Antral Follicle Populations and Embryo Production – In Vitro and In Vivo – of Bos indicus–taurus Donors from Weaning to Yearling Ages

Interest in indicus–taurus cattle has been increasing, as these animals are likely to present the best characteristics of Zebu and European bovine breeds. The aim of this study was to compare the embryo production of indicus–taurus donors with high vs low antral follicle counts obtained by ovum pickup/in vitro production (OPU/IVP) and superovulation (SOV)/embryo collection. Braford females at weaning age (3/8 Nelore × 5/8 Hereford, n = 137, 9 ± 1 month old) were subjected to six serial ovarian ultrasonographs and were assigned to two groups according to the number of antral follicles ≥3 mm as follows: G‐High antral follicular count (AFC, n = 20, mean ≥40 follicles) and G‐Low AFC (n = 20, mean ≤10 follicles). When the females (n = 40) reached 24 months of age, they were subjected to both OPU/IVP and SOV/embryo collection. The average number of follicles remained highly stable throughout all of the ultrasound evaluations (range 0.90–0.92). The mean number of COCs recovered (36.90 ± 13.68 vs 5.80 ± 3.40) was higher (p < 0.05) for females with high AFC, resulting in higher (p < 0.05) numbers of total embryos among females with high vs low AFC (6.10 ± 4.51 vs 0.55 ± 0.83). The mean number of embryos per collection was also higher (p < 0.05) for G‐High vs G‐Low (6.95 ± 5.34 vs 1.9 ± 2.13). We conclude that a single ultrasound performed at pre‐pubertal ages to count antral follicles can be used as a predictor of embryo production following IVP and SOV/embryo collection in indicus–taurus females.     

Influence of genetic type, slaughter weight and sex on ovine muscle fiber and fat-cell development

Histological properties from the longissimus (LD) and semimembranosus (SM) muscles of 51 wether and ewe lambs from Hampshire rams and two ewe genetic types (SR, 1/2 Suffolk and 1/2 Rambouillet, and FS, 1/2 Finnish Landrace and 1/2 Southdown) and three slaughter live weights (32, 41 and 50 kg) were compared. Fibers in both muscles were classified as beta R (red), alpha R (intermediate) or alpha W (white). All LD muscle fiber types from FS ewe lambs increased in diameter from 32 to 41 kg, but decreased in diameter from 41 to 50 kg. Also, this quadratic effect with slaughter weight was found in alpha R and alpha W fibers from the SM muscle of FS wether and ewe lambs. However, diameters of alpha R and alpha W fibers from SR wether and ewe lambs and beta R fibers from SR ewe lambs increased linearly in the SM muscle with increasing slaughter weight. As slaughter weight increased, the proportion of alpha R fibers decreased in both the LD and SM muscles for SR wether and FS wether and ewe lambs. Concurrent with the increase in slaughter weight and decrease in alpha R fiber percentage, the proportion of alpha W fibers increased in the LD muscle of SR wether lambs, the SM muscle of SR ewe lambs and both muscles of FS wether and ewe lambs. Genetic type and sex groups, except SR ewe lambs, support the theory of transformation of alpha R to alpha W fibers with increasing slaughter weights. Fat-cell diameters increased in both muscles of SR wether and FS ewe lambs with increasing slaughter weights. Increases in fat traits of lamb carcasses were related to increases in red-fiber size. Alpha red fiber numbers were inversely related (P less than .05) to alpha W fiber numbers in both the LD and SM muscles (r = -.83 and -.79). The proportion of alpha R to alpha W fibers might be used as an indicator of physiological maturity for lambs.     

Characteristics of cytochrome P450-dependent metabolism in the liver of the wild raccoon,Procyon lotor

Wildlife is exposed to a wide range of xenobiotics in the natural environment. In order to appropriately assess xenobiotic-induced toxicity in wildlife, it is necessary to understand metabolic capacities. Carnivores, in general, have low metabolic abilities, making them vulnerable to a variety of chemicals. Raccoons (Procyon lotor) in the wild have been found to have high levels of xenobiotics. However, little is known about the metabolic capacity of the cytochrome P450 (CYP) enzymes in this species. Thus, this study used liver samples to investigate the characteristics of CYP enzymes in wild raccoons. In 22 wild raccoons, CYP concentrations in hepatic microsomes were examined. To better understand the properties of CYP-dependent metabolism, in vitro metabolic activity studies were performed using ethoxyresorufin, pentoxyresorufin and testosterone as substrates. In addition, three raccoons were fed commercial dog food in the laboratory for one week, and the effects on CYP-dependent metabolism were investigated. In comparison to other mammalian species, raccoons had very low concentrations of CYP in their livers. In an in vitro enzymatic analysis, raccoons’ ethoxyresorufin O-deethylase (EROD) and pentoxyresorufin O-depentylase (PROD) metabolic capacities were less than one-fifth and one-tenth of rats’, respectively. These results indicate the possible high risk in raccoons if exposed to high levels of environmental xenobiotics because of their poor CYP activity. In this study, the features of CYP-dependent metabolism in wild raccoons are described for the first time.     

Environmental and maternal factors associated with gross placental morphology in dairy cattle

This article reports on a study of gross placental morphology of 282 expelled placentas from 89 primi‐ and 193 multiparous Holstein dams immediately after calving and examines associations with environmental factors such as typical herd features and season of calving, and maternal factors such as age at calving, level of milk yield at conception and cumulative amount of milk produced during gestation. The highest correlation between calf measurements and placental characteristics was found between the weight of the calf and the total cotyledonary surface (r = .643; p < .001), confirming the high importance of the cotyledonary surface available for nutrient transfer to the developing foetus. Younger age in adolescent and smaller heart girth in multiparous dams were associated with a higher cotyledon number, suggesting placental compensation in dams with lower capacities in terms of dry matter intake. No significant association between milk yield during gestation in multiparous animals and gross placental morphometrics could be detected, indicating that factors such as the amount of milk produced during gestation affect placental development less than foetal weight close to term. Therefore, placental growth may be sustained at the expense of other tissues in an attempt to maintain pregnancy and minimize the adverse consequences for the foetus. This study offers evidence concerning factors affecting the placental surface size for nutrient transfer from dam to calf in dairy cattle based on gross morphometrics, but needs confirmation from studies in which this surface size is more profoundly assessed by measuring the branches present in the cotyledonary villi.     

OC3Morphometry Characterisation of Catalan Donkey Spermatozoa and Identification of Sperm Morphometric Subpopulations

In order to determine the injure produced in boar spermatozoa through cryopreservation process, we analyzed the expression of the hexose transporters Glut-3 and Glut-5 and the zona pellucida binding protein As-A (P68) in three different steps of the freezing-thawed protocol: at 17°C (fresh BTS-diluted semen, 1 : 2 v/v, step 1), at 5°C (after glycerol addition; step 2), and post-thawing (step 3). All sperm analyses were carried out with immunogold techniques under electronic microscopy. For this study eight healthy post-pubertal Iberian boars were submitted to a collection of twice per week through 3 months, evaluating two ejaculates from each boar. Glut-3 maintains the expression in the acrosome region post-thawing but not along the tail where is reduced. The expression of Glut-5 and As-A is majority located at the post-acrosome region of the spermatozoa at step 1, but in step 2 and step 3 this expression is relocated to sperm tail area. In conclusion, while cryopreservation affects the localization and the expression of Glut-3 and Glut-5, its fertilizing capacity is not significantly reduced. The stabilization of boar semen at 5°C was found to be the most crucial step for sperm survival.     

Relation between respiratory activity and sperm parameters in boar spermatozoa cryopreserved with alpha‐tocopherol and selected by Sephadex

Our aim was to evaluate the effect of Sephadex filtration on respiratory activity of porcine spermatozoa and its relation with quality and functional sperm parameters. Samples were evaluated regarding oxygen uptake and sperm parameters: motility, plasma and acrosome membrane integrity, capacitation and acrosome reaction induction in vitro, plasma membrane functionality, determined by the hypo‐osmotic swelling test (HOST), and lipid peroxidation assessed by thiobarbituric acid assay. Sephadex filtration improved all routine quality parameters (motility, plasma and acrosome membrane integrity) and functional parameters (HOST, in vitro capacitation and true acrosome reaction levels) and produced a significant decrease in cryocapacitation and lipid peroxidation. Oxygen uptake increased in Sephadex samples (41 ± 7%) respect to single washing. Oxygen addition of carbonyl‐cyanide‐m‐chlorophenylhydrazone (CCCP) confirmed mitochondrial coupling in washed and Sephadex samples; showing an increase of 2.6 and 4.2 times for oxygen consumption in single washing and Sephadex ones, respectively. The increase in oxygen uptake with succinate addition with respect to basal oxygen uptake was significantly lower in Sephadex samples (63 ± 25%) than in the washed ones (183 ± 35%). Sephadex samples showed higher mitochondrial activity measured by oxygen consumption and improved quality and functional parameters. Our study recommends this protocol due to the fact that this filtration method removes dead or damaged spermatozoa allowing to obtain cryopreserved boar spermatozoa with optimized fertilizing capacity.     

Comparison of carprofen and butorphanol as post-surgical analgesics in cats

Post‐operative pain management by a single subcutaneous (SC) injection of carprofen has been found to be effective in cats and dogs. This clinical study compared the analgesic properties of injectable carprofen and butorphanol in 71 healthy cats (0.5–5 years, mean weight 3.24 ± 0.61 kg) undergoing ovariohysterectomy. Cats were randomly assigned to three groups: Group C received carprofen 4 mg kg^?1 SC at intubation and sterile saline 0.08 mL kg^?1 SC at extubation; Group B received sterile saline 0.08 mL kg^?1 SC at intubation and butorphanol 0.4 mg kg^?1 SC at extubation; Group S received sterile saline 0.08 mL kg^?1 SC at intubation and extubation. All cats were pre‐medicated with atropine (0.04 mg kg^?1 SC), acepromazine (0.02 mg kg^?1 SC), ketamine (5 mg kg^?1 SC), and induced IV with ketamine (5 mg kg^?1) and diazepam (0.25 mg kg^?1). Serum biochemistry values were taken at 24 and 48 hours post‐surgically and compared to a pre‐surgical baseline. Behavioral data were collected by a blinded investigator prior to surgery (baseline) and 1, 2, 3, 4, 8, 12, 16, 20, and 24 hours post‐surgery; the data were compiled into composite pain scores on a scale from 0 to 21 and complemented by visual analogue scores (VAS). Scoring was based on changes in behavior, posture, vocalization, and response to interactive stimulation. Cats with pain scores >12 were considered to be moderately painful, received meperidine (4 mg kg^?1 IM), and were excluded from further statistical analyses. Sixty of 71 cats completed the study. Anesthetic time was 88.5 ± 21.8 minutes (mean ± SD). Meperidine was given to one cat in C, three in B, and five in S. There were no significant differences in biochemistry values. There were no significant differences in pain scores between C and B at any time period; B and C pain scores were significantly lower than S at 1, 2, 12, 16, and 20 hours post‐operatively, and C lower than S at 3 and 8 hours post‐surgery. Pain scores decreased over the 24‐hour study in all groups; the greatest decrease in each group was between 4 and 8 hours post‐operatively. In this study, carprofen provided post‐surgical analgesia comparable to butorphanol.