The effect of stress on reproduction and reproductive technologies in beef cattle—A review

Researchers have contributed by increasing our understanding of the factors affecting reproduction in beef, mainly physical health and nutrition aspects, which have been main concerns during decades. Animal welfare is of outmost relevance in all animal production systems and it is strongly associated to stress. Stress responses involve endocrine, paracrine and neural systems and the consequences of this stress on the reproductive efficiency of specifically, beef cattle and bulls, need to be highlighted. We, therefore, describe the fundamentals of stress and its quantification, focusing in beef herds, reviewing the highly valuable pieces of research, already implemented in this field. We examine major factors (stressors) contributing to stress in beef cattle and their effects on the animals, their reproductive performance and the success of reproductive biotechnologies. We include terms such as acclimatization, acclimation or temperament, very relevant in beef systems. We examine specifically the management stress due to handling, social environment and hierarchy or weaning effects; nutritional stress; and thermal stress (not only heat stress) and also review the influence of these stressors on reproductive performance and effectiveness of reproductive biotechnologies in beef herds. A final message on the attention that should be devoted to these factors is highlighted

Fases finales del crecimiento y características metabólicas en bovinos de raza Wagyu y cruzados con Angus (Wangus) en un sistema de producción español

La raza wagyu (WY) se caracteriza por dar lugar a una carne con un alto grado de infiltración, de alta calidad (Shahrai et al. 2020) y de alto interés en el mercado mundial. Carne más engrasada que la tradicional en bovino también se origina en animales de raza Angus, aunque ambas razas presentan ritmos de crecimientos y calidad de la carne diferenciadas (Radunz et al. 2009; Shahrai et al. 2020). El cruce de la raza Angus con Wagyu (wangus, WN) es, por lo tanto, de interés productivo. Sin embargo, hay pocos estudios sobre las características productivas de animales WY y WN en sistemas de producción españoles. Por tanto, el objetivo de este estudio fue evaluar el crecimiento y las características metabólicas de WY y WN en la fase final del engorde

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

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

Crecimiento y características metabólicas diferenciadas de bovinos de razas con alto engrasamiento en un sistema de producción español

La producción de carne de vacuno con grasa altamente infiltrada tiene gran valor en el mercado mundial, debido a su excelente calidad y características organolépticas. Este tipo de carne puede obtenerse en su máxima calidad, de la raza wagyu (de origen japonés), de su cruce con la raza angus (wangus) o de la raza angus en pureza o en cruces con otras razas europeas (cruce comercial). La raza wagyu y sus cruces han sido poco estudiadas en sistemas de producción europeos y, por tanto, es difícil saber su comportamiento productivo y su eficiencia económica, comparada con razas europeas. El objetivo de este estudio fue comparar el crecimiento y las características metabólicas (diferenciadas en wagyu; Piao da C. et al., 2015) de animales wagyu (WY), wangus (WN) y cruces comerciales (CC) en las primeras etapas de su crecimiento

Beef Nutritional Characteristics, Fat Profile and Blood Metabolic Markers from Purebred Wagyu, Crossbred Wagyu and Crossbred European Steers Raised on a Fattening Farm in Spain

19 Pág.A high intramuscular fat content characterizes Wagyu (WY) cattle breed. Our objective was to compare beef from WY, WY-by-Angus, or Wangus (WN) steers with European, Angus-by-Charolais-Limousine crossbred steers (ACL), considering metabolic biomarkers pre-slaughtering and nutritional characteristics, including health-related indexes of the lipid fraction. The fattening system with olein-rich diets and no exercise restriction included 82 steers, 24 WY, 29 WN, and 29 ACL. The slaughter ages and weights were (median and interquartile range) 38.4 mo.-old (34.9-40.3 mo.) and 840 kg (785-895 kg) for WY; for WN, 30.6 mo. (26.9-36.5 mo.) and 832 kg (802-875 kg), and for ACL steers, 20.3 mo.-old (19.0-22.7 mo.) and 780 kg (715-852 kg). Blood lipid-related metabolites, except for non-esterified fatty acids (NEFA) and low-density level cholesterol (LDL), were higher in WY and WN than in ACL, while glucose was lower in WY and WN. Leptin was higher in WN than in ACL. Pre-slaughtering values of plasma HDL underscored as a possible metabolic biomarker directly related to beef quality. The amino-acid content in beef did not differ among experimental groups, except for more crude protein in ACL. Compared to ACL, WY steers showed higher intramuscular fat in sirloin (51.5 vs. 21.9%) and entrecote (59.6 vs. 27.6%), more unsaturated fatty acids in entrecote (55.8 vs. 53.0%), and more oleic acid in sirloin (46 vs. 41.3%) and entrecote (47.5 vs. 43.3%). Compared to ACL entrecote, WY and WN showed better atherogenic (0.6 and 0.55 vs. 0.69), thrombogenicity (0.82 and 0.92 vs. 1.1), and hypocholesterolemic/hypercholesterolemic index (1.9 and 2.1 vs. 1.7). Therefore, beef's nutritional characteristics depend on breed/crossbred, slaughtering age and cut, with WY and WN entrecote samples showing a healthier lipid fraction.This research was funded by the Centre for the Development of Industrial Technology from the Spanish Ministry of Science and Innovation, grant number CDTI-IDI-20180254.Peer reviewe

Reproductive efficiency of sows inseminated at single dose fixed time with refrigerated, cryopreserved and encapsulated spermatozoa

4 Pág. Departamento de Reproducción Animal​ (INIA)The aim was to assess the reproductive efficiency of different techniques used to preserve spermatozoa in artificial insemination semen doses (AI-doses) by evaluating refrigeration at 15°C, cryopreservation and encapsulation. Forty-two hyperprolific sows were treated with buserelin and inseminated once at a single fixed time. The fertility rate, embryonic vesicles viability and the early embryonic mortality (arrested conceptuses) evaluated post-mortem at 24th day of pregnancy, were analysed in order to assess the effectiveness of each proposed technique. Results show an overall reduction on fertility using the three proposal sperm preservation techniques (69.27%, 60.00% and 78.75% for refrigerated, frozen-thawed and encapsulated AI-doses, respectively). Total number of embryonic vesicles was very similar among the three treatments; yet, the number of viable vesicles was numerically different among groups, and thus, embryonic viability was 79.25%, 80.0% and 87.15% for refrigerated, frozen-thawed and encapsulated AI-doses, respectively.INIA project CON18-109, funded by the ‘Cinco Villas’ Artificial Insemination Center, Government of Aragon and European Agricultural Fund for Rural Development.Peer reviewe

Bull Semen Obtained on Beef Farms by Electroejaculation: Sperm Quality in the First Two Hours of Storing with Different Extenders and Holding Temperatures

Sperm quality decreases over time, so bull semen may need to be preserved after field collection. However, the effect of handling such semen samples from commercial farms and placing them in very short–term storage has not been elucidated. Therefore, ejaculate from 25 bulls from 1 dairy and 14 beef cattle farms were collected under farm conditions and evaluated for semen quality during the first two hours after collection. Two commercial extenders (AndroMed® and BIOXcell®) and two different storage temperatures (5 °C and room temperature) were used to evaluate the influence on semen quality and sperm kinetics in ejaculates grouped into three evaluation times, based on time since collection (Time 1: n = 7; Time 2: 75–105 min, n = 11; and Time 3: 105–120 min, n = 7). Classical semen parameters, sperm motion kinetics by CASA and colony-forming units were assessed. The differences between both extenders in curvilinear and straight–line velocities (VCL and VSL) for the different time groups (Time 2 and Time 3) were statistically significant for p ® showed lower VSL, straightness and linearity in sperm compared to BIOXcell® (p ® induced more curvilinear movement, while BIOXcell® stimulated straighter motility

Characteristics and in vitro fertilizing ability of giant panda (Ailuropoda melanoleuca) frozen-thawed epididymal spermatozoa obtained 4 hours postmortem: A case report

When Chu-Lin, a male giant panda (studbook #249), died at Madrid Zoo, his reproductive tract was removed 4 hr postmortem and the epididymal spermatozoa were collected. Extended sperm were kept at 5°C for 4 hr, loaded into straws, and frozen for 7 min in liquid nitrogen vapor before the straws were plunged into liquid nitrogen. Two straws were thawed and evaluated. Sperm motility was assessed in fresh, refrigerated, and thawed spermatozoa (75%, 60%, 35%, respectively). Sperm viability and acrosome status were estimated using a triple-stain technique (TST). The results showed 33% live sperm with intact acrosomes after thawing. A hypoosmotic swelling (HOS) test demonstrated the retention of membrane integrity in 72% of thawed sperm. To evaluate the in vitro fertilizing ability of thawed sperm, a sperm penetration assay (SPA) was performed. The values obtained for the percentage of penetration and the penetration index were 62% and 1.78 sperm/oocyte, respectively. The results obtained demonstrate that epididymal sperm recovered from a giant panda postmortem can be successfully cryopreserved. The sperm fertilizing ability demonstrated in vitro after thawing may provide a final opportunity for this male to contribute to the currently small germplasm reserves of this endangered species, and to reproduce in the future through assisted reproductive technology.Peer reviewe

Morphometric changes on the vulva from proestrus to oestrus of nulliparous and multiparous HYPERPROLIFIC sows

4 Pág. Departamento de Reproducción Animal (INIA)The aim of this study was to assess whether vulvar morphometric changes occurring in female pigs during proestrus and oestrus could be objective, accurate and predictive indicators of the onset to oestrus and thus performed artificial inseminations at the most appropriate time. For that purpose, pictures of vulvas from 60 hyperprolific females (30 gilts and 30 sows) during proestrus and oestrus were taken once a day. Vulva measurements (area, perimeter, length and width) on these pictures were performed using the image processing ImageJ software. Gilts and sows showed statistical differences (p < .01) in all vulvar morphometric measurements between proestrus and oestrus. Statistical differences in vulvar metrics were detected 24 h before the onset to oestrus, affecting all vulvar measurements in gilts, whereas only vulvar width was affected in sows. The image analysis used in this study may contribute to the development of smart technology in swine farming.This study was supported by CDTI-IDI-20180243 grant. Open access funding enabled and organized by ProjektDEALPeer reviewe