Morphological characterization of Pelibuey sheep in Colima, México

A study was conducted with the objective to characterize the morphology of Pelibuey sheep in the state of Colima, Mexico. A total of 386 sheep were scored for 12 body measurements in addition to live weight and five racial and eight functional indices were calculated. The influence of sex on the body measurements and indices was analyzed, and morphological harmony was determined through Pearson correlation. The sexual dimorphism was 1.21, with males being 67 % heavier than females. Females and males had a high and moderate degree of harmony in their morphological model, respectively. Pelibuey sheep were dolichocephalous, tended to be medium- to large-sized according to the thoracic index, with a convex curve rump; they were a homogeneous breed, well adapted to environmental and production conditions of the state of Colima, Mexico, and show an undefined zootechnical aptitude and therefore a great potential to be oriented towards meat or milk production through genetic selection or terminal crossbreeding systems using specialized breeds.     

Evaluation of a fluorescence-polarization assay for the diagnosis of bovine brucellosis in México.

A homogeneous fluorescence-polarization assay (FPA) was used for the serological diagnosis of bovine brucellosis in México. The assay uses O-polysaccharide prepared from Brucella abortus lipoplysaccharide (20-30 kDa) conjugated with fluorescein isothiocyanate as a tracer. To measure the fluorescence polarization, a FPM-1 fluorescence-polarization analyzer was used with the procedure described by Nielsen et al. (1996b). A cut-off value of 90 millipolarization (mP) units was used for testing 560 bovine sera from different areas of México. (305 positive sera and 255 negative sera according to the complement fixation test; CFT.) Some were tested with the Rose Bengal plate (RB) test (n = 490) and some with the rivanol-agglutination (RIV) test (n = 190). Sensitivities were 98.3%, 99.3% and 99.0%, and specificities were 68.8%, 55.4% and 96.9%, respectively, for RB, RIV and FPA. The FPA gave a kappa coefficient of agreement with respect to CFT of 0.96, while RB and RIV (relative to the CFT) gave coefficients of 0.70 and 0.61, respectively. Finally, ROC analysis suggested a cut-off value which agreed with the one recommended in the test procedure. We concluded that FPA is a suitable test to be used instead of the CFT in Mexican conditions.     

The presence of nicotinamide adenine dinucleotide-independent Haemophilus paragallinarum in México

Two isolates of Haemophilus paragallinarum were obtained from a layer chicken in Mexico. The isolates were confirmed as H. paragallinarum by polymerase chain reaction and conventional biochemical identification. The isolates were nicotinamide adenine dinucleotide (NAD) independent-growing on blood agar without the need of a nurse colony as well as on a complex medium that lacked both NAD and chicken serum. Both isolates were pathogenic, causing the typical clinical signs of infectious coryza in susceptible chickens. One isolate was Page serovar B/Kume serovar B-1 and the other isolate was Page serovar C/Kume serovar C-2. The isolates were associated with a field outbreak that involved an egg drop of 20% over a 3-wk period and a doubling of weekly mortality (from 0.1% to 0.2%). This is the first report of NAD-independent H. paragallinarum outside South Africa and is the first time that NAD-independent H. paragallinarum of serovar B has been reported.     

Live Weight Estimation of Donkeys in Central México from Measurement of Thoracic Circumference

Body measurements (length from nape of neck to the withers; height to withers; length from withers to tail root; length from shoulder to tuber ischii; thoracic circumference; umbilical circumference) were taken and correlated with live weight from 160 donkeys (mean ± standard deviation = 6 ± 2.6 years old) in Central México. The age was assessed from dentition. Sex of the donkeys was also recorded. Sex was an important factor of variation (p = 0.011). Live weight was estimated using two allometric models. Model 1: Live weight = β _o × (thoracic circumference)^β1. Model 2: Live weight = β _o × (height to the withers) ^βl × (thoracic circumference) ^β2. Separate prediction equations were produced for males and females, plus one for the total sampled. The ‘best fit’ models, were those using thoracic circumference to predict the live weight. Males: live weight = 0.018576 × (thoracic circumference)^1.84107 (R ² = 0.9839). Females: live weight = 0.031255 × (thoracic circumference)^1.72888 (R ² = 0.9839). The equations derived to estimate the live weight of donkeys in Britain, Morocco and Zimbabwe were less satisfactory for use with donkeys from Central México because they overestimated the live weight.     

Wool traits of three sympatric sheep populations in Chiapas Region, México

A total of 344 pure animals, representing seven American and South European breeds (White Chiapas Blanca, Brown Chiapas Café, Black Chiapas Negra, Churra Badana, Churra da Terra Quente, Chilean Latxa, and Spanish Merino), were randomly sampled and wool evaluated for isoalcohol scouring yield, length, and proportion for each type of fiber (long-thick, short-thin, and kemp), average of fiber diameter, and F30 (percentage of fibers with a diameter of >30 μm). The objective of this study was to characterize these breeds according to their wool traits. A low percentage of the phenotypic variability in the analyzed animals was due to differences among breeds, and that the largest part of that variability is due to differences within breeds. The obtained topology in the principal coordinates analysis showed the grouping of the three Chiapas breeds clearly separated, but the similarity with their original breed was only evident for Brown Chiapas Café. The three Chiapas sheep breeds must be regarded as clearly sympatric populations.     

Lack of cross-protection against Mycoplasma haemofelis infection and signs of enhancement in “Candidatus Mycoplasma turicensis”-recovered cats

“Mycoplasma haemofelis” and “Candidatus Mycoplasma turicensis” are feline hemoplasmas that induce hemolytic anemia. Protection from homologous re-challenge was recently demonstrated in cats recovered from primary infection. Here, we determined if cats recovered from “Cand. M. turicensis” infection were protected against infections with the more pathogenic M. haemofelis. Ten specified pathogen-free cats were exposed to M. haemofelis. Five of the ten cats had recovered from “Cand. M. turicensis” bacteremia (group A), and five cats were naïve controls (group B). No cross-protection was observed. By contrast, the “Cand. M. turicensis”-recovered cats displayed faster M. haemofelis infection onset (earlier PCR-positive and anemic) than the controls. No “Cand. M. turicensis” was detected in any cat. M. haemofelis shedding was observed in saliva, feces and urine. In both groups, evidence of a Th1 response was observed (high IFN-γ, low IL-4), but IL-10 levels were also high. In group A, total, CD4+ and CD8+ T cells increased within days after M. haemofelis exposure. At times of maximal bacteremia, macrocytic hypochromic anemia, neutropenia, monocytosis and a decrease in leukocyte, eosinophil, and lymphocyte counts and subsets thereof (B- and T-cells, CD4+, CD8+ and CD4+CD25+ cells) were particularly significant in group A. Moreover, an increase in protein concentrations, hypoalbuminemia and a polyclonal hypergammaglobulinemia were observed. Five of ten M. haemofelis-infected cats subsequently cleared bacteremia without antibiotic treatment. In conclusion, the study suggests that a previous hemoplasma infection, even when the cat has ostensibly recovered, may influence subsequent infections, lead to an enhancement phenomenon and other differences in infection kinetics.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-015-0240-x) contains supplementary material, which is available to authorized users.     

Aujeszky’s disease and the effects of infection on Japanese swine herd productivity: a cross-sectional study

Pseudorabies virus (PRV) is endemic in some regions of Japan. We investigated the effects of PRV infection status on herd productivity. Serum samples were obtained from 48 swine herds in Japan. Within each herd, three serum samples were obtained from growing pigs at four different ages, as well as from sows in low and high parity groups. Sera were tested for antibodies against wild-type PRV via competitive ELISA. Herds were classified into PRV positive and negative groups based on serological results. Herds infected with PRV exhibited postweaning mortalities (6.84%) that were significantly (P=0.0018) higher than those in unaffected herds (4.73%). Because of the reduced productivity in PRV positive herds, the current PRV eradication program must be strengthened.     

Expansion of intracellular IFN-γ positive lymphocytes during Mycoplasma agalactiae infection in sheep

A method to assess the expansion of antigen-specific intracellular IFN-γ positive T cell subsets during the infection will be helpful for a better understanding of mycoplasmal infections physiopathology in the sheep. We analysed the percentage of antigen-specific lymphocytes positive for intracellular IFN-γ during the infection of sheep with Mycoplasma agalactiae by culturing peripheral blood mononuclear cells of infected or uninfected animals with irradiated M. agalactiae. The expansion of antigen-specific IFN-γ positive lymphocytes in infected sheep was initially sustained by CD4⁺ T cells at day 15 after infection, when antigen specific IgG start to be detectable, followed by CD8/IFN-γ double positive cells. γδ T-cells were not expanded at any time point analysed. IFNγ⁺ T cells disappear 60 days after infection, suggesting that antigen specific IFNγ⁺ T cells, mainly detected in the early phase of the disease, could be useful to understand the role of cell-mediated immunity during M. agalactiae infection.     

Vaccination against Taenia solium cysticercosis in underfed rustic pigs of México: roles of age, genetic background and antibody response

Vaccination of pigs of mixed genetic make-up, raised as rustically as done in rural Mexico, resulted in effective protection to experimental challenge against Taenia solium cysticercosis. Maximum protection was achieved if pigs were immunized at 70 days of age. There was large variation of viable parasite load within vaccinated pigs and controls, which is suggestive of significant genetic factors influencing susceptibility, besides immunization. Our results strengthen the advisability of pig vaccination for control of T. solium cysticercosis, since it lowers the number of viable cysticerci capable of transforming into tapeworms.     

Chronic non-progressive pneumonia of sheep in New Zealand – a review of the role of Mycoplasma ovipneumoniae

Chronic non-progressive pneumonia (CNP) is a common disease which affects lambs in New Zealand during late summer and autumn. Mycoplasma ovipneumoniae can be recovered from a high proportion of lesions but it is also present in some normal lungs. Bacteria, especially Pasteurella haemolytica, can also be recovered from more than half the lungs of affected animals.

Isolates of M. ovipneumoniae are genetically heterogeneous, as demonstrated by examination of their DNA or total cellular proteins, and are serologically heterogeneous as shown by metabolic inhibition tests. The number of strains present in New Zealand is large and several distinguishable strains can be recovered from each affected lung. Mycoplasma ovipneumoniae has pathogenic potential as indicated by its ability to produce hydrogen peroxide, cause ciliostasis and by its possession of a capsule.

Chronic non-progressive pneumonia can be transmitted consistently to over 50% of lambs by inoculation of pooled pneumonic lung homogenate and transmission can be suppressed by broad spectrum antibiotics. In contrast, penicillin does not prevent the development of lesions but diminishes their severity. Pooled lung homogenate treated with digitonin, which inactivates mycoplasmas, has failed to transmit CNP. Pure cultures of M. ovipneumoniae produce only mild lesions in some animals, whereas inoculation with pooled lung homogenate (from which no viruses were isolated) containing mixed strains of M. ovipneumoniae and free from bacteria, is more effective in producing lesions.

Research work to date suggests that CNP may be initiated by colonisation of the lung by M. ovipneumoniae which causes ciliostasis and elicits an exudate allowing colonisation of the lungs by bacteria especially P. haemolytica and by other strains of M. ovipneumoniae. The immune response to the initial strain of M. ovipneumoniae may inhibit its replication but would be less effective in inhibiting heterologous strains of the organism allowing their sequential replication. Eventually production of a broad immune response to M. ovipneumoniae would lead to its elimination which in turn would facilitate the elimination of other microorganisms and the resolution of lesions. As natural immunity to CNP occurs within the first year, it may be possible to develop an effective and useful vaccine. Such a vaccine may need to include multiple strains of M. ovipneumoniae.     

Some effects of drugs in the “doping” of racehorses

Extract

At the request of the New Zealand Racing and Trotting Conferences the writer has carried out tests on racehorses using some of the drugs found in positive samples by the analyst. Most of these tests were carried out in close co-operation with the analysts to the two Conferences and were undertaken because reliable data on the excretion patterns and effects of the various drugs could not be obtained. It is often important to know how and when the particular drug was administered, and these tests have proved a valuable guide. Some of their results have been surprising and it is hoped that the findings will be of general interest since any veterinary surgeon might find himself involved in an inquiry and it is important that he should be as sure as possible of all relevant factors before entering the witness box. It is easy to make sweeping statements at an inquiry but whoever makes them must surely be prepared to verify them. Any of these doping cases, however simple their early stages may appear, might proceed to the Supreme Court where rash statements could be legally challenged. In the writer's dealings with the New Zealand Racing and Trotting Conference he has found them to be scrupulously fair and only interested in finding out the truth. Their aim is to keep racing clean; we, as veterinary surgeons, should share that aim.     

Identification of Staphylococcus aureus strains negative for enterotoxins A, B and C isolated from bovine mastitis in México

A total of 41 isolates of Staphylococcus aureus obtained from bovine mastitis in 7 different states in Mexico were analyzed by the polymerase chain reaction (PCR) to determine the presence of encoding genes for enterotoxins A, B and C. The oligonucleotides were designed by specific regions of the sea, seb, sec genes. Surprisingly, none of the isolates presented the prospective amplification bands when they were run on agarose gels. On the contrary, reference strains CECT 976 SEA; CECT 5191 SEB; and CECT 4465 SEC showed the prospective amplification products. In order to confirm these results, enterotoxin production A, B, C, D, and E was determined by enzyme linked fluorescent assay (ELFA) using a MiniVIDAS system, on 15 Staphylococcus aureus selected at random from among the 41 isolates. None of the analyzed strains was positive to the test, whereas reference strains enterotoxins producing: CECT 976 SEA; CECT 5191 SEB; CECT 4465 SEC, CECT 4466 SED; CECT 5192 SEE produced concentrations of the toxins detected for this technique. The role of enterotoxins in the pathogenicity of S. aureus in bovine mastitis in Mexico is discussed.     

A multi-criteria approach to identify favorable areas for goat production systems in Veracruz,México

This research identifies favorable areas for goat production systems in the state of Veracruz, Mexico. Through the use of the analytic hierarchy process, layers of biophysical and soil information were combined to generate a model of favorability. Model validation was performed by calculating the area under the curve, the true skill statistic, and a qualitative comparison with census records. The results showed the existence of regions with high (4494.3 km²) and moderate (2985.8 km²) favorability, and these areas correspond to 6.25 and 4.15%, respectively, of the state territory and are located in the regions of Sierra de Huayacocotla, Perote, and Orizaba. These regions are characterized as mountainous and having predominantly temperate-wet or cold climates, and having montane mesophilic forests, containing pine, fir, and desert scrub. The reliability of the distribution model was supported by the area under the curve value (0.96), the true skill statistic (0.86), and consistency with census records.     

Brucellosis due to Brucella suis in a swine herd associated with a human clinical case in the State of S?o Paulo, Brazil

Brucella suis has been recognized as the major etiological agent of human brucellosis in areas free from Brucella melitensis infection. However, with changes in swine management, the occurrence of swine brucellosis has decreased as has the human incidence of B. suis infection. A swine brucellosis outbreak within a herd from Jaboticabal (S?o Paulo, Brazil) was detected in July 2006. The herd comprised approximately 300 sows and 1,500 finishing animals. Many sows within this herd experienced abortions, while others exhibited vaginal discharge; three sows suffered posterior paralysis. Among 271 sows, 254 (93.7%) tested positive for brucellosis by complement fixation, and among 62 randomly bled finishing animals, 17 (27.4%) also tested positive. The B. suis biovar 1 was cultured from 14 aborted fetuses and six sows. Brucella was identified using routine methods. Fourteen farm workers were tested using agglutination tests, with three workers showing evidence of Brucella antibody titers. A 39-year-old woman, who worked with maternal pigs and had direct contact with aborted fetuses, presented an agglutinating titer of 480?IU/mL and displayed clinical signs of infection. Our findings suggest that despite a reduction of swine brucellosis throughout Brazil, B. suis infection still occurs, thereby posing a zoonotic risk.     

A cross-sectional study of swine influenza in intensive and extensive farms in the northeastern region of the state of São Paulo,Brazil

Swine influenza (SI) is a seasonal infectious disease highly important to the world pig industry. Loss of daily weight gain, increased costs for the prevention and treatment of secondary infections are the main economic losses associated with the presence of this disease. However, some epidemiological features of SI remain quite unclear. This study focused on assessing the prevalence of swine influenza virus (SIV) infection in intensive and extensive pig herds and associating risk factors. A set of 601 blood samples of five intensive farrow-to-finish farms and 361 blood samples from 56 extensive farms were analyzed using an indirect ELISA kit CIVTEST SUIS INFLUENZA®, Hipra (Amer, Spain), in order to detect anti-SIV antibodies. In total, 24.13 % of samples from intensive herds were positive, while no positive samples were detected in extensive rearing herds. Sow and weaning piglets had the highest prevalence values. In the intensive rearing system, occurrence of reproductive disorders and exposure to recently introduced animals were positively associated with the disease occurrence in swine herds. The findings highlight the importance of sows in the epidemiology of the disease and bring information about risk factors involved in the occurrence of swine influenza in intensive herds.     

Summer variation in the concentration of steroidal sapogenins in and the degree of fungal infection on Narthecium ossifragum plants from Møre og Romsdal County, Norway

Thirty-nine leaf samples of Narthecium ossifragum collected from eight sites in M?re og Romsdal County, Norway, during June-September 1997 and 41 leaf samples collected at five sites in the same county during June-August 1998 were analysed for the concentrations of steroidal sapogenins using GC-MS. The 1998 samples were also examined for fungal elements (conidia and hyphae) after incubation in a moist chamber for 10-14 days. The highest 1997 and 1998 leaf sapogenin concentrations (4881 and 7115 mg/kg dry matter, respectively) were 13-14 times greater than the lowest sapogenin concentrations found (344 and 531 mg/kg dry matter, respectively). The results did not reveal systematic differences in sapogenin concentrations between the two seasons, or between samples harvested early or late in the same seasons, or between sapogenin concentrations in plants harvested at different sites. Cladosporium magnusianum was the predominant fungus found in the samples. The degree of fungal infection on the samples was in generally low, but the number of C. magnusianum colonies in the moist chamber preparations and fungal elements (conidia and hyphae) in leaf washings and on leaves tended to increase with time. Factor analysis and multiple regression analysis performed on the chemical and fungal results suggest that sporulation may have occurred in the fungi in response to increase in sapogenin concentrations.     

Is the transmission of Mycobacterium avium subspecies paratuberculosis (MAP) infection through milk intended to feed calves an overlooked item in paratuberculosis control programs?

Tropical Animal Health and Production - As in many parts of the world, Chile shows a high Mycobacterium avium subsp. paratuberculosis (MAP) infection rate. Evidently, the control recommendations...     

The assessment and the farmers’ perceived ranking of feed resources and coping strategies with feed scarcity in smallholder dairy farming in selected district towns of Jimma Zone,Ethiopia

Inadequate quantity and quality of feed resources are major constraints limiting milk production and reproductive performance of dairy cattle in Ethiopia. The aim of this study was to assess dairy cattle feed resources, feeding practices, the farmers’ perceived ranking of feed resources, causes of feed shortage, and coping strategies to feed scarcity in smallholder dairy system in selected district towns of Jimma Zone, Ethiopia. Data were obtained by interviewing 52 randomly selected smallholder dairy farmers using structured questionnaires and through direct observations. Results showed that 20 main feed types used by dairy farmers were identified and categorized into natural pastures, crop residues, green feeds, hay, agro-industrial by-products, concentrate mix, and non-conventional feeds. Overall, natural pasture (mean rank = 0.453), non-conventional feeds (0.307), cut green feeds (0.086), conserved hay (0.076), crop residues (0.049), and concentrate feeds (0.029) were ranked as the main feed resources in decreasing order of importance. Natural pasture grazing (92.2% of the respondents), hay (35.6%), and green feeds (29.4%) were the most important conventional basal feeds used. Wheat bran (11.7% of the respondents) followed by commercial concentrate mix (9.4%), Noug seedcake (8.3%), grain (7.8%), and molasses (6.1%) were the concentrate supplements used. Overall, bulule-flour mill leftovers (67.2% of the farmers), bean and pea hulls (57.2%) and atella-local brew by-product (37.2%), enset (Ensete ventricosum, 34.4%), and sugarcane top (32.2%) were the non-conventional feeds available and used during feed scarcity. Barley and teff (Eragrostis teff) straws and maize and sorghum stovers were the main crop residues used in the dry seasons. Overall, 73.9, 12.2, 12.2, and 1.7% of the respondents practiced free grazing, zero grazing, semi-zero, and a combination of zero- and free-grazing systems, respectively. Over 84% of the respondents in the dry season and 50% in the wet season reported experiencing a shortage of feeds. Poor feed availability (73.9% of the respondents) was reported as the main causes of feed shortage followed by shortage of pastureland (7.8%). Increased use of bulule (55.6% of the respondents), crop residues (16.1%), non-conventional feed resources (14.4%), conserved hay (11.1%), purchased green feeds and concentrates (1.1%), and reducing herd size (1.1%) were the farmers’ adopted coping strategies to mitigate feed shortage. It is suggested that technical intervention to improve the quality and efficient utilization of the existing feed resources is crucial to enable sustainable feed supply and boost milk production. Technologies that are easy to adopt, feasible, and low cost are also needed to be developed in participatory manner.