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.

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.

Comparison of Pure and Crossbred Japanese Black Steers in Growth Performance and Metabolic Features from Birth to Slaughter at a Spanish Fattening Farm.

Japanese Black (Wagyu) cattle produce high-quality beef. However, whether Wagyu steers can be profitably raised under conditions different than the traditional Japanese ones remains unclear. From 2018 to 2020, we raised 262 Wagyu purebred steers, 103 Wagyu-by-Angus (Wangus) crossbred steers, and 43 Angus-by-European (ACL) crossbred steers on a Spanish farm with high welfare standards and a locally sourced, high-olein diet. Factors and factors' interactions impacting steer growth were analyzed using generalized linear models. ACL steers grew faster than the other two groups, with Wangus showing intermediate fattening and muscle development. Average daily weight gains (kg/day) were 0.916 for Wagyu, 1.046 for Wangus, and 1.293 for ACL during the weaning to growing period, and 0.628 for Wagyu, 0.64 for Wangus, and 0.802 for ACL during the growing to fattening phase. ACL showed the lowest marbling rates. Wagyu and Wangus usually showed higher cholesterol, triglycerides, and high-density lipoprotein than ACL. ACL calves may experience greater stress at weaning, as suggested by higher glucose, lactate, and ß-hydroxybutyrate than the other groups. The results suggest that Wagyu and Wangus steers showed adequate growth, health, and metabolic development in this type of production system, with Wagyu purebreds probably being more profitable than Wangus crossbreeds.

Optimization of post-cervical artificial insemination in gilts: Effect of cervical relaxation procedures and catheter type.

Post-cervical (pC) artificial insemination (AI) has been successfully developed for application in multiparous sows, although it has proved problematic in gilts. This study analyzes the use of pC-AI in gilts by two experiments. In the first experiment, the efficiency of pC-AI in gilts was evaluated using a multi-ring multiparous catheter (MpC), which led to 23.1% of the gilts being successfully inseminated. In gilts where insemination was not possible using an MpC, two alternatives were applied before a second attempt at insemination: 1) Vetrabutin Chlorhydrate (VC) was intramuscularly injected in order to relax the cervix; or 2) Warm extender (WE) was deposited in the cervix to modify the cervical muscle dynamics. After the application of these treatments, the success rates achieved with the MpC were 34.2% and 23.8% for VC and WE, respectively. No statistically significant differences were found in the reproductive parameters measured [farrowing (%), litter size and fecundity index] between the use of MpC, or the MpC combined with VC or WE, compared with gilts inseminated by cervical AI (control group). In the second experiment, new catheters based on the anatomical characteristics of gilts (GpC) were used, and the rate of successful pC-AI application were compared (experiment 2a): a) MpC: control; b) GpC1: multi-ring catheter of Ø 16 mm and inner cannula of Ø 3.5 mm; c) GpC2: a multi-ring catheter of Ø with an inner cannula of Ø 2.5 mm. The highest rate of successful cannula penetration was reached in the GpC2 group (60.3%) followed by GpC1 (37.0%) and MpC (19.6%) (p < 0.05). There were no differences in the above mentioned reproductive parameters using the three catheters compared with cervical AI method (control group). Moreover, prior cervical AI did not improve subsequent pC-AI application 24 h later (experiment 2b). In conclusion, Vetrabutin Chlorhydrate, warm extender or the new catheters can be considered as useful tools for improving the success rate of pC-AI technique in gilts.

Cooling and freezing of boar spermatozoa: supplementation of the freezing media with reduced glutathione preserves sperm function.

In this study, we evaluated the effects of glutathione (L-gamma-glutamyl-L-cysteinylglycine; GSH) supplementation of the freezing extender on semen parameters during the cooling (2 hours at 5 degrees C) and freezing phases of the cryopreservation process to compensate for the decrease in GSH content observed during sperm freezing. To fully address these questions, we incorporated a new set of functional sperm tests. These included tests of mitochondrial function, inducibility of the acrosome reaction, in vitro penetration (IVP) of oocytes, changes in sulfhydryl group content in membrane proteins, and capacitation status. The main findings emerging from this study were that the addition of GSH to the freezing media resulted in 1) an improvement in percent motility (%MOT) and motion parameters of thawed spermatozoa, as measured by both microscopic analysis and computer-assisted semen analysis (CASA); 2) a higher number of total viable spermatozoa; 3) a higher number of noncapacitated viable spermatozoa; and 4) a decrease in the number of spermatozoa with changes in the sulfhydryl groups in membrane proteins. This protective effect on sperm function was more pronounced with 1 mM of GSH than with 5 mM of GSH.