Estrus Detection Research Articles

Estrus and ovulation synchrony of buffaloes (Bubalus bubalis): A review

Synchronizing estrus and ovulation in buffalo using timed inseminations (TAI) protocols circumvents the limitations associated with estrus detection. Spontaneous estrus in buffalo may achieve more conception rate on insemination than those subjected to synchronization of estrus and timed insemination (TAI). The advantages of insemination following synchronization programs include higher detection rates combined with decreased embryonic losses and reduction in days open. A synchonization programme should ensure control of estrus cycle which entirely depends on ovarian status of animals before starting any protocol. Ovarian follicular status at the beginning of treatment protocols plays vital role for effective response shown by animals. Studies show that more precise alterations in follicular waves may be needed to achieve better synchrony of ovulation and more fertility. The protocols which use Gonadotropic Releasing Hormone (GnRH), follicle stimulating hormone (FSH), luteinizing hormone (LH), equine chorionic gonadotropin (eCG), human chorionic gonadotropin (hCG), prostaglandins, progesterone and estradiol have been helpful in achieving the estrus and ovulation synchrony. Use of estradiol esters and progesterone per-vaginum implants have also been incorporated in synchronization programs. Synchronous emergence of follicular waves using trans-vaginal ultrasound guided follicular ablation and estradiol administration is a recent concept for synchronization in buffalo. Further, a recent approach has been to allow the follicle of second follicular wave to ovulate as the fertility has been lesser when first wave follicle ovulates. Moreover, controlling environmental influences, nutritional and managemental strategies remain pre-requisite to achieve desired goals though hormonal administration. This is more particular in buffaloes suffering from anestrum more so in low or non-breeding season and pre-pubetal anestrum. This review will cover the available documented literature regarding estrous cycle physiology with emphasis on follicular wave dynamics and the future area of work to be focused to achieve more reproductive efficiency in buffalo.

Precision Livestock Farming Research: A Global Scientometric Review.

Precision livestock farming (PLF) utilises information technology to continuously monitor and manage livestock in real-time, which can improve individual animal health, welfare, productivity and the environmental impact of animal husbandry, contributing to the economic, social and environmental sustainability of livestock farming. PLF has emerged as a pivotal area of multidisciplinary interest. In order to clarify the knowledge evolution and hotspot replacement of PLF research, based on the relevant data from the Web of Science database from 1973 to 2023, this study analyzed the main characteristics, research cores and hot topics of PLF research via CiteSpace. The results point to a significant increase in studies on PLF, with countries having advanced livestock farming systems in Europe and America publishing frequently and collaborating closely across borders. Universities in various countries have been leading the research, with Daniel Berckmans serving as the academic leader. Research primarily focuses on animal science, veterinary science, computer science, agricultural engineering, and environmental science. Current research hotspots center around precision dairy and cattle technology, intelligent systems, and animal behavior, with deep learning, accelerometer, automatic milking systems, lameness, estrus detection, and electronic identification being the main research directions, and deep learning and machine learning represent the forefront of current research. Research hot topics mainly include social science in PLF, the environmental impact of PLF, information technology in PLF, and animal welfare in PLF. Future research in PLF should prioritize inter-institutional and inter-scholar communication and cooperation, integration of multidisciplinary and multimethod research approaches, and utilization of deep learning and machine learning. Furthermore, social science issues should be given due attention in PLF, and the integration of intelligent technologies in animal management should be strengthened, with a focus on animal welfare and the environmental impact of animal husbandry, to promote its sustainable development.

Targeted reproductive management for lactating Holstein cows: Reducing the reliance on exogenous reproductive hormones

Adoption of automated monitoring devices (AMD) affords the opportunity to tailor reproductive management according to the cow's needs. We hypothesized that a targeted reproductive management (TRM) would reduce the use of reproductive hormones while increasing the percentage of cows pregnant 305 d in milk (DIM). Holstein cows from 2 herds (n = 1,930) were fitted with an AMD at 251.0 ± 0.4 d of gestation. Early-postpartum estrus characteristics (EPEC; intense estrus = heat index ≥70; 0 = minimum, 100 = maximum) of multiparous cows were evaluated at 40 (herd 1) or 41 (herd 2) DIM and EPEC of primiparous cows were evaluated at 54 (herd 1) or 55 (herd 2) DIM. Control cows received the first artificial insemination at fixed time (TAI; primiparous, herd 1 = 82 and herd 2 = 83 DIM; multiparous, herd 1 = 68 and herd 2 = 69 DIM) following the Double-Ovsynch (DOV) protocol. Cows enrolled in the TRM treatment were managed as follows: (1) cows with at least one intense estrus were inseminated upon AMD detected estrus for 42 d and, if not inseminated, were enrolled in the DOV protocol; and (2) cows without an intense estrus were enrolled in the DOV protocol at the same time as cows in the control treatment. Control cows were re-inseminated based on visual or patch aided detection of estrus, whereas TRM cows were re-inseminated as described for control cows with the aid of the AMD. Cows received a GnRH injection 27 ± 3 d after insemination and, if diagnosed as nonpregnant, completed the 5-d Cosynch protocol and received TAI 35 ± 3 d after insemination. Among cows in the TRM treatment, 55.8 and 42.9% of primiparous and multiparous cows, respectively, received the first insemination in spontaneous estrus. The interaction between treatment and parity affected pregnancy 67 d after the first AI (primiparous: control = 37.6%, TRM = 27.4%; multiparous: control = 41.0%, TRM = 44.7%). The TRM treatment increased re-insemination in estrus (control = 48.3%, TRM = 70.5%). Pregnancy 67 d after re-inseminations tended to be affected by the interaction between treatment and EPEC (no intense estrus: control = 25.3%, TRM = 32.0%; intense estrus: control = 32.9%, TRM = 32.2%). The interaction between treatment and EPEC affected pregnancy by 305 DIM (no intense estrus: control = 80.8%, TRM = 88.2%; intense estrus: control = 87.1%, TRM = 86.1%). Treatment did not affect the number of reproductive hormone treatments among cows that had not had an intense estrus (control = 10.5 ± 0.3, TRM = 9.1 ± 0.2 treatments/cow), but cows in the TRM treatment that had an intense estrus received fewer reproductive hormone treatments than cows in the control treatment (2.0 ± 0.1 vs. 9.6 ± 0.2 treatments/cow). Selecting multiparous cows for first AI in estrus based on EPEC reduced the use of reproductive hormones without impairing the likelihood of pregnancy to first AI. The use of AMD for re-insemination expedited the establishment of pregnancy among cows that did not display an intense estrus early postpartum.

Timed artificial insemination protocols in dairy cattle: Functioning, shortcomings, and improvements

Oestrus detection is currently at the top of the factors limiting the success of artificial insemination in dairy herds. This limitation becomes more pronounced as milk production increases because of higher metabolic clearance rates of steroid hormones leading to low circulating oestradiol concentration near oestrus. The standard OvSynch has overcome this problem by enabling fixed-time artificial insemination, for it synchronises follicular wave emergence, luteolysis, and ovulation. However, it did not improve fertility compared to cycles with spontaneous ovulation, which motivated the development of “fertility programs”. These later are nothing but improved OvSynch protocol. This article explains what went wrong with the original OvSynch protocol, discusses the improvements made by “fertility programs”, and highlights the advantages and limits of the newly tested molecules.

Time of insemination in relation to pregnancy rates in beef cattle after oestrus detection with automated activity monitoring system

BackgroundThe timing of artificial insemination is critical to achieve acceptable results in cattle production systems. Over the past 60 years the length and expression of oestrus in dairy cattle has altered. Recent studies have indicated the optimal timing for insemination after the commencement of oestrus may now be earlier than traditional recommendations in beef cattle, as is the case in dairy cattle. The aim of the current study was to evaluate the effect of time from onset of oestrus [as determined by an automated activity monitoring system (AAMS)] to artificial insemination (AI) on pregnancy outcome in Norwegian beef cattle. Five commercial beef suckler herds participated in a cohort study by providing data on the time of AAMS alarm and time of AI. Blood sampling on the day of AI was performed and serum progesterone concentration measured. Pregnancy detection was performed by transrectal ultrasonography and aging of the fetus performed when necessary. A mixed logistic regression model was fitted to study the effect of time from AAMS alarm to AI on pregnancy outcome. Time categories used in the model were < 12 h, 12–24 h, and > 24 h.ResultsAI periods (n = 229) with serum progesterone concentration < 1 ng/mL were available for analysis. Overall pregnancy risk per AI for the whole study period was 65.5%, with an inter-herd variation from 10 to 91%. Median time elapsed from AAMS alarm to AI was 17.75 h. Herd affected pregnancy outcome (P = 0.001), while breed and parity status (heifer/cow) did not. The time category closer to AAMS alarm 0–12 h showed a numerically lower pregnancy risk as compared to the baseline group which had AI 12–24 h after onset of oestrus.ConclusionThis study found no evidence to support a change in the recommended timing of AI in beef suckler cows.

A single dose of FSH or hCG during a split-time AI program did not enhance follicular growth or pregnancy per artificial insemination in beef heifers

ABSTRACT The objective of this study was to evaluate the effect of a low dose of hCG or FSH on follicle growth and pregnancy per artificial insemination (AI) in crossbreed beef heifers subjected to a split-time AI program. All heifers (n = 386) were subjected to a 7-d Co-synch protocol and an intravaginal controlled internal drug release (CIDR) device (GnRH and CIDR insertion; 7 days later PGF2α, CIDR removal, and application of a tail head estrus detection patch; 36 hours later AI of heifers detected in estrus, 24 hours later timed AI of remaining heifers). At CIDR removal, heifers were randomly assigned to receive either 150 IU of hCG, 20 mg of FSH, or remained as untreated controls. The diameter of the preovulatory follicle and the pregnancy per AI did not differ among treatments. A smaller (P = 0.035) proportion of heifers in the hCG group were detected in estrus compared with control. Additionally, the incidence of premature ovulation was greater (P < 0.01) among heifers treated with hCG compared with control. In conclusion, using a low dosage of hCG or FSH at the time of device removal did not affect pre-ovulatory follicle growth or the proportion of pregnant heifers.

Influence of Estrus on Dairy Cow Milk Exosomal miRNAs and Their Role in Hormone Secretion by Granulosa Cells.

Estrus is crucial for cow fertility in modern dairy farms, but almost 50% of cows do not show the behavioral signs of estrus due to silent estrus and lack of suitable and high-accuracy methods to detect estrus. MiRNA and exosomes play essential roles in reproductive function and may be developed as novel biomarkers in estrus detection. Thus, we analyzed the miRNA expression patterns in milk exosomes during estrus and the effect of milk exosomes on hormone secretion in cultured bovine granulosa cells in vitro. We found that the number of exosomes and the exosome protein concentration in estrous cow milk were significantly lower than in non-estrous cow milk. Moreover, 133 differentially expressed exosomal miRNAs were identified in estrous cow milk vs. non-estrous cow milk. Functional enrichment analyses indicated that exosomal miRNAs were involved in reproduction and hormone-synthesis-related pathways, such as cholesterol metabolism, FoxO signaling pathway, Hippo signaling pathway, mTOR signaling pathway, steroid hormone biosynthesis, Wnt signaling pathway and GnRH signaling pathway. Consistent with the enrichment signaling pathways, exosomes derived from estrous and non-estrous cow milk both could promote the secretion of estradiol and progesterone in cultured bovine granulosa cells. Furthermore, genes related to hormonal synthesis (CYP19A1, CYP11A1, HSD3B1 and RUNX2) were up-regulated after exosome treatment, while exosomes inhibited the expression of StAR. Moreover, estrous and non-estrous cow-milk-derived exosomes both could increase the expression of bcl2 and decrease the expression of p53, and did not influence the expression of caspase-3. To our knowledge, this is the first study to investigate exosomal miRNA expression patterns during dairy cow estrus and the role of exosomes in hormone secretion by bovine granulosa cells. Our findings provide a theoretical basis for further investigating milk-derived exosomes and exosomal miRNA effects on ovary function and reproduction. Moreover, bovine milk exosomes may have effects on the ovaries of human consumers of pasteurized cow milk. These differential miRNAs might provide candidate biomarkers for the diagnosis of dairy cow estrus and will assist in developing new therapeutic targets for cow infertility.

Discrimination strategy using machine learning technique for oestrus detection in dairy cows by a dual-channel-based acoustic tag

Timely identification of cows in heat is a fundamental issue in dairy farming. Although current studies have confirmed that several cow vocalisation characteristics can be used for oestrus identification, the reliability and practicability of oestrus detection methods are limited due to background noise, a lack of data support for sound feature selection, and the unsatisfactory effectiveness of vocalisation recognition algorithms.To overcome these predicaments, a dual-channel recording device and a sound event extraction method were developed in this study. The experimental results in respect of 62 Holstein dairy cows showed that the sound sample recording accuracy was 80.4%, and the noise filtering accuracy was 94.3%, indicating the effectiveness of the vocalisation extraction algorithm in a noisy farm environment. Moreover, two unique sound features with remarkable discrimination ability, i.e., the number of consecutive vocalisations and the maximum consecutive times, were used to improve the effectiveness of oestrus detection. The Friedman test, the Spearman rank order correlation coefficient, and the Kruskal-Wallis test were used to obtain the combination of features with the most optimal discrimination. Subsequently, a dual-LSTM (Long Short-Term Memory) joint discriminant strategy based on optimal combinations was proposed to promote oestrus detection performance. The results of the blind test on the vocalisation data of 20 oestrus cows and 11 non-oestrus cows demonstrated that the oestrus detection rate of the discrimination strategy reached 100%, and had a temporal advantage over the activity-index-based method in determining the onset of oestrus.The improvements of the selection and-based oestrus detection method mainly included accurately extracting individual cow vocalisations, supplementing the explicability of feature selection, and enhancing the refinement of oestrus recognition. Meanwhile, it is of positive significance for applying sound acquisition devices in oestrus detection. Furthermore, combining sound identification with other automated detection techniques appears to be a promising method for promoting the oestrus detection rate.

Use of intravaginal lactic acid bacteria prepartum as an approach for preventing uterine disease and its association with fertility of lactating dairy cows

The objective of this study was to evaluate the effects of the use of intravaginal probiotics prepartum on the incidence risk of metritis postpartum and conception risk after first artificial insemination (AI). A total of 606 Holstein cows were enrolled 3 wk before their expected calving date from 2 farms. Cows were randomly assigned to either receive a 2-mL dose of a combination of 3 lactic acid bacteria (probiotic treatment) washed with approximately 2 mL of a sterile saline solution, into the vaginal canal twice weekly until parturition, or no intervention (control). Metritis diagnoses were carried out on 6 and 12 d postpartum. Vaginal discharge and rectal temperature were assessed, and vaginal discharge was scored on a scale from 1 to 4, where 1 = clear and 4 = fetid, purulent discharge. Metritis was defined as cows having a vaginal discharge score of 4 with or without fever (rectal temperature ≥39.5°C) on either 6 or 12 d postpartum, or both. Cows were bred after a 60-d voluntary waiting period primarily via the detection of estrus using automated activity monitors; cows not found in estrus were enrolled onto timed AI protocols to receive first breeding before 100 DIM. Pregnancy diagnosis was carried out at d 35 ± 7 post-AI on both farms. Data were analyzed via ANOVA using linear mixed regression models and survival analysis using a Cox proportional hazard model. Total incidence risk of metritis was 23.7% and 34.4% on farm A and farm B, respectively. Overall, the incidence of metritis was not different between treatment groups (control: 41.6 ± 3.8%; probiotic: 38.6 ± 4.0%); however, an interaction by farm was detected, where the probiotic treatment reduced metritis on one farm but not on the other. Conception risk after first AI was not affected by treatment. However, we detected an interaction between parity and treatment, where multiparous cows receiving the probiotic treatment were more likely to become pregnant compared with multiparous cows within the control group (hazard ratio: 1.33; 95% confidence interval: 1.10-1.60); no effect of probiotic treatment was found on the hazard of pregnancy for primiparous cows. In addition, the probiotic treatment was associated with an increased proportion of cows being detected in estrus for the first AI postpartum. In conclusion, vaginal probiotic treatment applied during the 3 wk prepartum was associated with a decreased incidence of metritis on one farm but not the other, suggesting that farm management may be a key player influencing treatment efficacy. Overall, probiotic treatment was found to have only limited effects on fertility in the current study.

Presynchronization with prostaglandin F2α and gonadotropin-releasing hormone simultaneously improved first-service pregnancy per artificial insemination in lactating Holstein cows compared with Presynch-14 when combined with detection of estrus

This study aimed to determine the effect of 2 simple breeding strategies combining artificial insemination (AI) after detection of estrus (AIED) and timed AI (TAI) on first-service fertility in lactating Holstein cows. Weekly, lactating Holstein cows (n = l,049) between 40 and 46 d in milk (DIM) were randomly assigned to initiate 1 of 2 breeding strategies for first service: Presynch-14 and PG+G. Presynch-14 is a presynchronization strategy with 2 PGF2α treatments 14 d apart with the last PGF2α 14 d before the initiation of the Ovsynch protocol. Cows treated with PG+G receive a simpler presynchronization program that uses PGF2α and GnRH simultaneously 7 d before Ovsynch. In both treatments, cows detected in standing estrus by tail chalk at any time ≥55 DIM were inseminated, and treatment was discontinued (n = 525). Cows completing treatment received TAI from 78 to 84 DIM (n = 526). In a subgroup of cows that received TAI, blood was collected (n = 163) to assess circulating concentrations of progesterone, and ultrasonographic evaluations of ovaries were performed on the day of first GnRH of Ovsynch (n = 162) and PGF2α of Ovsynch (n = 122). The proportion of cows that received TAI was greater for PG+G compared with Presynch-14 (63.5 vs. 31.9%), which increased DIM at first service for cows treated with PG+G compared with Presynch-14 (75.5 ± 0.4 vs. 68.7 ± 0.4). For cows receiving TAI, the ovulatory response to first GnRH of Ovsynch (73.8 vs. 48.8%) and the proportion of cows with functional corpora lutea (92.6 vs. 73.1%) were greater for PG+G than Presynch-14. Cows treated with PG+G had greater overall pregnancy per AI (P/AI) 42 ± 7 d after AI (40.2 vs. 33.6%) and calving per AI (32.1 vs. 25.2%) than Presynch-14. For cows receiving AIED, treatment did not affect P/AI 42 ± 7 d after AI. However, for cows receiving TAI, PG+G increased P/AI compared with Presynch-14 (44.6 vs. 35.2%). Overall, cows receiving TAI had greater P/AI 42 ± 7 d after AI (42.5 vs. 31.5%) and calving per AI (34.1 vs. 23.7%) and decreased pregnancy loss (16.8 vs. 25.2%) than cows receiving AIED. In summary, PG+G increased the proportion of cows receiving TAI and the DIM at first service, P/AI, and calving per AI compared with Presynch-14 when both TAI programs were combined with AIED.

72 Seminal Plasma Uterine Priming Reduces Offspring Growth and Alters Uterine Artery Indices of Vascular Resistance in Embryo-Recipient Beef Cows

Abstract Uterine priming with seminal plasma has been shown to alter endometrial gene expression as well as uterine cytokines and chemokines. However, the effects of seminal plasma uterine priming on uterine blood flow, fetal and postnatal offspring growth performance have yet to be elucidated. Therefore, we investigated the effects of pooled seminal plasma uterine priming at estrus on embryo crown-rump length, uterine blood flow, and birth weights. Commercial cows (n = 65) were synchronized, evaluated for standing estrus (day 0), and randomly assigned to treatment groups: seminal plasma or control. Seminal plasma treated cows (n = 27) received 0.5 mL of pooled seminal plasma from commercial bulls mismatched from embryo sire placed in their uterine body via artificial insemination rod2 hours after estrus detection (day 0). Control cows (n = 27) were passed through the chute without receiving treatment. On day 7, cows underwent non-surgical embryo transfer and were confirmed pregnant on day 35 via ultrasonography. Final treatment numbers were n = 9 seminal plasma and n = 7 control. On days 35, 40, and 45 embryo crown-rump length was measured via transrectal ultrasonography. On days 140, 180, 200 and 220, uterine artery hemodynamics were measured via Doppler ultrasonography. Birth weights were collected within 24 hours of birth. Data collected over time were analyzed using repeated measures of ANOVA with fixed effects of treatment, day, and their respective interaction. Birth weights and gestation length were analyzed using ANOVA. Embryo sire and dam, side of pregnancy, and fetal sex were included as covariates if P &amp;lt; 0.10. Covariance structure was selected based on lowest AIC and BIC. Embryo crown-rump length was decreased (P = 0.0483) among seminal plasma treated cows compared with controls. Embryo crown-rump length increased (P &amp;lt; 0.0001) by day. Total uterine blood flow increased (P &amp;lt; 0.0001) as gestation proceeded. Ipsilateral resistance index was increased (P = 0.0431) among seminal plasma treated cows compared with controls. Ipsilateral resistance index was increased (P = 0.0107) on day 180 of gestation compared with days 200 and 220 of gestation. Ipsilateral pulsatility index was decreased (P &amp;lt; 0.0001) on day 220 of gestation compared with days 140 and 180 of gestation. Contralateral blood flow was decreased (P = 0.0037) on day 140 of gestation compared with days 180, 200, and 220 of gestation. There were no differences in contralateral uterine artery blood flow, resistance index, or pulsatility index, or gestation length between treatment groups. Birth weights were decreased (P = 0.0102) among calves from seminal plasma treated cows compared with calves from control cows. In summary, seminal plasma uterine priming reduced offspring growth while increasing uterine artery resistance index, which indicates uterine vascular bed anomalies that persisted into the third trimester of pregnancy.

58 Reproductive Performance of Beef Cow-Calf Operations in VA with a Fall or Spring Breeding Season

Abstract Establishing two breeding seasons (Fall and Spring) is a common practice in the southeast USA, including VA. We performed a retrospective analysis of data from 11 years, 22 breeding seasons and 14 locations in VA to compare reproductive performance between Fall and Spring breeding seasons. A total of 30,191 breeding records (24,032 for cows and 6,259 for heifers) from the VA Department of Corrections beef cattle operations were analyzed. Every year, each cow and heifer were enrolled in estrous synchronization protocols and received fixed-time artificial insemination (TAI) and were then exposed to natural service bulls for an approximately 65-day breeding season. Fall breeding occurred from November until January, and Spring breeding from March until May. Body condition score (BCS; 1 to 9, scale) was determined at the initiation of the TAI protocol. Estrus detection before TAI was performed by scoring an estrus detection aid prior to insemination. Pregnancy rate was determined by ultrasonography between days 55-65 post-TAI and 40-50 after the end of the breeding season. Data were analyzed using the SAS GLIMMIX procedure for binary data and MIXED procedure for continuous data. Average BCS was greater (P &amp;lt; 0.001) for Fall cattle than Spring cattle (5.7 ± 0.02 and 5.1 ± 0.02, respectively); however, days postpartum at TAI was similar between Fall and Spring (P = 0.645; 77.8 and 76.2 ± 0.5 days, respectively). Pregnancy rate to TAI differed (P &amp;lt; 0.0001) between Fall and Spring, 53.0 ± 0.03% and 48.6 ± 0.05%, respectively. Interestingly, estrus expression was greater (P &amp;lt; 0.001) for Spring than Fall (58.4 ± 0.05% and 50.4 ± 0.06%, respectively) and also was greater for cows that became pregnant to TAI compared with cows that failed to become pregnant to TAI (P &amp;lt; 0.001; 61.7 ± 0.03% and 46.9 ± 0.04%, respectively). End of breeding season pregnancy rate differed between season and was greater for Fall than Spring (P &amp;lt; 0.001; 90.7 ± 0.04% and 87.9 ± 0.04%, respectively). Calf birth weight was similar between seasons (P = 0.478; 34.1 and 34.4 ± 0.09 kg, for Fall and Spring, respectively). However, 205-day adjusted weaning weights differed (P &amp;lt; 0.001) between seasons with Spring calves being heavier than Fall calves (246.3 ± 0.12 kg and 227.8 ± 0.21 kg, respectively). In conclusion, for beef cow-calf operations in VA reproductive performance is enhanced for Fall breeding seasons; however, weaning weights were greater for calves born during the Spring seasons.

113 Precise regulation of ovarian function increased fertility of lactating dairy cows compared to detection of oestrus

113 Precise regulation of ovarian function increased fertility of lactating dairy cows compared to detection of oestrus

Measuring the effects of estrus on rumen temperature and environment, behavior and physiological attributes in Korean Native breeding cattle.

In this study, rumen temperature and environment in estral and non-estral Korean Native breeding cattle were evaluated by using a bolus sensor. Behavioral and physiological changes in study animals were also assessed. To assess the rumen temperature and environment, we inserted bolus sensors into 12 Korean Native cattle with an average age of 35.5 months, then measured temperature and activity within the rumen using the wireless bolus sensor. Drinking, feeding and mounting behavior, and measured vaginal temperature and levels of intravaginal mucus resistance were recorded. We found that cattle in estrus exhibited more acts of mounting (37.4 vs. 0 times/day), increased vaginal temperature (39.0°C vs. 38.4°C), and decreased vaginal mucus resistance (136.3 Ω vs 197.4 Ω), compared with non-estral animals. Furthermore, increased levels of rumen activity were most significant in estrus cattle at the highest activity levels (p < 0.01). Overall, the estrus group exhibited increased rumen temperature (p = 0.01), compared with the non-estrus group. In conclusion, the results of this study not only provide basic physiological data related to estrus in improved Korean Native breeding cattle, but also suggest that monitoring of rumen temperature and activity might be used as an effective smart device for estrus detection.

Survey of Herd Management on Conventional Dairy Farms in North Algeria

A survey was conducted to evaluate husbandry practices and herd health management in dairy farms in Mostaganem province, located in north Algeria. Data was collected through face-to-face interviews with 56 farmers, followed by a visit to the production environment of the dairy cows. The results showed that 64% of farmers feed their cows a basic ration of oat hay and straw, while 32% use corn silage. On average, 9.85 ±0.32 kg of concentrate was distributed per dairy cow. Most farms didn’t have efficient forage production, while only 21% of them produced all the necessary forage. The average milk production per cow on the surveyed farms was 18.19 ±0.45 L, with a lactation length of 293.5 ±1.65 days. The cows were milked using a portable milking machine in poor hygienic conditions. Estrus detection was performed occasionally by farmers, and natural breeding was the main method of insemination, occurring at a rate of 63%. The voluntary waiting period was on average 76.6 ±3.56 days, and the average calving interval was 14.35 ±0.2 months. The culling rate in dairy farms was 23% on average, with the most common reasons for culling being mastitis and age at a rate of 23% and 21% respectively. The main diseases reported by the farmers were mastitis (82%), followed by lameness (57%). All surveyed farmers vaccinated their herds against only rabies and foot-and-mouth disease. This survey can help to identify the challenges and potential opportunities for improving dairy farm productivity and welfare in the Mostaganem province. The agricultural and economic sectors should work with farmers towards improving dairy farming techniques and practices, using efficient feeding systems and enhanced technology of dairy herd management, providing training and education to farmers, and resolving herd health issues to increase the economic efficiency of the dairy industry.

Infrared Thermography as a Potential Non-Invasive Tool for Estrus Detection in Cattle and Buffaloes.

The productivity of dairy animals has significantly increased over the past few decades due to intense genetic selection. However, the enhanced yield performance of milk animals caused a proportional increase in stress and compromised reproductive efficiency. Optimal reproductive performance is mandatory for the sustainable production of dairy animals. Reproductive efficiency is marked by proper estrus detection and precise breeding to achieve maximum pregnancies. The existing conventional methods of estrus detection are somewhat labor intensive and less efficient. Similarly, the modern automated methods that rely on detecting physical activity are expensive, and their efficiency is affected by factors such as type of housing (tie stall), flooring, and environment. Infrared thermography has recently emerged as a technique that does not depend on monitoring physical activity. Furthermore, infrared thermography is a non-invasive, user-friendly, and stress-free option that aids in the detection of estrus in dairy animals. Infrared thermography has the potential to be considered a useful non-invasive tool for detecting temperature fluctuations to generate estrus alerts without physical contact in cattle and buffaloes. This manuscript highlights the potential use of infrared thermography to understand reproductive physiology and practical implementation of this technique through discussing its advantages, limitations, and possible precautions.

Identification of oestrus cows based on vocalisation characteristics and machine learning technique using a dual-channel-equipped acoustic tag

Timely and accurate detection of oestrus in cows is an essential element of the good management of dairy farms. At present, the detection of cows in oestrus by acoustic means is impeded by the problems of filtering, incomplete feature selection, and poor recognition accuracy. To overcome these difficulties, this study proposes a sound detection method for cows in oestrus based on machine learning technology using an optimal feature combination and an optimal time window. Firstly, a dual-channel sound detection tag consisting of a unidirectional microphone and an omnidirectional microphone (OM) was developed. The Least Mean Squares adaptive algorithm based on wavelet thresholds was used to filter the signals from the OM, and the dual-channel endpoint detection algorithm was used to identify the lowing of individual cows. The Friedman analysis was then used to select the sound features with significant differences before and after oestrus in terms of time, frequency, and cepstrum, and these were used to determine the most acceptable feature combination. We then analysed the effects of Back Propagation Neural Network (BPNN), Cartesian Regression Tree, Support Vector Machine, and Random Forest classification on the accuracy, precision, sensitivity, specificity, and F1 score of oestrus discrimination. Different time windows were used, and the discrimination performance of these algorithms was evaluated using the Area under Receiver Operating Characteristic Curve to find the most satisfactory match between the time window and the recognition algorithm. The dual-channel acoustic tag’s accuracy, precision, sensitivity, and specificity results were 91.25, 98.83, 91.75, and 83.68%, respectively. BPNN with the 70 ms time window and the feature combination (spectral roll-off + spectral flatness + Mel-Frequency Cepstrum Coefficients) was confirmed as the most suitable oestrus recognition method. The average accuracy, precision, sensitivity, specificity, and F1 score of this method were 97.62, 98.07, 97.17, 97.19, and 97.63%, respectively. Based on these results, the approach was shown to be a feasible means of oestrus detection in dairy cows. Based on its ability to differentiate cows and its consistency, it was demonstrated that sound has the potential to replace accelerometers as an early indicator of oestrus in dairy cows.

Cervical opening during estrus in Aceh Local Cows based on camera-equipped artificial insemination endoscope

Twelve healthy and not pregnant local cows, aged 3-6 years, 1-3 parity. The cows were synchronized using the PGF2α of 5 ml/cow intramuscularly, twice at 11 days intervals. The Estrus detection based on the scoring of van Eerdenburg was conducted 24 hours after the second prostaglandin injection three times daily for three days. The changes in cervical dilatation were observed at 0, 6, and 12 hours from the onset of estrus. The result showed that 8 of 12 cows were estrus after twice PGF2α injection. All the estrus cows showed mild cervical dilatation with liquid and transparent mucus (opening cervix score 1) at 0-hour observation. Six hours later, 62.50% of cows remained at opening cervix score 1, and 37.50% changed to opening cervix score 2 (optimum cervical dilatation with thick and transparent mucus). At 12 hours after the onset of estrus, 25% of estrus cows had cervical closure (opening cervix score 0, closed cervical with thick and turbid mucus), and 75% changed to opening cervix score 2. In this study, 75% of the cows experienced an optimum open cervix at 12 hours from the onset of estrus. It could be concluded that opening the external cervical canal of local Aceh cows reaches optimum at 12 hours from the onset of estrus.

Cervical opening during estrus in Aceh Local Cows based on camera-equipped artificial insemination endoscope

Twelve healthy and not pregnant local cows, aged 3-6 years, 1-3 parity. The cows were synchronized using the PGF2α of 5 ml/cow intramuscularly, twice at 11 days intervals. The Estrus detection based on the scoring of van Eerdenburg was conducted 24 hours after the second prostaglandin injection three times daily for three days. The changes in cervical dilatation were observed at 0, 6, and 12 hours from the onset of estrus. The result showed that 8 of 12 cows were estrus after twice PGF2α injection. All the estrus cows showed mild cervical dilatation with liquid and transparent mucus (opening cervix score 1) at 0-hour observation. Six hours later, 62.50% of cows remained at opening cervix score 1, and 37.50% changed to opening cervix score 2 (optimum cervical dilatation with thick and transparent mucus). At 12 hours after the onset of estrus, 25% of estrus cows had cervical closure (opening cervix score 0, closed cervical with thick and turbid mucus), and 75% changed to opening cervix score 2. In this study, 75% of the cows experienced an optimum open cervix at 12 hours from the onset of estrus. It could be concluded that opening the external cervical canal of local Aceh cows reaches optimum at 12 hours from the onset of estrus.

Exploring synchrony of lying on commercial dairy farms in relation to management

Synchronous lying may be an indicator of positive welfare in dairy cows. However, little is known about whether farms differ in the level of lying synchrony and how consistent this is within a farm. Moreover, the level of synchrony may vary within the day. Accelerometers used for estrus detection of cows enable continuous monitoring of synchronous lying of herds. We studied the level, timing and duration of synchronous lying in 8 Holstein Friesian or Holstein dairy herds across 1 year, in relation to grazing and milking management (robotic milking, 2x and 3x daily milking). In ‘winter’ months (November-March), herds were housed; in ‘summer’ months (May-September), 6 of 8 herds had access to pasture for 5–8 h per day, the other 2 herds were full-time housed. April and October were excluded because of variable management. Herds had 0.9–1.4 cubicles available per cow. After cleaning individual accelerometer data, herd average lying time was computed per 15-min (900 s) interval. An interval was defined as synchronous lying when the herd average lying time > 540 or > 630 s (i.e. assuming 60% or 70% of the herd was lying). Daily synchronous lying time was defined as the number of synchronous intervals × 15 min. A general linear model was used to assess effects of farm, season, and their interaction on synchronous lying time per day; with Tukey-adjusted pairwise comparisons. Correlations were made per farm per season to assess the association between total daily lying time and synchronous lying time. Across all herds and calendar days, the highest level of synchrony reached was on average 78%. Most synchronous lying occurred between 2AM and 6AM, though this was not true for all farms. Synchronous lying occurred least between 4 and 8 PM. Across farms, average synchronous (60% threshold) lying time per day was 5.9 h in summer (range: 2.7 – 7.9 h) and 5.5 h in winter (range: 1.6 – 9.1 h). In 3 out of 6 farms with grazing, synchronous lying time was higher in summer due to occurrence of synchronous lying during periods with pasture access. On 2 farms, synchronous lying time was higher in winter than summer due to increased synchronous lying at night. Across farms, average daily lying time and synchronous lying time generally showed moderate correlations. Monitoring synchronous lying in dairy herds using accelerometers was feasible, and 24-h synchrony patterns seemed consistent within farms. Its validity as a positive or negative welfare indicator requires further study.