Ruminants have co-evolved with their gastrointestinal microbial communities that digest plant materials to provide energy for the host. Some arctic and boreal ruminants have already shown to be vulnerable to dietary shifts caused by changing climate, yet we know little about the metabolic capacity of the ruminant microbiome in these animals. Here, we use meta-omics approaches to sample rumen fluid microbial communities from Alaskan moose foraging along a seasonal lignocellulose gradient. Winter diets with increased hemicellulose and lignin strongly enriched for BS11, a Bacteroidetes family lacking cultivated or genomically sampled representatives. We show that BS11 are cosmopolitan host-associated bacteria prevalent in gastrointestinal tracts of ruminants and other mammals. Metagenomic reconstruction yielded the first four BS11 genomes; phylogenetically resolving two genera within this previously taxonomically undefined family. Genome-enabled metabolic analyses uncovered multiple pathways for fermenting hemicellulose monomeric sugars to short-chain fatty acids (SCFA), metabolites vital for ruminant energy. Active hemicellulosic sugar fermentation and SCFA production was validated by shotgun proteomics and rumen metabolites, illuminating the role BS11 have in carbon transformations within the rumen. Our results also highlight the currently unknown metabolic potential residing in the rumen that may be vital for sustaining host energy in response to a changing vegetative environment.

Four experiments determined the kinetics of in vitro maturation and fertilization of cat oocytes and the effects of prolonged cold storage of ovaries before oocyte recovery on in vitro maturation/in vitro fertilization (IVM/IVF) success. Domestic cat ovaries were collected at ovariohysterectomy and stored at 4 degrees C in PBS until oocyte recovery and culture in Eagle's minimal essential medium (EMEM) containing FSH, LH, oestradiol and BSA for maturation. In Expt 1, meiotic maturation was assessed at 0, 12, 24, 38 and 48 h of culture. After 24 h, > 61% of oocytes were in telophase I or metaphase II. In Expt 2, oocytes were recovered from ovaries stored for 24, 48 or 72 h and cultured in EMEM for 24 h. There was no difference among groups (P > 0.05) in the ability to achieve nuclear maturation (mean +/- SEM, 57.1 +/- 5.3%, 60.4 +/- 5.4%, 55.4 +/- 15.1% for 24, 48 and 72 h, respectively). Fertilization and embryo development after insemination at 16, 24, 32, 40 and 48 h of culture were examined in Expt 3. Of 98 oocytes inseminated at 32 h, 69% cleaved, 59% developed into morulae and 13% into blastocysts, more (P < 0.05) than those oocytes inseminated at earlier and later times. Development to blastocysts occurred after insemination at 16 (1.2%), 24 (9.1%) and 32 (13.3%) h of culture, but not after insemination at 40 or 48 h. Expt 4 involved cold storage of ovaries for 24, 48 or 72 h before oocyte recovery and insemination at 32 h of culture (the optimal time measured in Expt 3). Compared with storage for 24 h, fertilization success was lower (P < 0.05) in the 48 and 72 h groups, and, although 9.1% of inseminated oocytes from the 24 h storage group developed to blastocysts, none (P < 0.05) achieved this stage after 48 or 72 h of storage. These results indicate that domestic cat oocytes reach nuclear maturity by 24 h in culture and can be fertilized and develop to blastocysts optimally after insemination at 32 h. Oocytes recovered from ovaries stored at 4 degrees C for up to 72 h are capable of reaching telophase I or metaphase II in vitro. However, only oocytes stored within the ovary for 24 h produce blastocysts, indicating that the ability to achieve nuclear maturation is an inadequate indicator of fertilization and developmental competence.

The efficiency of sperm capacitation and of the acrosome reaction was studied in the teratospermic domestic cat to evaluate further the etiology of compromised zona pellucida penetration and oocyte fertilization. Specific objectives were to compare normospermic and teratospermic cat ejaculates for 1) the kinetics and timing of sperm capacitation in vitro as determined by an ionophore-induced acrosome reaction; 2) the incidence of spontaneous acrosomal loss; 3) the ability of capacitated, swim-up processed sperm to acrosome-react in response to chemical (calcium ionophore) or physiological (solubilized zonae pellucidae) inducers; and 4) differences in acrosomal ultrastructure by use of transmission electron microscopy (TEM). Acrosomal status was determined with the fluorescent probe Arachis hypogaea (peanut) agglutinin. The timing of in vitro capacitation differed (p < 0.05) between cat populations. Normospermic samples were capacitated at 2.0 h postcentrifugation, whereas teratospermic samples required 2.5 h to become capacitated. At 2.5 h, sperm from teratospermic males were less capable (p < 0.05) of completing the acrosome reaction after ionophore exposure (49.3 +/- 8.0%) than sperm from normospermic males (73.3 +/- 3.8%). Levels of spontaneous acrosomal loss/reaction over time were similar (p > 0.05) between cat groups (range, 7.6-17.8%). In swim-up separated sperm from normospermic cats, ionophore A23187 was a more potent inducer (p < 0.05) of the acrosome reaction (70.1 +/- 6.5%) than solubilized zonae pellucidae (31.1 +/- 1.2%). Swim-up separated sperm from teratospermic cats, however, were compromised in the ability to acrosome react, regardless of inducer (ionophore, 23.9 +/- 3.3%; solubilized zonae pellucidae, 23.9 +/- 4.7%; p > 0.05). Sperm motility patterns over time indicated that differences in acrosomal status were not influenced by cell death. The frequency of abnormal acrosomes detected by TEM was higher (p < 0.05) in teratospermic (30.0 +/- 3.9%) than in normospermic (3.1 +/- 1.3%) samples. Swim-up separation failed to reduce (p > 0.05) the proportion of sperm cells with malformed acrosomes (swim-up, 33.5 +/- 3.5%; washed, 26.6 +/- 4.6%). These results indicate that sperm from teratospermic cats exhibit a high incidence of malformed acrosomes detectable only at the ultrastructural level. Nevertheless, acrosomal dysfunction is not related exclusively to structural defects because > 40.0% of swim-up separated sperm with structurally normal acrosomes still are incapable of completing the acrosome reaction. This suggests that compromised capacitation and acrosomal dysfunction may be responsible for low fertilization success in the teratospermic domestic cat.

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Introduction In the United States, gonadectomy is common and widely promoted as a component of responsible pet ownership. The recent publication of several studies examining the effect of gonadectomy on future health has challenged long-held assumptions and recommendations for gonadectomy in companion animals. The purpose of this study was to characterize the associations between gonadectomy and two outcomes: overweight/obesity and orthopedic injuries, in a large prospective study of Golden Retrievers. Methods Age at gonadectomy was divided into four categories: intact (reference), ≤ 6 months, > 6 months ‒ ≤ 12 months, and > 12 months. Dogs with a Purina Body Condition Score of 7 or greater were classified as overweight or obese. Orthopedic injuries considered were the first instance of veterinary-reported cranial cruciate ligament injury and clinically evident osteoarthritis. We performed survival analyses on a cohort of Golden Retrievers to estimate the associations of interest using proportional hazards. We adjusted for age at study enrollment, owner-reported activity level, and dog’s sex. Results Compared to intact dogs, all gonadectomy age categories showed increased risk for the development of overweight/obesity. (≤ 6 months, HR: 1.81, 95% CI: 1.36–2.40), p-value: <0.0001; 6 months to ≤ 12 months, HR: 2.21, 95% CI: 1.77–2.73, p-value: < 0.0001; > 12 months, HR: 1.56, 95% CI: 1.24–1.96, p-value: 0.0001). Compared to intact dogs, dogs who were ≤ 6 months at gonadectomy had increased risk for orthopedic injury (HR: 4.06, 95% CI: 2.15–7.67, p-value: <0.00001). Discussion This study presents prospectively acquired data demonstrating that gonadectomy is a risk factor for both overweight/obesity and chronic non-traumatic orthopedic injuries in a prospective cohort of Golden Retrievers. Our data suggest that gonadectomy at any age is a risk factor for overweight or obesity, but delaying gonadectomy until dogs are at least 6–12 months of age may help to decrease the risk for orthopedic injury.

We studied the Persian onager (Equus hemionus onager), an endangered equid subspecies. The objective was to characterize endocrine patterns and ovarian follicular dynamics of females as well as seminal traits and sperm sensitivity to cryopreservation in males as a prerequisite to testing the feasibility of artificial insemination (AI). Urinary progesterone and estrogen metabolite profiles were determined by enzyme immunoassay in 11 females. Serial ultrasonography of ovarian activity was performed for 2 mo in a subset of four females. Females were seasonally polyestrous (June-November). Ovarian morphometry via ultrasonography and urinary progesterone profiles were more reflective of reproductive events than urinary estrogen patterns, and preovulatory follicle size was smaller than reported for other equid species. There was evidence for lactational suppression of estrus for up to 1.5 yr in nursing dams. Electroejaculation allowed recovery of highly motile sperm from 7, anesthetized males on 57% of occasions. Spermatozoa, including motility and acrosomal integrity, were resilient to freeze-thawing. Artificial insemination was successful in 2 of 3 females following detection of a dominant follicle and deslorelin administration, resulting in births of a healthy female and male foal by using fresh/chilled and frozen/thawed sperm, respectively.

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Pregnancy success and embryo survival are low with the use of assisted reproduction in felids treated with exogenous gonadotropins. In this study, the pharmacokinetics and ovarian-stimulatory effects of eCG and hCG were evaluated in the domestic cat. Catheterized anestrual queens (n = 4 per treatment [Trt] group) were given 100 IU eCG i.v. (Trt 1), 100 IU eCG i.m. (Trt 2), 75 IU hCG i.v. (Trt 3), 75 IU hCG i.m. (Trt 4), or 100 IU eCG i.m. followed 80 h later by 75 IU hCG i.m. (Trt 5). Blood samples were collected at 0, 5, 30, and 60 min and 4, 8, 12, 24, 36, 48, 72, 96, 120, 144, and 168 h postinjection, and serum samples were analyzed for estradiol-17beta, progesterone, eCG, and hCG. Pharmacokinetic traits (volume of distribution, Vd; elimination half-life, t1/2beta; clearance rate, Clr) were calculated for eCG and hCG. When i.v. and i.m. administration were compared, no differences (p > 0.05) were observed in follicle or corpus luteum (CL) number or hormone concentrations for queens receiving eCG or hCG alone. Number of mature ovarian follicles (> or = 2 mm diameter) observed at 168 h postinjection did not differ (p > 0.05) for eCG (mean +/- SEM, 10.5 +/- 2.0) vs. hCG (11.1 +/- 3.0), indicating that these were equally effective in inducing follicular growth. In most queens (> 90%) given single gonadotropins (i.m. or i.v.), eCG and hCG persisted in circulation for at least 120 h and 96 h after injection, respectively, reflecting similar (p > 0.05) pharmacokinetic (i.v.) values for Vd (eCG, 91.4 +/- 24.8 ml/kg; hCG, 59.1 +/- 7.9 ml/kg), t1/2beta (eCG, 23.0 +/- 2.4 h; hCG, 22.9 +/- 4.1 h), and Clr (eCG, 2.7 +/- 0.5 ml/h per kg; hCG, 1.8 +/- 0.1 ml/h per kg). Sequential treatment with eCG+hCG did not affect (p > 0.05) the t1/2beta of individual gonadotropins. In summary, eCG and hCG have comparable pharmacokinetics and ovarian-stimulatory activity when administered alone to the domestic cat. These findings suggest that hCG promotes the ancillary follicle formation that is frequently observed after ovulation in cats treated with eCG+hCG regimens, possibly disrupting the maternal environment and decreasing fecundity following assisted reproductive procedures.