PRNP haplotype and genotype frequencies in Brazilian sheep: issues for conservation and breeding programs

Polymorphisms of PRNP gene have been strongly correlated to the susceptibility/resistance to scrapie in sheep. Variants at the coding positions 136, 154 and 171 have been the most frequently associated to susceptibility to classical scrapie. The aim of this study was to estimate PRNP haplotype and genotype frequencies in a sample of 1400 sheep from 13 different breeds that are representative of the main production regions in Brazil. A total of four different alleles (ARR, ARQ, AHQ and VRQ) and nine genotypes were observed at different frequencies among the investigated breeds. There were distinct patterns of allelic distribution between naturalized and commercial/specialized breeds and different geographic regions. These results will influence the development and management of breeding and conservation programs and will help to develop Brazilian efforts to avoid scrapie epidemics.     

Prevalence of cryptosporidiosis in dairy cattle,cattle-keeping families,their non-cattle-keeping neighbours and HIV-positive individuals in Dagoretti Division,Nairobi, Kenya

The breeding of wild animals for commercial purposes is becoming more frequent nowadays. This situation has led to an increase in contact rates between wild and domestic animals, with subsequent reciprocal transmission of parasites. In this study, we characterized the gastrointestinal and blood parasites of a group of 15 semi-captive guanacos (Lama guanicoe). We characterized gastrointestinal parasites by analyzing fecal samples through the sedimentation–flotation technique and hemoparasites by using blood smears stained with Giemsa. We found several gastrointestinal parasites including Nematoda and protozoans. The most frequently found parasites were Nematodirus sp. and Eimeria sp. In contrast with previous studies, neither Cestoda nor Fasciola were found. The only hemoparasite detected was Mycoplasma haemolamae, a parasite already described in llamas and alpacas. We conclude that the most frequent gastrointestinal parasites of semi-captive guanacos were nematodes and protozoans. Also, the hemoparasite M. haemolamae seems to be prevalent among captive populations of South American camelids. Finally, captive guanacos share several parasites with the traditional livestock. Therefore, keeping captive or semi-captive guanacos without an adequate sanitary protocol might have adverse consequences to adjacent traditional cattle farming and/or for wild animals.     

Effects of a single day of feed restriction on changes in serum leptin, gonadotropins, prolactin, and metabolites in aged and young mares

In a variety of species, short-term feed restriction leads to rapid changes in the reproductive axis and reduces serum levels of leptin. Two experiments were performed to test the hypothesis that a single day of feed restriction in aged and young mares would cause a suppression of the gonadotropins and serum leptin concentrations. The estrous cycles of 12 aged (>eight years; Exp. 1) and eight young (相似文献   

Tropical tanniniferous legumes used as an option to mitigate sheep enteric methane emission

This study presents the first results from Brazil using SF₆ tracer technique adapted from cattle to evaluate the capability of condensed tannin (CT) present in three tropical legume forages, Leucaena leucocephala (LEU), Styzolobium aterrimum (STA), and Mimosa caesalpiniaefolia Benth (MIM) to reduce enteric CH₄ production in Santa Inês sheep. Twelve male lambs [27.88?±?2.85 kg body weight (BW)] were allocated in individual metabolic cages for 20-day adaptation followed by 6 days for measuring dry matter intake (DMI) and CH₄ emission. All lambs received water, mineral supplement, and Cynodon dactylon v. coast-cross hay ad libitum. The treatments consisted of soybean meal (710 g/kg) and ground corn (290 g/kg) [control (CON)]; soybean meal (150 g/kg), ground corn (30 g/kg), and Leucaena hay (820 g/kg) (LEU); soybean meal (160 g/kg), ground corn (150 g/kg), and Mucuna hay (690 g/kg) (STA); and soybean meal (280 g/kg), ground corn (190 g/kg), and Mimosa hay (530 g/kg) (MIM); all calculated to provide 40 g/kg CT (except for CON). DMI (in grams of DMI per kilogram BW per day) was lower for LEU (22.0) than CON (29.3), STA (31.2), and MIM (31.6). The LEU group showed emission of 7.8 g CH₄/day, significantly lower than CON (10.5 g CH₄/day), STA (10.4 g CH₄/day), and MIM (11.3 g CH₄/day). However, when the CH₄ emission per DMI was considered, there were no significant differences among treatments (0.37, 0.36, 0.33, and 0.35 g CH₄/g DMI/kg BW/day, respectively, for CON, LEU, STA, and MIM). The sheep receiving STA had shown a tendency (p?=?0.15) to reduce methane emission when compared to the CON group. Therefore, it is suggested that tropical tanniniferous legumes may have potential to reduce CH₄ emission in sheep, but more research is warranted to confirm these results.     

The prion hypotheses

Abstract

Extract

I read with interest the letter by P.R. Wills (New Zealand Veterinary Journal 44, 33-36, 1996). I hope someone more learned than I will reply, because I think a reply is necessary. Some post-modem science seems to be bypassing basic scientific principles. Isn't science all about analysis of observations, the measurement of entities that can be quantitated — data, finding, etc. — not just intuition?     

Satellite teaching hospitals and public-private collaborations in veterinary medical clinical education

Veterinary teaching hospitals (VTHs) are facing more and greater challenges than at any time in the past. Changes in demand, expanding information, improving technology, an evolving workforce, declining state support, and an increasingly diverse consumer base have combined to render many traditional VTH modes of operation obsolete. In pursuit of continued success in achieving their academic mission, VTHs are exploring new business models, including innovative collaborations with the private sector. This report provides details on existing models for public-private collaboration at several colleges and schools of veterinary medicine, including those at Kansas State University, Purdue University, the University of Florida, and Tufts University. Although each of these institutions' models is unique, several commonalities exist, related to expansion of the case load available for teaching, the potential positive impact on recruitment and retention of clinical faculty, and the potential for easing financial pressures on the associated VTH. These new models represent innovative approaches that work to meet many of the key emerging challenges facing VTHs today.     

Multivariate analysis for characteristics of heat tolerance in horses in Brazil

The environment in which the horse is reared affects its ability to maintain thermal balance which is in turn related to thermal characteristics and regulatory physiological mechanisms. In this study a multivariate analysis of physiological traits in relation to heat tolerance in horses was carried out in the Federal District, Brazil. The aim was to test the ability of these analyses to separate groups of animals and determine which physiological traits are most important in the adaptation to heat stress. Forty adult horses (4 to 13 years) were used, ten from each of four different genetic groups (English thoroughbred, Brazilian showjumper, crossbred and Breton). The traits examined included heart and breathing rate, rectal temperature as well as blood parameters. The data underwent multivariate statistical analysis including cluster, discriminate and canonical using Statistical Analysis System - SAS ® procedures CLUSTER, STEPDISC, CANCORR and DISCRIM. The tree diagram showed clear distances between groups studied and canonical analysis was able to separate individuals in groups. The discriminate analysis identified the variables which were most important in separating these groups. The multivariate analysis was able to separate the animals into groups with RR, HR and RT being important in this separation.     

Skin and coat traits in sheep in Brazil and their relation with heat tolerance

The objective of this study was to evaluate and compare physical parameters in groups of sheep with different phenotypic characteristics in the Centre-west region of Brazil. Five groups of sheep, with nine animals per group, were selected, three groups of Santa Inês animals with different coat colours (white, brown and black), one group with crossbred animals (Santa Inês × Bergamasca) and one group with animals of the Bergamasca breed. The following traits were evaluated: coat thickness, number and length of hair, pigmentation level in the coat and the skin as well as the percentage area of sweats glands in the skin tissue, carried out by histological analysis. The number of hairs and the area of sweats glands were not significantly different between the evaluated groups. The Bergamasca breed showed low pigmentation of the skin and long hairs. The levels of pigmentation of the hair and of the skin were highly correlated. Between the Santa Inês groups, the group with white hair showed the better parameters for heat adaptation, while the brown hair group showed the lower heat adaptation when compared with another hair breed groups.