The effects of low levels of dietary trace minerals on the plasma levels, faecal excretion, health and performance of pigs in a hot African climate

The present study was performed in order to evaluate the effects of lower than usual industry levels of dietary trace minerals on plasma levels, faecal excretion, performance, mortality and morbidity in growing-finishing pigs in a hot African climate. Group 1 (n = 100 pigs) received a diet with common industry levels of trace minerals. Group 2 (n = 100 pigs) received reduced dietary trace mineral levels but were fed the same basic diet as Group 1. Mortality, morbidity, pig performance and carcass measurements were evaluated. Two pigs in Group 1 and three pigs in Group 2 died. Thirteen pigs in Group 1 and 27 pigs in Group 2 were medically treated (P < 0.05). Carcass masses, back fat depth, loin depth, and lean percent were not significantly different between the groups. However, the carcasses when evaluated revealed a non-significant higher back fat thickness, lower loin eye area and percentage of fat-free lean in barrows compared to gilts within each group. Despite lower initial masses, pigs fed diets containing industry levels of trace minerals were heavier (P < 0.05) and had a higher (P< 0.05) than average daily gains compared to those that received a diet containing lower levels of trace minerals. Faecal zinc excretion was significantly lower (P < 0.05) in pigs fed with lower dietary zinc levels. Copper, manganese and iron excretion were not affected (P > 0.05) by the dietary levels of these trace minerals. Plasma trace mineral concentrations were not affected by the dietary treatment.     

A retrospective analysis of radiation therapy for the treatment of feline vaccine‐associated sarcoma*

We retrospectively evaluated predictive prognostic factors in 73 cats with vaccine‐associated sarcoma given postsurgical curative (n = 46, most with clean margins) or coarse fractionated radiotherapy (n = 27, most with either macroscopic disease or dirty margins). The former animals displayed a median survival of 43 months and a median progression free interval (PFI) of 37 months, the latter reached a median survival of 24 months and a median PFI of 10 months. In cats undergoing coarse fractionated therapy, factors predictive of a better outcome included lack of visible mass (n = 10) as opposed to macroscopic disease (n = 17, survival: 30 versus 7 months, P = 0.025; PFI: 20 versus 4 months, P = 0.01), adjuvant chemotherapy for gross disease (n = 5/17, survival: 29 versus 5 months, P = 0.04) and a smaller number of surgeries preceding radiation therapy (coeff = 0.41, P = 0.03). The Ki67 index was not predictive for survival. We concluded that postsurgical curative and coarse fractionated radiotherapy are effective legitimate options for managing vaccine‐associated sarcomas.     

In vitro evaluation of metacarpophalangeal joint loading during simulated walk

Reasons for performing study: Insight into the loading pattern of the articular cartilage surface during the complete stride is important as biomechanical factors play a pivotal role in the pathogenesis of joint trauma and osteoarthritis (OA). Objectives: To determine the loading pattern in the equine MCP articulation in vitro during simulated walk. Methods: Eight cadaveric limbs from mature Dutch Warmblood horses were loaded in a pneumatic loading device in 6 different positions (A1‐A6). The pressure distribution on the articular surface of the proximal phalanx (P1) was measured at 7 sites (S1‐7) using intra‐articularly placed pressure sensitive films, which were analysed by scanning and densitometry. Results: Pressures recorded after mid‐stance (A4, 5, 6) were significantly (P<0.05) higher than those before (A1, 2, 3) and showed the biphasic loading pattern of the walk at all sites, except for the site halfway along the sagittal groove (S7). At S7, there was a linear increase in pressure during the progress of the stance phase of the stride in most horses. Medially (S4, 5, 6) the pressure was significantly higher than laterally (S1, 2, 3) (P<0.05). Conclusions and potential relevance: The heavier medial loading coincides with the location where articular cartilage degeneration in the process of OA in the equine MCP joint is known to start. The discrepancy between the loading of the central groove and the other parts of the joint may result in large stress differences at the end of the stance phase, which might be related to the pathogenesis of stress fractures in the first phalanx and distal third metacarpal bone.     

Composition of individual nucleobases in diets containing different products from bacterial biomass grown on natural gas, and digestibility in mink (Mustela vison)

The objectives of the present study were to quantify the amount of nucleic acids, to examine the nucleobase composition and to determine the digestibility of individual nucleobases in diets containing various products from bacterial biomass grown on natural gas, including autolytic and hydrolytic fractions, using mink (Mustela vison) as a model animal. The diets consisted of cod fillet (control), commercial basic BioProtein, and five experimentally produced autolytic and hydrolytic fractions of the bacterial protein meal as protein sources. Each diet was assigned to four adult male mink, housed individually in cages equipped for controlled feeding and quantitative collection of faeces. Faeces were collected for 4 days, and the individual nucleobases in diet and faeces were analysed by HPLC after hydrolysis using HClO(4). The content of nucleobases in the diets containing bacterial protein meal was 37% to 205% higher than in the control diet. The nucleobase-nitrogen in the control diet amounted to 4.3% of the total nitrogen content, whereas the experimental bacterial protein diets contained from 7.4% to 17.4% of the total N content in the form of nucleic acids. The various methods used to produce the bacterial protein fractions clearly affected both the amount of nucleic acids and the molar proportions of the individual nucleobases. The average digestibility of the nucleobases was 95%, and all the individual nucleobases were highly digestible. Uracil showed the highest digestibility (on average 96.8%), whereas thymine showed the lowest digestibility (on average 93.6%).     

Physical Rehabilitation Alters Body Composition in Chronically Obese Cat

Successful weight loss in obese dogs and cats is difficult, and even more so in pets who don't exercise regularly or are inactive. Over the past 10 years, physical rehabilitation (or physio‐therapy) as a treatment or wellness modality has been gaining popularity in small animal veterinary practice. This case report describes the use of physical rehabilitation to achieve weight loss and a decreased body condition score in a chronically obese cat. A 7‐year old, female‐spayed domestic, short‐haired cat, weighing 15 lbs, was evaluated by the Nutrition Support Service at Michigan State University's Veterinary Teaching Hospital for a weight management consultation. The cat had a history of chronic obesity and the owner reported feeding a variety of reduced or restricted‐calorie foods, both canned and dry versions, over the previous 5 years. The home environment included three other cats, none of which were overweight. All cats were fed once daily in the evening; separate food bowls were provided for each cat, but multiple water bowls and litter boxes were shared. A course of 8 weeks of physio‐therapy was recommended, with a target weight of 12 lbs identified, to which the owner agreed. Body weight, body condition score and circumference measures of axillary, rib and flank areas were taken at the initial visit, and at 3 weeks and 8 weeks. At the beginning of the 8^th week, the cat's body weight had dropped from 15 lbs to 14.2 lbs, and the body condition score shifted down from 9 to 8 out of 9. More dramatically, however, were changes measured in body circumference: from 43 cm to 38.6 cm in the axilla (11% decrease); 50.3 cm to 42.5 cm in the ribs (15.5% decrease); 46 cm to 41 cm in the flank (11% decrease). To the author's knowledge, this is the first report confirming weight loss, reduced body condition score, and altered body composition in a cat as a direct result of physical rehabilitation.     

Effects of Oxygen Exposure and Gentamicin on Stallion Semen Stored at 5 and 15°C

This study was undertaken to investigate the effects of storage of stallion semen in a defined milk protein extender at 5 and 15°C under either anaerobic or aerobic conditions, with or without addition of the antibiotic gentamicin. Semen samples were collected from eight fertile stallions and stored for 96 h (day 0–4) and assessed daily for motility, velocity and membrane integrity (viability) using a CASA system. Samples for bacteriology assessment were taken on day 2 of storage. No significant (p > 0.05) differences in motility, velocity or viability were observed between treatments on days 0–2. On days 3 and 4, semen stored without gentamicin at 5°C had a significantly (p < 0.05) better semen quality compared with storage at 15°C without gentamicin, irrespective of oxygen exposure. On days 3 and 4, motility and velocity were greater in samples stored at 15°C with gentamicin, compared with the corresponding treatments without antibiotic (p < 0.05). This effect was also evident for viability on day 4. The decline in semen quality observed at 15°C most likely resulted from the effect of bacterial growth. Bacterial growth was the greatest in samples stored at 15°C without gentamicin, under both anaerobic and aerobic conditions (p < 0.05). Bacterial growth was inhibited by adding of gentamicin at 15°C, which accordingly reduced the decline in semen quality. Addition of antibiotic to samples stored at 5°C had no significant effect on any parameter analysed. In conclusion, storage at 15°C can be achieved by using an extender containing the antibiotic gentamicin. Storage at 5°C tended to maintain better semen quality irrespective of oxygen exposure, and did not necessitate an antibiotic treatment.     

Effects of exercise on the morphology of the myenteric neurons of the duodenum of Wistar rats during the ageing process

This study aimed to evaluate the effects of regular physical activity on the morphology of the myenteric plexus of the duodenum in rats during the ageing process. To this end, 45 Wistar rats were divided into three groups: C (sedentary – 6 months old), S (sedentary – 12 months old) and T (trained – 12 months old). The animals of group S were given with a physical activity programme consisting of a 10-min-treadmill workout once a week. The animals of group T were submitted to the physical activity programme five times a week. Their duodenums were collected and submitted to the techniques of nicotinamide adenine dinucleotide (NADH)-diaphorase enzyme histochemistry for whole-mount preparations and transmission electron microscopy. No differences in the constitution of the myenteric plexuses were found when the sedentary and trained groups were compared with the control group. The ultrastructural features were similar for the three groups. However, it was verified that the physical activity of the trained animals resulted in a similar myenteric neuron morphology to that of the adult animals (6 months old), thereby confirming its beneficial effect, as the sedentary animals had larger alterations in the collagen fibrils and the basal membrane that occur through ageing. The quantitative analysis showed that the NADH-diaphorase positive neurons decreased with ageing and increased with physical activity ( P  > 0.05). No significant alteration ( P  > 0.05) in the neuronal profile area of the NADH-diaphorase positive neurons has been observed with ageing.