A simulation model of a breeding ewe flock

A simulation model was constructed of a self-replacing flock of Merino ewes grazing a predominantly Wimmera ryegrass and subterranean clover pasture in the Eppalock catchment of northern Victoria, Australia. The model was used to predict the likely physical, biological and economic consequences of changes in stocking rate and date of lambing.Routines for simulating the local climate, together with expected levels of pasture production, were based on available local data. The herbage produced was utilised for animal maintenance, growth, pregnancy, lactation and wool production. Predictions were made of the ovulation and fertilisation rates of the breeding ewes and the subsequent survival of embryos and lambs. Lamb growth rates were determined relative to their predicted intake levels of milk and herbage.The economic consequences of different combinations of ewe stocking rate and date of lambing were evaluated by simulating the cash flow of the property. Financial returns were obtained from the sale of wool, cast-for-age and culled ewes, and wether lambs.     

COMPUTED TOMOGRAPHIC ANATOMY OF THE DISTAL EXTREMITY OF THE HORSE

X-ray computed tomography (CT) is an imaging tool that is becoming increasingly available for use in veterinary medicine. Advantages, including depiction of detailed cross-sectional anatomy, improved contrast resolution, and computer reformatting, make it a potentially valuable diagnostic technique. Veterinary application of CT has been primarily limited to use in small animals. Current reports describe the technique for use in the horse, but there are no published studies correlating serial CT images with equine cross-sectional anatomy. A study of the distal extremity of the horse was undertaken to facilitate interpretation of images produced using CT. Transverse CT images of the distal forelimb of equine cadavers were evaluated relative to gross anatomic dissection. Resolution of bone architecture in transverse plane images was satisfactory, but soft-tissue' resolution, although satisfactory for visualization of major structures, was relatively poor, probably due to lack of interposed fat and insufficient differences in physical density and atomic number. Thus it appears in the equine distal limb that CT may be most useful for evaluation of complex bone abnormalities.     

Evaluation of two test procedures for diagnosis of giardiasis in dogs.

Two commercially available tests, an antigen-capture ELISA for use on fecal samples, and a peroral nylon string test for use in dogs, were compared with a zinc sulfate fecal concentration technique (ZSCT) for detection of giardiasis in dogs. Of 77 dogs and 164 fecal samples (from these dogs), 33 and 52, respectively were found to be Giardia-positive on the basis of results of the ZSCT. The ELISA gave false-negative results for 10 and 14% of ZSCT-positive dogs and fecal samples, respectively, and false-positive results (relative to the ZSCT test results) in 13 and 10% of ZSCT-positive dogs and fecal samples, respectively. Of the 18 string-tested dogs, 14 were positive by results of the ZSCT. Of the 4 dogs that were Giardia-negative by ZSCT, 2 were Giardia-positive by ELISA. Dogs were sedated and given water and metoclopramide to aid passage into the duodenum of the capsule containing a nylon string. Of the 21 string tests performed on the 18 dogs, only 5 strings reached the duodenum, and 0 of the 5 yielded positive results for Giardia sp. Because the string broke in 1 dog (leaving most in the gastrointestinal tract and, therefore, producing a risk of string foreign body) further string tests were not done.     

Pharmacokinetics of transdermal flunixin in sows

The objective of this study was to describe the pharmacokinetics (PK) of flunixin in 12 nonlactating sows following transdermal (TD) flunixin (3.33 mg/kg) and intravenous (IV; 2.20 mg/kg) flunixin meglumine (FM) administration using a crossover design with a 10‐day washout period. Blood samples were collected postadministration from sows receiving IV FM (3, 6, 10, 20, 40 min and 1, 3, 6, 12, 16, 24, 36, and 48 hr) and from sows receiving TD flunixin (10, 20, 40 min and 1, 2, 3, 4, 6, 8, 12, 16, 24, 36, 48, 60, and 72 hr). Liquid chromatography and mass spectrometry were used to determine plasma flunixin concentrations, and noncompartmental methods were used for PK analysis. The geometric mean ± SD area under the plasma concentration–time curve (AUC) following IV injection was 26,820.59 ± 9,033.88 and 511.83 ± 213.98 hr ng/ml for TD route. Mean initial plasma concentration (C₀) was 26,279.70 ± 3,610.00 ng/ml, and peak concentration (C_max) was 14.61 ± 7.85 ng/ml for IV and TD administration, respectively. The percent mean bioavailability of TD flunixin was 1.55 ± 1.00. Our results demonstrate that topical administration is not an efficient route for delivering flunixin in mature sows.     

Mammomonogamus auris infection in the middle ear of a domestic cat in Saipan, Northern Mariana Islands, USA

A 2-year-old female domestic shorthair cat on the island of Saipan was presented to a local veterinarian for headshaking. Otoscopic examination showed mild erythema of the right tympanic membrane, but was otherwise unremarkable. Headshaking resolved with topical gentamicin/betamethasone/clotrimazole therapy; however, erythema persisted. Further otoscopy revealed movement of the erythematous region, which was in fact the red-colored strongylid nematode, Mammomonogamus auris, residing within the middle ear. Myringotomy and a saline flush were performed under heavy sedation. A silastic tube was inserted into the incision and the worms were retrieved by applying negative pressure. Follow-up treatment included topical thiabendazole/dexamethasone/neomycin ointment as well as selamectin. Mammomonogamus auris has previously been documented only three times, once each in China, Sri Lanka and Japan. This is the first report of M auris in cats from Saipan.     

Dormant Season Grazing: Effect of Supplementation Strategies on Heifer Resource Utilization and Vegetation Use

Grazing dormant forage under low-input heifer development strategies typically exposes cattle to low-quality forage. Protein supplementation while grazing dormant range can enhance heifer growth and reproductive performance. We examined resource utilization of heifers and the effects of dormant season grazing on residual vegetation characteristics under two supplementation management strategies. Approximately 100 weaned composite heifer calves were randomly selected and placed into one of two supplementation treatments in each of 2 yr, one receiving a free access 62% crude protein self-fed concentrate and the other receiving a daily hand-fed 20% crude protein cake. Grazing occurred from December (2015 and 2016) through March (2016 and 2017). Thirty transects were randomly located within each pasture for measuring vegetation quality and structure before and after grazing. Daily space use and behavior was evaluated for 21 individuals within each treatment using global positioning system (GPS) collars and resource utilization functions. Heifers supplemented with concentrated protein spent more time grazing per day than heifers supplemented with cake (6.92 ± 0.18, 6.24 ± 0.17 h). Relative use by heifers in the cake treatment was negatively related to horizontal distance from the supplement delivery site early to midwinter ($\stackrel{?}{\overline{\beta }}$ = ? 0.41 ± 0.16, ? 0.53 ± 0.17). Both treatments selected grazing locations relative to standing biomass of perennial grasses ($\stackrel{?}{\overline{\beta }}$ = 0.0005 ± 0.00004) and crude protein ($\stackrel{?}{\overline{\beta }}$ = 0.12 ± 0.007). However, resource selection was highly variable among individuals for both supplementation treatments. We found no treatment effects on pre-post grazing differences in residual cover of litter, grass, forbs and shrubs (P > 0.24). However, the time period when grazing occurred had an effect on residual vegetation conditions (P < 0.01). Our results indicate high levels of variability in grazing site selection by heifers, suggesting future research should incorporate individual animal measurements in an attempt to account for individual animal variability.     

Influence of Post‐Mortem Sperm Recovery Method and Extender on Unstored and Refrigerated Rooster Sperm Variables

Many post‐mortem sperm collection techniques have been described for mammalian species, but their use in birds is scarce. This paper compares the efficacy of two post‐mortem sperm retrieval techniques ‐ the flushing and float‐out methods ‐ in the collection of rooster sperm, in conjunction with the use of two extenders, i.e., L&R‐84 medium and Lake 7.1 medium. To determine whether the protective effects of these extenders against refrigeration are different for post‐mortem and ejaculated sperm, pooled ejaculated samples (procured via the massage technique) were also diluted in the above extenders. Post‐mortem and ejaculated sperm variables were assessed immediately at room temperature (0 h), and after refrigeration at 5°C for 24 and 48 h. The flushing method retrieved more sperm than the float‐out method (596.5 ± 75.4 million sperm vs 341.0 ± 87.6 million sperm; p < 0.05); indeed, the number retrieved by the former method was similar to that obtained by massage‐induced ejaculation (630.3 ± 78.2 million sperm). For sperm collected by all methods, the L&R‐84 medium provided an advantage in terms of sperm motility variables at 0 h. In the refrigerated sperm samples, however, the Lake 7.1 medium was associated with higher percentages of viable sperm, and had a greater protective effect (p < 0.05) with respect to most motility variables. In conclusion, the flushing method is recommended for collecting sperm from dead birds. If this sperm needs to be refrigerated at 5°C until analysis, Lake 7.1 medium is recommended as an extender.     

The Inability to Screen Exhibition Swine for Influenza A Virus Using Body Temperature

Agricultural fairs create an unconventional animal–human interface that has been associated with swine‐to‐human transmission of influenza A virus (IAV) in recent years. Early detection of IAV‐infected pigs at agricultural fairs would allow veterinarians to better protect swine and human health during these swine exhibitions. This study assessed the use of swine body temperature measurement, recorded by infrared and rectal thermometers, as a practical method to detect IAV‐infected swine at agricultural fairs. In our first objective, infrared thermometers were used to record the body surface temperature of 1,092 pigs at the time of IAV nasal swab collection at the end of the exhibition period of 55 agricultural fairs. IAV was recovered from 212 (19.4%) pigs, and the difference in mean infrared body temperature measurement of IAV‐positive and IAV‐negative pigs was 0.83°C. In a second objective, snout wipes were collected from 1,948 pigs immediately prior to the unloading of the animals at a single large swine exhibition. Concurrent to the snout wipe collection, owners took the rectal temperatures of his/her pigs. In this case, 47 (2.4%) pigs tested positive for IAV before they entered the swine barn. The mean rectal temperatures differed by only 0.19°C between IAV‐positive and IAV‐negative pigs. The low prevalence of IAV among the pigs upon entry to the fair in the second objective provides evidence that limiting intraspecies spread of IAV during the fairs will likely have significant impacts on the zoonotic transmission. However, in both objectives, the high degree of similarity in the body temperature measurements between the IAV‐positive and IAV‐negative pigs made it impossible to set a diagnostically meaningful cut point to differentiate IAV status of the individual animals. Unfortunately, body temperature measurement cannot be used to accurately screen exhibition swine for IAV.