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Copyright of Journal of Animal Production & Processing Technology / JurnalIlmu Produksi dan Teknologi Hasil Peternakan is the property of IPB University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As the beef industry moves towards efficient animal production to improve sustainability in agriculture, new production and management approaches are emerging. Among the many facets of the beef industry, cow–calf operations have the most opportunity for efficiency improvement, including improvements in fertility. This project accounts for measures and methods of (1) twinning reproductive technologies and (2) twin calf perinatal care and pre-weaning rearing. The overall objective was to produce twin calves using two reproductive technologies—embryo transfer and artificial insemination. The subobjectives were to determine accuracy of twin pregnancies embryo/fetal losses using ultrasonography, evaluate parturition and dystocia, and determine the effects of different twin-raising methods on neonatal behavior and growth. A fixed-time artificial insemination (FTAI) protocol was applied to 77 multiparous Angus-cross cows from a commercial beef herd in northcentral South Dakota during the summer of 2019. Cows were assigned to two different treatments groups: only artificially inseminated (AI) or received an embryo transfer following artificial insemination (ET + AI). They were estrous-synchronized, artificially inseminated (AI) with black Angus semen at day 0, and received and embryo transfer (ET) at day 7. Ultrasound examination detected 56% pregnancy risk for both groups, with sensitivity, specificity, and accuracy of 75%, 100%, and 90.5%, respectively, for bilateral twin detection. Calves were born during spring 2020. Twin calves (n = 34) and singleton calves (n = 11) were assigned to one of three raising methods: (1) twin born and twin raised (TT; n = 16), (2) twin born and single raised (TS; n = 18), and (3) single born and single raised (S; n = 11). Neonatal nursing behavior and birth weights were recorded, and adjusted day 200 and day 280 were calculated measures of vitality and growth. Blood samples were collected at age 24 h for colostrum intake measures (total serum protein, IgG1, and IgM). Twin calves were born 20% (p < 0.05) lighter in body weight than singletons; however, weights did not differ at day 280 between TT and S calves. TS calves had the shortest average latency to stand, but immunoglobulin concentrations did not differ among treatments. At weaning, cows that had birthed and raised twins produced more kilograms of live weight per pregnancy than cows birthing and raising singletons. Using ET + AI proved to increase twinning rate, and growth was maintained when raising both twins with their dam. [ABSTRACT FROM AUTHOR]

This research was conducted in person in Diyarbakir province, Kayapınar district, by means of a questionnaire with a total of 120 people engaged in cattle breeding in 21 settlements. The questionnaire addresses the existence of cattle farms, the general structural status of cattle farms, information provided by owners, feed supply and feeding practices, animal health and treatment practices, reproduction and artificial insemination practices, production and marketing of animal products on farms, housing status and support utilization status. It has been shown that the farms are small farms and 92% of the farms have closed barns. The fact that the majority of farm owners are between 40 and 61 years old can be seen as a danger signal for livestock. It was found that there is no cooperative in the villages except Cumhuriyet district, which brings the problem of marketing raw milk and dairy products. In the study area, it it has been observed that activities such as animal care feeding, estrus monitoring and application, and automation in animal husbandry are insufficient. For sustainable animal production, relevant public institutions and organizations need to work more intensively and carry out training, monitoring and evaluation activities to increase productivity per animal in enterprises, to train operators on herd management, care and feeding and animal health, and to meet expectations by solving problems in enterprises. This research provides us with important data about the general structure of cattle breeding in Kayapınar district of Diyarbakır province. [ABSTRACT FROM AUTHOR]

This study investigated the effects of timed artificial insemination (TAI) and equine chorionic gonadotropin (eCG) administration on lactating dairy cows under heat-stress conditions (average temperature-humidity index: 80). Timed artificial insemination was performed on the cows with (n = 57) or without (control, n = 41) supplementation with 500 IU of eCG at the day of PGF2α treatment using the CIDR-Ovsynch protocol. GnRH was administered, and a progesterone device (CIDR) was inserted on Day -10 of the treatment protocol. The CIDR was removed on Day -3, and the cows were treated with PGF2α. Two days later, a 2nd GnRH injection was administered. Subsequently, AI was performed on Day 0 (16-20 h after the 2nd GnRH injection), and pregnancy was diagnosed on Days 32 and 60. Plasma progesterone (P4) concentrations were measured after AI. Results showed that the eCG group had a higher pregnancy per AI (P/AI) than the control group (43.9 vs. 12.2%, P = 0.002), which was also accompanied by elevated P4 levels. Four cows in the eCG group had multiple calves, representing 7.0 and 16.0% of the group and pregnant cows, respectively. In conclusion, 500 IU of eCG combined with CIDR-Ovsynch in lactating dairy cows under severe heat stress conditions successfully improved fertility. However, the protocol may have a slight risk of multiple births. [ABSTRACT FROM AUTHOR]

The objectives of the study were to evaluate: I. the predictive value of estrus expression on pregnancy rate at timed artificial insemination (TAI); II. the causal effect of administering GnRH at the time of TAI on the pregnancy rate in cows that did not express estrus; III. if GnRH administration in cows that do not exhibit estrus allows achieving pregnancy rates at TAI similar to those obtained in cows that exhibit estrus. A total of 406 suckled Angus cows were synchronized using a protocol based on intravaginal progesterone devices (IVPD), estradiol benzoate, a luteolytic agent, and estradiol cypionate (CPE). All animals were painted in the sacro-coccygeal region upon removal of the IVPD, and they were considered to be in estrus if they had at least 30% of the tail-paint rubbed-off. The cows that did not exhibit estrus were randomly allocated to receive or not receive a dose of gonadorelin acetate (GnRH) at the time of timed artificial insemination (TAI). All cows were inseminated within 48 to 54 hours after removal of the IVPD. Pregnancy diagnosis was performed 37 days post-TAI by ultrasonography. Estrus expression was associated with a higher pregnancy rate at TAI [56.1% (148/264) vs. 29.6% (21/71); P< 0.001]. GnRH administration improved the pregnancy rate at TAI in cows that had not expressed estrus [49.3% (35/71) vs. 29.6% (21/71); P= 0.026]. GnRH administration in cows that had not exhibited estrus allowed achieving pregnancy rates closer to those obtained in cows that exhibited estrus [56.1% (148/264) vs. 49.3% (35/71); P= 0.312]. In conclusion, estrus expression between IVPD removal and TAI is associated with a higher pregnancy percentage at TAI. Moreover, treatment based on GnRH application in cows that do not exhibit estrus improves the pregnancy rate at TAI, approaching the pregnancy rate achieved in cows that exhibit estrus. [ABSTRACT FROM AUTHOR]

This study aims to identify the differences in reproduction performance of Ongole cross (PO), Limousine cross (Limpo), and Simmental cross (Simpo) in Kerek district, Tuban regency. Primary data was taken by interviewing inseminators and farmers, while secondary data was taken from the Fisheries and Animal Husbandry Department of Tuban regency. The total sample was 360 cows consisting of 30 PO, Limpo, and Simpo cows aged 3, 4, 5, and 6 years respectively which were calculated based on the Roscoe formula. Data was analyzed using the Simple Linear Regression and ANOVA followed by Duncan's multiple range test at a significance level of 95%. The results showed that the services per conception (S/C), conception rate (CR), and calving rate (CvR) were not significantly different (p >0.05) between PO, Limpo and Simpo cows. Meanwhile, days open (DO) and fertility status (FS) of PO cows were higher (p <0.05) than Limpo and Simpo cows. There was no significant difference (p >0.05) in DO and FS between Limpo and Simpo cows. The linear equation with age as a predictor (X) of S/C, DO, and CI (Y) values were not significant (p >0.05) in PO, Limpo, and Simpo cows. It could be concluded that the reproductive performance of PO cows was better than Limpo and Simpo cows. [ABSTRACT FROM AUTHOR]

Copyright of Indonesian Journal of Animal & Veterinary Sciences / Jurnal Ilmu Ternak dan Veteriner is the property of Indonesian Center for Animal Science Research & Development and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Animal Health, Production & Hygiene is the property of Animal Health, Production & Hygiene and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bovine leukocyte adhesion deficiency syndrome (BLAD) is an autosomal recessive hereditary disease in Holstein-Friesian cattle. The extensive use of artificial insemination led to the rapid spread of the condition during the 1990s worldwide. Irrespective of the introduction of genetic testing programs there are still carriers found among breeding animals. Therefore the problem needs to be popularized as rare but economically relevant that should be distinguished from other common causes for calfhood maladies. [ABSTRACT FROM AUTHOR]

Pote goats are kept by the rural community in Bangkalan regency, Madura island, Indonesia. Symptoms of estrus in goats are usually unclear, causing low fertility. This study aims to evaluate intracervical artificial insemination performed in early and mid-estrus on Pote does. Twenty four does were randomly divided into two groups and their estrous was synchronized using two injections of 200 µg PGF2a intramuscularly with 11 days interval. In the T1 group, Pote does that were in estrus were inseminated at early estrus (0-12 hours after signs of estrus appeared), while in the T2 group, Pote does that were in estrus were inseminated at mid-estrus (12-24 hours after signs of estrus appeared). The insemination conducted artificially using frozen-thawed Boer semen. The observed variables were non-return rate at day-21 post-insemination (NRR21), and pregnancy rate (PR) based on abdominal palpation diagnosis. The result showed that frozen-thawed Boer semen was qualified (spermatozoa motility more than 40%) for artificial insemination. All Pote does were in estrus after two intramuscular injection of PGF2a with an interval of 11 days. The onset of estrus was 48-72 hours after the second injection PGF2a. The NRR21 and PR of the T2 group (66.7 and 100%) were higher than those of the T1 group (37.5 and 66.7%), respectively. It could be concluded that intracervical artificial insemination in Pote does in mid-estrus was more effective, resulting in higher NRR21 and PR than in early estrus. [ABSTRACT FROM AUTHOR]

Twelve healthy non-pregnant local cows, aged 3-6 years with parity of 1-3, were used in this study. The cows were synchronized using PGF2a (5 ml/cow, intramuscularly), twice at 11 days intervals. Estrus detection based on the scoring of van Eerdenburg was conducted 24 hours after the second prostaglandin injection. Estrus was detected three times daily for three days. The changes in cervical dilation were observed at 0, 6, and 12 hours after the onset of estrus using camera-equipped artificial insemination endoscope. The results showed that 8 out of 12 cows were in estrus after two injections of PGF2a. All cows in estrus showed slight cervical dilation with clear liquid mucus (cervical opening score 1) at 0-hour observation. Six hours later, 62.50% of cows remained at cervical opening score 1, and 37.50% changed to cervical opening score 2 (optimum cervical dilation with clear thick mucus). At 12 hours after the onset of estrus, 25% of estrus cows had cervical closure (cervical opening score 0, closed cervix with thick and cloudy mucus), and 75% changed to cervical opening score 2. In this study, 75% of the cows experienced an optimum cervical opening at 12 hours after the onset of estrus. It could be concluded that the opening of the external cervical canal of local Aceh cows is optimal at 12 hours after the onset of estrus. [ABSTRACT FROM AUTHOR]

Copyright of Journal of the Chinese Society of Animal Science is the property of Chinese Society of Animal Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Kocatepe Veterinary Journal / Kocatepe Veteriner Dergisi is the property of Afyon Kocatepe University, Faculty of Veterinary Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The gonadotropin-releasing hormone (GnRH) is a decapeptide, synthesized by the GnRH neurons in the hypothalamus, which stimulates the synthesis and secretion of gonadotrophins (follicle-stimulating hormone, FSH and luteinizing hormone, LH) from the anterior pituitary or adenohypophysis. GnRH agonists with a structure identical or similar to nature have been commercially available since the 1970's and were initially used for the treatment of follicular cysts and the improvement of fertility in cattle (1). The ovulation of ovarian follicles after GnRH administration was first reported by Schams et al. (2) and Britt et al. (3), but it was not until the 1990's that GnRH began to be used to control follicular dynamics during the bovine estrous cycle. Studies have shown that a new follicular wave emerges within 2 days after ovulation of the dominant follicle present at the time of GnRH treatment (4,5). This finding facilitated the development of synchronization protocols based on GnRH in combination with prostaglandins (PGF) that allow fixed-time artificial insemination (FTAI), without the need for heat detection. These GnRH-based protocols are part of the reproductive management, especially in dairy cattle, in many commercial herds around the world. There are several GnRH and PGF-based protocols available for estrus and ovulation synchronization in cattle, most of these protocols have been explained and discussed in detail in other publications (6,7). The objective of this review is to describe the factors associated with the release of LH and ovulatory response after the administration of GnRH, to present relevant information on the effect of steroid hormones on the response to GnRH and, finally, to briefly postulate strategies that could improve the efficacy of GnRH and PGF-based protocols. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of injectable progesterone (P4)/ estradiol combination on the onset of puberty in heifers and on pregnancy rates to fixed-time AI (FTAI) in beef cows and heifers when it was used 15 prior to the initiation of the synchronization protocol. In Experiment 1, 15-month-old Angus x Charolais heifers (n=79) were randomly divided into two treatments. In Group 1 (GI): they received 4 ml of BullSynch i.m. on Day 0 (Agropharma, Argentina) containing 200 mg P4 and 2 mg estradiol benzoate (BE) and on Day 8: 1 mg BE i.m. Heifers from GII remained as an untreated control group. The experiment was repeated for two consecutive years. In both groups, blood samples were obtained to determine plasma P4 concentrations (Day -10 and 0) and transrectal ultrasonographic examinations were carried out (Days -10, 0, 8 and 5 after estrus) to determine follicular diameter and absence or presence of a corpus luteum (CL). Estrus was detected by visual observation every 12 h, from Day 8 to Day 12. In Experiment 2, multiparous cows (n=92), dry cows (n=177), and heifers (n=53) were randomly divided in two groups (G), regardless of ovarian status: 1) GI (treated): received a dose of 4 mL of P4/BE injectable (BullSynch, Agropharma, Argentina) on Day 0, 2) GII (control) remained untreated. In both groups, a conventional hormonal treatment for FTAI was started on Day 15 after the BullSynch administration. Pregnancy was determined by ultrasonography 35 days after insemination. In Experiment 1, estrus (GI:75.6% vs. GII:17.2%) and ovulation rates (GI:86.5% vs. GII: 27.5%) were greater (P<0.05) in GI than in GII and this result was repeated in both years. In Experiment 2, the pregnancy rate in GI was numerically higher than that in controls, although the difference was not significant in any category (P>0.05). However, overall pregnancy rate to FTAI was greater in animals that were treated with BullSynch (GI) than in those in the GII (GI: 52% vs GII: 40%; P=0.04). It is concluded that the application of a combination of injectable progesterone/estradiol benzoate induces puberty in heifers and increases the pregnancy rate to FTAI when applied 15 days prior to the initiation of the synchronization protocol. [ABSTRACT FROM AUTHOR]

The reproductive efficiency of a herd is of enormous importance in the viability of a livestock business. A technical update was made of the most common handling errors that affect artificial insemination (AI) efficiency, with the aim of implementing simple but highimpact corrective measures. The AI technique encompasses multiple management factors that impact on the pregnancy rate, several of them will be considered. The review is framed in the following aspects: a) Errors in the management of heat detection: practical, simple and economical solutions b) Errors in the handling of frozen semen, thawing technique and elements to carry out the AI y c) Rectal-cervical method: difficulties in sowing and errors in the place of semen deposition in the female genital tract. [ABSTRACT FROM AUTHOR]

Background: The intensive reproductive management in the dairy farms requires inclusion of a large group of replacement heifers in the breeding program for a shorter period. In this aspect, a creation of effective estrus synchronization protocols with timed artificial insemination (TAI) by sexed semen and optimization of the current ones have a crucial role for obtaining high pregnancy rate. These protocols are beneficial, because they led to reduced interval to first AI, lack of need for estrus detection, and allow obtaining a large group of female calves for on time. Because of limited fertilizing potential of sexed spermatozoa this type of semen is applied mainly for heifers, as fertility is higher compared to lactating cows. The main objective of the present study was to investigate the effect of ovarian status on the reproductive performance in dairy heifers subjected to estrus synchronization and timed artificial insemination with sexed semen. Materials, Methods & Results: Forty-eight Holstein healthy heifers separated in 2 groups were subjected to PGF2α-GnRH pre-treatment and Ovsynch or PRID-5-day estrus synchronization protocol and timed artificial insemination (TAI) with sex-sorted semen, staring 6 days after end of the hormonal pre-treatment. The ovarian status (presence of follicles with or not a corpus luteum) of the heifers at the begin of the treatment, on day of TAI and pregnancy rate in different groups were determined and compared. Additionally, the ovarian status at the begin of the treatment, ovarian status and size of preovulatory follicle (PF) on day of TAI and total values for both groups according to reproductive performance (pregnant or non-pregnant) were also analyzed. On day of TAI the animals with PF and a lack of corpus luteum (CL) in both groups were more that those with PF and CL (39.3% and 30% vs. 60.7 % and 70%), with significant (P < 0.05) difference in PRID-5-day group. The pregnancy rate tended to be higher in PRID-5 day than Ovsynch treatment (65% vs. 35.7%). A higher percentage (100% and 67.9%) of the pregnant animals in both treatments had not CL on day of TAI, and the size of the PF (1.58 ± 0.12 cm and 1.64 ± 0.13 cm) was increased (P < 0.05). Similar effects of the ovarian status on reproductive performance were obtained after a comparison of the total values between pregnant and non-pregnant animals. The percentage of heifers with observed PF without CL on day of TAI was significantly greater (P < 0.05) in pregnant compared to non-pregnant group (91.3% vs. 40%). The opposite dependence was determined for the parameter presence of follicles and corpus luteum (8.7% vs. 60%; P < 0.05). Furthermore, the size of the PF measured immediately before TAI was increased in animals became pregnant (1.60 ± 0.12 cm vs. 1.34 ± 0.17 cm; P < 0.05). Discussion: The analysis of the obtained results showed that the ovarian status on day of TAI affects the reproductive performance in dairy heifers subjected to estrus synchronization and timed artificial insemination with sexed semen. Hormonal pre-treatment with onset of PRID-5-day protocol 6 days later and TAI with sex-sorted semen ensure acceptable pregnancy rate. The greater preovulatory follicle and a lack of corpus luteum before insemination provide significantly (P < 0.05) more pregnant animals, compared to the cases when CL is presented. Ultrasound determination of the ovarian function before insemination can be used in selection of heifers for TAI with sex-sorted semen. [ABSTRACT FROM AUTHOR]

Meiotic de novo mutation (DNM) is one of the important phenomena contributing to gamete genome diversity. However, except for humans and a few model organisms, they are not well studied in livestock, including cattle. Moreover, bulk sperm samples have been routinely utilized in experiments, which include millions of single sperm cells and only report high-frequency variants. In this study, we isolated and sequenced 143 single sperms from two Holstein bulls and identified hundreds of candidate DNM events in ten sperms with deep sequencing coverage. We estimated DNM rates ranging from 1.08 x 10-8 to 3.78 x 10-8 per nucleotide per generation. We further validated 12 out of 14 selected DNM events using Sanger sequencing. To our knowledge, this is the first single sperm whole-genome sequencing effort in livestock, which provided useful information for future studies of point mutations and male fertility. Our preliminary results pointed out future research directions and highlighted the importance of uniform whole genome amplification, deep sequence coverage, and dedicated software pipelines for genetic variant detection using single-cell sequencing data. [ABSTRACT FROM AUTHOR]

The article discusses case study of inbreeding within Black cattle and mentions heritability estimates of carcass traits of beef cattle. Topics discussed include accomplishment of breeding strategy of quality of meat similar to that of Japan, goal of cooperating breeder to build nucleus population of Wagyu for breeding program, and calculation of Artificial Insemination (AI) sires.

Тhe domestic rabbit is a valuable species because of the qualities of its meat. It is also used for the production of wool and fur. In Bulgaria, the rabbit is mainly raised for the production of rabbit meat. Breeding of rabbits in intensive and semi-intensive farms is carried out mainly through hormonal stimulation and artificial insemination. In recent years, in rabbit breeding has been used modern molecular methods including various analyzes at the DNA level – microsatellite markers, RFLP, QTL etc. In Bulgaria, there are very few studies associated with the genome of rabbits and the phenotype expression of genes. Тhе experimental work at the molecule level and the application of new techniques contributes to the development and fast progress in this direction, and this has a significant advantage in creating different ways of working in this field. [ABSTRACT FROM AUTHOR]

The technique of timed artificial insemination (TAI) has been transformed into a tool to standardize the reproductive management of commercial beef and dairy herds. It has recently been shown an increase in pregnancy rates to TAI in dairy heifers using protocols that reduce the period of insertion of the device and prolong the proestrous period, called 5-day Co-Synch protocols. In South America, TAI protocols used mainly estradiol benzoate (EB) and progesterone devices. The J-Synch protocol is a protocol that uses estradiol and progesterone devices in which the device insertion period is reduced to 6 days and the proestrous period is prolonged by administering GnRH and perforoming the TAI at 72 hours after removal of the progesterone device. This protocol is presented as an interesting option for its practicality of implementation and the results are very encouraging in terms of pregnancy rates. The aim of this study was to compare the J-Synch protocol with the 5- day Co-Synch protocol (both have prolonged proestrus) to the conventional protocol (short proestrus), one of the most widely used TAI protocols in South America. The results confirm that the J-Synch protocol presents a proestrus that was, on average, 21 hours longer than the conventional protocol. Although, pregnancy rates were not significantly different between protocols, pregnancy results were higher in the J-Synch protocol than in the conventional protocol in all replicates performed. The J-Synch treatment was efficient to synchronize ovulation in dairy heifers and in addition, its application is practical because it requires to manage the animals only three times. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to evaluate the effect of pre-synchronization with progesterone (P4) for 3 and 6 days in Nelore cows in postpartum anestrus period, submitted to a fixed-time artificial insemination program (FTAI). Materials and methods: Seventy-four multiparous Nelore cows with a body condition of 2.5 were used. The cows were submitted to three experimental groups, control group and groups pre-synchronized with P4 for a period of 3 and 6 days. For the determination of postpartum anestrus status, ultrasound scans and blood samples were taken to verify the absence of endogenous P4. Forty-five days after AI, gestation was diagnosed. Data were obtained by descriptive analysis and in the case of presentation of significant differences the Chi-square test was used, considering a frequency of P < 0.05. Results: A higher gestation rate was observed for the group that was pre-synchronized for three days with P4 (40 %), in relation to the groups of six days of pre-synchronization and control (25 % and 32 %, respectively). Conclusion: It is possible to conclude that the pre-synchronization with P4 for three days improved the gestation rate of Nelore cows in the postpartum anestrus period. [ABSTRACT FROM AUTHOR]

The goal of this study was to assess if a designed prostaglandin (PGF2α)-protocol when used against natural mating (NM) in well-managed Mpwapwa cattle would improve pregnancy rates during the breeding season. Of the PGF2α oestrus synchronization protocols, a standard 14-day PGF2α protocol accompanied with fixed-time artificial insemination (FTAI) was tested against NM. Totals of 39 and 49 cows became pregnant in the FTAI and NM groups respectively following completion of the study of 100 cows for each group. Statistically, the difference between the two groups was not significant (P=0.21), even though there was a lower risk of pregnancy in the FTAI group compared to the NM group (unadjusted relative risk: 0.8, 95%CI: 0.58-1.09). The results from this study suggest that PGF2α–based synchronization protocol and FTAI, especially when combined with NM in Mpwapwa breed cattle, can yield better reproductive performance and enhance greater genetic improvement compared to being naturally serviced. Few cows (only 10/100 cows) displayed behavioural oestrus signs after receiving the first PGF2α injection. The poor oestrus response might be due to either ineffective detection of oestrus or cows lacked a responsive corpus luteum (CL) at the time of synchronisation. Therefore, this might reflect a large number of cows to have been in anoestrus. Further investigation on the reproductive status and performance of Mpwapwa cows is needed to identify the effects of anoestrus. [ABSTRACT FROM AUTHOR]

Copyright of Jurnal Veteriner is the property of Fakultas Kedokteran Hewan, Universitas Udayana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Veterinarska Stanica is the property of Croatian Veterinary Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Dairy cattle breeding is one of the most important branches of livestock production, which has been facing, for several decades, the chronic problem of declining reproductive performance. In 2005, the number of cattle worldwide was about 1,370,000,000, while in 2015 that number dropped below one billion, and in 2021 it shows a slight recovery as it was 1,000,970. This indicates the importance of applying different reproductive protocols in order to increase the number of cows in production. The type of bedding on which the animals stay, as well as the characteristics of the lying area itself, shows a significant impact on numerous physiological functions such as food intake, chewing, milk yield, but also levels of sex hormones. The type of bedding and lying area, which causes chronic pain and stress, leads to disorders of physiological and reproductive processes, since stress has direct negative impact on numerous cellular functions. A total of 66 dairy cows, 50 Holstein-Friesian cows kept on PD Butmir and 16 Simmental cows kept on a private mini farm, were included in the study. At PD Butmir, cows were kept in tie-stall housing system, while on a mini-farm they were kept free. Hormonal protocols of estrus and ovulation synchronization were used in April, May and June 2019. Cows were subjected to two estrus synchronization and ovulation protocols, Ovsynch and Cosynch72. At PD Butmir, 25 cows were subjected to Ovsynch and Cosynch72 protocols, respectively. At the mini-farm only Ovsynch protocol was applied. The Ovsynch protocol applied on PD Butmir had success in conception rate of 12% (n = 3), while the Cosynch72 protocol gave a score of 36% (n = 9). On the mini-farm, Ovsynch resulted in a conception of 25% (n = 4). Based on our results, the Cosynch72 protocol, compared to the Ovsynch protocol, was a better choice in the case of Holstein-Friesian cows kept in the tie-stall housing system. In the Simmental cows kept in the free stall system, the Ovsynch protocol proved to be better choice in achieving conception, compared to the Holstein-Friesian cows. Therefore, it is necessary to test several different protocols of estrus and ovulation synchronization, in order to find the most optimal one for a certain breed, type of keeping and breeding. [ABSTRACT FROM AUTHOR]

The present study aims to assess the influence of the age of first insemination and first calving in Holstein-Friesian heifers on the cost of breeding and the cost of their marketing as breeding animals. For this purpose, a study was conducted on 7 farms (A, B, C, D, E, F, G) situated in Central and Southern Bulgaria in which Holstein-Friesian cattle are bred. The results of the study indicated that the age of first insemination in the controlled farms was 17.2 months on average, and the age of first calving (AFC) was 26.6 months, which was within the established norms for the Holstein-Frisian breed raised in the country. The heifers from farm A, which entered breeding age the earliest (at 16 months), as well as the age of first calving (25.3 months) had the longest utilisation period - 4.9 lactations. However, they did not develop the highest milk yield either and the economic performance from their raising was low. The heifers on farm F, with age of first insemination of 17.3 months, and first calving age of 26.8 months, and the ones from farm G, with ages 17.4 and 26.6 months, respectively, developed maximum milk yield per lactation. The expenses for raising a heifer of the Holstein-Frisian breed varied from BGN 1922 up to BGN 2389, with an average sum of cost for the studied farms amounting to BGN 2123. This indicated that the raising of heifers from a high-yield breed was an expensive undertaking, but when taking the necessary care for their breeding at a younger age during the period of use they developed higher milk productivity. [ABSTRACT FROM AUTHOR]

The article focuses on clinical significance of vaginal leakage in dairy cattle. Topics discussed include reason for concern lies in the fact that vaginal discharge can be associated with inflammation of the uterus; economic impact on the herd delaying uterine involution, delaying first insemination, reducing the rates of conception, increasing the risk of elimination involuntary rodeo cows and chronic inflammation of the uterus are associated with the presence of a corpus luteum persistent.

This study aimed to elevate of fertility rate eCG and bovine polyclonal anti eCG toward the rate of pregnancy in Madura cows at Bangkalan, Madura. The experimental animal used in this study comprised of 30 cows, with normal estrus cycle and 3 years old of age. The Madura cows are all healthy with a body score of at least 3. The Control Group (p0) was injected with PGF2á 25 mg intramuscular (im) twice on day 0 and day 11. Treatment Group 1 (p1) was injected with PGF2á 25 mg and eCG dosage administration to increase of fertility rate of 750 IU im. Treatment Group 2 (p2) was injected with PGF2á 25 mg and eCG dosage of 750 IU im as dosage to increase of fertility rate and bovine polyclonal anti eCG 750 IU at 48 h or 60 h after PGF. On day 14, the Madura cows both control and Treatment Group respectively showed signs of estrus 100% p >0.05. Few hours' later artificial insemination was performed on the same day. On day 30, all 30 Madura cows were checked for pregnancy using Ultrasonography (USG). The Madura cows were assumed to be pregnant because there were signs of enlargement in cornua uteri unilaterally. Therefore, this indicates that there was no significant difference between Treatment Group 1 and Treatment Group 2 in pregnancy rate. Based on the results, Control Group (T0) showed 50% of the Madura cows were pregnant. Meanwhile, Treatment Group 1 (T1) 60% and Treatment Group 2 (T2) showed 70% pregnant from Madura cows p > 0.05 on day 35. Therefore, this research showed a positive feedback consistent with the objective. [ABSTRACT FROM AUTHOR]

The current study aimed to evaluate motility and viability of chilled ram semen collected by artificial vagina and electroejaculation during the non-breeding season. A total of 18 ejaculates from clinically healthy rams in a non-breeding season were collected by artificial vagina (AV; n = 9) and electroejaculation (EE; n = 9) and submitted to preliminary evaluation. After that all ejaculates were diluted through a Tris-based extender containing low concentration (5%) of glycerol and egg yolk and stored at 5°C for 48 hours. Motility and viability of semen samples were evaluated at 0, 6, 24 and 48 h of storage. Estimation of motility was carried out by a microscopic digital system, and viability was assessed by the one-step eosin-nigrosin staining technique. Until 6 h of storage, the differences between motility and viability of semen collected by AV or EE were non-significant, while at 24 and 48 h the parameters were higher (P < 0.05) in semen collected by AV. The increasing time of storage correlated negatively with the evaluated parameters (P < 0.05). In conclusion, the chilled semen from ram in the non-breeding season collected by AV demonstrated better motility and viability until 48 h, compared with the semen collected by EE, and could be recommended for artificial insemination up to 24 h after storage at 5°C. The time of storage had a negative effect on sperm motility and viability (P < 0.05). [ABSTRACT FROM AUTHOR]

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Previous research has indicated that gender-sorted semen has decreased conception rates compared to conventional semen. A new method to skew the gender ratio of semen has been developed that does not use traditional sorting technology. Thus, the objective of this study was to evaluate the use of gender-ablated semen in a fixed-time AI protocol. Beef heifers and cows (n = 878) from six herds were synchronized with the 7-d CO-Synch plus CIDR protocol, and artificially inseminated (AI) after CIDR removal (cows 60–66 h; heifers 52–56 h). Estrus detection aids were applied at CIDR removal and estrus activity was determined at time of AI. Animals remained separated from bulls for at least 10 d after AI. Pregnancy success and fetal age were determined between d 28 and 70 after AI. Semen from five sires was utilized in this study, with two sires used in each herd. Sire 1 was used in all herds and the use of the second sire varied by herd (both conventional and gender-ablated semen from each sire was used in each herd). Data were analyzed using the GLIMMIX procedure in SAS and included the influence of semen type, estrus expression, semen type by estrus expression, dam age, and sire in the model. Herd was included as a random variable. Overall, conventional semen had greater conception rates compared to gender-ablated semen (P < 0.01; 67% vs 52%), and cows that had fully activated patches and partially activated patches had greater conception rates compared to animals that had not exhibited estrus (P < 0.01; 69%, 65%, and 45%). There was no semen type by estrus expression interaction (P = 0.24). Conception rates tended to be greater for conventional semen among animals that had activated patches (P = 0.06; 73% vs 65%) and partially activated patches (P = 0.06; 72% vs 59%). Conception rates were greater for conventional semen (P < 0.01; 56% vs 33%) among animals that did not exhibit estrus. There was no effect of dam age (P = 0.40) or sire (P = 0.92) on conception rates. In conclusion, Sexcel™ gender-ablated semen can successfully be used in fixed-time AI protocols among animals that exhibit estrus, but caution should be used among animals that do not exhibit estrus. • Conventional semen had greater conception rates compared to gender-ablated semen. • Estrus increased conception rates with both gender-ablated and conventional semen. • Gender-ablated semen conception rates only tended to be decreased among animals in estrus. • Conventional semen had greater conception rates when animals did not exhibit estrus. [ABSTRACT FROM AUTHOR]

Artificial insemination technique is essential biotechnology in bull reproduction, chilled semen is an easy and inexpensive preservation method of semen when compared to cryopreservation technique. Researchers have been more interested in developing a preservation method by adding natural improvement elements to the extender that is used in chilled semen. Thus, this study was designed to evaluate the effectiveness of adding different concentrations of ω-3 to tris-egg-yolk extender of chilled bull semen. It involved the addition of 1%, 2% and 4% of ω-3 to tris-egg-yolk extender followed by evaluation of sperm parameters at three different time after incubation (24h, 48h and 72h) at 5C°. We found that the addition of 1% concentration of ω-3 significantly improved sperm parameter on day three from incubation. Conclusions: The results indicate that the addition of 1% omega-3 to trisegg yolk extender could be beneficial for the improvement of the quality of bull spermatozoa parameters included motility, viability and hypo-osmotic test. [ABSTRACT FROM AUTHOR]

A study was designed to assess factors affecting response to oestrus synchronization, conception and calving rate of communal cows following timed artificial insemination (AI) in Limpopo province, South Africa. A total of 140 cows were selected from communal villages based on; body condition score (BCS) of 2 and above (1-5 scale), not pregnant (excluding heifers), 90 days' post-partum, negative of contagious abortion (CA). A 9 day CIDR® protocol was used to synchronize the selected cows. The AI was done at 36 and 48 hours post synchronisation using Nguni frozen thawed semen. Pregnancy diagnosis was performed 90 days following AI. Data was analysed using logistic regression procedure of SAS. Cows that responded were 75%; of which 41% conceived and 36% calved. None of the factors such as district, age, parity, frame size and breed type significantly affect synchronization response and conception. However, BCS significantly affected calving rates. Small framed Nguni and Bonsmara type cows in their first parity with a BCS =3 had greater odds of conceiving to timed AI. In conclusion, acceptable oestrus synchronization response, conception and calving rate was achieved in communal setup regardless of BCS affecting calving. It is recommended that superior genetic materials can be successfully introduced through ARTs in organized communal production systems in South Africa. [ABSTRACT FROM AUTHOR]

Aim: Define the evolution of the seasonal behavior of births in cattle during the period 1982-2017 in Camagüey, Cuba. Materials and methods: The artificial insemination data of the Camagüey Milk Basin, corresponding to the period from January 1982 to December 2017, were registered in the provincial delegation of the Ministry of Agriculture of Camagüey, Cuba. The information was divided into four stages, 1982 to 1990 (stage I), 1991 to 1999 (stage II), 2000 to 2008 (stage III) and 2009 to 2017 (stage IV), considering the changes in Cuban agriculture with respect to the form of land tenure. Seasonal decomposition of births was performed with a multiplicative model, throughout the period and at each stage. The criterion used to consider the existence of seasonal variation was a minimum difference of 10%. Results: The seasonal factors reached positive values between February and July, with peaks in April and May throughout the period, with a seasonal pattern, common in the four stages characterized by the maximum values in the months of April and May. Conclusions: The results achieved determine the seasonality of births, which reaffirms the tendency of the dairy cow in Camagüey to match its biological behavior with the time of greater availability of pastures and, in this sense, the feasibility of strategically managing dairy herds regardless of the organizational changes that occurred in Cuban agriculture. [ABSTRACT FROM AUTHOR]

This study wants to demonstrate the importance of the feeding program on preparing heifers for first insemination. The study was done on a group of 35 heifers aged between 9-12 months on Agroserv Dairy Măriuţa. The varieties of the experimental group belong to the Holstein breed and are inseminated at the age of 12 months and the body weight of 400 kilos. The role of the dissimilar feeding program is to help the heifersto reach the body weight 75% of the adult weight, to show the heat and to install gestation. [ABSTRACT FROM AUTHOR]

The iSperm is a newly released semen analysis tool from Aidmics Biotechnology Co. LTD, which allows an iPad Mini to be transformed into a handheld microscope with objective semen analysis software for equine available through the Apple Store (version 4.5.2). The aim of this study was to compare iSperm values for sperm motility and sperm concentration to current acceptable methods for semen analysis and to determine the agreement with these methods using statistical methods. Two ejaculates from each of five Standardbred stallions were used to compare sperm motility (computer-assisted semen analysis [CASA] vs. iSperm) and concentration (NucleoCounter SP-100 [NC] vs. hemocytometer vs. iSperm). Data were analyzed by first testing for the differences between the means of each method using a linear mixed-effects model. The agreement between the two continuous measurements for each method was then investigated by computing Lin's concordance correlation coefficient (CCC), with a value of 1 indicating perfect agreement between methods. Results are reported as the CCC with the associated 95% confidence interval in parentheses. Means for both total motility (TM) and progressive motility (PM) were equal between CASA and iSperm values (P = 0.0741 and P = 0.725, respectively). However, means for all velocity measurements were significantly different between CASA and iSperm readings (P < 0.001). For concentration, means were equal between NC and iSperm values (P = 0.748) and for hemocytometer and iSperm values (P = 0.953). The CCC for TM was 0.871 (0.788, 0.923) and for PM was 0.916 (0.847, 0.955) indicating good agreement between methods. Low levels of agreement were observed for all velocity measurements. Finally, the CCC for concentration compared by iSperm and NC was 0.970 (0.949, 0.982) and for iSperm and hemocytometer it was 0.962 (0.934, 0.978), both close to the line of perfect concordance. Although more work is needed to improve the iSperm software for velocity measurements to be acceptable by research standards, in its present form the iSperm will introduce a low-cost and affordable method for on-farm semen analysis (TM, PM, concentration) for breeders and veterinarians. As a result, more farms will have access to accurate sperm analysis tools which will help to standardize semen processing procedures leading to better overall quality of semen used for artificial insemination. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to evaluate the impact of complexed trace mineral supplementation on ovum pick-up (OPU) and in vitro embryo production in lactating beef cows. Thirty days prior to fixed-time artificial insemination (FTAI; day −30), 68 postpartum cows were stratified by BW, BCS, and parity before being randomly assigned to 10 pens of either a treatment (TRT; n = 5) or a control (CNT; n = 5) group. Each group received a weekly mineral supplement allotment of 1.16 kg × week−1 × cow–calf pair−1 for 14 wk. Cows assigned to the TRT group received a mineral supplement that contained amino acid complexes of zinc, copper, and manganese, as well as cobalt glucoheptonate (Availa Plus; Zinpro Corp. Eden Prairie, MN, USA), while cows assigned to the CNT group received a mineral supplement that was formulated to contain similar concentrations of these trace minerals from inorganic sources. All cows were submitted to a 7 d CO-Synch + CIDR protocol on day −10 and bred using FTAI on day 0. Pregnancy diagnosis was performed on day 28 and nonpregnant cows were removed. All pregnant cows were subjected to ovum pick-up (OPU) on day 52 and 67 of gestation. Cumulus-oocyte complexes (COCs) were evaluated and graded prior to in vitro fertilization (IVF). Analysis of variance was conducted to determine effects of treatment on response variables, and pen was considered the experimental unit. Supplement consumption did not differ (P = 0.48) between treatments (1.16 ± 0.12 vs. 1.07 ± 0.15 kg of DM × week−1 × cow–calf pair−1 for TRT and CNT, respectively). Total COC recovery was greater (P = 0.03) from TRT when compared with CNT cows (22.4 ± 2.0 vs. 16.4 ± 1.4 COCs × pen−1, respectively) and the number of COCs meeting maturation criteria was increased in TRT cows (P = 0.05) when compared with CNT cows (15.9 ± 1.6 vs. 11.8 ± 1.0 COCs × pen−1, respectively). Production of transferable embryos tended to be greater (P = 0.06) for TRT than CNT cows (4.7 ± 0.6 vs. 2.7 ± 0.7 embryos × pen−1, respectively). Furthermore, when expressed as a ratio, the number of recovered COCs meeting maturation criteria that were required to produce a transferable embryo tended to be lower for TRT than CNT cows (3.10 ± 0.93 vs. 7.02 ± 1.60; P = 0.06). In summary, complete replacement with complexed trace mineral improved COC recovery and in vitro embryo production when compared with inorganic forms of these trace minerals in beef cows. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to evaluate the impact of complexed trace mineral supplementation on ovum pick-up (OPU) and in vitro embryo production in lactating beef cows. Thirty days prior to fixed-time artificial insemination (FTAI; day −30), 68 postpartum cows were stratified by BW, BCS, and parity before being randomly assigned to 10 pens of either a treatment (TRT; n = 5) or a control (CNT; n = 5) group. Each group received a weekly mineral supplement allotment of 1.16 kg × week−1 × cow–calf pair−1 for 14 wk. Cows assigned to the TRT group received a mineral supplement that contained amino acid complexes of zinc, copper, and manganese, as well as cobalt glucoheptonate (Availa Plus; Zinpro Corp. Eden Prairie, MN, USA), while cows assigned to the CNT group received a mineral supplement that was formulated to contain similar concentrations of these trace minerals from inorganic sources. All cows were submitted to a 7 d CO-Synch + CIDR protocol on day −10 and bred using FTAI on day 0. Pregnancy diagnosis was performed on day 28 and nonpregnant cows were removed. All pregnant cows were subjected to ovum pick-up (OPU) on day 52 and 67 of gestation. Cumulus-oocyte complexes (COCs) were evaluated and graded prior to in vitro fertilization (IVF). Analysis of variance was conducted to determine effects of treatment on response variables, and pen was considered the experimental unit. Supplement consumption did not differ (P = 0.48) between treatments (1.16 ± 0.12 vs. 1.07 ± 0.15 kg of DM × week−1 × cow–calf pair−1 for TRT and CNT, respectively). Total COC recovery was greater (P = 0.03) from TRT when compared with CNT cows (22.4 ± 2.0 vs. 16.4 ± 1.4 COCs × pen−1, respectively) and the number of COCs meeting maturation criteria was increased in TRT cows (P = 0.05) when compared with CNT cows (15.9 ± 1.6 vs. 11.8 ± 1.0 COCs × pen−1, respectively). Production of transferable embryos tended to be greater (P = 0.06) for TRT than CNT cows (4.7 ± 0.6 vs. 2.7 ± 0.7 embryos × pen−1, respectively). Furthermore, when expressed as a ratio, the number of recovered COCs meeting maturation criteria that were required to produce a transferable embryo tended to be lower for TRT than CNT cows (3.10 ± 0.93 vs. 7.02 ± 1.60; P = 0.06). In summary, complete replacement with complexed trace mineral improved COC recovery and in vitro embryo production when compared with inorganic forms of these trace minerals in beef cows. [ABSTRACT FROM AUTHOR]

The effect of artificial insemination (AI), embryo transfer (ET) to bull dams (BD), and sexed semen (SS) to cow dams (CD) with and without controlling inbreeding were studied using stochastic simulation. Three levels of embryo transfer (no ET, ET on all BD, and ET on 20% of BD), five levels of sexed semen (no SS: control, SS-X on all CD, SS-X on 20% CD, SS-Y on all CD, and SS-Y on 20% CD), three levels of artificial insemination (no AI, AI on 50% cows, and AI on 90% cows), two levels of mating system (random and minimum consistory) were combined together to make 66 scenarios in which the combination of no ET, no SS, and no AI are assigned as a control. The simulated population consisted of 40 herds with 50 cows each was monitored for 30 years. The results showed that the use of AI, ET, and SS techniques increased the annual change of total merit index (TMI), inbreeding, and selection accuracy. Compared to control, the rate of annual change in TMI and inbreeding were increased as 41.95, 36.91 and 83.91%; and 192, 57 and 207%, for using of AI, ET and combination of SS + AI + ET, respectively. The minimum consistory mating decreased inbreeding, but not affected other parameters. The results suggested that using of ET on 20% BD, SS-Y for all CD, and 90% AI alone or in combination with each other along with minimum consistory mating might resulted in high genetic progress and low inbreeding rate. These technologies and inbreeding control strategies may increase the ratio of annual change of TMI to inbreeding. [ABSTRACT FROM AUTHOR]

Our objective was to compare the insemination dynamics and time to pregnancy for up to 100 d after the beginning of the artificial insemination period (AIP) for heifers managed with first artificial insemination (AI) service programs that relied primarily on insemination at detected estrus (AIE) after PGF2α treatments, timed artificial insemination (TAI), or a combination of both. Holstein heifers were randomly assigned to receive first AI service with sex-selected semen after 368 ± 10 d of age with (1) AIE after synchronization of estrus with up to 3 PGF2α treatments every 14 d starting on the first day of the AIP (PGF+AIE; n = 317). Heifers not AIE up to 9 d after the third PGF2α received a 5-d Cosynch protocol with progesterone supplementation [GnRH + controlled internal drug release insert (CIDR)–5 d–CIDR removal and PGF2α–3 d–GnRH and TAI] before TAI. Heifers detected in estrus from CIDR removal and PGF2α until the day before TAI received AIE with no GnRH treatment; (2) 2 PGF2α treatments 14 d apart with the second treatment at the beginning of the AIP (PGF+TAI; n = 334). Heifers received AIE for up to 9 d after the second PGF2α treatment. Heifers not AIE received TAI after the 5-d Cosynch protocol and (3) TAI after the 5-d Cosynch protocol (ALL-TAI; n = 315). Heifers failing to conceive to a previous AI received a subsequent AI with conventional semen at detected estrus or TAI after the 5-d Cosynch protocol. Binomial outcomes were analyzed by logistic regression, whereas time to AI and pregnancy were analyzed with Cox’s regression. The hazard of first AI up to 45 d of the AIP was greater for ALL-TAI than for PGF+AIE [hazard ratio (HR) = 1.72; 95% confidence interval (CI) =1.45 to 2.03] and PGF+TAI (HR = 1.51; 95% CI = 1.28 to 1.77), but similar for PGF+AIE and PGF+TAI (HR = 1.14; 95% CI = 0.97 to 1.33). A greater proportion of heifers received AIE in PGF+AIE (98.7%) than in PGF+TAI (78.5%). Overall, first service pregnancy per AI did not differ (PGF+AIE = 42.0%; PGF+TAI = 47.3%, ALL-TAI = 43.8%). Time to pregnancy was reduced for ALL-TAI compared with PGF+AIE (HR = 1.20, 95% CI = 1.02 to 1.42), but was similar to that of PGF+TAI (HR = 1.13, 95% CI = 0.96 to 1.33). Time to pregnancy did not differ for PGF+AIE and PGF+TAI (HR = 1.07, 95% CI = 0.91 to 1.25). Median days to pregnancy were 27, 23, and 21 for heifers in PGF+AIE, PGF+TAI, and ALL-TAI, respectively. We concluded that an ALL-TAI program for first service reduced time to pregnancy, albeit a relatively small reduction, when compared with a program that relied primarily on AIE after induction of estrus with PGF2α treatments. The program that combined synchronization of estrus and TAI (PGF+TAI) resulted in similar time to pregnancy than the predominant TAI and predominant AIE programs. [ABSTRACT FROM AUTHOR]

Abstract The goal of this study was to evaluate the effect of long-acting progesterone supplementation on pregnancy rates and gestational losses in Nelore females (Bos taurus indicus) submitted to Timed Artificial Insemination (TAI). Ovulations of multiparous (n = 534), primiparous (n = 117) and nulliparous (n = 81) Nelore females were synchronized for TAI and the day of insemination was considered D0. After TAI, the animals were allocated into three groups. Two groups received 150 mg of long acting injectable progesterone (P4) in a single dose, 5 (D = 5) or 11 (D = 11) days after TAI, resulting in the following treatments: 1) Group P4 - D5 (n = 235); 2) Group P4 - D11 (n = 245); and 3) Control Group (n = 252). The animals in the control group did not receive any supplementation. Pregnancy was checked by ultrasonography, 30 days after the TAI. The gestational losses were evaluated at two different periods: 1) from 30 to 60 days, and 2) from 60 to 90 days. The pregnancy rate and the gestational losses as a function of the treatments were tested by the non-parametric binomial test with 5% significance level. The pregnancy rates were different between the groups P4 - D5 and Control (47 and 39%, respectively) (P < 0.05), but no difference was observed in relation to the P4 - D11 group. There was a difference in gestational losses from 30 to 60 days and total losses between the groups treated with P4 on the fifth day and eleventh day after TAI in relation to the control group (P = 0.0173; P = 0.0454), but no difference was observed between the treatments in relation to the losses between 60 and 90 days (P ≥ 0.0578). Among the animals that were cycling at the beginning of the protocol, the groups supplemented with progesterone at day 5 or 11 after insemination had gestational losses significantly lower (P = 0.04) than the control group (P4 - D5 = 2%; P4 - D11 = 2%, control = 14%). The animals in anestrous that received supplementation 5 days after TAI had lower gestational losses (P = 0.049) compared with the other groups (P4 - D5 = 3%, P4 - D11 = 7% Control = 10%). Under the conditions of this study, the use of long-acting injectable progesterone 5 days after TAI in Nelore females increased the pregnancy rates, but when supplemented 11 days after TAI, it did not have the same effect. Also, when used 5 days after TAI, it significantly decreased gestational losses on both anestrous and cycling animals. Therefore, it may be an interesting alternative to increase reproductive and productive efficiencies. Highlights • Pregnancy losses from 30 to 60 days were significant different between treated groups. • There was difference (P = 0.049) in pregnancy losses considering cyclicity. • For anestrous animals, control group presented pregnancy losses higher than P4-D5. [ABSTRACT FROM AUTHOR]

Abstract This study evaluated the effect of equine chorionic gonadotropin (eCG) on reproductive performance, when incorporated into the first Ovsynch + P4 synchronization following planned start mating (PSM) in pasture-based lactating dairy cows. Two synchrony programs were compared in a randomized controlled trial in Queensland, Australia. Lactating cows from a single dairy herd (n = 782) were randomly allocated to Control and eCG groups. Control cows had their estrous cycles synchronized by treatment with 100 μg gonadotropin releasing hormone (GnRH; im) and insertion of a progesterone (P4) releasing intravaginal device that contained 1.0 g of P4 on Day 0; removal of P4 device and administration of 500 μg of an analogue of PGF2α on Day 7 (cloprostenol; im); 100 μg im of GnRH on Day 9, and fixed-time artificial insemination (FTAI) on Day 10. The eCG group were treated the same as the Control group except for the addition of 400 IU of eCG, im on Day 7 of the first synchronized estrous cycle. Following the first insemination, non-pregnant cows from both groups had their estrous cycles synchronized with the same treatment protocol without using eCG. The effects of eCG on 42d cumulative incidence of pregnancy and pregnancy per AI (P/AI) were determined using logistic regression models. The effect of eCG on time to pregnancy was determined using Kaplan-Meier survival analysis and Cox proportional hazards models. Adjusted 42 d cumulative incidence of pregnancy for eCG and control groups were 47.2 and 39.3% respectively (Odds ratio [OR] = 1.38, 95% CI: 1.01–1.88). Hazard of pregnancy tended to be higher in eCG cows overall (Hazard ratio [HR] = 1.18, 95% CI: 0.99–1.41) and was significantly higher when restricting to the first 42 days after PSM (HR = 1.31, 95% CI: 1.04–1.64). Hazards of pregnancy were not different between groups when restricting to > Day 42 post PSM (HR = 1.00, 95% CI: 0.77–1.31). P/AI tended to be higher in eCG treated cows at the first AI (44.0 vs 37.7%, OR = 1.30, 95% CI: 0.94–1.78). P/AI for second and third AIs were not significantly different between groups. In this herd, a single treatment of eCG at the first synchronized estrus after PSM improved reproductive performance in the short term, but not at subsequent inseminations. Highlights • A research trial compared the effects of including eCG into a FTAI program in pasture-based dairy cows in Qld, Australia. • Treatment with eCG at the first synchrony improved short-term reproductive performance, but did not have lasting benefits. • Treatment with eCG significantly increased adjusted 42 d pregnancy risk (47.2 vs. 39.3%, OR=1.38, 95% CI: 1.01–1.88). • Treatment with eCG tended to increase P/AI at the first AI (44.0 vs 37.7%, OR = 1.30, 95% CI: 0.94–1.78). [ABSTRACT FROM AUTHOR]

Highlights • BoHV-4 is highly prevalent in Flemish dairy farms with SCE problems. • A combination of qPCR and RT-qPCR was used in order to discriminate latent and productive BoHV-4 infections. • The presence of SCE was associated with a reduced pregnancy outcome at AI. • There was no association between SCE and latent/productive BoHV-4 infections in the nose, uterus and vagina. Abstract In the past, bovine herpesvirus 4 (BoHV-4) has been suggested to be associated with metritis and endometritis. However, not many field studies investigated the association between BoHV-4 and subclinical endometritis (SCE). In the present study, the association between the intrauterine presence of BoHV-4 and SCE diagnosed during artificial insemination (AI) was examined on two dairy farms in Belgium. An immunoperoxidase monolayer assay (IPMA) and an enzyme-linked immuno sorbent assay (ELISA) were used to screen the serum for anti-BoHV-4 antibodies. A SYBR green based one step real time qPCR was used to detect and quantify BoHV-4 (ORF20) in nasal, uterine and vaginal samples collected at AI. A reverse transcription qPCR (RT-qPCR) was used to detect mRNA (gB) as proof of a productive BoHV-4 infection. BoHV-4 was detected in 39.4% (farm A)/23.8% (farm B) of the nasal samples, 48.5% (farm A)/19.0% (farm B) of the uterine samples and 51.5% (farm A)/42.9% (farm B) of the vaginal samples. Active replication was only detected in farm A in 38.5% of the BoHV-4 positive nasal samples and in 5.9% positive cases of the vaginal samples. The prevalence of SCE diagnosed at AI was 45.5% and 42.9% in farm A and farm B, respectively. The presence of SCE was associated with a reduced pregnancy outcome at artificial insemination (AI) (P＜0.001). The occurrence of SCE at AI was not associated with the presence of latent or productive BoHV4 infections in the uterus nor in the vagina and nose (P＞0.05). [ABSTRACT FROM AUTHOR]