Repeat Breeding Syndrome Research Articles

Bovine reproductive tract and microbiome dynamics: current knowledge, challenges, and its potential to enhance fertility in dairy cows

The cattle production system focuses on maintaining an animal-based food supply with a lower number of cattle. However, the fecundity of dairy cows has declined worldwide. The reproductive tract microbiome is one of the important factors which can influence bovine fecundity. Therefore, reproductive tract microbiomes have been explored during the estrus cycle, artificial insemination, gestation, and postpartum to establish a link between the micro-communities and reproductive performance. These investigations suggested that microbial dysbiosis in the reproductive tract may be associated with declined fertility. However, there is a scarcity of comprehensive investigations to understand microbial diversity, abundance, shift, and host-microbiome interplay for bovine infertility cases such as repeat breeding syndrome (RBS). This review summarizes the occurrence and persistence of microbial taxa to gain a better understanding of reproductive performance and its implications. Further, we also discuss the possibilities of microbiome manipulation strategies to enhance bovine fecundity.

Repeat Breeder Syndrome Therapies in Dairy Cows: A Review.

Repeat breeder (RB) cows are clinically healthy animals with regular oestrous cycles that do not become pregnant after three or more services. This syndrome has an incidence ranging between 10.1% and 24%. Repeat breeder syndrome (RBS) in dairy cows leads to economic losses to dairy farmers by increasing the calving interval and consequently reducing milk and calf production. RBS has a complex oetiopathogenesis as many factors are involved in its onset. The causes can be grouped into two categories: causes leading to fertilisation failure and factors leading to early embryonic death. Accurate identification of the cause and early diagnosis of RBS is essential to minimise the problems that this issue brings to the farm, but is not always possible. Hypothesising the underlying aetiology of the syndrome is also crucial for targeted therapy, whether pharmacological or managerial. The aim of this review is to report the different therapies, proposed in the literature, for the treatment of RBS in cattle, based on the knowledge of possible aetiological causes.

Prevalence and Risk Factor of Repeat Breeder Syndrome in Dairy Cows in KUD Bebarengan Anggayuh Tentrem Urip, Batu City, East Java Province

This study aims to contribute valuable insights to readers and serve as a reference for dairy farmers looking to enhance their operations. By examining the prevalence and risk factors associated with repeat breeder syndrome in dairy cows within the Village Unit Cooperation (KUD) Bebarengan Anggayuh Tentrem Urip, Batu City, East Java Province, this study aims to aid in preventing such occurrences and ultimately improve dairy cow productivity. The survey method was employed, utilizing data sourced from cooperative and farmer records, as well as observations, interviews, and questionnaire responses. Analysis revealed that out of 50 farmers owning a total of 281 cows, 30 farmers possessed a combined total of 58 dairy cows classified as repeat breeders. Consequently, the prevalence rate of repeat breeders among farmers was found to be 20.64%. Descriptive analysis was conducted on the collected data, with additional SPSS Chi-Square (X²) analysis performed to identify risk factors associated with repeat breeders. These risk factors include breeder experience, knowledge of reproduction and estrus phases, communication with artificial inseminators and veterinarians, housing conditions, as well as factors related to livestock feed and water.

348 Repeat breeding syndrome: Dexamethasone decreases the prevalence of anti-sperm antibodies in dairy cows

Abstract Cows that require greater than two inseminations to conceive are diagnosed with repeat breeding syndrome (RBS). Anti-sperm antibodies (ASA) in serum are in greater abundance among individuals exhibiting fertility challenges. In humans, treatment with glucocorticoids has been shown to decrease the prevalence of ASA and improve fertility. Therefore, the purpose of this study was to determine the impact of dexamethasone on ASA and pregnancy outcomes in RBS cattle. Holstein multiparous cows (n = 18) diagnosed as having RBS were randomly allotted to one of three treatment groups: Control (C; n = 6), low dexamethasone (LD; n = 6) and high dexamethasone (HD; n = 6). Intramuscular injections of saline (C), 0.05 mg/kg of BW of dexamethasone (LD), or 0.10 mg/kg of BW of dexamethasone (HD) were administered daily starting 4 d prior to insemination (d 0) through insemination (d 4). All treatment volumes were standardized with saline to achieve the same treatment level. Blood was collected on d 0, 4, 8 and 18, with serum extracted on d 0 through 8. Additionally, milk weights were recorded until d 34. For breeding, cows were synchronized using the Double Ovsynch protocol and only one insemination was conducted at the time of breeding. The MIXED procedure in SAS was used to determine the relationship of treatment with the repeated measures of ASA abundance and milk yield. Additionally, a non-parametric chi-square analysis was conducted in SAS using PROC GENMOD to determine the relationship of treatment with immune cell count and pregnancy outcomes. Day, Treatment and Treatment × Day were designated as fixed effects, and a protected post hoc analysis was conducted to account for multiple comparisons. Anti-sperm antibodies tended to decrease (P ≤ 0.082) as dexamethasone increased compared with C, however, there was no Treatment × Day interaction. Daily milk yields for both LD and HD decreased (P < 0.002) compared with C cows, but there was no interaction with day. Though there was an effect for Treatment × Day (P ≤ 0.002) for white blood cell count, percentage lymphocytes, eosinophils, and neutrophils, there was no effect of treatment (P ≥ 0.181). Therefore, interaction differences were largely driven by day (P < 0.001). Surprisingly, there was a trend (P = 0.069) for an increase in pregnancy rates for C cows compared with LD and HD cows. In fact, one-half of the C cows achieved pregnancy compared with just one cow for LD and HD treatments. Overall, dosage of dexamethasone did not differ for ASA or pregnancy outcomes. However, dexamethasone did decrease ASA but did not increase pregnancy rates. Based on these results, we suggest that alternative treatment measures should be explored to improve pregnancy rates in RBS cows.

Exploring Prevalence and Contributing Risk Factors of Repeat Breeding Syndrome of Crossbred Dairy Cows in Bangladesh

The dairy sector suffers significant financial losses due to repeat breeding syndrome (RBS), a significant reproductive disease in dairy cattle. For a very long time, repeat breeding has been regarded as one of the most critical reproductive issues in cattle. The objective of this study is to investigate the frequency and identify the risk factors related to repeat breeding in dairy cows in the Bogura district of Bangladesh. Additionally, the study aims to assess the influence of repeat breeding on reproductive performance in this population. This study collected indigenous and crossbred 179 cow's data using a pre-structured questionnaire. The cows that needed more than three consecutive inseminations to conceive were considered repeat breeders, and those that needed ≤3 inseminations were regular cyclic cows. The incidence rate of RBS in this study was 33.50%. In BCS 2.5 to 3.0, the incidence rate was significantly higher (58.30%) in repeat breeders than in others. Cows with < 5-litre average daily milk production and reared in intensive farming systems with moderate to poor levels of hygienic management have a significant (p<0.005) effect of repeat breeding syndrome. Different reproductive diseases have a significant (p<0.001) effect on the conception rate of cows. Stillbirth (77.87%) followed by fetal death (76.47%) were recorded as major reproductive obstacles in repeat breeding, whereas pyometra (71.43%), followed by abortion (66.67%), dystocia (70.00%) and endometritis (57.14%) were the major recorded complications in repeat breeders. The rate of conception would go up if cows had optimal BCS, good hygiene and management practices were used, and farmers were trained on how to manage cattle reproduction. This would lower the repeat breeding syndrome.

Studies on the efficacy of certain phyto therapeutic agents in treating repeat breeding syndrome in cross-bred cows

Studies on the efficacy of certain phyto therapeutic agents in treating repeat breeding syndrome in cross-bred cows

Repeat Breeding Syndrome: Prime Challenge for the Success of One Calf a Year

Repeat Breeding Syndrome: Prime Challenge for the Success of One Calf a Year

Application of Exogenous GnRH in Food Animal Production.

Over several decades, exogenous GnRH and agonists have been employed for controlling reproductive cascades in animals, and treating some reproductive morbidities. The administration of GnRH is used in animals to counter ovarian dysfunction, induce ovulation, and to increase conception and pregnancy rates. GnRH and its agonists are used in the treatment of cystic ovarian degeneration and repeat breeder syndrome. The development of protocols for GnRH administration by intramuscular injection, intramuscular or subcutaneous implants, and intravaginal deposition has empowered their clinical use worldwide. Currently, exogenous GnRH products are a central part of several pre- and post-breeding programs for the enhancement of fertility, including the control of estrous cycles and timing of ovulation, development of fixed-time artificial insemination protocols, improved embryo survival, and the treatment of reproductive morbidity. The aim of the present review is to summarize the application of exogenous GnRH agonists in food animal production.

Genetic structure of some candidate genes of repeat breeder syndrome in Egyptian buffaloes

BackgroundThis study aimed to explore the association between polymorphisms in three genes: leptin (LEP), leptin receptor (LEPR), and BMP4, and incidence of repeat breeding in Egyptian buffaloes. MethodsDNA was extracted from 160 female buffaloes, involving 108 fertile and 52 repeat breeders. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Sequence analysis and alignment were performed by employing NCBI/BLAST/blastn suite, to identify SNPs among different patterns and alleles. We utilized PredictSNP software to predict the non-synonymous SNPs influences on protein function. Moreover, the conservation score of the amino acids within the target proteins was computed by ConSurf server. ResultsThe genotyping results showed that LEP and BMP4 genes were monomorphic (CC, GG) in all tested fertile and repeat breeder buffaloes. Leptin gene sequencing showed a non-synonymous C73T SNP, replacing R to C at position 25 within the leptin polypeptide (position 4 in the mature form; R4C) which is a neutral mutation, not affecting function or structure of LEP protein. For LEPR, one synonymous SNP (T102C) and two non-synonymous SNPs (A106G and C146A), triggering V967A and G954C replacements, respectively in LEPR protein. Moreover, they are neutral mutations. Sequencing results of BMP4 showed HinfI restriction site indicate fixed GG genotype (CC genotype in the anti-sense strand) in all sequenced samples. No SNPs were observed within the amplified region. ConclusionGenotyping and sequencing results of the surveyed three genes revealed that there is no association between these genes mutations and the incidence of repeat breeding in Egyptian buffaloes.

Diagnostic and therapeutic management of subclinical endometritis in dairy bovine: A Review

Subclinical endometritis (SCE) is one of the major causes of repeat breeding syndrome in dairy bovines, characterized by the presence of polymorpho nuclear (PMN) cells within uterine cytology sample during early postpartum period. In dairy bovines, on an average 20-53 % animals suffer from SCE between 20 and 60 days post-calving due to variable risk factors. Among various diagnostic techniques, cytotape method of sample collection is comparatively superior to cytobrush and other techniques for early diagnosis of SCE in dairy bovine. A variable result of conventional therapy for successful management of uterine infections justifies the interest in stimulation of uterine defence mechanism to combat uterine infections. Natural resources particularly phyto-medicines can help to overcome the losses due to SCE in dairy bovines. Proper understanding of risk factors for SCE and its early identification followed by timely therapeutic interventions can minimize the losses incurred by the farmers in dairy bovines owing to SCE.

Cytological, Bacteriological and Antibiogram Studies for the Management of Uterine Infection in Repeat Breeder Bovines

Background: Repeat breeding syndrome (RBS) associated with sub-clinical uterine infection (UI) remains to be a major reproductive problem faced by Indian farmers. Present study documents its diagnosis, prevalent etiological agents, antibiogram pattern and efficacy of the treatment at field level. Methods: Seventy-eight RBS affected bovines were selected. The cervical mucous (CM) was collected for study of its characteristics, white-side test, endometrial cytology, microbial examination and antibiogram. The treatment protocol was developed and the animals’ response to the treatment was assessed. Result: The overall incidence of RBS was found to be 12.9% and the cases associated with uterine infection (RBS/UI+ve) and without uterine infection (RBS/UI-ve) were 44.87% and 55.13%, respectively. The mean scores of CM character, odour, pH and number of polymorphonuclear cells in RBS/UI +ve were 2.09±1.39, 1.14±0.12, 8.49±0.08 and 12.46±0.96, respectively, and differed significantly (P less than 0.05) from RBS/UI-ve cases. The microbial examination revealed the presence of gram negative bacilli, Trueperella spp., Pseudomonas spp., Staphylococcus spp., Escherichia coli and yeast infection. Antibiogram studies recorded the response of Tetracyclin as best (48.57%) followed by Cephalexin (22.86%), Chloramphenicol (20.0%) and Streptomycin (8.57%). The RBS/UI+ve cases were treated individually, on one-to-one basis, obeying antibiogram. The infection appeared to be considerably controlled and overall success rate was observed in the form of confirmed pregnancy in 71.43% cases. Thus, it was concluded that prompt diagnosis using endometrial cytology and antibiogram guided therapeutic approach may aid for effective management of RBS/UI +ve cases, under field conditions.

Repeat breeding syndrome in dairy cows: is it luckily being solved by itself?

Repeat breeding syndrome in dairy cows: is it luckily being solved by itself?

Bacterial communities from vagina of dairy healthy heifers and cows with impaired reproductive performance

Vaginal microenvironment plays a significant role in bovine fertility since its resident microorganisms interact with the host mucosa and constitutes the first barrier against ascending pathogens in the reproductive tract. In this study, the vaginal microbiome of healthy heifers (H) and cows with impaired reproductive performance, metritis complex (MT) or repeat breeders (RB), was assessed using a 16S rRNA gene sequencing approach. Analysis revealed that even though a vaginal microbiological guild (Firmicutes, Bacteroidetes, Proteobacteria, Tenericutes, Fusobacteria and Actinobacteria) was shared among healthy heifers and cows with uterine disease; further analysis at genus level showed significant differences depending on the reproductive health status. The relative abundances of recognized uterine pathogens such as Bacteroidetes, Fusobacterium and Helcococcus were higher in MT when compared with H and RB; therefore, their presence in vagina can be considered as a risk factor for fertility. The present study describes for the first time, the composition of native bacterial communities in the vagina of cows undergoing the repeat breeding syndrome (RBS), and reports an association between this disease and the presence of Porphyromonas and unassigned genera of the Pasteurellaceae family. In addition, this work highlights the bacteria associated with a healthy vagina: genera from the families Lachnospiraceae, Rikenellaceae and the genera Acinetobacter, Bacillus, Oscillospira, CF231 and 5-7NS. Results highlighted herein, signify the potential of the evaluation of the bovine vaginal microbiome to future design therapeutic interventions to improve pregnancy rates however, further research is needed to elucidate the balance of bacterial species resulting in an optimal reproductive health.

Heamatological parameters, endocrinological profiles, antioxidant and oxidative stress profiles of repeat breeding crossbred cows in Andaman and Nicobar Islands

The present study was carried out to assess the effect of repeat breeding syndrome (RBS) on heamatological, antioxidant, oxidative stress and endocrinological profiles in crossbred cows under tropical island ecosystem of Andaman and Nicobar Islands. Each of the twelve number of cows was selected (which were affected with repeat breeding syndrome) as Group 2 and normal cyclic breeding cows as Group 1. These cows were maintained under similar type of managemental conditions. Heamatological profiles, antioxidant and hormone profiles were estimated by automatic blood analyser and commercial diagnostic kits, respectively. The result revealed that the crossbred cows with RBS suffered severe anaemia. The RBS affected animals showed significantly lower level of antioxidant profiles and significantly higher malondialdehyde (MDA) than the unaffected animal groups. Similarly, endocrinological profiles revealed that the RBS affected animals had significantly higher level of cortisol, prolactin and lower level of 17 β-estradiol (E2), progesterone (P4), follicle stimulating hormone (FSH), luteinizing hormone (LH), thyroxine (T4) and insulin like growth factor-1 (IGF-1) than the unaffected crossbred cows. The study concluded that the RBS was due to anaemia, lack of antioxidants, overproduction of free radicals and disturbances of endocrinological profiles in crossbred cows of Andaman and Nicobar Islands.

Effect of Extra-mammary Diseases on Udder Health and Biochemical Changes in Crossbred Cows with Subclinical Mastitis

Background: Infectious diseases and metabolic disorders are common in crossbred cows and adversely affect optimum production as well as quality of milk. The quality of milk plays a significant role in the production of high-quality dairy products. High somatic cell count (SCC) in the milk significantly decreases the potential of such milk for the production of high quality dairy products. In this study, it is hypothesized that the extra-mammary infections and metabolic disorders increase probability of intra-mammary infections thereby increasing somatic cell count in the milk making it unsuitable for dairy industry.Methods: Cows were grouped based on the diseases or disorders like Teat Stenosis (Gp SCM-TS), Ruminal Acidosis (Gp SCM-RA), Nonspecific Diarrhea (Gp SCM-ND), Respiratory Tract Infections (Gp SCM-RTI) and Repeat Breeder Syndrome (Gp SCM-RD). Diagnosis of subclinical mastitis was made on the basis of California Mastitis Test (CMT) scores and by Somatic Cell Count (SCC) by automatic somatic cell counter. Biochemical parameters analyzed in automatic biochemical analyzer using commercially available kits.Result: The mean SCC values significantly higher in cows with sublinical mastitis and with concurrent infectious and metabolic diseases. Similarly, the concentrations of serum alkaline phosphatase (ALP), aspartate amino transferase (AST), and alanine amino transferase (ALT) were higher in affected cows. Concentrations of serum total proteins (TP) and blood urea nitrogen (BUN) in all the groups of affected animals were higher. The changes in the calcium (Ca) and phosphorus (P) levels were not observed in cows with subclinical mastitis and with other diseases under study. The SCC values did not correlate with the values of ALP, AST, ALT, TP, BUN, Ca and P among the studied groups. It can be concluded that animals with concurrent infections and metabolic disorders increase the SCC and influence the alteration in the biochemical parameters of subclinical mastitic animals.

Prevalence of Repeat Breeding Syndrome in Dairy Cattle in Selected Regions of Kenya

The optimum production in dairy cows aims at getting a calf per cow per year. This, however, is limited by repeat breeding syndrome (RBS), which has multiple etiologies that cause either fertilization failure or early embryonic death. This study objective was to determine the prevalence of repeat breeding syndrome in dairy cattle within the selected regions of Kenya. A cross-sectional study design was carried out in 205 smallholder dairy farms in Makueni, Kakamega and Nandi counties. A total of 553 cows/heifers were recruited and examined per rectal to determine their reproductive status. Information on the breeding history of the cow and heifer was acquired at the farm. The results revealed that cross bred cattle were most affected by RBS at 38.9% followed by Jersey, Guernsey Ayrshire and least in Frisians at 21.1, 16.7, 25 and 14%, respectively. The overall animal level prevalence of RBS in cattle in the three counties was at 18.4%, while the overall farm-level prevalence was 58.3%. However, per county prevalence’s were different with animal level prevalence at 31.9, 20.9 and 12.5% in Makueni, Kakamega and Nandi, respectively. The farm-level prevalence’s at the counties were 75.4, 58.3 and 48.4% in Makueni, Kakamega and Nandi counties, respectively. Cattle kept in the zero-grazing/intensive system had the highest level of RBS at 30.1% compared to semi-intensive and extensive farming systems. The prevalence of RBS was also higher in multipara at 76% in comparison to primipara cows. Finally cows over four years which were in third or more parities had the highest prevalence of RBS, accounting for 65%) of the cases. In conclusion, the prevalence of RBS is significantly high in the Kenyan smallholder dairy farms. Further research should be undertaken to identify risk factors and appropriate intervention approaches for RBS to enhance its management.

PARTICULARITIES OF FOLLICULOGENESIS DURING THE OESTROUS CYCLE IN COWS WITH THE REPEAT BREEDING SYNDROME

Particularities of folliculogenesis during the oestrous cycle in cows with the repeat breeding syndrome were detected. It was found that the repeat breeders that previously had suffered from endometritis or retention of the placenta, as well as animals with post-oestrual metrorrhagia show considerable shifts in the dynamics of follicular growth both with two and three waves of follicular development. In repeat breeders with no genital patho-morphological abnormalities there were no found considerable changes in the dynamics of follicular development compared to healthy animals. The two-wave oestrous cycles were registered in 70.6% of repeat breeders in the absence of clinical signs of genital pathology; in 50% of cows with the repeat breeding syndrome that previously had had endometritis or retention of placenta; in 66.7% of cows with post-oestrual metrorrhagia and in 66.7% of healthy animals. In cows with two waves of follicle growth, the duration of the oestrous cycle was shorter (the difference between healthy animals and cows with post-oestrual metrorrhagia made 3.4 days, P<0.025). The duration of the 1st wave of follicular growth was shorter in animals with the three-wave follicular growth. The maximum duration of the 1st wave of follicular growth was registered in the repeat breeders that previously had endometritis or retention of placenta, as well as in the animals with post-oestrual metrorrhagia (7.6 and 8.3 days against 6.4 days in healthy cows, respectively, P<0.025). The duration of the 1st wave of follicular growth in cows with two waves of follicular development did not differ significantly. In healthy cows with two waves of follicular growth, in comparison with animals with the repeat breeding syndrome, the second growth wave was longer and averaged 10.5 days. It was the shortest in cows with post-oestrual metrorrhagia (7.3 days, P<0.05). The duration of this wave was significantly shorter in cows with endometritis and retention of placenta (8.6 days, P<0.05). In healthy cows with three growth waves of follicles, the duration of the 2nd growth wave was 8.6 days. The most significant changes in follicle growth were found in repeat breeders with three growth waves that had suffered from endometritis or retention of placenta, and in animals with the repeat breeding syndrome,and post estrual metrorrhagia. In cows with post-oestrual metrorrhagia the duration of the 2nd growth wave in comparison with healthy animals was shorter by 2.4 days (P>0.05), and the third wave, on the contrary, was longer by 1.2 days (P<0.1).

Metabolomic profiles of plasma and uterine luminal fluids from healthy and repeat breeder Holstein cows

BackgroundRepeat breeding is a critical reproductive disorder in cattle. The problem of repeat breeder cattle remains largely unmanageable due to a lack of informative biomarkers. Here, we utilized metabolomic profiling in an attempt to identify metabolites in the blood plasma and uterine luminal fluids. We collected blood and uterine fluid from repeat breeder and healthy cows on day 7 of the estrous cycle.ResultsMetabolomic analysis identified 17 plasma metabolites detected at concentrations that distinguished between the two groups, including decreased various bile acids among the repeat breeders. However, no metabolites that varied significantly were detected in the uterine luminal fluids between two groups. Among the plasma samples, kynurenine was identified as undergoing the most significant variation. Kynurenine is a metabolite produced from tryptophan via the actions of indoleamine 2,3-dioxygenase (IDO). As IDO is key for maternal immune tolerance and induced in response to interferon tau (IFNT, ruminant maternal recognition of pregnancy factor), we examined the responsiveness to IFNT on peripheral blood mononuclear cells (PBMC) isolated from healthy and repeat breeder cows. The mRNA expression of IFNT-response makers (ISG15 and MX2) were significantly increased by IFNT treatment in a dose-dependent manner in both groups. Although treatment with IFNT promoted the expression of IDO in PBMCs from both groups, it did so at a substantially reduced rate among the repeat breeder cows, suggesting that decreased levels of kynurenine may relate to the reduced IDO expression in repeat breeder cows.ConclusionsThese findings provide valuable information towards the identification of critical biomarkers for repeat breeding syndrome in cattle.

Standard feeding strategies with natural insemination improved fertility in repeat breeding dairy cows.

Objective:The experiment was designed to establish suitable management strategies through the different feeding and breeding approaches on fertility improvement in the experimental repeat breeding (RB) cows.Materials and Methods:80 RB cows were selected for this experiment. Before grouping, all cows were deworming and then divided into four equal groups, namely Group–TF1 [traditional feeding practice and natural insemination (NI)], Group–TF2 [traditional feeding practice and Artificial insemination (AI)], Group–SF1 [standard (STD) feeding practice and NI], and Group–SF2 (STD feeding practice and AI). These allocated RB cows were fed by traditional and STD feeding methods for 90 days and then inseminated by AI and NI breeding systems. The dominant follicle (DF) diameter, hemato-biochemical elements, and estrogen (E2) hormone were estimated during the insemination of cows. Estimation of the pregnancy rate was carried out at days 45–90 post-insemination in the cows.Results:The pregnancy rate was significantly (p < 0.05) higher in STD feeding practice with NI when compared to traditional feeding practice irrespective of breeding systems, and it was also significantly (p < 0.05) higher in NI than in AI breeding system, irrespective of feeding strategies. The results also showed that the diameter of DF, serum E2, total erythrocyte count, hemoglobin, packed cell volume, total cholesterol, total protein, glucose, calcium, phosphorus, ferric iron, copper, zinc, and magnesium at the time of insemination were significantly (p < 0.01) elevated in the experimental RB cows with STD feeding practice. The diameter of DF and serum E2 were significant (p < 0.01) and positively correlated with all hemato-biochemical elements in the cows at the time of insemination.Conclusion:The results suggest that NI with STD feeding practice may increase fertility in RB cows by improving general health status. Finally, it could support the veterinarians and researchers to define the management strategies using feeding and breeding strategies to prevent repeat breeding syndrome in dairy cows.

Pemberian silase, complete feed, dan growth promoter pada sapi perah kawin berulang terhadap Services per Conception dan produksi susu

Repeat breeding is a reproductive disorder that harms dairy farmers because of the unachieved target to obtain one calf per year and decreased milk production. The repeat breeding syndrome can be caused by malnutrition. This study aimed to determine the effect of feeding silage, complete feed, and growth promoters in repeat breeder cows to restore the services per conception (S/C) and daily milk production. Thirty repeat breeder Holstein Friesian cows were divided randomly into three groups. The control group (P0) was fed 30-40 kg forage and 3-4 kg concentrate/head/day. Group P1 was given 8-10 kg silage or complete feed alternately every day; whereas P2 was given the same as for the P1 group, added with 10 ml growth promoter/head/day. Milk production and S/C were measured after six months of treatment. The results showed that the P1 and P2 groups returned S/C to normal (1.40 ± 0.52 and 1.30 ± 0.48), while the S/C of P0 group was 3.20 ± 0.63 (p &lt;0.05). Daily milk production in the P1 and P2 groups (14.20 ± 1.40 and 14.60 ± 1.43 l/d) was also higher (p &lt;0.05) than the control group (8.30 ± 1.06 l/d). It could be concluded that feeding silage and complete feeds alternately daily, with or without the addition of growth promoter, improved the S/C to the normal range and increased milk production.