Strategies for increasing fertility in high productivity dairy herds

Abstract

Over the years, the dairy cow has been selected and managed for high performance and efficiency in milk production. Thus, different factors influence the fertility of dairy cows of high productivity. It has been observed that genetic selection for large productions and metabolic adaptations may explain the greater requirement to maintain reproduction at satisfactory levels. Also, these animals are more susceptible to environmental factors such as increased temperature and humidity. Studies have shown that heat stress results in reduced estrous expression and impairs ovarian function, interfering with folliculogenesis and steroidogenesis. Likewise, under heat stress conditions, dry matter intake is reduced, prolonging the after calving negative energy balance and calving-conception interval. Thus, suboptimal reproductive performance is one of the main factors responsible for the economic losses in large dairy farms. In this context, numerous management practices have been introduced to improve reproduction in high productivity animals, making reproductive management increasingly complex in dairy farms. Among them, we can mention the implementation of management and nutrition conditions adapted to the periods of heat stress, as well as protocols and biotechniques that improve the quality of the follicles and oocytes. Thus, because genetic selection for better fertility animals is a characteristic of low heritability, the success of reproductive programs in highly productive herds depends on the association of the control of genetic and physiological factors with those of environmental, nutritional and management. This paper aims to discuss reproductive aspects of dairy cows of high productivity, the role of heat stress in this context, and the implementation of management, nutrition and biotechnology conditions, to minimize the adverse effects on the reproduction of these animals.

Examination of the haematological profile of pregnant Polish Holstein-Friesian black-and-white cattle in the early stage

“…The optimum ambient temperature for cows is 5 to 25°C. Above this range, it is more difficult for cows to thermoregulate ( 6 ). During heat stress, animals consume less feed to maintain optimal body temperature ( 37 ), and stress of this kind can have a negative effect on the success of fertilisation and embryo viability ( 2 , 34 ).…”

The impact of stress and selected environmental factors on cows’ reproduction

“…mastitis (El-Tarabany et al 2016). In high-yielding cows, fertility is often reduced or even absent (Bragança and Zangirolamo 2018). The infertility period may be extended during the postpartum period when following a more energy demand than supply (El-Tarabany et al 2016).…”

“…The physiological and metabolic disorders are the results of stress. This type of stress can have a negative influence on the success of cow fertilization, pregnancy during the peri-implantation period, as well as a negative influence on hormonal disorders and embryo mortality (Bragança and Zangirolamo 2018;Schüller et al 2014;Liu et al 2017). In the warm seasons, the efficiency of artificial insemination of dairy cows is lower than in winter.…”

“…Dairy herds were set a voluntary waiting period of about 50 days. After this time we can begin further reproduction and increase the breeding (Bragança and Zangirolamo 2018). Shortening the calving interval in cows results in an increase in the detection sensitivity of oestrus (Bekara and Bareille 2019).…”

Recent Strategies to Enhance Fertility in Farm Animals: An Overview

“…The high yielder modern dairy cows remain subfertile during lactation. However, in addition to milk production, other factors are likely to decrease reproductive efficiency in these herds (Bragança and Zangirolamo, 2018).…”