Anoestrus in Dairy Cows: Causes, Prevalence and Clinical Forms

Abstract

Contents This article reviews some of the recent advances in veterinary research regarding the causes, prevalence and clinical forms of pathological anoestrus in dairy cows. It is one of the few components responsible for occurrence of postpartum infertility in cattle, expressed in four clinical forms: silent heat, cystic ovarian disease, ovarian afunction and corpus luteum pseudograviditatis. The prevalence of these four forms in different herds is dependent on the managerial, environmental and nutritional status of the farm. Anything, regardless of its nature, that impedes the physiological mechanism involved in oestrus expression is liable to cause anoestrus. Nutrition (energy deficiency), interacted with other factors, is the major cause of this phenomenon (anoestrus). It has direct control of the postpartum anoestrus by negatively affecting the endocrine pathways responsible for proper functioning of the reproductive system through the blockage of pulsatile release of gonadotropin‐releasing hormone in the hypothalamus. Lack of proper training by the stockman substantially contributes to silent heat occurrence. Numerous attempts have been made to prevent or treat pathological anoestrus with exogenous hormones, or nonhormonal remedies like uterine palpation and infusion of Lugol's solution, all of which have produced variable but positive results. Specific treatment for each one of the four clinical forms is briefly outlined.

Plasma oxidative stress biomarkers and progesterone profiles in a dairy cow diagnosed with an ovarian follicular cyst

“…The clinical signs of anoestrus and the presence of an enlarged persistent follicular structure in cow 1258 were consistent with the diagnosis of a follicular cyst (Mwaanga & Janowski 2000). Low progesterone concentration (<1 ng/ml) in plasma has also been reported as one of the characteristics of follicular cysts (Mwaanga & Janowski 2000).…”

“…Low progesterone concentration (<1 ng/ml) in plasma has also been reported as one of the characteristics of follicular cysts (Mwaanga & Janowski 2000). The low progesterone concentration may be the direct result of an absence of any luteal tissue being present in the ovaries of cows with cystic ovarian disease.…”

Risk factors for postpartum anestrus in crossbred cows in Bangladesh

“…It was worse in farms when an employee managed them than those managed by farmers themselves in the present study. The high rate of anestrus cases is a result of the stockman's failure to properly observe and record animals in estrus, which substantially contributes to subestrus occurrence (12). The maintenance of a good level of knowledge of both primary and secondary estrus symptoms and the observations of cows at the appropriate time of day is critical for farm staff (19).…”

Effect of season on luteal activity during the post partum period of dairy cows in temperate areas

“…This problem can be caused either by a failure of cyclic cows to show estrous behavior or by a failure of the cows to re-commence cycling after calving. Cows can remain acyclic because of the presence of persistent follicular cysts, persistent corpora lutea or inactive ovaries with no follicular development beyond the early antral stage (Mwaanga and Janowski, 2000;. The presence of inactive ovaries is accompanied by a lack of estrus and the absence of corpora lutea (Markusfeld, 1987).…”