Symposium review: Linking activity-sensor data and physiology to improve dairy cow fertility

Abstract

Several studies have demonstrated that the intensity of estrous expression is associated with ovulation, ovarian and uterine function, and fertility, and is dependent on social hierarchy and the housing system used. Data from recent studies involving spontaneous and induced estrus have shown that a greater relative increase and longer estrus (captured by different automated activity monitors; AAM) are both associated with improved pregnancy per artificial insemination (AI; around 10 to 14% increase) and decreased pregnancy losses. Intensity and duration of estrus were surprisingly weakly associated with preovulatory follicle diameter and concentrations of plasma estradiol at estrus, whereas ovulation failure was associated with low estrus intensity. Studies have also shown that the display of estrous behavior near AI was associated with the modification of expression of genes related to the immune system, adhesion molecules, and prostaglandin synthesis in the endometrium. Transcripts in leukocytes and in the conceptus tissue associated with maternal recognition of pregnancy as well as conceptus elongation were all associated with differences in the intensity of estrous expression. Most recently, studies from the United States and Canada have demonstrated that reproductive programs emphasizing detection of estrus using AAM can be successful and comparable to intensive timed AI protocol-based programs that incorporate GnRH and PGF 2α treatments. Further, one study concluded that the administration of GnRH at AI for spontaneous estrus events greatly improved pregnancy per AI, but only for cows with reduced intensity of estrous expression, showing the potential to use AAM data as a tool in targeted reproductive programs. Quantitative information from estrus events could be used to improve estrus detection and develop decision-making strategies at the farm level. Future studies in this field should aim to better understand ovarian, conceptus, and endometrial mechanisms associated with either the expression or the intensity of estrus, and to refine the identification of phenotypes related to estrus (relative increase, absolute increase, baseline levels, duration, and repeatability within cow) to improve data usage, estrus detection, and possibly genetic selection.

Estrus Detection Using Background Image Subtraction Technique in Tie-Stalled Cows

“…However, it should be noted that the present method was validated on ten estrous cycles of six cows. Various factors are known to affect the intensity and duration of estrus, such as parity, milk production, and body condition score [ 15 ]. Hence, a follow-up study with a larger sample size is required.…”

[The role of reproductive biology in SDGs] Global warming and cattle reproduction: Will increase in cattle numbers progress to global warming?

“…As sensing is also available for health management, sensors are expected to be useful for fertility improvement by promoting not only estrus detection but also health protection of the herd. In addition, estrus synchronization technique using hormone treatments was reported to promote estrus symptoms and improve the conception rate after AI [ 31 ]. A modified method, timed-AI, by which cattle can be inseminated without checking for estrus, can increase the number of cows to be inseminated and improve the breeding coefficient [ 32 ].…”

Continuous real-time cow identification by reading ear tags from live-stream video

“…With the developments in precision dairy farming, on-farm data streams are increasing rapidly (Kamphuis et al, 2012;Cerri et al, 2020). Data are collected by devices such as neck collars (Rutten et al, 2017), by farm equipment such as milking systems and feeding stalls (Foris et al, 2019;Deng et al, 2020), and from measuring devices that analyze milk or other cow output such as manure and breath air (Negussie et al, 2017).…”