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.     

Identification of a novel hemotropic mycoplasma in a splenectomized dog with hemic neoplasia

A 3-year-old sexually intact male Bull Mastiff underwent splenectomy for splenic thrombosis; prior to and after splenectomy, multiple blood transfusions were administered. Two weeks after the procedure, T-cell lymphoproliferative disease was diagnosed. Treatment with prednisone and chlorambucil was initiated, and 2 weeks later, cytologic examination of a blood smear revealed small (0.3 microm), coccoid basophilic bodies on the surface of approximately 70% of the RBCs. Morphologically, these resembled "Candidatus Mycoplasma haemominutum." A polymerase chain reaction assay was used to amplify a partial 16S rRNA sequence in blood obtained from the dog; the product was sequenced and compared with 16S rRNA gene sequences of other hemotropic mycoplasmas. The sequence was 98% homologous to that of "Candidatus M haemominutum", but only 77% homologous to that of M haemocanis and M haemofelis.     

Veterinary school admission interviews, part 3: strategies for increasing interview validity

The veterinary school admission interview is a widely used selection tool, yet concerns persist about its reliability, validity, and cost. Relative to medicine, optometry, and dentistry schools, veterinary schools have been more likely to conduct panel interviews and to fix the interview's weight in selection decisions, strategies that increase interview validity. This article provides strategies for further increasing the veterinary school interview's validity. Interview reliability and validity studies point to key strategies the veterinary school admissions committee can implement before the interview: (1) establishing the interview's purpose(s); (2) conducting a "job" analysis to identify desirable candidate skills, knowledge, and attributes; (3) developing a structured and panel interview where interviewers, if possible, are blind to other admission data; (4) training interviewers; (5) setting a reasonable interview schedule; and (6) determining methods for analyzing applicant data. During the interview, interviewers should proceed through a structured series of steps: (1) open the interview with a specified agenda; (2) probe for information using structured questions and anchored rating scales; (3) close the interview to allow for candidate questions; and (4) evaluate the interview data. After the interview, the admissions committee should (1) analyze the interview data within and across interviewers and (2) analyze the data across all selection tools in order to assign relative weights to the selection tools.     

Effects of contact dermatitis on hepatic gene expression in broilers

1.?Severe foot and hock dermatitis in broiler chickens can reduce growth rate and increase susceptibility to bacterial infection, affecting both profitability and welfare. However, little is known about the underlying physiological changes associated with foot and hock lesions.

2.?This study compared global hepatic gene expression in control birds and those with ammonia-induced foot and hock lesions using Agilent 44?K chicken oligonucleotide microarrays (8 birds per group).

3.?In total, 417 genes were differentially expressed of which 174 could be mapped onto the genome. Genes associated with energy metabolism, thyroid hormone activity and cellular control were affected, while there was also evidence of an up-regulation of genes linked to a pro-inflammatory response.

4.?It is conceivable that pain is the underlying cause for the observed changes in energy metabolism genes.

5.?Changes in hepatic gene expression provide new information on how a chicken's physiological mechanisms alter to cope with foot and hock lesions. The findings support other data indicating that birds with increased severity of lesions are likely to be in pain and that growth will be compromised. Reduction of the incidence of dermatitis by improved husbandry should therefore benefit both welfare and commercial performance.