Holstein-Friesian Bulls Research Articles

Increasing the frequency of ejaculate collection in young dairy bulls increases semen production and field fertility

Younger bulls typically produce lower volumes of semen per ejaculate with a lower sperm concentration than older more mature, bulls and often fail to meet semen demand using standard collection frequency schedules. The objective of this study was to assess the effect of ejaculate collection frequency on semen output, sperm quality and field fertility in young bulls under commercial conditions. Holstein Friesian bulls aged 366 ± 8 days (mean ± SEM) were assigned one of two ejaculate collection frequencies: (i) HF (n = 14 bulls), where ejaculates were collected twice a day, five days in each two-week period or (ii) LF (n = 12 bulls), where ejaculates were collected once a day, two days per week. The trial period continued until each bull reached both 20 ejaculates and 1000 marketable frozen semen straws. Subjective motility was assessed on all ejaculates pre-freeze and post-thaw (at 0 and 2 h). A subset of ejaculates were assessed post-thaw by computer-assisted sperm analysis for motility, kinematics and morphological defects and by flow cytometry for viability, membrane fluidity, acrosome integrity, reactive oxygen species and DNA fragmentation. A total of 13,846 inseminations (9,541 for HF and 4,305 for LF) were carried out on dairy cows and heifers. HF reached the 1000 straw threshold 41 days earlier than LF (P < 0.01) with the same number of ejaculates. Ejaculate volume and sperm concentration were not affected by treatment but the first ejaculate of the day (HF only) had a greater volume (P < 0.001) and sperm concentration (P < 0.05) than the second ejaculate. HF had higher pre-freeze total (P < 0.01) and gross (P < 0.05) motility than LF. HF had higher post-thaw (2 h) total and gross motility than LF (P < 0.05). Ejaculate rejection rates did not differ between treatments. There was no effect of treatment, week or ejaculate number of the day (HF only) on post-thaw motility and kinematic parameters or sperm viability, membrane fluidity, acrosome integrity and DNA fragmentation. However, HF had lower superoxide production than LF (P < 0.05). Pregnancy per artificial insemination was 64.5 ± 1.0% and 59.9 ± 1.1% for the HF and LF bulls, respectively (mean ± SEM; P = 0.05). In conclusion, collecting ejaculates more frequently from young bulls significantly reduced the number of days required to obtain 1000 straws, increased semen quality in terms of lower superoxide production and increased field fertility.

An ex-vivo assessment of differential sperm transport in the female reproductive tract between high and low fertility bulls

Despite passing all quality control checks at animal breeding centres, bulls with apparently normal semen quality can yield unacceptably low field fertility rates. This study took an ex-vivo approach to assess if bulls of divergent field fertility differ in the ability of their spermatozoa to interact with the female reproductive tract and its secretions. Six high and six low fertility Holstein Friesian bulls (+4.0 ± 0.2 and −15.7 ± 3.13, respectively; adjusted mean fertility ± s.e.m. mean of the bull population was 0) were selected from a population of 840 bulls with >500 field inseminations per bull. Thawed spermatozoa from each bull were analysed across a range of in vitro assays to assess their ability to transverse the female reproductive tract including; motility and kinematic parameters using computer-assisted sperm analysis, viability, membrane fluidity and acrosomal integrity using flow cytometry as well as mucus penetration tests, rheotactic behaviour and sperm binding ability to the oviductal epithelium. While there was no significant difference between high and low fertility bulls in most of the sperm motility, kinematic and sperm functional parameters (namely, motility, average path velocity, linearity, straightness, amplitude of lateral head movement), viability, membrane fluidity or acrosome intactness, high fertility bulls had higher curvilinear velocity compared to the low fertility group (P < 0.05) and a higher straight-line velocity was observed although it did not reach statistical significance (P = 0.08). There was no difference between treatment groups in the ability of spermatozoa to penetrate periovulatory cervical mucus or in their rheotactic response (P > 0.05). Interestingly, there was a positive correlation between the straight-line velocity of spermatozoa and their rheotactic response (r = 0.45, P < 0.001) and further linear regression analysis indicated 18.9% of the variance in sperm rheotaxis was accounted for by straight line velocity. A higher number of spermatozoa from the high fertility group compared to the low fertility group bound to oviductal explants (15.1 ± 0.98 and 12.5 ± 0.76, respectively; mean ± s.e.m; P < 0.05). In conclusion, the differences in the kinematics of sperm motility and ability to bind to oviductal explants between high and low fertility bulls were modest and are unlikely to explain the inherent differences in fertility between these cohorts of bulls.

Correlation of Polymorphism of AQP7 Gene with the Sperm Cells Quality Traits of the Polish Holstein Friesian Bulls

Correlation of Polymorphism of AQP7 Gene with the Sperm Cells Quality Traits of the Polish Holstein Friesian Bulls

Fatty Acid Profile of Intramuscular Fat in the Longissimus Lumborum and Semimembranosus Muscles of Bulls Fed Diets Based on Virginia Fanpetals, Grass and Maize Silages

Abstract The aim of this study was to determine the effect of Virginia fanpetals (Sida hermaphrodita) silage on the fatty acid profile and the content of selected nutrients and vitamins in the Longissimus lumborum (LL) and Semimembranosus (SM) muscles of young bulls. Forty Polish Holstein-Friesian bulls aged 16 months were assigned to four dietary treatments (n=10) and were fed different types of silage during a 7-month fattening period. The proportion (g/kg dry matter) of silage in the diets was as follows: (1) grass silage (GS) (600); (2) Virginia fanpetals silage (VFS) (600); (3) VFS (300) and GS (300); and (4) VFS (300) and maize silage (MS) (300). Silage was supplemented with concentrate at 400 g/kg DM in each diet. The animals were slaughtered at the end of the fattening period. The intramuscular fat (IMF) of bulls fed GS had the highest (P&lt;0.05) concentrations of n-3 polyunsaturated fatty acids (PUFAs) and linolenic acid (LNA), whereas the IMF of bulls receiving GS and VFS was characterized by the highest proportion of MUFAs, mostly oleic acid (C18:1 cis 9). In comparison with the LL muscle, the SM muscle contained less IMF (by 40%) with a more nutritionally desirable profile. The SM muscle was characterized by a more desirable mineral composition and a higher concentration of α-tocopherol.

Enhancing muscle fatty acid profile by pasture finishing within a dairy-origin calf-to-steer beef production system and its potential to authenticate the dietary history of the cattle

The influence of modifying a traditional 24-mo dairy steer calf to beef production system on the fatty acid composition of the longissimus muscle and its potential to authenticate beef provenance was examined. Fifty-four male calves (n = 18 per sire breed), progeny of Holstein-Friesian cows mated with Holstein-Friesian (HF), Aberdeen Angus (AA) and Belgian Blue (BB) bulls were at pasture from March until August of their second year when they were assigned to a 3 (breed types) × 3 (finishing strategies) factorial experiment. The three finishing strategies were (i) pasture only for a further 94 d prior to slaughter (21 mo of age) (Grass), (ii) concentrates ad libitum indoors for 94 d prior to slaughter (21 mo of age) (EC) and (iii) pasture only for a further 94 d followed by concentrates ad libitum indoors for 98 d prior to slaughter (24 mo of age) (LC). Compared to EC, muscle from Grass had a lower intramuscular fat concentration and omega-6: omega-3 polyunsaturated fatty acid (PUFA) ratio and higher proportion of conjugated linoleic acid. A longer period at pasture pre-concentrate finishing increased the concentration of omega-3 PUFA which was still lower than in Grass. To maximise the omega-3 PUFA concentration, a late-maturing breed is more appropriate while to maximise conjugated linoleic acid, an early-maturing breed is more appropriate and both should be finished on grass. Chemometric analysis confirmed that the fatty acid profile can authenticate “Grass-Finished” beef per se and has potential to distinguish “Concentrate-Finished” beef based on the length of grazing prior to finishing, but not distinguish between sire breeds.

Effects of age at feedlot entry on performance, carcass characteristics, and beef quality traits of Holstein Friesian bulls reared in high altitude of Eastern Turkey

The objective of this research was to determine the effects of different initial fattening ages on the fattening performance, carcass features, and meat quality traits of Holstein Friesian bulls. A total of 24 Holstein-Friesian intact males were used in the study. The bulls were allocated to the initial fattening age groups named as Young Group (8-10 months old) (YG), Middle Aged Group (12-14 months old) (MAG) and Older Group (15-17 months old) (OG) and then placed in the feedlot based on three age groups at feedlot entry. The data that has normal distribution were analysed by using the LSMM in GLM, while others were analysed by using the nonparametric Kruskal - Wallis H test. The average daily weight gain of the YG, MAG and OG were 1.09 ± 0.27 kg, 1.01 ± 0.48 kg and 0.95 ± 0.60 kg (p < 0.01), respectively. Additionally, YG was the most effective group in terms of feed efficiency ratio (FER) compared to others. However, carcass measurements and carcass weight had lower values in the YG. Effects of age at feedlot entry had also insignificant effect on the carcass traits. Besides, measurements of the carcass muscularity including area of Musculus longissimus dorsi (MLD), SEUROP carcass conformation scores of the bulls in the MAG, and OG were superior to Holstein Friesian bulls in the YG. Different initial fattening ages had no significant effects on the chemical composition of MLD samples except for percentage of protein value. In conclusion, taking animals into feedlot at early ages resulted in accelerated weight gain, higher marbled meat, and improvement of the FER of Holstein Friesian bulls reared in harsh environmental conditions of the Eastern Turkey. However, the young animals had the lowest carcass weights and carcass measurements along with muscularity parameters.

Quantifying genetic differences between exported dairy bull calves and those sold for domestic beef production

Selection bias is introduced when selection among individuals exists but the information used to inform that selection decision is not considered in downstream genetic evaluations. Genetic evaluations are undertaken in several countries for carcass-related metrics in prime cattle; no consideration is generally taken for animals that are harvested at a younger age for veal production and thus do not express the prime carcass phenotype. Although no veal industry exists in Ireland, dairy calves are routinely exported to continental Europe for veal production. The objective of the present study, based on a cross-sectional analysis of calf export data, was to determine quantitatively if genetic variability exists in whether purchased dairy-bred bull calves are immediately exported or retained within the country for domestic production. Also of interest was whether such a genetic difference was associated with differences in carcass weight, conformation score, and fat score in prime cattle relatives. Editing criteria were imposed to consider only Holstein-Friesian bull calves. Post-editing, the fate of 43,890 Holstein-Friesian bull calves (<100 d of age) was available; variance components for the binary phenotype (sold for export or not) were estimated using both linear and threshold animal models, and genetic correlations with carcass traits from 56,366 prime cattle were estimated. The heritability (standard error) of whether or not a calf was exported was 0.04 (0.01) on the linear scale and 0.07 (0.02) on the threshold scale. Although no explicit maternal genetic effect was detected, the proportion of the phenotypic variance due to maternal effects was 0.03 to 0.07. The genetic correlation (standard error) between the export phenotype with carcass weight, conformation score [scale 1 (poor) to 15 (excellent)], and fat score [scale 1 (thin) to 15 (fat)] in prime cattle was 0.002 (0.12), −0.25 (0.12), and −0.32 (0.11), respectively. The low heritability of the calf export phenotype and lack of a strong genetic correlation with carcass metrics suggest that other calf features might be greater determinants of the eventual fate of the calf. Accounting for the export phenotype in genetic evaluations of carcass traits in prime cattle had a negligible effect on the estimated breeding values for carcass merit.

Intestinal adaptations to energy source of milk replacer in neonatal dairy calves

Most milk replacers (MR) contain more lactose compared with whole milk, which, when fed at a large meal size, could influence gut barrier function in calves. This study evaluated how replacing lactose in MR with fat (on a wt/wt basis) affects intestinal histomorphology and permeability in neonatal dairy calves. Thirty-four Holstein-Friesian bull calves were blocked by dam parity and randomly assigned to 1 of 2 treatments (n = 17): a high-lactose (46.1% lactose, 18.0% crude fat, and 23.9% crude protein of dry matter) or a high-fat MR (HF; 39.9% lactose, 24.6% crude fat, and 24.0% crude protein of dry matter). Calves were individually housed and fed pooled colostrum at 1.5 h and 12 h postnatally, at 18 and 9% of metabolic body weight (BW0.75), respectively. From 24 h postnatally until the end of the study (d 7), calves were transitioned to be fed MR (prepared at 15% solids) at 18% of BW0.75 twice daily at 0700 and 1900 h. During postprandial sampling on d 6, intestinal permeability was assessed by mixing lactulose (1.03 g/kg of BW0.75) and d-mannitol (0.31 g/kg of BW0.75) into the morning meal without altering total meal volume. Sequential blood samples were collected via jugular catheter, and total urine was collected for 12 h to measure the marker content. Calves were euthanized 3 h after the morning meal on d 7, and gastrointestinal tract tissues and digesta were collected for analysis of histomorphology, digesta osmolality, and gene expression. The empty gastrointestinal tracts of HF calves were heavier, although length did not differ and differences in histomorphology were minor. Digesta osmolality changed along the tract without differences between treatments. Plasma lactulose was greater in HF, although plasma d-mannitol and the recovery of both markers in urine were unaffected. No significant differences were detected in gene expression, although HF calves tended to have lower expression of TJP1 and CLDN2 and higher expression of proinflammatory cytokine IL1B in ileum tissue. In conclusion, partially replacing lactose in MR with fat resulted in a heavier and more permeable gut, with minor histomorphological differences.

First report of cholesterol deficiency associated APOB mutation causing calf mortality in Indian Holstein Friesian population

Cholesterol deficiency is a new monogenic autosomal recessive inherited defect in Holstein cattle and is associated with chronic and recurrent diarrhea followed by death of calves during the first six months of life. We have successfully screened the causative mutation for cholesterol deficiency in indigenous, exotic and crossbred cattle of India. This is the first report about the presence of APOB mutation causing calf mortality in the Indian Holstein Friesian population. The mutation associated with cholesterol deficiency was not detected in any of indigenous breeds of cattle suggesting that the mutation could be specific to Holstein Friesian breed only. The occurrence of causal mutation for cholesterol deficiency in one of the Holstein Friesian bull under study (with carrier frequency of 1.67%) clearly indicates that mutation has already been transmitted into Indian Holstein-Friesian population. In our opinion it is the right time to take stringent actions in order to check its further spread. Further, this study accentuates the need for regular screening of existing as well as importing breeding bulls, especially of Holstein-Friesian lineage, for CDH genetic defect before introduction of bulls into genetic improvement programs. It is also highly recommended that the screening for CDH mutation must be made mandatory for all the semen producing/importing agencies under the minimum standards for production of bovine semen.

Biochemical and textural changes in beef from bulls and steers of different crossbreeds shortly after slaughter and during ageing

The aim of this study was to investigate the course of glycogenolysis, ATP breakdown and fragmentation of myofibrillar proteins in the semitendinosus muscle of a progeny of Limousin×Holstein-Friesian (LMx) and Charolaise×Holstein-Friesian (CHx) (bulls and steers) and to describe the changes in the above parameters over time and its relationship with beef texture. The hypothesis that beef from bulls and steers of different crossbreeds required the same ageing time to achieve satisfactory tenderness was also tested. Cattle crossbreeding did not affect the amount of muscle glycogen, and castration did not differentiate it until 3 h post-mortem. The interaction between crossbreeding and castration was found, and the highest shear force values were observed in CHx bulls, whereas the lowest was in CHx steers. Beef obtained from CHx was found to be more predestined to short ageing, and LMx required longer ageing to achieve good tenderness. The R-values more strongly influenced subsequent beef texture than pH values.

Dietary supplementation with fish oil and safflower oil, during the finishing period, alters brisket muscle fatty acid profile and n-6/n-3 ratio but not carcass traits of dairy beef bulls

With increases in the global population, there is a need to identify strategies that increase beef output while maintaining or improving health benefits of beef products. Studies have demonstrated that there are many benefits to human health in response to reducing the dietary ratio of n-6 to n-3. The aim of this study was to characterize the carcass characteristics and brisket muscle fatty acid profile of young dairy-bred bulls following dietary supplementation with n-6 or n-3 PUFA. Holstein-Friesian (n = 43) and Jersey (n = 7) bulls with a mean ± SEM age and BW of 420.1 ± 5.86 d and 382.0 ± 8.94 kg, respectively, were offered a cereal-based concentrate diet on an ad libitum basis, fortified with 1 of 3 lipid supplements: control (CTL; no supplementary lipid), n-6 PUFA safflower oil (SO), or n-3 PUFA enriched fish oil (FO). Bulls were individually offered their respective diet for 12 wk before slaughter. Carcass weight, conformation, and fat score were recorded at slaughter for all animals. Brisket muscle was collected from 26 randomly selected bulls, and lipid profile was analyzed using gas chromatography. Total n-3 PUFA concentration was greater for FO than for either SO or CTL diets ( P < 0.05). Although there was no difference in the muscle total n-6 concentration between diets ( P = 0.52), the ratio of n-6 to n-3 was 3.2 and 3.9 times lower for FO ( P < 0.001) than either CTL or SO diets, respectively. Total intake of n-3 PUFA accounted for 72% of the variation in the ratio of n-6 to n-3. Despite the differences in fatty acid profiles, there was no effect of dietary lipid supplementation on carcass weight ( P = 0.63), conformation ( P = 0.79), or fat score ( P = 0.84). Beef producers can feed diets enriched with n-6 and n-3 PUFA, which would result in beef having potential health benefits and greater branding potential.

Influence of first colostrum pasteurization on serum immunoglobulin G, iron, and activity of gamma-glutamyltransferase in newborn dairy calves.

Background and Aim:Colostrum pasteurization is an established procedure in dairy farms in developed countries. This practice can improve the health status of the offspring by reducing several pathogens. This study aimed to focus on the pasteurization of bovine first colostrum and its influence on certain important bioactive components.Materials and Methods:This study was conducted in Holstein-Friesian bull calves, which were randomly divided into two groups and fed with 6 L of untreated (UT, n=10) or 6 L of heat-treated (HT, 63.5°C for 30 min, n=10) colostrum from their own dam within the first 12 h after birth. Blood samples were taken before, 24 h, and 48 h after first colostrum intake to determine the concentrations of immunoglobulin G (IgG) and iron and the activity of gamma-glutamyltransferase (GGT) in the serum.Results:The level of IgG was not affected by pasteurization (p=0.19). However, a slower increase in GGT activity (p<0.05) and a lower serum iron concentration (p=0.04) were observed in the HT group.Conclusion:It can be concluded that pasteurization influences the absorption of colostrum components and therefore, the passive transfer of immunity, although the level of IgG was not affected by pasteurization in this study.

The Quality, Intake, and Digestibility of Virginia Fanpetals (Sidahermaphrodita L. Rusby) Silage Produced under Different Technologies and Its Effect on the Performance of Young Cattle.

Simple SummaryCompetition for high-quality arable land has prompted a search for alternative forage crops. For example, Virginia fanpetals is a high-yielding perennial plant with low soil requirements. Due to its chemical composition, it can be a valuable component of ruminant diets. Previous research has shown that it cannot be used for hay production, and the natural moisture content of silage was unsatisfactory. Laboratory analyses suggest that the quality and feed value of Virginia fanpetals silage may be affected by harvesting and preservation methods. However, to date, most studies have focused on the nutritional value of Virginia fanpetals silage and its inclusion in animal diets. Therefore, the present study investigated different harvesting and preservation methods, such as direct-cut harvesting with a forage harvester, and harvesting after field wilting with a forage harvester or a round baler. The quality parameters, intake and digestibility of silage, and the performance of growing bulls, fed the experimental silage, as the sole forage was evaluated. It was discovered that the highest-quality silage was produced when herbage was harvested with a forage harvester after field wilting.Different harvesting and preservation methods of Virginia fanpetals herbage were evaluated, based on the chemical composition and digestible organic matter (OM) content (D-value) of silage fed to adult sheep, the intake and digestibility of silage, and the performance of young cattle. The following harvesting methods were compared: direct-cut harvesting with a precision-cut forage harvester (DC), harvesting after field wilting with a precision-cut forage harvester (WC) or a round baler (WRB). The silage was fed for 81 days to 24 Polish Holstein Friesian (HF) bulls, as the sole forage supplemented with 3.0 kg of concentrate/head/day. Harvesting methods affected the density (p < 0.001) and water-soluble carbohydrate (WSC) content (p = 0.047). Differences were found among the groups in the digestibility coefficients of OM (DC-73.7, WC-78.9, WRB-79.9%) (p = 0.007), and crude protein (CP) (69.8%, 77.1%, 78.5%, respectively) (p < 0.001). Dry matter intake (DMI) reached 8.38 kg (DC), 8.74 kg (WC) and 7.21 kg (WRB). Live weight gain (LWG) differed (p < 0.001) among groups (0.939, 1.033, 0.813 kg/day, respectively). The feed conversion ratio (FCR) tended to improve in WC (8.66 kg DMI/kg LWG) (p = 0.08). The highest-quality silage was produced in group WC, and it could be successfully fed to growing bulls as the sole forage.

Dynamics of mitochondrial membrane potential and DNA damage during cryopreservation of cattle and buffalo bull spermatozoa

Understanding the changes in the spermatozoa during cryopreservation is indispensable for tailoring and increasing the efficiency of cryopreservation process success. However, the dynamics of damage to sperm organelles during different stages of cryopreservation is underexplored. This study assessed the mitochondrial membrane potential (MMP) and DNA damage during different stages of cryopreservation, viz. immediately after ejaculation, after equilibration and after freezing and thawing in cattle and buffalo spermatozoa using flow cytometry. Proportion of spermatozoa with high MMP decreased significantly after equilibration (from 66.06±4.59 to 42.58±6.30 in Holstein bulls and from 60.32±5.51 to 39.98±7.58 in buffalo bulls). Sperm DNA integrity [DNA fragmentation index (DFI %)] in Holstein Friesian (HF) bulls did not differ significantly between fresh and equilibrated samples but a significantly higher % DFI was observed in frozen-thawed semen samples as compared to both fresh and equilibrated samples. In contrast, % DFI in buffalo spermatozoa did not differ among the three stages of cryopreservation. It was concluded that mitochondrial damages occur during equilibration while chromatin damages occur during freezing and thawing of cattle bull spermatozoa; whereas buffalo bull spermatozoa were lesser susceptible to DNA damage during cryopreservation as compared to cattle spermatozoa.

Improving the quality of sous-vide beef from Holstein-Friesian bulls by different marinades

The aim of the study was to determine effects of four commercial marinades on the colour, tenderness, cooking loss and sensory characteristics of semimembranosus beef muscles before and after sous-vide (SV) treatment. Muscles (n = 24) were marinated using Odessa (O; red pepper, garlic, onion), Mexico (M; red pepper, tomato), Old Polish (OP; pepper, garlic), and Bordeaux (B; pepper, red pepper, garlic) marinades for 24 h at 4 °C. Marinades uptake ranged from 3.3% (M) to 4.4% (B). Marinating and SV significantly affected all colour parameters. In SV beef, the highest values of L* were noted in OP and O samples, whereas the highest a* and b* values in M samples. Overall, marinating reduced (P < 0.05) cooking loss (34.6%) and shear force (19.5%). The use of marinating prior to SV treatment beneficially affected taste, tenderness and juiciness of beef. OP marinade allowed to obtain beef steaks with the best sensory quality and the lowest shear force.

Effect of plane of nutrition during the first 12 weeks of life on growth, metabolic and reproductive hormone concentrations, and testicular relative mRNA abundance in preweaned Holstein Friesian bull calves.

The objective of this study was to examine the effect of nutrition during the first 12 wk of life on aspects of the physiological and transcriptional regulation of testicular and overall sexual development in the bull calf. Holstein Friesian bull calves with a mean (SD) age and bodyweight of 17.5 (2.85) d and 48.8 (5.30) kg, respectively, were assigned to either a high (HI; n = 15) or moderate (MOD; n = 15) plane of nutrition and were individually fed milk replacer and concentrate to achieve overall target growth rates of at least 1.0 and 0.5 kg/d, respectively. Throughout the trial, animal growth performance, feed intake, and systemic concentrations of metabolites, metabolic hormones, and reproductive hormones were assessed. Additionally, pulsatility of reproductive hormones (luteinizing hormone, follicle-stimulating hormone, and testosterone) was recorded at 15-min intervals during a 10-h period at 10 wk of age. At 87 ± 2.14 d of age, all calves were euthanized, testes were weighed, and testicular tissue was harvested. Differential expression of messenger ribonucleic acid (mRNA) candidate genes involved in testicular development was examined using quantitative polymerase chain reaction assays. All data were analyzed using the MIXED procedure in Statistical Analysis Software using terms for treatment as well as time for repeated measures. Blood metabolites and metabolic hormones generally reflected the improved metabolic status of the calves on the HI plane of nutrition though the concentrations of reproductive hormones were not affected by diet. Calves on the HI diet had greater mean (SED) slaughter weight (112.4 vs. 87.70 [2.98] kg; P < 0.0001) and testicular tissue weight (29.2 vs. 20.1 [2.21] g; P = 0.0003) than those on the MOD diet. Relative mRNA abundance data indicated advanced testicular development through upregulation of genes involved in cellular metabolism (SIRT1; P = 0.0282), cholesterol biosynthesis (EBP; P = 0.007), testicular function (INSL3; P = 0.0077), and Sertoli cell development (CLDN11; P = 0.0054) in HI compared with MOD calves. In conclusion, results demonstrate that offering dairy-bred male calves a high plane of nutrition during the first 3 mo of life not only improves growth performance and metabolic status but also advances testicular development consistent with more precocious sexual maturation.

Associations between the breeding values of Holstein-Friesian bulls and longevity and culling reasons of their daughters

Taking into account functional traits in the breeding practice should lead to a longer productive life of cows. However, despite the increased contribution of these traits in bull selection indices, their daughters are frequently culled as early as the 2nd or 3rd lactation. The problem is whether and to what extent the genetic potential of animals is realized in the production practice. Therefore, the purpose of this study was to determine the associations between the breeding value (BV) of bulls and their daughters for cow longevity and culling reasons in the Holstein-Friesian cattle population in Poland. Data for 532 062 cows culled in 2012, 2015, and 2018 were analyzed. A majority of 5 045 cow sires originated from Poland, Germany, France, the Netherlands, and the United States. The highest variation in the contribution of culling reasons was for the cows culled at the age of 2–4 years. The contribution of the culling reasons, analyzed in relation to the cow culling age, remained similar and the only exception was culling because of old age, for which a significant increase was observed only for the culling age of at least 9 years (13.8%), which was reached by only 7.3% of the cows. The sires were characterized by generally high BV for conformation and reproductive traits. However, they had, at most, the average genetic potential for functional longevity. There were a number of beneficial associations found between the BV of bulls and the distribution of culling reasons in their daughters. For example, it concerns relations between the somatic cell score in milk and culling due to udder diseases and low milk yield, between the interval from calving to first insemination and low milk yield, between the protein yield and old age, or between the BV for certain conformation traits (size, udder) and cow culling due to age. In these cases, as the BV increased for a given trait, the contribution of the corresponding cow culling reason tended to decrease. Our study showed that it seems reasonable to consider Holstein-Friesian cows aged at least 9 years at culling to be long-living animals. This is primarily evidenced by the rapid increase in the culling due to old age in relation to younger cows. Nowadays the above age limit can be suggested as a criterion of longevity for Holstein-Friesian cows but the criterion should be updated to the relation genotype-environment-economy that tends to change over time.

Colostrum source and passive immunity transfer in dairy bull calves

Colostrum is essential for good neonate health; however, it is not known whether different calves absorb the nutrients from colostrum equally well. In this study, the absorption of protein, IgG, and γ-glutamyl transferase was compared in newborn dairy bull calves for 1 wk after feeding colostrum from different sources. Thirty-five Holstein-Friesian bull calves were randomly allocated into 3 groups and fed colostrum within 4 h after birth. Group A calves (n = 12) were bottle fed colostrum from their own dam for 3 d. Colostrum from these group A cows was also used as foster cow colostrum for the group B calves (n = 12), such that each group A and B calf pair received identical colostrum from each milking of the respective group A dam (10% of birth weight per day). The group C calves (n = 11) were fed 1 bottle (2 L) of pooled colostrum and transition milk (referred to as pooled colostrum), as was the standard practice on the dairy farm. The pooled colostrum was collected from the other dairy cows on the farm 0 to 4 d postpartum and stored at 4°C for less than 12 h. Blood was sampled from calves before the first feeding and at 1, 2, 3, and 7 d after birth. Levels of total solids, total protein, and IgG were higher in the dam colostrum than in the pooled colostrum. At birth, there were no differences between the calf groups for any measurements, and all calves had very low IgG levels. After receiving colostrum, the glucose, plasma γ-glutamyl transferase, serum total protein, and IgG concentrations increased significantly in all calves. There were no differences in any blood measurements at any time point between the pairs of group A and group B calves that received colostrum from the same cow except for the IgG concentration 2 d after birth. However, the group A calves had a higher total serum protein level and IgG concentration than the group C calves for all the time points after the first feeding. The group B calves had a higher IgG concentration than the group C calves on d 1, 2, and 7 after birth. Compared with groups A and B, there was no difference in the proportion of calves in group C that failed to have passive immunity transferred adequately based on the IgG threshold (<10 g/L). Thus, the calves receiving identical colostrum from the same cow had the same levels of IgG, and even the pooled colostrum provided sufficient transfer of IgG as the calves were fed within 4 h after birth.

155 Effect of early life nutritional status on the transcriptional profile of hepatic tissue in Holstein Friesian bull calves

155 Effect of early life nutritional status on the transcriptional profile of hepatic tissue in Holstein Friesian bull calves

Sire contribution to fertilization failure and early embryo survival in cattle

Despite passing routine laboratory tests of semen quality, bulls used in artificial insemination (AI) exhibit a significant range in field fertility. The objective of this study was to determine whether subfertility in AI bulls is due to issues of sperm transport to the site of fertilization, fertilization failure, or failure of early embryo or conceptus development. In experiment 1, Holstein-Friesian bulls (3 high fertility, HF, and 3 low fertility, LF) were selected from the national population of AI bulls based on adjusted fertility scores from a minimum of 500 inseminations (HF: +4.37% and LF: -12.7%; mean = 0%). Superovulated beef heifers were blocked based on estimated number of follicles at the time of AI and inseminated with semen from HF or LF bulls (n = 3-4 heifers per bull; total 19 heifers). Following slaughter 7 d later, the number of corpora lutea was counted and the uteri were flushed. Recovered structures (oocytes/embryos) were classified according to developmental stage and stained with 4',6-diamidino-2-phenylindole to assess number of cells and accessory sperm. Overall recovery rate (total structures recovered/total corpora lutea) was 52.6% and was not different between groups. Mean (± standard error of the mean) number of embryos recovered per recipient was 8.7 ± 5.2 and 9.4 ± 5.5 for HF and LF, respectively. Overall fertilization rate of recovered structures was not different between groups. However, more embryos were at advanced stages of development (all blastocyst stages combined), reflected in a greater mean embryo cell number on d 7 for HF versus LF bulls. Number of accessory sperm was greater for embryos derived from HF than for LF bulls. The aim of experiment 2 was to evaluate the effect of sire fertility on survival of bovine embryos to d 15. Day 7 blastocysts were produced in vitro using semen from the same HF (n = 3) and LF (n = 3) bulls and transferred in groups of 5-10 to synchronized heifers (n = 7 heifers per bull; total 42 heifers). Conceptus recovery rate on d 15 was higher in HF (59.4%,) versus LF (45.0%). Mean length of recovered conceptuses for HF bulls was not affected by fertility status. In conclusion, while differences in field fertility among AI sires used in this study were not reflected in fertilization rate, differences in embryo quality were apparent as early as d 7. These differences likely contributed to the higher proportion of conceptuses surviving to d 15 in HF bulls.