Review: Effect of Protein Nutrition on Ovarian and Uterine Physiology in Dairy Cattle

• Published in: Journal of dairy science 1998-09, Vol.81 (9), p.2533-2539
• Main Author: Butler, W.R.
• Format: Article
• Language: English
• Subjects: AMMONIA; AMMONIAC; AMONIACO; Animal Nutritional Physiological Phenomena; Animals; BLOOD PLASMA; Cattle - physiology; CONCEPTION RATE; CONTENIDO DE MATERIA SECA; DAIRY COWS; DIET; DIETA; Dietary Proteins - administration & dosage; DRY MATTER CONTENT; Embryonic and Fetal Development; FEED INTAKE; Female; INGESTION DE PIENSOS; MILK YIELD; Ovary - physiology; PERFORMANCE DE REPRODUCTION; PLASMA SANGUIN; PLASMA SANGUINEO; POSTPARTUM INTERVAL; Pregnancy; PRISE ALIMENTAIRE (ANIMAUX); PROGESTERONA; PROGESTERONE; Progesterone - blood; protein; PROTEINAS; PROTEINE; PROTEINS; Proteins - metabolism; PUERPERIO; PUERPERIUM; REGIME ALIMENTAIRE; RENDEMENT LAITIER; RENDIMIENTO LECHERO; REPRODUCTIVE PERFORMANCE; REPRODUCTIVIDAD; TENEUR EN MATIERE SECHE; UREA; UREE; UTERO; UTERUS; Uterus - physiology; VACAS LECHERAS; VACHE LAITIERE
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.S0022-0302(98)70146-8

Milk production and dry matter intake of dairy cows are stimulated in response to increased intake of dietary protein, but, unfortunately, decreased fertility is often associated with this nutritional strategy. Ruminally degradable protein or ruminally undegradable protein in excess of requirement can contribute to reduced fertility in lactating cows. Dietary protein nutrition or utilization and the associated effects on ovarian or uterine physiology have been monitored with urea nitrogen in plasma or milk; concentrations above 19 mg/dl have been associated with altered uterine pH and reduced fertility in dairy cows. The uterine pH changed dynamically and inversely with plasma urea nitrogen, signaling possible changes in the uterine milieu. Mechanisms for reduced fertility include exacerbation of negative energy balance and reduced plasma progesterone concentrations when cows were fed rations that were high in ruminally degradable intake protein. Alternatively, changes in uterine secretions that are associated with high protein intake and elevated plasma urea nitrogen might be detrimental to embryos. Bovine endometrial cells in culture respond directly to increasing urea concentrations with alteration in pH gradient but respond most notably with increased secretion of prostaglandin F2α (PGF2α). Increased uterine luminal PGF2α interferes with embryo development and survival in cows, thus providing a plausible link between elevated plasma urea nitrogen concentrations and decreased fertility. Poor fertility in high producing dairy cows reflects the combined effects of a uterine environment that is dependent on progesterone and rendered suboptimum by the antecedent effects of negative energy balance or postpartum health problems and that is further compromised by the effects of urea resulting from intake of high dietary protein.