Cow metabolic status assessed from fat/protein ratio in milk affected ovarian response and number of transferable embryos after superovulation

Abstract

This work aimed to evaluate the quantity and the quality of flushed embryos based on the metabolic status of dairy cows, lactation number, and size of the ovaries. Fifty-nine Holstein cows on 1<sup>st</sup> to 5<sup>th</sup> lactation were enrolled in the experiment. Monitoring took place during the period from October to November and from March to June. Cows with corpus luteum were included for the hormonal treatment – superovulation and timed insemination. The cow was inseminated, resp. re-inseminated, during the induced heat with insemination doses from one bull from the same batch. Embryo flushing was performed on the 7<sup>th</sup> day after the first insemination. We isolated individual embryos after flushing, and morphologically evaluated them under a stereo microscope. The metabolic status of tested cows was determined based on the ratio between fat and protein in milk around the period of embryo flushing (< 1.1; 1.1–1.3; > 1.3). Data about fat and protein content were taken from milking parlour records. Data were evaluated in SAS v9.4 with GLM procedure. The results of our study showed that there is a significant relationship between the fat/protein ratio and the total number of flushed embryos, resp. the number of transferable embryos. The highest number of flushed and transferable embryos were collected from the group of cows with fat/protein ratio between 1.1–1.3. The fat/protein ratio within these values represents cows in an optimal metabolic state. We also observed a significant positive relationship between the size of the ovaries and the number of flushed and transferable embryos. Lactation number did not significantly affect monitored parameters. The assessment of the fat/protein ratio might become a useful tool for the evaluation of cows selected for embryo transfer. Our findings could be used to improve the efficacy of the superovulation system, with the aim to extract the maximum number of transferable embryos.

The most common reproductive disorders of cows in Holstein cattle breeding

“…Negative correlations between CYS resistance and productive traits are often mentioned in the literature (Koeck et al 2012;Gernand and Konig 2017;Jamrozik et al 2021). For example, Stadnik et al (2022) found that ovarian response depended on the metabolic status of the cow and reflected the competition for energy and nutrients between production and reproduction. Hooijer et al (2001) estimated that in the Dutch Black and White cattle population, the selection for milk yield would increase the incidence of CYS by 1.5% per 500 kg increase in milk.…”

Long-term pedigree analysis: An effective tool for managing congenital malformations in cattle

“…Finally, the health status was studied from different points of view such as heat stress, metabolic status, semen quality etc. (Bezdicek et al 2021; Pytlik et al 2022;Stadnik et al 2022). But beyond all doubt the first task is breeding for health.…”

The interaction between the milk production, milk components with a low frequency of analysis and factors affecting the milk composition in dual-purpose Simmental cows

“…future sustainability of the milk production of the cow and the milk producing enterprise through increased costs of maintain the animal's welfare and feeding. The less frequently analysed milk components will provide important and vital information that can effectively be used in dairy management decision making to ensure the efficient production of good volumes and quality milk while ensuring high standards in the management of the dairy herd health and reproductive performance (Stadnik et al 2022). During times of climatic change, the less frequently analysed components are very important indicators in tracking the successes and failures of dairy managers to support the health and nutritional status of lactating cows and provide indicators of the welfare status and resilience of such cows (Kasna et al 2022).…”

“…These more frequently analysed milk components mainly include the milk proteins, fat, and sugar, as well as the number of somatic cells (somatic cell count). Monitoring of the "less frequently analysed" milk components (urea, casein, ketones, citric acid, free fatty acids, and others) gives a strong indication of the nutritional status of dairy cows and can serve as a basis for the prevention of production disorders, and, thus, also for the promotion of animal health (Stadnik et al 2022). Literature reviews suggest a very low frequency of analysis of these components (Hanus et al 2011;Melfsen et al 2012).…”