Japanese Black Heifers Research Articles

Measurement of serum short-chain fatty acid concentrations in cattle after oral administration of difructose anhydride III.

We previously reported the mitigation effects of difructose anhydride III (DFA III) on mycotoxins, such as zearalenon and sterigmatocystin, based on the urinary concentrations of these molecules in calves. This study was aimed at evaluating the effects of dietary supplementation of DFA III and the fermented status of DFA III in the intestine by comparing serum levels of short-chain fatty acid (SCFAs) in DFA III-supplemented cattle with those in non-supplemented control cattle. Serum SCFA concentrations were measured in 30 Japanese Black heifers, aged 9-10 months, from two herds, using gas chromatography on days 0 (before DFA III supplementation), 9, and 14 after DFA III supplementation. A notably different trend was observed for isobutyric acid and enanthic acid, which may reflect the different fermentation status of supplementary DFA III in the intestine. Our results indicate the possibility that this trend observed in the intestinal tract following DFA III administration is associated with changes in the environment of intestinal bacterial flora, which may partially reflect the effects of DFA III supplementation on cattle. Difructose anhydride III supplementation for at least 2 weeks affects the trend of blood SCFA concentrations in cattle. Our results provide evidence supporting the effects of DFA III on the intestinal environment and intestinal barrier function.

Ethanolamine plasmalogens derived from whale brain stimulate both follicle-stimulating hormone and luteinizing hormone secretion by bovine gonadotrophs.

Ethanolamine plasmalogens (EPls) are the only known ligands of a novel receptor, G protein-coupled receptor 61, and bovine brain EPls stimulate follicle-stimulating hormone (FSH) but not luteinizing hormone (LH), secreted by bovine gonadotrophs. We hypothesized that the brain EPls of whales (Balaenoptera edeni), another Cetartiodactyla with at least twice the lifespan of bovines, could stimulate FSH secretion by gonadotrophs. To test this hypothesis, bovine gonadotrophs (from approximately 2-year-old Japanese Black heifers) were cultured for 3.5days and treated with increasing concentrations of brain EP1s from whales (approximately 22 years old). FSH and LH secretion was stimulated by all tested concentrations of whale EPls (p < 0.05). To clarify the important differences between bovine and whale EPls, we utilized two-dimensional liquid chromatography-mass spectrometry, which revealed 35 peaks. Among them, we observed significant differences between 12 EPl molecular species. Additionally, we identified differentially expressed genes for enzymes involved in EPl synthesis or degradation in the hypothalamus of young heifers and old cows (approximately 10years old) as compared to whales (approximately 28 years old) via deep sequencing of the transcriptome. We conclude that whale brains contain unique EPls that stimulate both FSH and LH secretion by bovine gonadotrophs.

MOET Efficiency in a Spanish Herd of Japanese Black Heifers and Analysis of Environmental and Metabolic Determinants.

Simple SummaryEmbryo transfer procedures have been widely implemented in bovine all around the world. These techniques help to accelerate the increase in the genetic merit and to keep the level of inbreeding under control, which is especially important in breeds, such as Japanese Black cattle, in areas outside of Japan, where there are scarce individuals and few herds. Our study describes an adequate embryo productivity of Japanese Black heifers under Spanish management and environmental conditions, like that which has been previously reported, demonstrating the adequate adaptation capacity of these animals. No effect on embryo production or quality was found due to plasma metabolic parameters of the donors, suggesting an optimal nutritional and body conditioning of the donors’ herd. Pregnant recipients after embryo transfer showed significantly higher levels of cholesterol-related parameters, glucose, and urea, which may be related to higher availability of nutrients for the future pregnancy. Heat stress at embryo transfer negatively impacted conception rates as expected, while larger parity and ET number corresponded to numerically higher conception rates.Multiple ovulation and embryo transfer (MOET) systems have been intensively implemented in Japanese Black cattle in Japan and to create Japanese Black herds out of these areas. Environmental conditions influence MOET efficiency. Thus, we describe results of 137 in vivo, non-surgical embryo flushings performed between 2016–2020, in a full-blood Japanese Black herd kept in Spain and the possible effects of heat, year, bull, donor genetic value, and metabolic condition. Additionally, 687 embryo transfers were studied for conception rate (CR) and recipient related factors. A total of 71.3% of viable embryos (724/1015) were obtained (5.3 ± 4.34/flushing). Donor metabolites did not affect embryo production (p > 0.1), although metabolite differences were observed over the years, and by flushing order, probably related to the donor age. CR was not affected by embryo type (fresh vs. frozen), recipient breed, and whether suckling or not suckling (p > 0.1). CR decreased significantly with heat (44.3 vs. 49.2%; (p = 0.042)) and numerically increased with recipient parity and ET-number. Pregnant recipients showed significantly higher levels of cholesterol-related metabolites, glucose, and urea (p < 0.05). Therefore, adequate MOET efficiency can be achieved under these conditions, and heat stress should be strongly avoided during Japanese Black embryo transfers. Moreover, recipients’ metabolites are important to achieve pregnancy, being probably related to better nutrient availability during pregnancy.

Effects of feeding high volumes of milk replacer on reproductive performance and on concentrations of metabolites and hormones in blood of Japanese black heifer calves.

We evaluated the effects of feeding high volumes of milk replacer on growth and reproductive performances in Japanese black heifers. Fifty-one heifers were fed milk replacer at 9L/day for 60days (9L×60days; n=18) or 41days (9L×41days; n=15), or at 7L/day for 40days (7L×40days; n=18). Artificial insemination (AI) was performed on heifers with ≥270kg body weight and ≥116cm body height at 300days of age. The age at the first AI was 0.35month later for 7L×40days than the other groups (p<.01). However, age at calving did not differ among treatments (22.1months). The interval from the first AI to pregnancy tended to be ~2months longer for the 9L×60days than the other groups (p=.07). Our results showed that feeding high volumes of milk replacer may reduce the age at calving via an improved rate of growth. In addition, we propose that feeding a maximum of 7L milk replacer for 40days may be the most appropriate rearing regime because the success of pregnancy per AI may be reduced in calves fed a maximum of 9L for 41 and 60days.

Anti-Müllerian hormone is expressed and secreted by bovine oviductal and endometrial epithelial cells.

In this study, we investigated whether bovine oviducts and endometria produce anti-Müllerian hormone (AMH) (for paracrine and autocrine signaling). Reverse transcription-polymerase chain reaction and western blotting detected AMH expression in oviductal and endometrial specimens. Immunohistochemistry revealed robust AMH expression in the ampulla and isthmus epithelia, and the glandular and luminal endometrial epithelia (caruncular endometria). AMH mRNA (measured by real-time PCR) and protein expression in these layers did not significantly differ among estrous phases in adult Japanese Black (JB) heifers (p>.1). Furthermore, the expression in these layers also did not differ among Holstein cows (93.8±5.8months old), JB heifers (25.5±0.4months old), and JB cows (97.9±7.9months old). We also compared AMH concentrations in the oviduct and uterine horn fluids among the three groups (measured by immunoassays). Interestingly, the AMH concentration in the oviduct fluid, but not in the uterine horn fluid, of Holstein cows was lower than those in JB heifers and cows (p<.05). Therefore, bovine oviducts and endometria express AMH and likely secrete it into the oviduct and uterine fluids.

Efficacy of a single blood anti-Müllerian hormone (AMH) concentration measurement for the selection of Japanese Black heifer embryo donors in herd breeding programs.

We evaluated the relationship between plasma anti-Müllerian hormone (AMH) concentrations in Japanese Black (JB) heifers at 7−10 months of age and the number of embryos recovered after superovulation treatment in selected ovum pick-up donors, concomitantly with changes in their AMH concentrations before and after parturition. Plasma AMH concentrations in heifers were positively correlated with the total number of follicles (r = 0.647, P < 0.01) and embryos (r = 0.681, P < 0.01) recovered from the animals postpartum, when selected as donor cows, but did not correlate with the total number of transferable embryos. No difference was observed between the plasma AMH concentration at the heifer period and the postpartum period. Additionally, serum AMH concentrations of heifers weakly correlated with the number of follicles and embryos recovered by virgin flush after superovulation treatment at 13−15 months of age. Therefore, a single blood AMH concentration measurement may accelerate intensive JB cattle breeding.

Bovine sperm selection procedure prior to cryopreservation for improvement of post-thawed semen quality and fertility

BackgroundThe application of cryopreservation and artificial insemination technology have contributed to the advancement of animal reproduction. However, a substantial proportion of spermatozoa undergoes alterations and loses their fertility during cryopreservation, rendering the frozen-thawed semen impractical for routine use. Cryopreservation is known to reduce sperm lifespan and fertility. Variation in cryosurvival of spermatozoa from different sires and even with the individual sire is common in artificial insemination (AI) centers. Our goal is to improve post-thawed semen quality by optimization of cryopreservation technique through sperm selection prior to cryopreservation process.ResultsOur strategy of sperm selection based on rheotaxis and thermotaxis (SSRT) on macrosale in a rotating fluid flow demonstrated the ability to maintain the original pre-freezing structural integrity, viability and biological function related to fertilization competence. This strategy has a positive effect on the cryosurvival and fertilizing abilities of spermatozoa as supported by the improvement on pregnancy rate of Japanese Black heifers and Holstein repeat breeders. This technique protected further sublethal damage to bovine spermatozoa (higher % cryosurvival than the control) and resulted in the improvement of DNA integrity. Prefreeze selected spermatozoa demonstrated slower and controlled capacitation than unprocessed control which is thought to be related to sperm longevity and consequently to appropriate timing during in vivo fertilization.ConclusionsThese results provide solid evidence that improvement of post-thawed semen quality by SSRT method is beneficial in terms of cryosurvival, longevity of post-thawed sperm, and optimization of in vivo fertilization, embryo development and calving as supported by the favorable results of field fertility study.

Genetics of heifer reproductive traits in Japanese Black cattle.

ObjectiveThe objective of this study was to identify environmental factors strongly associated with and to estimate genetic parameters of reproductive traits in Japanese Black heifers.MethodsData included reproduction records of Japanese Black heifers born between 2004 and 2014. First service non-return rate (NRR) to 56 days from first to successful insemination (FS), number of services per conception (IN), age at first calving (AFC) and gestation length were analyzed with the use of the general linear model. Genetic parameters were estimated with the use of the univariate animal model of the residual maximum likelihood.ResultsAverages of reproductive traits over eleven years were assessed, and the effects of farm, year, month, artificial insemination technician and interaction of farm×year on the traits were determined. Estimated heritability of FS was very low and that of AFC was higher than that of the other traits. A close genetic relation was observed among NRR, IN, and FS; however, their heritabilities were very low. AFC shows favorable genetic correlation with IN and FS.ConclusionLow heritabilities of most reproductive traits in Japanese Black heifers are strongly influenced by farm management practices, and that large residual variances make genetic evaluation difficult. Among the reproductive traits, AFC is potentially more useful for genetic improvement of heifer reproductive traits because it has high heritability and favorable genetic correlations with IN and FS.

Different penalty methods for assessing interval from first to successful insemination in Japanese Black heifers

ObjectiveThe objective of this study was to determine the best approach for handling missing records of first to successful insemination (FS) in Japanese Black heifers.MethodsOf a total of 2,367 records of heifers born between 2003 and 2015 used, 206 (8.7%) of open heifers were missing. Four penalty methods based on the number of inseminations were set as follows: C1, FS average according to the number of inseminations; C2, constant number of days, 359; C3, maximum number of FS days to each insemination; and C4, average of FS at the last insemination and FS of C2. C5 was generated by adding a constant number (21 d) to the highest number of FS days in each contemporary group. The bootstrap method was used to compare among the 5 methods in terms of bias, mean squared error (MSE) and coefficient of correlation between estimated breeding value (EBV) of non-censored data and censored data. Three percentages (5%, 10%, and 15%) were investigated using the random censoring scheme. The univariate animal model was used to conduct genetic analysis.ResultsHeritability of FS in non-censored data was 0.012±0.016, slightly lower than the average estimate from the five penalty methods. C1, C2, and C3 showed lower standard errors of estimated heritability but demonstrated inconsistent results for different percentages of missing records. C4 showed moderate standard errors but more stable ones for all percentages of the missing records, whereas C5 showed the highest standard errors compared with non-censored data. The MSE in C4 heritability was 0.633×10−4, 0.879×10−4, 0.876×10−4 and 0.866 ×10−4 for 5%, 8.7%, 10%, and 15%, respectively, of the missing records. Thus, C4 showed the lowest and the most stable MSE of heritability; the coefficient of correlation for EBV was 0.88; 0.93 and 0.90 for heifer, sire and dam, respectively.ConclusionC4 demonstrated the highest positive correlation with the non-censored data set and was consistent within different percentages of the missing records. We concluded that C4 was the best penalty method for missing records due to the stable value of estimated parameters and the highest coefficient of correlation.

Relationship Between Bovine Abdominal Fat Necrosis, Sire, Market Weight Per Day and Meat Productivity of Japanese Black Heifers

Relationship Between Bovine Abdominal Fat Necrosis, Sire, Market Weight Per Day and Meat Productivity of Japanese Black Heifers

黒毛和種育成雌牛 (除解) の飼料に対する接近順位について

黒毛和種育成雌牛 (除解) の飼料に対する接近順位について

Changes in body weight and blood profiles following long-distance and long-time transportation in Japanese Black heifers

Changes in body weight and blood profiles following long-distance and long-time transportation in Japanese Black heifers

Relationship between plasma anti-Müllerian hormone concentrations during the rearing period and subsequent embryo productivity in Japanese black cattle

To use plasma anti-Müllerian hormone (AMH) concentrations as early-stage markers for donor cow selection, we investigated the relationship between plasma AMH concentrations in Japanese black heifers and subsequent embryo productivity following superovulation treatment. Plasma AMH and nonesterified fatty acid (NEFA) concentrations in 6 heifers were evaluated once per month from 3 mo before successful AI for primiparity to 3 mo postpartum. Following calving, embryo collection by superovulation treatment was performed at 3- to 4-mo intervals. There were no significant differences in plasma AMH concentrations between the time points throughout the study period. There were, however, significant inter-animal differences in plasma AMH concentrations (P < 0.05). These findings suggest that plasma AMH concentrations were stable over time and individually specific. There were significant positive correlations between plasma AMH concentrations before AI and embryo productivity variables, including the number of ova/embryos (number of transferable embryos, degenerated embryos, and unfertilized oocytes) and numbers/proportions of fertilized and transferable embryos. There was no significant correlation between plasma AMH and NEFA concentrations throughout the study period. These findings reveal that plasma AMH concentrations during the rearing period can be used to predict subsequent embryo productivity following superovulation treatment, suggesting that these concentrations are useful early-stage markers for selecting donor cows.

Inferring causal structures and comparing the causal effects among calving difficulty, gestation length and calf size in Japanese Black cattle

The objectives of this study were to infer phenotypic causal networks involving gestation length (GL) and calving difficulty (CD) for the primiparity of 1850 Japanese Black heifers, and the birth weight (BWT), withers height (WH) and chest girth (CHG) of their full blood calves, and to compare the causal effects among them. The inductive causation (IC) algorithm was employed to search for causal links among these traits; it was applied to the posterior distribution of the residual (co)variance matrix of a multiple-trait sire-maternal grand sire (MGS) model. The IC algorithm implemented with 95% and 90% highest posterior density intervals detected only one structure with links between GL and BWT (WH or CHG) and between BWT (WH or CHG) and CD, although their directions were not resolved. Therefore, a possible causal structure based on the networks obtained from the IC algorithm [GL→BWT (WH or CHG)→CD] was fitted using a structural equation model to infer causal structure coefficients between the traits. The structural coefficients of GL on BWT and of BWT on GL on the observable scale showed that an extra day of GL led to a 270-g gain in BWT, and a 1-kg increase in BWT increased the risk for dystocia by 1.1%, in the causal structure. Similarly, an increase in GL by 1 day resulted in a 2.1 (2.0)-mm growth in WH (CHG), and a 1-cm increase in WH (CHG) increased the risk of dystocia by 1.2% (0.9%). The structural equation model was also fitted to alternative causal structures, which involved the addition of a directed link from GL to CD, or GL→CD to the structures described above. The inferred structural coefficients with the alternative structures were almost the same as the corresponding ones that had GL→BWT (WH or CHG)→CD. However, the direct causal effect of the extra link from GL on CD was similar to the indirect causal effect of GL through the mediating effect of BWT (WH or CHG) on CD and significant (P<0.05). This suggest that maternal genetic effects might not be removed completely from the residual variance components in the sire-MGS model, and the application of the IC algorithm to the variances from the model could detect an incorrect structure. Nonetheless, fitting the structural equation model to the causal structure provided useful information such as the magnitude of the causal effects between the traits.

Expression of macrophage migration inhibitory factor (MIF) in bovine oviducts is higher in the postovulatory phase than during the oestrus and luteal phase.

Whether macrophage migration inhibitory factor (MIF) in the bovine oviduct is important for early embryogenesis has not been well substantiated. The aim of the present study was to test the hypothesis that bovine oviduct expresses higher levels of MIF during the post-ovulation phase. Both ampullary and isthmic samples were collected from Japanese black heifers during oestrus (Day 0; n=5), postovulation (Day 3; n=6) and luteal phase (Days 9-12; n=5). MIF mRNA and protein were extracted from the ampullary and isthmic samples and their levels measured by real-time polymerase chain reaction and western blot analysis respectively. Fluorescent immunohistochemistry was performed on frozen ampullary and isthmic sections using antibodies against MIF. MIF mRNA and protein expression was higher in the postovulatory phase than during oestrus and the luteal phase (P<0.05). Fluorescent immunohistochemistry confirmed that in all phases of the oestrous cycle evaluated, the primary site of MIF expression in the ampulla and isthmus was the tunica mucosa. In conclusion, the bovine ampulla and isthmus have higher MIF expression during the postovulatory phase. Further studies are needed to clarify the role of MIF in bovine oviducts.

Method for isolating pure bovine gonadotrophs from anterior pituitary using magnetic nanoparticles and anti-gonadotropin-releasing hormone receptor antibody.

No methods are currently available for rapidly isolating gonadotrophs from the anterior pituitary (AP) in any species. We developed a method for preparing pure bovine gonadotrophs from a heterogeneous AP cell mixture by magnetic separation and our original antibody against the N terminus of bovine gonadotropin-releasing hormone receptor (GnRHR). A bovine AP cell mixture was incubated with the anti-GnRHR antibody, anti-dextran antibody-conjugated secondary antibody and dextran-coated magnetic nanoparticles for magnetic isolation. Approximately 5.2 × 106 cells were isolated per AP of Japanese Black heifers (26 months of age) and cultured, and confocal microscopy confirmed to be GnRHR- and luteinizing hormone-positive, corresponding to a purity of 100%. Approximately 44.5 µg of total protein was extracted from the pure gonadotrophs per AP.

Deep sequencing of transcriptomes of anterior pituitary before and after ovulation in Japanese Black heifers

Deep sequencing of transcriptomes of anterior pituitary before and after ovulation in Japanese Black heifers

Seasonal foraging patterns of forest-grazing Japanese Black heifers with increased plasma total antioxidant capacity.

Forest-grazing enables the intake of high total antioxidant capacity (TAC) plants that might be beneficial for the TAC status of cattle. This study evaluated the relation between the seasonal foraging patterns of forest-grazing Japanese Black (JB) heifers or the TAC levels in shrubs and trees and the changes of plasma TAC. We examined 12 JB heifers, four each of which were allocated to forest-grazing (F), pasture-grazing, and pen-housed groups. The plasma TAC level in F heifers on July 26, August 13, 30 and September 17 were significantly higher than those on April 27 and June 4 (P < 0.05). In F group, the mean rates of foraging frequency (FF) of shrubs and trees during July 5-8 and September 13-16 were much higher than that during May 31-June 3 (P < 0.05). The rate of FF of grass significantly decreased later in the season (P < 0.05). The mean TAC levels in these shrubs and trees were higher than those in grasses, concentrates, and timothy hay. Results suggest that an important factor in the increase of plasma TAC in forest-grazing cattle might be the increased foraging of TAC-rich shrubs and trees during summer-fall.

Comparison of composting process and quality between rubbed bamboo and sawdust used as bedding materials for Japanese black heifers

Comparison of composting process and quality between rubbed bamboo and sawdust used as bedding materials for Japanese black heifers

Increase in plasma total antioxidant capacity of grazing Japanese Black heifers and cows in forestland in Japan

Blood total antioxidant capacity (TAC) has become a key bio-marker for animal health. Forest-grazing cattle are known to forage various native plants that have high TAC. This study evaluated differences of plasma TAC between forest-grazing (FG) and pasture-grazing cattle (PG). Experiment 1 monitored the plasma TAC levels of 32 Japanese Black cattle. The level in PG did not change throughout the grazing period. However, that in FG, which increased from summer, was significantly higher than that in PG through fall (P < 0.05). In experiment 2, we used nine Japanese Black heifers and investigated their blood antioxidant parameters and the TAC in plants that the cattle consumed in late June and September. The plasma TAC levels in FG were significantly higher than those in PG in both periods (P < 0.05). Plasma levels of lipid peroxidation in FG tended to be lower than that in PG (P = 0.098). Furthermore, the TAC levels in various species of shrubs and trees consumed by FG were higher than those in pasture grasses. Results of this study show that plasma TAC of grazing Japanese Black cattle in forestland increase from summer through fall.