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315 result(s) for "Whitlock, Brian"
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Effect of age, sex, and county on postmortem findings in goats and sheep in Tennessee (USA), 2017–2021
Small ruminants, including sheep and goats, play an important role in the economy of American agriculture. They are susceptible to a variety of diseases that impact animal welfare and production. This study evaluated postmortem data from two different diagnostic laboratories in the state of Tennessee to discern common causes of death of small ruminants that were brought in for necropsy between 2017 to 2021. Data were prepared for analysis by selecting the predominant conditions observed at postmortem examination and risk factors including sex, age, season, and region were included in analysis. The predominant condition seen in both small ruminant species was endoparasitism. In both sheep and goats, female juvenile animals were more likely to be diagnosed with this condition at necropsy during summer months. Abortive diseases were the next most prominent condition diagnosed in both small ruminant species. The majority of these cases were due to an unknown cause and age was a significant risk factor in both sheep and goats. Neurological disorders in goats and pneumonia in sheep were included in the most prevalent diagnoses at postmortem examination with age being a significant risk factor. These findings suggest that many small ruminant deaths are attributed to infectious diseases that have herdwide implications. Producer education could be beneficial to help identify and implement control measures in a timely manner to help minimize production loss associated with common diseases.
Control of Salmonella Dublin in a bovine dairy herd
Salmonella enterica serovar Dublin (S. Dublin) was diagnosed in a dairy herd after signs of acute gastroenteritis and sepsis. Two hundred eighty‐three Holstein cattle were sampled resulting in 700 observations, and serology for S. Dublin was performed. Holstein cattle sampled were divided by origin and arrival date to determine on‐farm exposure. Prevalence estimates were calculated and compared with control measures implemented on the dairy during the outbreak. One group of cows, presumed to be the original carrier animals, had the highest overall seroprevalence (76.5%). Seroprevalence decreased throughout the study, coinciding with testing and management changes. This report documents biosecurity measures that identified S. Dublin after the purchase of subclinical carrier cattle and the steps taken to successfully control herd transmission.
Residues of Tetracycline, Erythromycin, and Sulfonamides in Beef, Eggs, and Honey from Grocery Stores in Knoxville, Tennessee, USA: Failure of Cooking to Decrease Drug Concentrations
This study evaluated the concentrations of tetracycline, erythromycin, and sulfonamide in beef, eggs, and honey products sold at grocery stores and whether standard cooking to 160 °F (71 °C) reduced the concentrations of antimicrobials spiked into the evaluated food products. In June 2021, the concentrations of selected antimicrobials in 65 samples (8 beef, 48 eggs, 9 honey samples) purchased from grocery stores within Knoxville, Tennessee, were measured using enzyme-linked immunosorbent assays. The Kruskal–Wallis test was used to assess the differences in the median tetracycline concentrations across food types, while the Mann–Whitney test was used to compare the erythromycin residue concentrations between beef and honey. Linear regression was used to analyze whether standard cooking at 160 °F (71 °C) reduced antimicrobial concentrations. Detectable tetracycline concentrations were found in all beef (8/8, 100%), eggs (46/48, 96%), and honey (9/9, 100%) samples, with median concentrations of 7.73, 5.62, and 13.13 µg/kg, respectively. Honey had significantly higher tetracycline concentrations than eggs (p = 0.002). Detectable erythromycin concentrations were found in beef (5/8, 63%) and honey (9/9, 100%), with median concentrations of 0.14 µg/kg for beef and 0.48 µg/kg for honey. None of the antimicrobial concentrations found in the beef and egg products exceeded the U.S. FDA’s maximum residue limits (MRL). Sulfonamide concentrations were undetectable in the beef and egg products. The concentrations of tetracycline, erythromycin, and sulfonamide spiked into the food products did not change significantly in response to cooking to 160 °F (71 °C). The antimicrobial concentrations found in the selected commercial food products were below the MRL, and cooking appeared to not reduce the spiked antimicrobial concentrations in the evaluated food products.
Effects of central and peripheral administration of an acute-phase protein, α-1-acid-glycoprotein, on feed intake and rectal temperature in sheep
Abstract In rodents, an acute-phase protein, α-1-acid-glycoprotein (AGP), was shown to provide a link between inflammation and suppression of feed intake by acting as a leptin receptor agonist. The objective of this study was to determine the effects of AGP on feed intake and rectal temperature in sheep. Ewes were ovariectomized, implanted with a cannula into a lateral ventricle of the brain, and kept indoors in individual pens. Feed intake and rectal temperature were determined for sheep in all experiments. In the first experiment, ewes (n = 4) received 1 of 4 treatments [0 (control), 0.012 (low), 0.06 (medium), or 0.30 (high) mg/kg BW AGP] into the lateral ventricle (ICV). All sheep received all treatments in a Latin square design balanced for carryover effects with 10 d between treatments. In the second experiment, ewes (n = 10) received 1 of 2 treatments (0 and 3 mg/kg BW of AGP) intravenously (IV) in a completely randomized design. In the third experiment, ewes (n = 19) received peripheral treatments (IV) of an antipyretic [0 (control) or 2.2 mg/kg BW flunixin meglumine (FLU)] 30 min before receiving central AGP [0 (control) or 0.3 mg/kg BW of AGP] in a completely randomized design. All data were analyzed using a mixed model analysis of variance and tested for effects of treatment, time, and the interaction of treatment and time. Cumulative 48-h feed intake after administration of treatments was also determined. In the first experiment, there was no effect of ICV treatment (P = 0.37) on feed intake rate or on cumulative feed intake (P = 0.31). There was an effect of ICV treatment (P = 0.002) on rectal temperatures, which were greater (P < 0.05) after the high dose of centrally administered AGP. In the second experiment, there was no effect of AGP administration IV on feed intake rate (P = 0.98), on cumulative feed intake (P = 0.41) or on rectal temperature (P = 0.71). In the third experiment, there was an effect of central AGP treatment (P < 0.0001) and an interaction of central AGP and time (P < 0.0001) on rectal temperature, whereas FLU had no effect (P = 0.93), demonstrating that AGP increased rectal temperatures regardless of antipyretic treatment. These results indicate that central AGP increases rectal temperature in sheep by pathways that do not involve prostaglandins. Further research is needed to determine whether AGP may be an important integrator of energy balance and inflammation.
Distribution and regulation of gonadotropin-releasing hormone, kisspeptin, RF-amide related peptide-3, and dynorphin in the bovine hypothalamus
Recent work has led to the hypothesis that kisspeptin/neurokinin B/dynorphin (KNDy) neurons in the arcuate nucleus (ARC) play a key role in gonadotropin-releasing hormone (GnRH) pulse generation and gonadal steroid feedback, with kisspeptin driving GnRH release and neurokinin B and dynorphin acting as pulse start and stop signals, respectively. A separate cell group, expressing RFamide-related peptide-3 (RFRP-3) has been shown to be a primary inhibitor of GnRH release. Very little is known regarding these cell groups in the bovine. In this study, we examined the relative immunoreactivity of kisspeptin, dynorphin, and RFRP-3 and their possible connectivity to GnRH neurons in the hypothalami of periestrus and diestrus bovine. While GnRH and RFRP-3 immunoreactivity were unchanged, kisspeptin and dynorphin immunoreactivity levels varied in relation to plasma progesterone concentrations and estrous status. Animals with higher plasma progesterone concentrations in diestrus had lower kisspeptin and increased dynorphin immunoreactivity in the ARC. The percentage of GnRH cells with kisspeptin or RFRP-3 fibers in close apposition did not differ between estrous stages. However, the proportions of GnRH cells with kisspeptin or RFRP-3 contacts (∼49.8% and ∼31.3%, respectively) suggest direct communication between kisspeptin and RFRP-3 cells to GnRH cells in the bovine. The data produced in this work support roles for kisspeptin and dynorphin, within the KNDy neural network, in controlling GnRH release over the ovarian cycle and conveying progesterone-negative feedback onto GnRH neurons in the bovine.
Effect of oral meloxicam administration on growth performance and behavior of pre-weaning age calves following band castration
The objective of this study was to determine if oral meloxicam (M; a nonsteroidal anti-inflammatory drug) administered at castration to pre-weaning age calves affected average daily gain (ADG) or behavior. Prior to castration (d −14), Angus bulls were weighed and randomly assigned to be band castrated (BAN; n = 8; age = 90.2 ± 6.5 d; BW = 146.3 ± 11.4 kg; scrotal circumference = 16.0 ± 0.5 cm) or castrated with M (BAN + M; n = 9; age = 102.1 ± 6.2 d; BW = 146.0 ± 7.7 kg; scrotal circumference = 16.1 ± 0.3 cm). Six bulls selected to remain bulls based on pedigree and phenotype were maintained in the same pasture (BULL; age = 104.2 ± 6.1 d; BW = 172.1 ± 8.7 kg; scrotal circumference = 17.5 ± 0.4 cm). On d 0, BAN and BAN + M had a rubber band applied tightly around the scrotum, and BAN + M also received oral M (2 mg/kg BW). On d 1, 14, and 28, animals were weighed and a blood sample was collected to determine circulating concentrations of haptoglobin and fibrinogen. Data loggers were affixed to the legs of calves immediately prior to castration (d 0) to record behaviors [mean lying time (h/d), mean lying bouts (n/d), and steps (n/d)] at 1-min intervals and removed on d 28. Behavior and plasma data were tested for effect of treatment, day, and treatment × day interaction, and ADG data were tested for effect of treatment, period (d −14 to 1, d 1 to 14, and d 14 to 28), and treatment × period interaction using JMP procedures for repeated measures (SAS Inst. Inc., Cary, NC). BULL in period d 0 to 14 had greater ADG than all other treatment period combinations, and BULL had greater ADG than BAN or BAN + M overall (P < 0.05). There was no effect of M treatment on circulating concentrations of fibrinogen or haptoglobin (P > 0.05). On d 7 and 15, BAN took more steps than BAN + M (P < 0.05). BAN + M had more lying bouts than BAN on d 13 and 14 (P < 0.05). Overall, M administration had no effect on ADG post-castration and only had minor impacts on behavior in calves band castrated pre-weaning.
Kisspeptin receptor agonist (FTM080) increased plasma concentrations of luteinizing hormone in anestrous ewes
Kisspeptin receptor (KISS1R) agonists with increased half-life and similar efficacy to kisspeptin in vitro may provide beneficial applications in breeding management of many species. However, many of these agonists have not been tested in vivo . These studies were designed to test and compare the effects of a KISS1R agonist (FTM080) and kisspeptin on luteinizing hormone (LH) in vivo . In experiment 1 (pilot study), sheep were treated with FTM080 (500 pmol/kg BW) or sterile water (VEH) intravenosuly. Blood was collected every 15 min before (1 h) and after (1 h) treatment. In experiment 2, sheep were treated with KP-10 (human Metastin 45-54; 500 pmol/kg BW), one of three dosages of FTM080 (500 (FTM080:500), 2500 (FTM080:2500), or 5000 (FTM080:5000) pmol/kg BW), or VEH intravenously. Blood was collected every 15 min before (1 h) and after (4 h) treatment. In experiment 1, FTM080:500 increased ( P < 0.05) plasma LH concentrations when compared to VEH. The area under the curve (AUC) of LH following FTM080:500 treatment was also increased ( P < 0.05). In experiment 2, plasma LH concentrations increased ( P < 0.05) following treatment with KP-10 and FTM080:5000 when compared to VEH and FTM080:500. The AUC of LH following KP-10 was greater than ( P < 0.05) all other treatments and the AUC of LH following FTM080:5000 was greater than ( P < 0.05) all treatments except KP-10. These data provide evidence to suggest that FTM080 stimulates the gonadotropic axis of ruminants in vivo . Any increased half-life and comparable efficacy of FTM080 to KP-10 in vitro does not appear to translate to in vivo in sheep.
Uterine Torsion Dystocia Complicated by Perosomus Elumbis in an Angus Calf Associated with a Consanguineous Mating
A six-year-old multiparous Angus cow was presented for dystocia. Vaginal and rectal examinations revealed an approximately 360° counterclockwise uterine torsion. The torsion was corrected by rolling the cow counterclockwise (three episodes) with the aid of a plank coupled with manual detorsion via the vagina. The placement of obstetric chains followed by manual traction ultimately delivered a stillborn male calf with evidence of vertebral aplasia, arthrogryposis, and abdominal organ herniation. Patient history and subsequent parentage verification revealed that the calf was the result of a consanguineous (mother to son) mating. Tissue samples from the affected calf and blood samples from the dam, sire, and ten half siblings were collected for genetic testing and parentage verification. Necropsy, radiographic, and computed tomography examinations all supported a diagnosis of perosomus elumbis. Perosomus elumbis is a congenital abnormality of unknown origin(s), and this is the first report of a case associated with a consanguineous mating.
Effect of age, sex, and county on postmortem findings in goats and sheep in Tennessee
Small ruminants, including sheep and goats, play an important role in the economy of American agriculture. They are susceptible to a variety of diseases that impact animal welfare and production. This study evaluated postmortem data from two different diagnostic laboratories in the state of Tennessee to discern common causes of death of small ruminants that were brought in for necropsy between 2017 to 2021. Data were prepared for analysis by selecting the predominant conditions observed at postmortem examination and risk factors including sex, age, season, and region were included in analysis. The predominant condition seen in both small ruminant species was endoparasitism. In both sheep and goats, female juvenile animals were more likely to be diagnosed with this condition at necropsy during summer months. Abortive diseases were the next most prominent condition diagnosed in both small ruminant species. The majority of these cases were due to an unknown cause and age was a significant risk factor in both sheep and goats. Neurological disorders in goats and pneumonia in sheep were included in the most prevalent diagnoses at postmortem examination with age being a significant risk factor. These findings suggest that many small ruminant deaths are attributed to infectious diseases that have herdwide implications. Producer education could be beneficial to help identify and implement control measures in a timely manner to help minimize production loss associated with common diseases.