The effect of salt-free - salt diet on the reproductive performance of Ile de France ewes

Abstract

The aim of the present study was to establish the effect of salt-free - salt diet (SFSD) on the size of antral follicles during salt consumption, the duration of controlled breeding campaign and the ferti¬lities of ewes from the Ile de France breed. Тhe experiment was carried out with 57 ewes, which were divided into 3 groups (19 ewes in each) depending on whether they were subjected to SFSD and their contacts with rams during the first 8 days of the beginning of breeding: Group I – SFSD + ram con-tact; Group II – only SFSD; Group III – no SFSD, only ram contacts. The first day of the salt diet coincided with the first day of ram contacts. Transrectal ultrasound examinations of the ovaries were done on days 1, 2, 3, 5, 6 and 7. The time of manifestation of estrus (in days), pregnancy rate and fecundity were studied. A significant effect of time (P<0.05) and diet (P<0.01) on the size of follicles was established. The onset of the first estrus, the shortest terms of breeding campaign, the fertility and the fecundity results gave us reason to favour the scheme applied to Group II. A stimulatory effect of the diet in that study was demonstrated, but the pattern was different from our previous studies.

Keywords

• estrus
• ewes
• fertility
• follicles
• salt