A mechanistic model for predicting the nutrient requirements and feed biological values for sheep

The Cornell Net Carbohydrate and Protein System (CNCPS), a mechanistic model that predicts nutrient requirements and biological values of feeds for cattle, was modified for use with sheep. Published equations were added for predicting the energy and protein requirements of sheep, with a special emphasis on dairy sheep, whose specific needs are not considered by most sheep-feeding systems. The CNCPS for cattle equations that are used to predict the supply of nutrients from each feed were modified to include new solid and liquid ruminal passage rates for sheep, and revised equations were inserted to predict metabolic fecal N. Equations were added to predict fluxes in body energy and protein reserves from BW and condition score. When evaluated with data from seven published studies (19 treatments), for which the CNCPS for sheep predicted positive ruminal N balance, the CNCPS for sheep predicted OM digestibility, which is used to predict feed ME values, with no mean bias (1.1 g/100 g of OM; P > 0.10) and a low root mean squared prediction error (RMSPE; 3.6 g/100 g of OM). Crude protein digestibility, which is used to predict N excretion, was evaluated with eight published studies (23 treatments). The model predicted CP digestibility with no mean bias (-1.9 g/100 g of CP; P > 0.10) but with a large RMSPE (7.2 g/100 g of CP). Evaluation with a data set of published studies in which the CNCPS for sheep predicted negative ruminal N balance indicated that the model tended to underpredict OM digestibility (mean bias of -3.3 g/100 g of OM, P > 0.10; RMSPE = 6.5 g/100 g of OM; n = 12) and to overpredict CP digestibility (mean bias of 2.7 g/100 g of CP, P > 0.10; RMSPE = 12.8 g/100 g of CP; n = 7). The ability of the CNCPS for sheep to predict gains and losses in shrunk BW was evaluated using data from six studies with adult sheep (13 treatments with lactating ewes and 16 with dry ewes). It accurately predicted variations in shrunk BW when diets had positive N balance (mean bias of 5.8 g/d; P > 0.10; RMSPE of 30.0 g/d; n = 15), whereas it markedly overpredicted the variations in shrunk BW when ruminal balance was negative (mean bias of 53.4 g/d, P < 0.05; RMSPE = 84.1 g/d; n = 14). These evaluations indicated that the Cornell Net Carbohydrate and Protein System for Sheep can be used to predict energy and protein requirements, feed biological values, and BW gains and losses in adult sheep.     

Treatment of experimental ureteral strictures by endourological ureterotomy and implantation of stents in the porcine animal model

The objective of this study is to evaluate the dilation of the ureter using endoureterotomy and an expanding-sheath double pigtail ureteral stent in the treatment of experimentally induced ureteral strictures in the porcine animal model. This is a new treatment in the ureteral strictures resolution in Veterinary Urology, although it is not a common affection, it usually appears as a consequence of ureteritis and in the iatrogenic female genital surgery. The experimental study is design in three phases: induction of experimental stricture, diagnosis and treatment of the stricture and follow-up. We have used 10 healthy Large White female pigs. The internal ureteral diameter was measured prior to laparoscopic ligature stricture induction using retrograde ureteropyelography (RUPG). Experimental stricture was diagnosed 4 weeks after intervention, using RUPG and ultrasound, and treated by endoureterotomy and subsequent placement of a double pigtail ureteral stent, which was removed 6 weeks later. The study finished 4 weeks later with measurement of ureteral diameters using RPUG and ultrasound evaluation. Except in one case, all ureters displayed permanent dilation of the strictured area for 10 weeks after treatment (6 weeks with ureteral stent and 4 more weeks without stent). Finally, this technique proved to be effective in cases of short-length and short-living ureteral strictures, and represents a viable alternative to conventional surgery in animals.     

Analysis of differential protein expression in Actinobacillus pleuropneumoniae by Surface Enhanced Laser Desorption Ionisation--ProteinChip (SELDI) technology

Actinobacillus pleuropneumoniae (APP) is the aetiological agent of porcine pleuropneumonia. An increased understanding of its molecular basis of pathogenicity and vaccine development will be facilitated by the availability of sequence data from a complete genome which, by analogy to other bacteria, is predicted to encode many proteins in the molecular mass range 3-20kDa. However, conventional techniques to study bacterial protein expression, such as SDS-PAGE and 2-dimensional electrophoresis, typically focus on the 15-200kDa range. In this study we have evaluated Surface Enhanced Laser Desorption Ionisation-ProteinChip (SELDI) technology for the analysis of protein expression, in particular those of <20kDa, of APP grown under different environmental conditions. Cytoplasmic/periplasmic and outer membrane protein fractions were obtained from the APP wildtype serotype 1 strain 4074 grown in Brain Heart Infusion (BHI) broth (+different concentrations of NAD), BHI containing pig serum or defined medium. Optimum conditions for SELDI profiles included a sample size of 1 microg and the use of sinapinic acid as the energy absorbing matrix. In the <20kDa range, the SELDI profiles obtained from wild-type bacteria grown in rich medium plus 33-66% pig serum were most similar to those grown in defined medium. The SELDI profiles of extracts of the wild-type and of an rpoE mutant were similar although there were clear differences. The results suggest that SELDI is a useful complementary approach to conventional proteomic analytical methods with APP, and presumably other bacterial pathogens, being particularly suited for analysis of proteins in the <20kDa mass range.     

Piscine mycobacteriosis: a literature review covering the agent and the disease it causes in fish and humans

Mycobacterium marinum, M. fortuitum and M. chelonae are the etiological agents of fish mycobacteriosis. Fish mycobacteriosis is a disseminated infection reported in more than 150 fish species and is usually accompanied by emaciation and death over a period of months to years. Granulomas are formed both externally and scattered throughout the internal organs. Treatment is in most cases unsatisfactory and the overall recommendation is to destroy the diseased stock, particularly since these pathogens are capable of affecting man as well as fish. Especially fish handlers and aquarium hobbyists are infected and the disease is mostly confined to the superficial, cooler body tissues, most often the extremities. Dissemination is apparently rare but has been reported.     

Biochemical evaluation of mitochondrial respiratory chain enzymes in canine skeletal muscle

OBJECTIVE: To perform respiratory chain enzymatic activity assays on canine skeletal muscle biopsy specimens and establish reference range values of skeletal muscle enzyme activities for dogs. SAMPLE POPULATION: Biopsy specimens from the vastus lateralis muscle were obtained from 24 dogs (8 sexually intact males and 14 sexually intact females) ranging from 15 months to 6 years of age. PROCEDURE: Mean values of citrate synthase, cytochrome-c oxidase, succinate dehydrogenase, succinate dehydrogenase-cytochrome-c reductase, nicotinamide adenine dinucleotide (NADH) dehydrogenase, and NADH dehydrogenase-cytochrome-c reductase activities were established by use of 6 standard spectrophotometric assays for respiratory chain enzyme analysis. RESULTS: Compared with published data for skeletal muscle enzyme activities in humans, skeletal muscle enzyme activities in dogs were 2- to 4-fold higher. Additionally, citrate synthase activity, a marker for mitochondrial volume, was positively correlated with age in dogs, suggesting that mitochondrial volume increases with age, although no apparent change in respiratory chain enzymatic activity with an increase in age was found. CONCLUSIONS AND CLINICAL RELEVANCE: Reference range values for skeletal muscle enzyme activities of dogs are needed to accurately interpret results of respiratory chain enzymatic activity assays. During investigation of metabolic myopathies, if skeletal muscle biopsy specimens are evaluated for respiratory chain enzyme kinetics, they should be performed and evaluated in concert with skeletal muscle biopsy specimens from clinically normal animals of the same species.     

A Comparative Review of Vitamin E and Associated Equine Disorders

Vitamin E is a primary chain‐breaking antioxidant that prevents cyclic propagation of lipid peroxidation. Across species, vitamin E is essential for normal neuromuscular function by acting as a potent antioxidant, as well as by modulating the expression of certain genes, inhibiting platelet aggregation and stabilizing plasma membranes. This review focuses on vitamin E structure, absorption, metabolism, current equine dietary recommendations, the interplay between antioxidants and exercise, a discussion of the necessity of vitamin E supplementation in the horse above the Nutritional Research Council (NRC) 2007 requirements, and a review of equine diseases that are associated with a vitamin E deficiency. Particular emphasis is placed on the proteins involved in vitamin E absorption, transport, and metabolism as potential candidates for vitamin E‐associated diseases across species.