Postweaning nutritional programming of ovarian development in beef heifers

Area of Science:

• Reproductive biology
• Animal science
• Endocrinology

Background:

• Peripubertal caloric restriction can increase primordial follicle numbers, potentially improving reproductive potential.
• The mechanisms involve hormonal regulation, possibly through leptin or anti-Müllerian hormone (AMH).

Purpose of the Study:

• To investigate the effect of a stair-step compensatory growth diet on ovarian reserve in heifers.
• To determine if feed restriction influences follicle development via leptin and AMH pathways.

Main Methods:

• Heifers were subjected to a control diet or a stair-step feed restriction and refeeding regimen.
• Ovarian tissue was collected at 8, 11, and 13 months of age for histological analysis and gene expression.
• Plasma leptin concentrations and ovarian mRNA abundance for specific genes were measured.

Main Results:

• Stair-step heifers had significantly more primordial follicles at 13 months of age compared to controls.
• Plasma leptin was lower in stair-step heifers at 11 months.
• Ovarian mRNA abundance showed distinct patterns between treatment groups and ages, with higher levels in stair-step heifers at 11 months.

Conclusions:

• A stair-step compensatory growth strategy in developing heifers enhances ovarian reserve before breeding.
• This dietary approach may positively impact long-term reproductive lifespan in cattle.