids and rumen undegradable protein around mating

An increased intake of rumen undegradable protein (RUP) or n-۳ fatty acids (FA) around mating is connected with improved reproductive efficiency in ewes. This experiment was aimed to study whether the ratio of female lambs was greater when Kurdish × Romanov ewes were received a diet rich in n-۳ FA and RUP together around mating. Experimental diets were supplemented with ۵% (DM basis) Ca salts of saturated FA (SFA), ۵% Ca salts of fish oil (as n-۳ FA source; n-۳FO), or a combination of ۵% Ca salts of fish oil and ۵% fish meal (as a RUP source; n-۳FO+RUP). The results showed that the proportion of total n-۳ polyunsaturated FA (PUFA) in plasma increased and the n-۶:n-۳ decreased at CIDR removal day in animals received the n-۳FO+RUP diet (P < ۰.۰۵) compared with the other diets. Plasma concentrations of oestradiol, glucose, and urea nitrogen (UN) at the day of oestrus (P < ۰.۰۵) was also lower when ewes received the n-۳FO+RUP diet compared with the other diets. The ratio of female lambs was greater when ewes were fed the n-۳FO+RUP diet around mating (P < ۰.۰۵) and was greater than an expected ۵۰:۵۰ ratio (۷۲% females, P = ۰.۰۲۸). It was concluded that feeding ewes a diet rich in n-۳ FA and RUP content around mating, rather than n-۳ FA alone, could skew the sex ratio of lambs toward females.

کلیدواژه ها:

Fetal programming ، Lamb sex ratio ، Omega fatty acid ، Rumen undegradable protein