Reproductive Efficiency In Dairy Cattle Research Articles

Ameliorating Effect of Sodium Selenite on Developmental and Molecular Response of Bovine Cumulus-Oocyte Complexes Matured in Vitro Under Heat Stress Condition.

Selenium (Se), an essential trace element, plays an important role in the antioxidative defense mechanism, and it has been proven to improve fertility and reproductive efficiency in dairy cattle. The present study evaluated the potential protective action of Se supplement of in vitro maturation (IVM) media on the maturation and subsequent development of bovine cumulus-oocyte complexes (COCs) exposed to heat stress (HS). The treatment with Se improved the viability of cumulus cells (CCs) and oocytes (P < 0.05). The proportion of oocytes reached metaphase II (MII) and those arrested at metaphase I (MI) was greater and lower in treatment than control respectively (P < 0.05). Supplementation with Se increased the percentage of cleaved embryos, total blastocysts, and blastocyst/cleavage ratio (P < 0.05). Moreover, the upregulation of CCND1, SEPP1, GPX-4, SOD, CAT, and downregulation of GRP78, CHOP, and BAX in both Se-treated CCs and oocytes were recorded. The upregulation of NRF2 was detected in Se-treated CCs other than in oocytes, which showed upregulation of IGF2R and SOX-2 as the markers of quality as well. Se supplement in IVM media improved the viability, maturation, and the level of transcripts related to antioxidant defense and quality of heat-treated oocytes, which coincided with greater subsequent development outcomes. Se ameliorated the viability of CCs along with upregulation of antioxidative candidate gene expression and downregulation of apoptosis-related ones to support their protective role on restoring the quality of oocytes against compromising effects of HS.

Associations between polymorphisms in the growth hormone locus and reproductive efficiency in dairy cattle in Pujon

Selection using genetic markers (MAS) is carried out in an effort to accelerate livestock breeding programs, through molecular studies individual superior livestock can be detected earlier so that the selection program can be directed and controlled. This study aims to analyze genetic diversity at the growth hormone locus that is thought to have a relationship with reproductive and production traits in Friesian Holstein Crossed (FHC) dairy cattle through the polymerase chain reaction - restriction fragment length polymorphisms (PCR-RFLP) method. The study was conducted in Pujon subdistrict using 53 FHC cattle samples. The results showed that at the GH gene locus only one genotype was found, AA with an allele frequency of 1.00. Based on these results, it was concluded that the GH gene in FHC cattle is monomorphic. The information in this study can be used as a reference in formulating livestock breeding programs.

Unrevealing functional candidate genes for bovine fertility through RNA sequencing meta-analysis and regulatory elements networks of co-expressed genes and lncRNAs.

The high genetic heterogeneity and environmental effects of subfertility in livestock species make the elucidation of the genetic mechanisms associated with reproductive efficiency a difficult task. Network and co-expression network meta-analyses were applied alongside genetic variant calling and long non-coding RNA (lncRNA) characterization to identify functionally relevant target genes and regulatory subnetworks associated with fertility in dairy cattle. In total, 505 lncRNAs (441 previously annotated in the bovine reference genome ARS-UCD 1.2 and 64 novel lncRNAs) were identified. Seven differentially expressed genes between high-fertile (HF) and sub-fertile (SF) Holstein cows were identified in the network meta-analysis (CA5A, ENSBTAG00000051149, ENSBTAG00000003272, DEFB7, DIO2, TRPV3, and COL4A4). Additionally, seven functional candidate differentially co-expressed (DcoExp) modules with a differential regulatory pattern (|z-score|>2) were identified between HF and SF cows. The functional candidate genes and DcoExp modules identified were associated with fertility relevant processes such as the regulation of embryonic implantation and proliferation, interaction and molecule transfer between the fetus and the cow, and the immune system. These results help to better understand the genetic mechanisms associated with reproductive efficiency in dairy cattle through the identification of potential biomarkers and genetic variants associated with differentially expressed regulatory gene and lncRNAs regulatory element networks.

Effect of inseminator on reproductive performance in dairy cattle.

The reproductive efficiency of dairy cattle is critical to the economic success and sustainability of the enterprise. Due to its many advantages, artificial insemination has inevitably taken its place in herd management today, and different artificial insemination methods have been developed until today. At the same time, artificial insemination is carried out by commercial artificial insemination operators or do-it-yourself operators in cattle farms. One of the factors affecting the success of artificial insemination is inseminators. The aim of this study was to determine the effect of inseminators on conception rates in reproductive challenges and to reveal the differences between the success rates of inseminators. A total of 227,297 artificial insemination acts carried out by 35 inseminators for 4years belonging to the Konya Cattle Breeders' Association in Turkey were assessed for this purpose. In the study, the insemination success rate was determined as 41.36%. In addition, the percentage of inseminators with a total insemination success rate of more than 50% is very low, such as 2.9%, and the percentage of those who achieved 35.9% and below was 9.3%. As a result, it can be stated that the inseminators having a lower success rate than the overall should be retrained to avoid costs or losses in the farms.

Implications of cryopreservation on structural and functional attributes of bovine spermatozoa: An overview.

Sperm cryopreservation is an important adjunct to assisted reproduction techniques (ART) for improving the reproductive efficiency of dairy cattle and buffaloes. Improved understanding of mechanisms and challenges of bovine semen cryopreservation is vital for artificial insemination on a commercial basis. Although cryopreservation of bovine spermatozoa is widely practiced and advanced beyond that of other species, there are still major gaps in the knowledge and technology. Upon cryopreservation, disruption of spermatozoal plasma membrane configuration due to alterations in metabolic pathways, enzymes and antioxidants activity add to lower efficiency with loss of sperm longevity and fertilising ability. Therefore, the effective amalgamation of cryo-variables like ambient temperature, cooling and thawing rates, nucleation temperature, type and concentration of the cryoprotectant, seminal plasma composition, free radicals and antioxidant status are required to optimise cryopreservation. Novel strategies like supplementation of cholesterol-loaded cyclodextrins (CLC), nanovesicles, osteopontin, antioxidants, etc., in an extender and recent techniques like nano-purification and modified packaging have to be optimised to ameliorate the cryodamage. This article is intended to describe the basic facts about the sperm cryopreservation process in bovine and the associated biochemical, biophysical, ultra-structural, molecular and functional alterations.

Non-specific Bacterial Profiles in Reproductive Tract of Dairy Cattle during Artificial Insemination

One of the causes of low reproductive efficiency in dairy cattle is the presence of reproductive disorders caused by a non-specific bacterial infection. The aim of the present study was to isolate and identify the genus of non-specific bacteria in the reproductive tract of dairy cattle during artificial insemination. A total of 10 samples in the form of mucus attached to the plastic sheath used after artificial insemination in dairy cattle were collected in the study. The samples were subjected to bacterial isolation and identification. The obtained results of the study indicated that Staphylococcus was the dominant genus found (90%). On the other hand, other genera were Escherichia (60%) and Corynebacterium (20%).

Application of P4 rapid test and exogenous source of progesterone in prevention of early embryonic death in dairy cows

Abstract. The objectives of this study were: 1) to determine the percent of cows with low P4 at Day 7-8 post-AI; 2) to treat the animal with low progesterone for 14 days with a P4-releasing intravaginal device (PRID DELTA); 3) to analyze the influence of P4 exogenous supplementation on pregnancy rate in treated and non-treated cows and 4) to create a protocol using “P4 Rapid” test allowing increased pregnancy rate under farm conditions. For this purpose, the current study has been conducted on 155 repeat breeding Holstein cows (&lt;3 artificially inseminated – AI) with prolonged estrus cycle (&lt;26 days). At day 7 and 8 post-AI, the milk progesterone levels were measured (P4 Rapid test). The cows with low P4 (n=104 or 67%) were divided into two groups each n=52. In Group I the progesterone devices were inserted for two weeks and control Group II without progesterone devices. At days 40 and 50 post artificial insemination (AI) all animals (n=104) were submitted to ultrasound pregnancy detection. Pregnancy was registered in 27 animals (51.9%) for Group 1, and in 16 cows (30.7%) for Group II. P4 Rapid is a quick, easy and practically applicable test to measure milk progesterone levels in dairy farms. The method is highly accurate and detects animals with low or high P4 at Day 7-8 after insemination. It also allows identification of conditions such as ovarian cysts, ovarian hypofunction and distinguishing of cycling and non-cycling cows. The combination of P4 measurement by P4 Rapid test and treatment with exogenous P4 to increase circulating concentrations in the first few days after conception can prevent embryo death and improve reproductive efficiency in dairy cattle.

Influences of sire conception rate on pregnancy establishment in dairy cattle.

Establishment of pregnancy in cattle is complex and encompasses ovulation, fertilization, blastocyst formation and growth into an elongated conceptus, pregnancy recognition signaling, and development of the embryo and placenta. The objective here was to investigate sire influences on pregnancy establishment in cattle. First, 10 Holstein bulls were classified as high or low fertility based on their sire conception rate (SCR) value. In a field trial, pregnancy at first timed insemination was not different between high and low SCR bulls. Next, 5 of the 10 sires were phenotyped using in vitro and in vivo embryo production. There was no effect of SCR classification on in vitro embryo cleavage rate, but low SCR sires produced fewer day 8 blastocysts. In superovulated heifers, high SCR bulls produced a lower percentage of unfertilized oocytes and fewer degenerated embryos compared to low SCR bulls. Recipient heifers received three to five in vivo produced embryos from either high or low SCR sires on day 7 postestrus. Day 16 conceptus recovery and length were not different between SCR groups, and the conceptus transcriptome was not appreciably different between high and low SCR sires. The reduced ability of embryos from low SCR bulls to establish pregnancy is multifactorial and encompasses sperm fertilizing ability, preimplantation embryonic development, and development of the embryo and placenta after conceptus elongation and pregnancy recognition. These studies highlight the importance of understanding genetic contributions of the sire to pregnancy establishment that is crucial to increase reproductive efficiency in dairy cattle.

The number of service per conception of Indonesian Friesian Holstein with artificial insemination in Selo, Boyolali, Central Java, Indonesia

Boyolali is an area in Central Java Indonesia, it has large number of Indonesian Friesian Holstein (IFH; dairy cattle). To improve its population as well as genetic quality of milk production, artificial insemination (AI) is widely applied as mating program. The success of AI can be evaluated from the number of service per conception (S/C), represent a number of service using AI to achieve one pregnancy. Its mirroring mating management and reproductive efficiency in dairy cattle, estimated in herd during specific time and location. For that, this study aims to estimate S/C in Selo, Boyolali during October 2016 to January 2017. Data were gathered with 95% confidence level. Sample size were 367 IFH, visited and selected purposively based on criteria one-time partus, 3 y.o and have complete AI record. Animal data were collected in reproduction and mating management. In addition, 124 dairy farmer who have minimum 5 years experiences in rearing IFH cow were interviewed as respondent in estrus detection, followed with 2 skilled inseminators for AI performing time data. Result shows that S/C is 1.71, this mean one pregnancy need 1.71 times AI services. In the estrus detection, most of dairy farmers were able to observe estrus sign in vulva color, size and the present of mucus by visual. Moreover, AI was performed in 9 to 12 hours after the sign of estrus observed. It is concluded that AI of IFH in Selo, Boyolali has been successfully applied, however there are still rooms to improve the reproduction efficiency through mating management in regard to lower S/C.

Effect of nutrition on reproductive efficiency of dairy animals

Nutrition plays a key role in the maintenance of animal reproductive performance. Reduced reproductive efficiency can decrease the profitability of dairy production by increasing days open, calving interval, the number of services per conception, culling rate, and veterinary services. Nutritional requirements increase rapidly with milk production after calving, but an improper diet plan could result in a negative energy balance (NEB). NEB delays the time of first ovulation through uncoupled hormones production. A diet high in fat could prevent the NEB state by increasing the energy status of animals. Protein supplementation supports high production but can also have severe effects on the reproductive performance of the animal. Deficiency of minerals can also alter the reproductive performance of the animal. This article has generally focused on the effects of various nutrients on reproductive efficiency of dairy cattle. .

English

Bovine tuberculosis (bTB) has a direct impact in the productive and reproductive efficiency of dairy cattle. Nowadays, disease control programs based on tuberculin testing and removal of infected cattle are unaffordable for the developing countries, since there is no program of financial compensation, especially in high bTB-prevalence herds. Thus, control strategies based on vaccination are considered the best alternative. The aim of this study was to evaluate whether a low dose of BCG-Phipps vaccine induces reactivity to tuberculin skin test and its duration in neonatal calves and adult cows. For the analysis of the former, 69 TB-free Holstein-Friesian calves less than one-month old were used; of which, 54 calves were subcutaneously inoculated with 104 CFU of the BCG-Phipps vaccine, while the rest remained without vaccination. Under similar conditions of immunization, 133 single intradermal comparative cervical (SICCT) reactors and 133 non-reactors Holstein-Friesian cows of different age were also analyzed. In calves, the SICCT-reactivity was evaluated periodically in the first 14 months post-vaccination (mpv) while, in adult cows, the effect of vaccination on the test was evaluated at six months post-vaccination. A comparative ELISA was used by measuring the antibody levels in the groups. In calves, reactivity frequencies of 7.4 and 3.7% at 3 and 5 mpv, respectively were recorded. This reactivity disappeared at six months. None calves in the control group were reactor during the study. There were no variations in the degree of reactivity in the group adult reactor cows. However, in the non-reactor group, a conversion of 12.8% at six mpv was recorded. In addition, the conversion percentage was higher in older cows than in younger cows (p<0.05). The specific antibody levels did not increase in the vaccinated groups. Data indicate that the low dose of BCG-Phipps vaccine used had a reduced effect on the development of a delayed type hypersensitivity to tuberculin in neonatal calves, and heifers lesser than one-year-old. Key words: Bacillus Calmette-Guerin, bovine tuberculosis, M. bovis, single intradermal comparative tuberculin test.

Effects of HACCP system implementation on reproduction, milk quality, and milk sanitation on dairy farms in Korea

The objective of this study was to investigate the influence of hazard analysis critical control point (HACCP) system implementation on the reproductive efficiency of dairy cattle, milk quality, and veterinary medicine use in dairy farms across Korea. Data were collected from 50 dairy farms before and after the implementation of the HACCP system. Importantly, somatic cell number and bacterial count in raw milk, and monthly expenses for medicine were lower after HACCP system implementation (p&lt;0.05). However, the breeding interval, use of different classes of antibiotics, milk protein, and milk fat content were not changed by implementing the HACCP system. These results indicated that implementation of the HACCP system on dairy farms may reduce the use of veterinary medicine and improve milk sanitation levels.

Association of single nucleotide polymorphisms of PPP1R11 gene with conception rate in Karan Fries bull

Bull fertility is an important component of reproductive efficiency in dairy cattle. PPP1R11 is a potent candidate gene for bull fertility being involved in the pathway of spermatogenesis. Present investigation was carried out in twenty Karan Fries (KF) bull to identify SNPs of PPP1R11 gene and their association with conception rate. Genomic DNA was extracted from frozen semen straws by phenol-chloroform method. Primer pair targeted to exonic II region of PPP1R11 gene was designed using Primer 3.1 software. PCR reactions were carried out in thermal cycler after optimizing. The PCR product was checked on 1.5% horizontal agarose gel electrophoresis to verify the amplification of target region. Samples were sequenced and SNPs were identified using multiple alignment programme with respect to reference sequence and visual inspection of chromatograms. Sequencing results revealed only two SNPs [G28708846A, T28708860C] at exonic II region of PPP1R11 gene in KF bulls. Each bull was genotyped with respect to each of the two identified SNPs. Association of SNP genotype with conception rate was analyzed using least square ANOVA taking genotypes as fixed effect. The result indicated that, only one SNP [T28708860C] had significant (p&gt;0.01) effect on conception rate. The bulls with TT genotype revealed significantly (p&gt;0.01) highest conception rate (53.20±2.96%) followed by bulls with TC (43.12±2.39%) and the lowest in bulls with CC (34.59± 2.28%) genotypes. The results of present finding suggested that association of SNPs with conception rate after validation on large population might be useful in marker assisted selection for selection of bull with high fertility in future.

Consumers’ attitudes about milk quality and fertilization methods in dairy cows in Germany

Major advances in assisted reproductive technologies have improved reproductive efficiency in dairy cattle. However, these developments occurred regardless of the perception of consumers, who often distrust biotechnology in food production. Therefore, the objective of this study was to investigate consumers’ attitudes toward reproductive management practices in dairy cattle. In November 2012, 1,646 participants were interviewed by a commercial market research institute. Participants were selected from all regions and demographic categories to represent the general public in Germany. Seven questions regarding milk-drinking preferences and reproductive technologies were asked in face-to-face interviews. Descriptive statistics and multivariable logistic regression models were used. The majority of people drank milk at least weekly (63%) and found the taste of milk important (60%). Most people perceived advanced reproductive technologies negatively [e.g., the use of sexed semen (53%), embryo transfer (58%), cloning (81%), and hormone treatments to increase fertility (65%)]. Many people lacked basic knowledge about milk production (22% did not know that cows only give milk after calving; 51% did not know that milk naturally contains hormones); however, participants with a high school education, older participants, and those who had concerned themselves with dairy farming were more knowledgeable. Education and providing information might help to inform the public about reproductive management practices in dairy cows.

Prevalencia de endometritis sub-clínica post-parto en tres hatos lecheros de Puerto Rico

La endometritis es una de las causas asociadas con baja eficiencia reproductiva en el ganado lechero. Se determinó la prevalencia de endometritis subclínica (ES) en tres hatos lecheros de Puerto Rico en dos épocas del año (calurosa y fresca). La ES, la cual se definió como la presencia de ≥5% de células polimorfo nucleares en muestras de tejido endometrial, se diagnosticó por citología endometrial en vacas a los 45±7 días postparto. La prevalencia general de ES (n=101 vacas) fue 8.9% y no se encontró efectos significativos sobre la misma por raza (P=0.73), época (P=0.34), número de lactancias (P=0.60), ni localidad (P=0.56). En vacas Holstein, Pardo Suiza, Jersey y cruces la prevalencia de ES fue 10.4, 18.7, 0 y 6.3%, respectivamente. Vacas primíparas mostraron un valor de 7.1% y multíparas de 10.2%. Durante la época de calor se observó una prevalencia de ES de 6.1% versus 11.5% para la época fresca. En las vaquerías ubicadas en Moca, Lajas y Camuy se detectó esta condición en 5.5%, 6.6% y 12.0% de las vacas, respectivamente. En comparación a estudios realizados en otros países, los presentes resultados indican que la ES está relativamente bien controlada en los hatos lecheros locales estudiados.

Métodos de detecção de estro e falhas relacionadas

This paper seeks a better understanding of the accurate detection of estrus, which is a limiting factor in reproductive efficiency of dairy cattle and is considered one of the major deficiencies in bovine reproduction. The biggest difficulty lies in the practice of artificial insemination is the detection of estrus so that causes a decrease in conception rate and thus increase the period of service. The low percentage of animals detected in estrus, in some cases, due to the absence of ovarian activity, but in most cases the main factor is the inefficiency in estrus detection, which is one of the biggest barriers to achieving satisfactory rates in artificial insemination programs. Recognition of signs of estrus for choosing the most appropriate method and timing of mating is a priority task in the creation of livestock due to its influence pregnancy rate, calving interval and thus the reproductive efficiency of breeding.&#x0D; &#x0D;

A systems approach to determine the effect of changes in gene expression in adipose tissue on productive and reproductive efficiency in dairy cattle

In order to assess the patterns of metabolism that affect efficiency, an existing mechanistic metabolic model of dairy cows (Molly) was expanded to include transcriptional control of metabolism in adipose tissue and reproductive processes. Our objective was to test the effects of changes in gene transcription in adipose tissue on patterns of metabolism, reproductive processes and efficiency. The model describes the substrate sensitivity and maximum velocity for lipogenesis, esterification and lipolysis. Data were collected from first and second parity cows from various studies, and included nutrient intake, milk component output, changes in adipose tissue lipid, visceral and body protein and lipid, and metabolism rates in adipose tissue and gene transcription. The lipogenic pathways were primarily controlled by transcriptional changes, whereas lipolysis varied primarily by post-translational control. We used the difference in transcriptional and post-translational metabolic control to alter Vmax and Ks for lipogenesis and lipolysis; in addition, we modelled a range of energy costs for ion transport and protein turnover in liver, muscle and adipose tissues. Changing rates of lipogenesis and lipolysis (~four-fold) did not affect milk production or feed intake, but altered maintenance costs, fat accretion, energetic efficiency and reproduction. Increases in lipogenesis decreased postpartum interval to first ovulation; increases in rates of lipolysis increased the interval. Changes in metabolic rate from changing either adipose tissue metabolism or rate of ion transport and protein turnover affected rates of oestrogen and progesterone degradation, which affected follicular growth and corpus luteum function. This model may be used to help interpret genomic and transcriptomic data to pinpoint the most effective ways to select and manage for changes in productive and reproductive efficiency.

Genome‐wide association study identifies candidate markers for bull fertility in Holstein dairy cattle

The decline in the reproductive efficiency of dairy cattle has become a challenging problem worldwide. Female fertility is now taken into account in breeding goals while generally less attention is given to male fertility. The objective of this study was to perform a genome-wide association study in Holstein bulls to identify genetic variants significantly related to sire conception rate (SCR), a new phenotypic evaluation of bull fertility. The analysis included 1755 sires with SCR data and 38,650 single nucleotide polymorphisms (SNPs) spanning the entire bovine genome. Associations between SNPs and SCR were analyzed using a mixed linear model that included a random polygenic effect and SNP genotype either as a linear covariate or as a categorical variable. A multiple testing correction approach was used to account for the correlation between SNPs because of linkage disequilibrium. After genome-wide correction, eight SNPs showed significant association with SCR. Some of these SNPs are located close to or in the middle of genes with functions related to male fertility, such as the sperm acrosome reaction, chromatin remodeling during the spermatogenesis, and the meiotic process during male germ cell maturation. Some SNPs showed marked dominance effects, which provide more evidence for the relevance of non-additive effects in traits closely related to fitness such as fertility. The results could contribute to the identification of genes and pathways associated with male fertility in dairy cattle.

Efficacy of a Monovalent Leptospira borgpetersenii Serovar Hardjo Strain hardjobovis Vaccine Protocol on Measures of Fertility in Holstein Dairy Cattle

Leptospira borgpetersenii serovar Hardjo strain hardjobovis may hamper reproductive efficiency of dairy cattle, and controlling infection would be of economic value. To assess the efficacy of a commercial monovalent strain of L. borgpetersenii serovar Hardjo hardjobovis vaccine the vaccine was administered in conjunction with systemic oxytetracycline. Cows and heifers (n= 1,894) from a dairy herd naturally infected with strain hardjobovis were enrolled in a prospective, randomized, clinical trial.

Incorporation of a rapid pregnancy-associated glycoprotein ELISA into a CIDR-Ovsynch resynchronization program for a 28 day re-insemination interval

The objective was to compare two resynchronization programs; one that used a blood-based ELISA for pregnancy-associated glycoproteins (PAG) for pregnancy diagnosis so that non-pregnant cows were re-inseminated at 28 d after first TAI, and another that used transrectal ultrasonography for pregnancy diagnosis so that non-pregnant cows were re-inseminated at 35 d after first TAI. The PAG_resynch cows (n = 103) began CIDR-Ovsynch resynchronization on Day 18 after first TAI (Day 0). On Day 25, the CIDR was removed and pregnancy diagnosis with a PAG ELISA was performed. If a cow was not pregnant on Day 25, she was treated with PGF 2α, treated with GnRH 2 d later (Day 27), and TAI on Day 28. Control cows (n = 99) were observed for estrus until Day 25, when they began an identical CIDR-Ovsynch program with pregnancy diagnosis by transrectal ultrasonography on Day 32. If a cow was not pregnant on Day 32, then she was treated with PGF 2α, treated with GnRH 2 d later (Day 34), and TAI on Day 35. There was no difference in pregnancy per AI (P/AI) for either group at first or second insemination. For cows without pregnancy loss, the interval between first and second (P < 0.001) or second and third (P < 0.016) TAI was shorter for PAG_resynch cows compared with Control cows. The interval between first and second or second and third TAI was not different if pregnancy loss cows were included in the analysis. Plasma progesterone concentrations were similar at PGF 2α treatment, and plasma estradiol concentrations increased similarly after PGF 2α treatment for PAG_resynch and Control cows. In conclusion, the 28 d CIDR-Ovsynch resynchronization protocol was comparable to a 35 d CIDR-Ovsynch resynchronization protocol that also included estrus detection. Shortened resynchronization protocols that do not require estrus detection may improve reproductive efficiency in dairy cattle.