Shedding of feline immunodeficiency virus in semen of domestic cats during acute infection

OBJECTIVE: To examine shedding of cell-free and cell-associated feline immunodeficiency virus (FIV) in semen of domestic cats during acute infection. ANIMALS: 7 specific-pathogen-free sexually intact male cats. PROCEDURE: 6 cats were inoculated IV with 5 x 10(6) 50% tissue culture infective doses of FIV-NCSU1, and 1 cat served as an uninfected (control) cat. Infection was confirmed in the 6 cats. Periodically for up to 16 weeks after inoculation, cats were anesthetized and ejaculates obtained by use of electroejaculation. Virus was isolated from filtered seminal plasma and washed seminal cells by co-cultivation with a feline CD4+ T-cell line. Seminal cell lysates were also examined for a 582-base pair segment of FIV gag provirus DNA, using a nested polymerase chain reaction amplification. RESULTS: During the acute phase of FIV infection, virus was evident in semen of 5 inoculated cats. Five cats had virus-positive seminal plasma and 3 had virus-positive cellular constituents during the study. Virus was isolated from 8/22 (36%) seminal plasma samples and 2/17 (18%) seminal cell specimens. Provirus DNA was detected in 5/24 (21%) seminal cell lysates. Cell-free virus was isolated as early as 6 weeks after inoculation, whereas cell-associated virus was isolated as early as 12 weeks after inoculation. Provirus DNA was detected in seminal cells from one cat as early as 1 week after inoculation. CONCLUSIONS AND CLINICAL RELEVANCE: Cell-free and cell-associated FIV are shed in semen of cats early during the course of infection. Samples obtained before seroconversion may contain virus. Virus shedding in ejaculates varies between and within cats during acute infection.     

Evaluation of life-cycle herd efficiency in cow-calf systems of beef production

A deterministic beef efficiency model (BEM) was used to evaluate life-cycle herd efficiency (LCHE) in cow-calf beef production systems using four breed groups of beef cattle. The breed groups were Beef Synthetic #1 (SY1), Beef Synthetic #2 (SY2), Dairy Synthetic (DS), and purebred Hereford (HE). The LCHE was defined over the lifetime of the herd as the ratio of total output (lean meat equivalent) to total input (feed equivalent). Breed differences in LCHE were predicted with the larger/slower maturing DS being most efficient at each age of herd disposal and reproductive rate. This was mainly because, at any average age at culling, the dams of DS breed group were less mature and so had been carrying relatively lower maintenance loads for shorter periods and positively influencing LCHE. Higher LCHE was predicted with improvement in reproductive performance if there were no associated extra costs. However, this declined markedly if there was a delay in marketing of offspring. As average age at culling increased from 4 to 6 yr, efficiency declined sharply, but it began to recover beyond this age in most breed groups. We concluded that the slower maturing DS breed group may be more efficient on a herd basis in cow-calf systems and that improvements in reproductive rate not associated with extra costs improve life-cycle efficiency. Culling cows soon after their replacements are produced seems efficient.     

Evaluation of in vitro culture systems for goat preantral follicles using reused ovaries from reproductive biotechniques: An alternative to maximize the potential of reproduction

This study aimed to examine the in vitro culture of secondary preantral follicles, using reused ovaries, to compare both the 2D and 3D methods of in vitro culture of preantral follicles, and the system of medium replacement. Twenty‐five pairs of ovaries from mixed‐breed goats were used for the experiment. Follicular puncture of antral follicles was performed for in vitro production. After this procedure, the secondary preantral follicles were submitted to a microdissection procedure. The isolated preantral follicles were randomly divided into three treatments: (a) Two‐dimensional culture with partial replacement of medium during culture (2D PR), (b) Three‐dimensional culture with addition of medium during culture (3D AD) and (c) Three‐dimensional culture with partial replacement of medium (3D PR). The culture period was 18 days. All treatments at the end of the in vitro culture period (18 days) presented a follicular survival rate which ranged from 59% to 70%, demonstrating that it was possible to perform an experiment with preantral follicles using ovaries that had previously been used in another reproductive biotechnique. The 3D AD treatment showed a survival percentage and follicular diameter higher than the 2D PR treatment, however, it did not differ from the 3D PR treatment. In conclusion, experiments employing the use of preantral follicles can be performed with success after the ovaries have been used for experiments with antral follicles. Moreover, the three‐dimensional system with the addition of medium is recommended for in vitro culture of preantral follicles, since this system is more practical and financially feasible.     

Long-term downward trend in total solar irradiance

The first 5 years (from 1980 to 1985) of total solar irradiance observations by the first Active Cavity Radiometer Irradiance Monitor (ACRIM I) experiment on board the Solar Maximum Mission spacecraft show a clearly defined downward trend of -0.019% per year. The existence of this trend has been confirmed by the internal self-calibrations of ACRIM I, by independent measurements from sounding rockets and balloons, and by observations from the Nimbus-7 spacecraft. The trend appears to be due to unpredicted variations of solar luminosity on time scales of years, and it may be related to solar cycle magnetic activity.     

Ultrasonography to investigate the effect of supplementing whole milk with complex carbohydrates and specific amino acids on curd retention in the abomasum of dairy calves

AIM: To determine whether the retention time of curd in the abomasum of calves was influenced by supplementing milk with a plant-derived carbohydrate and amino acid supplement, evaluated non-invasively using ultrasonography.

METHODS: Female dairy calves aged between 2–6 days of age were sourced from a commercial farm in March 2013. All calves were fed whole milk until weaning (4?L per day); 21 calves were supplemented with a probiotic until 18 days of age, and thereafter with a plant-derived complex carbohydrate and amino acid supplement until weaning, and 22 calves were just fed whole milk. Treatment groups were balanced for age, weight and breed. At 9–14, 24–29 and 52–57 days of age, the abomasum of each calf was examined using ultrasonography immediately before and after feeding, 1 and 2 hours after feeding, and then at 30 minute intervals until curd was no longer visible in the abomasum. Abomasal volume and curd size were recorded to assess retention time of curd in the abomasum.

RESULTS: At 9–14 days of age, mean retention time of curd in the abomasum was similar (4.6 hours) in both groups. At 24–29 days of age, when the supplemented calves had been receiving the supplement for approximately 10 days, mean curd retention time was longer by 1.4 (SE 0.28) hours in supplemented compared with unsupplemented calves (p<0.001). At 52–57 days of age, mean retention time was longer by 0.7 (SE 0.34) hours compared to unsupplemented calves (p=0.05).

CONCLUSION: Using ultrasonography, changes in abomasal content could be followed non-invasively over time and it was demonstrated that the plant-derived complex carbohydrate supplement increased the curd retention time in the abomasum. We speculate that the increased retention time enables an increased availability of nutrients following a more complete digestion of milk, thereby improving animal performance.     

Presence and coincidence of Listeria spp., motile aeromonads and Yersinia enterocolitica in a cold-smoked salmon processing and packing plant

Environmental samples and samples of partially processed fish from a cold-smoked salmon processing and packing plant, and product samples purchased from retail outlets, were examined for the presence of Listeria monocytogenes and other Listeria spp., motile aeromonads and Yersinia enterocolitica. Listeria spp. were not isolated from raw fish but were a contaminant of processed and partially processed fish. Listeria spp. were also detected in 18.8% of surfaces in contact with fish. Unlike Listeria spp., motile aeromonads were isolated from the raw fish but not from the finished product. They were more frequently isolated from environmental sources than Listeria spp. Yersinia enterocolitica was not isolated from any of the samples tested. Little evidence was found to show a coincidence of motile aeromonads and Listeria spp., since only one subset of samples showed such a link. It is concluded that contamination by Listeria spp. was from environmental sources at the processing plant at, or beyond, the slicing stage. Reducing the number of wet areas and special cleaning and sanitation considerations for a contaminated site (the freezer seal) are suggested as ways of reducing contamination of the product.     

Clinical anatomy of the canine brain using magnetic resonance imaging.

The purpose of this study was to produce an magnetic resonsnce (MR) image atlas of clinically relevant brain anatomy and to relate this neuroanatomy to clinical signs. The brain of a large mixed breed dog was imaged in transverse, sagittal, and dorsal planes using a 1.5 T MR unit and the following pulse sequences: Turbo (fast) spin echo (TSE) T2, T1, and T2- weighted spatial and chemical shift-encoded excitation sequence. Relevant neuroanatomic structures were identified using anatomic texts, sectioned cadaver heads, and previously published atlases. Major subdivisions of the brain were mapped and the neurologic signs of lesions in these divisions were described. TSE T2-weighted images were found to be the most useful for identifying clinically relevant neuroanatomy. Relating clinical signs to morphology as seen on MR will assist veterinarians to better understand clinically relevant neuroanatomy in MR images.     

Activity of pulmonary intravascular macrophages in cats and dogs with and without adult Dirofilaria immitis

Pulmonary intravascular macrophages (PIMs), large (20-80 microm diameter) monocytes are present in sheep, pigs, and horses, but not in dogs, rats, rabbits, or primates. The present study evaluated the phagocytic activity of various organs in cats and dogs and determined the influence of Dirofilaria immitis infections on PIM activity. Live or dead adult heartworm (HW) was transplanted via jugular venotomy into cats and dogs. Cats (four per group) were allocated to five groups: surgical controls--no HW, dead HW for 1 week, live HW for 1 week, dead HW for 3 weeks, or live HW for 3 weeks. Radioactive technetium (Tc-99m, 1.2mCi in 0.3ml) sulfa-colloid was injected intravenously. All cats with HW were clinically asymptomatic and developed radiographic pulmonary parenchymal changes. No gross changes were visible at necropsy for cats with HW; inflammatory changes were less severe in cats with live HW. In cats with dead HW for 3 weeks, worms were present but folded, flattened, and located in distal pulmonary arteries. Uninfected control dogs and those with dead HW did not demonstrate any PIM activity. In control cats, lungs were the primary phagocytic organ after systemic IV colloid injection (72.5% of the total recovered radioactive dose). The lung and liver together represented over 95% of the recovered Tc-99m colloid in all cats. In each group of cats with HW, phagocytic activity of the lung was significantly less (p < 0.001) than the PIM activity of controls. Cats with dead HW at 1 week (50.1%) had a significant (p < 0.019) decrease in PIM activity compared with cats with dead HW at 3 weeks (59.5%). The PIM activity in cats with live HW was significantly decreased (p < 0.001) from that in groups with dead HW, but there was no significant difference between the two groups infected with live worms. There were no significant differences in recovery between any groups in pairwise analysis of the spleen, heart, skeletal muscle, kidney, bone marrow, or blood. Significant increases (p < 0.001) in liver activity for each group inversely reflected the decreased lung activity; consistent with increased hepatic uptake of Tc colloid "escaping" a relatively suppressed lung macrophage system. Transmission electron microscopy confirmed PIM glycocalyx changes and vacuolization, moderate Type 1 cell damage and Type II cell hypertrophy in cats with dead HW. There was no evidence of PIM death. The significant decrease in PIM activity in groups with dead HW and a greater decrease in groups with live HW are consistent with a down-regulation of PIM function in cats with live HW.     

Equine gastrointestinal motility research: where we are and where we need to go

Equine gastrointestinal motility is a central issue in cases of equine colic, post operative convalescence and alimentary conditions encountered in practice. There are significant syndromes of intestinal dysmotility in the horse such as obstructive disorders and post operative ileus that are still poorly understood. This review describes the various areas of research that aim to elucidate the pathogenesis of intestinal hypo- or hypermotility by research methods, which include studies at the cellular level, and those that employ in vitro or in vivo techniques of evaluating the physiology and mechanical means of ingesta transit through the alimentary tract. The review discusses future directions for studies which will hopefully lead to better understanding and appropriate measures for diagnosis, therapy and prevention of ileus and other motility disorders.