NUTRITIONAL MANAGEMENT

Nutritional management plays a crucial role in preventing and managing delayed ovulation in cattle, particularly during the transition period and early lactation when the animal’s metabolic state is most vulnerable [176]. Inadequate nutrition directly affects ovarian function, follicle growth, and reproductive hormone secretion [177]. Therefore, controlling BCS and meeting micromineral requirements are key strategies to support timely ovulation [47].

Maintaining an optimal BCS is an important indicator of energy balance and metabolic reserves in cows [178]. Cows with a low BCS (≤2.5) in early lactation are at higher risk of prolonged NEB, which decreases IGF-1 and insulin production and reduces ovarian sensitivity to LH, delaying dominant follicle maturation and increasing the risk of persistent follicle formation [179, 180]. Conversely, a high BCS (≥4.0) may cause excessive lipomobilization, fatty liver, and metabolic disorders that disrupt endocrine function [181]. Therefore, targeting a BCS of 3.0–3.5 during the dry period and early lactation is recommended to optimize ovulation and reproductive success [182].

Practical feeding strategies include formulating transition diets that provide controlled energy intake: net energy for lactation of 1.30–1.34 Mcal/kg dry matter during the close-up period, increasing to 1.55–1.65 Mcal/kg dry matter in early lactation, with balanced crude protein levels (14–16%) and an appropriate forage-to-concentrate ratio [183]. Gradual ration adaptation and adequate fiber content help stabilize rumen function and minimize metabolic stress, supporting endocrine recovery postpartum [184].

In addition to energy management, micromineral supplementation is critical, particularly selenium, zinc, copper, manganese, and vitamin E, which support steroidogenesis, antioxidant defense, and follicular development [185]. Organic or chelated mineral sources are preferred due to higher bioavailability and reduced antagonistic interactions. Ensuring adequate mineral status improves ovarian responsiveness to gonadotropins and contributes to more consistent ovulatory outcomes, especially under transition period stress [186].