When is a cow in estrus? Clinical and practical aspects

We investigated the effect of maternal sire on early pregnancy failure (between D0, day of insemination and D90) in their progeny during the first and second lactations (n = 3508) in the Holstein breed. The estimated breeding value (EBV) for cow fertility of 12 bulls (reliability ⩾ 0.95) was used to create the following three groups: low, medium and high EBV (EBV from − 0.7 to 1 expressed as genetic standard deviation relative to the mean of the breed). In their daughters (93 to 516 per bull), progesterone measurement was carried out on the day of artificial insemination (AI; D0) to check whether the cows were in the follicular phase and on D18 to 25 to assess non-fertilisation-early embryonic mortality (NF-EEM). Late embryonic mortality (LEM) and early foetal death (FD) were determined by ultrasonography on D45 and D90 and by the return to oestrus after the first AI. Frequencies of NF-EEM, LEM, FD and pregnancy were 33.3%, 11.7%, 1.4% and 48.5% and incidences were 35.1, 19.0, 2.7 and 51.1, respectively. Sire EBV was significantly related to the incidences of pregnancy failure between D0 and D90, fertilisation failure-early embryonic mortality (FF-EEM) and LEM but not to the incidence of FD between D45 and D90 of pregnancy. The relative risk (RR) of FF-EEM was significantly higher (RR = 1.2; P < 0.05) for the progeny group of low EBV bulls when compared with high EBV bulls. The same effect was observed when comparing LEM of the progeny groups from the low EBV bulls to those from moderate and high EBV bulls (RR, respectively, of 1.3 and 1.4; P < 005). The incidence of FF-EEM was significantly higher when cows were inseminated before 80 days postpartum compared with later, and for the extreme values of the difference between milk fat and protein content measured during the first 3 months of lactation. FF-EEM was also significantly related to the year of observation. The incidence of LEM was higher for the highest producing cows and was influenced by interaction between milk yield × lactation rank and milk yield × milk protein content. In conclusion, this study showed large differences in early pregnancy failure between progeny groups and highlights the interest of accurate characterisation of embryonic death in order to identify potential candidate genes for female fertility.Keywords: dairy cow, female fertility, embryonic death, genetic evaluation, genetic selection ImplicationsThe objective of this study was to improve our understanding of genetic effects on early pregnancy failure in Holstein dairy cows. Daughters of 12 bulls of known fertility estimated breeding value (calculated using the calving rate of their lactating progeny) were followed between D0 (day of first artificial insemination) and D90 to identify non-fertilisationearly embryonic death, late embryonic death and early foetal death. We showed that the sire had a large effect on the incidence of NF-EEM and LEM, but this did not explain all the differences between progeny groups. Consequently, this study highlights the importance of defining the pre...

Section: Introductionmentioning

confidence: 81%

mentioning

confidence: 87%

Sire effect on early and late embryonic death in French Holstein cattle

Ledoux

Ponsart²,

Grimard

et al. 2015

“…Equations were determined to calculate the probability of each of these three oestrus expression levels associated with an ovulation. The oestrus expression level is strongly increased by the concomitant presence of at least one other cow in oestrus (Kerbrat and Disenhaus, 2004;Roelofs et al, 2010). Expression is lower for first ovulation than subsequent ovulations.…”

Section: Description Of the Modelmentioning

confidence: 97%

“…The lactation stage is a key driver of individual milk production in dairy cows, and the demography of the herd is a key driver of the herd milk production. However, in most of the current dairy herd production models, the representation of the reproductive process is usually either oversimplistic, using fixed calving to ovulation intervals or fixed cycle length of 21 days (Allore et al, 1998;Blanc et al, 2001;Blanc and Agabriel, 2008), or well out of date relative to modern dairy genotypes (Oltenacu et al, 1980;Dijkhuizen et al, 1986;Plaizier et al, 1998), where 15% to 30% of the cycles are affected by prolonged luteal phase (PLP) (Grimard and Disenhaus, 2005), duration of normal cycles has increased (Sartori et al, 2004) and oestrus expression (Kerbrat and Disenhaus, 2004;Roelofs et al, 2010) and conception rate (Lucy, 2001;Grimard et al, 2006) have strongly decreased. More recently, a dynamic simulation model was developed by Inchaisri et al (2010a) to investigate the economic consequences of reproductive -E-mail: philippe.faverdin@rennes.inra.fr performance.…”

Section: Introductionmentioning

confidence: 99%

An individual reproduction model sensitive to milk yield and body condition in Holstein dairy cows

Brun-Lafleur

Cutullic

Faverdin

et al. 2013

To simulate the consequences of management in dairy herds, the use of individual-based herd models is very useful and has become common. Reproduction is a key driver of milk production and herd dynamics, whose influence has been magnified by the decrease in reproductive performance over the last decades. Moreover, feeding management influences milk yield (MY) and body reserves, which in turn influence reproductive performance. Therefore, our objective was to build an up-to-date animal reproduction model sensitive to both MY and body condition score (BCS). A dynamic and stochastic individual reproduction model was built mainly from data of a single recent long-term experiment. This model covers the whole reproductive process and is composed of a succession of discrete stochastic events, mainly calving, ovulations, conception and embryonic loss. Each reproductive step is sensitive to MY or BCS levels or changes. The model takes into account recent evolutions of reproductive performance, particularly concerning calving-to-first ovulation interval, cyclicity (normal cycle length, prevalence of prolonged luteal phase), oestrus expression and pregnancy (conception, early and late embryonic loss). A sensitivity analysis of the model to MY and BCS at calving was performed. The simulated performance was compared with observed data from the database used to build the model and from the bibliography to validate the model. Despite comprising a whole series of reproductive steps, the model made it possible to simulate realistic global reproduction outputs. It was able to well simulate the overall reproductive performance observed in farms in terms of both success rate (recalving rate) and reproduction delays (calving interval). This model has the purpose to be integrated in herd simulation models to usefully test the impact of management strategies on herd reproductive performance, and thus on calving patterns and culling rates.Keywords: dairy cow, reproduction, model, milk yield, body condition score Implications This paper describes an up-to-date stochastic reproduction model of Holstein dairy cows. This model is sensitive to both milk production and body reserves and takes into account the recent evolutions of reproductive performance in dairy cows. This model is able to well simulate the overall reproductive performance observed in commercial farms. Therefore, it can be used in dynamic individual-based herd simulation models to anticipate the consequences of management strategies (in terms of reproduction or feeding) on dairy herd demography and global performance.

“…Using cow information, reproductive dynamics and economics representative for the dairy situation in the Netherlands, Inchaisri et al (2010) predicted that an improvement in the oestrus detection rate from 0.30 to 0.50 and from 0.50 to 0.70 will reduce the net economic loss by €53.29 and €11.20 per cow per year, respectively. Various oestrus detection methods aimed at improving detection rate have been developed, evaluated and compared (Diskin and Sreenan, 2000;Firk et al, 2002;Roelofs et al, 2010;Holman et al, 2011). Despite this, modern dairy farming would substantially benefit from an improved oestrus detectability via an increased expression of oestrous behaviour in cows, that is, if cows would generally show the various signs of oestrus during a longer period of time and at a higher intensity and if more cows would show standing oestrus.…”

Section: Introductionmentioning

confidence: 99%

Central genomic regulation of the expression of oestrous behaviour in dairy cows: a review

Woelders

Lende²,

Kommadath

et al. 2014

The expression of oestrous behaviour in Holstein Friesian dairy cows has progressively decreased over the past 50 years. Reduced oestrus expression is one of the factors contributing to the current suboptimal reproductive efficiency in dairy farming. Variation between and within cows in the expression of oestrous behaviour is associated with variation in peripheral blood oestradiol concentrations during oestrus. In addition, there is evidence for a priming role of progesterone for the full display of oestrous behaviour. A higher rate of metabolic clearance of ovarian steroids could be one of the factors leading to lower peripheral blood concentrations of oestradiol and progesterone in high-producing dairy cows. Oestradiol acts on the brain by genomic, non-genomic and growth factor-dependent mechanisms. A firm base of understanding of the ovarian steroid-driven central genomic regulation of female sexual behaviour has been obtained from studies on rodents. These studies have resulted in the definition of five modules of oestradiol-activated genes in the brain, referred to as the GAPPS modules. In a recent series of studies, gene expression in the anterior pituitary and four brain areas (amygdala, hippocampus, dorsal hypothalamus and ventral hypothalamus) in oestrous and luteal phase cows, respectively, has been measured, and the relation with oestrous behaviour of these cows was analysed. These studies identified a number of genes of which the expression was associated with the intensity of oestrous behaviour. These genes could be grouped according to the GAPPS modules, suggesting close similarity of the regulation of oestrous behaviour in cows and female sexual behaviour in rodents. A better understanding of the central genomic regulation of the expression of oestrous behaviour in dairy cows may in due time contribute to improved (genomic) selection strategies for appropriate oestrus expression in high-producing dairy cows.Keywords: sexual behaviour, dairy cow, oestrus, gene expression, brain ImplicationsReduced oestrus expression is one of the factors contributing to the current suboptimal reproductive efficiency in dairy cows. A recent series of publications that correlated the level of oestrous behaviour expression to gene expression levels in the cow brain and anterior pituitary are reviewed here and their findings placed in perspective of what is known about sexual behaviour from studies on other species. The improved understanding of the central genomic regulation of oestrous behaviour expression may in due time contribute to improved (genomic) selection strategies for appropriate oestrus expression in high-producing dairy cows. IntroductionMaintaining good fertility and thereby optimum reproductive performance in dairy cows is of great economic importance for the dairy industry. Artificial insemination of cows is widely practiced in modern dairy farming. To ensure timely insemination and thereby maximize conception rates in the herd and profitability of the farm, it is important that the farmer does not m...