Impact of short nutrient stimuli with different energy source on follicle dynamics and quality of oocyte from hormonally stimulated goats

Abstract

The aim of this study was to verify the effect of the energy source for a short-term diet supplementation on follicular dynamics, ovarian response and oocyte recovery in goats. Thirty Anglo Nubian crossbred does received a diet for 4 weeks to satisfy the nutritional requirements of breeding for adult non-dairy goats. Seven days prior to oocyte recovery (OR), a group of does (n = 10) was supplemented with ground full-fat linseed in the diet (Diet A), whereas a second group of does (n = 10) received crude glycerine in the diet (Diet B). The total mixed ration (TMR) diet was maintained as the Control Diet (n = 10). All animals were oestrous-synchronized by the use of a progesterone insert for 12 days prior to OR. Follicles were stimulated by using pFSH (five 40-mg/ml doses) during the supplementation time. At OR, follicles were counted and recovered oocytes were classified as viable or degenerated. Follicular dynamics was monitored by ultrasonography, and plasma glucose, cholesterol and triglyceride levels were measured during supplementation. Glucose was higher in Diet B and cholesterol in Diet A. Diet B had a lower proportion of small (<3 mm) and large follicles (≥3 mm; p = 0.01). The follicular growth rate was higher in Diet A (p < 0.01), with follicles emerging in the 5th day of supplementation. No differences were observed for follicles counted and oocytes recovered. Thus, the type of energy source supplemented for a short term was capable to alter the follicular dynamics, without affecting the proportion of morphologically viable oocytes upon recovery.

Keywords: follicular dynamics; goats; nutritional balance; oocyte quality.