Tulathromycin enhances humoral but not cellular immune response in pigs vaccinated against swine influenza

The effect of a standard, single dose therapy with tulathromycin was investigated on the postvaccinal humoral and cellular immune response in pigs vaccinated against swine influenza. Forty‐five pigs, divided into 3 groups, were used (control not vaccinated (C, n = 15), control vaccinated (CV, n = 15), and experimentally received tulathromycin (TUL, n = 15)). For vaccination of pigs, an inactivated, commercial vaccine was used. Pigs from TUL group received single dose of tulathromycin intramuscularly, at the recommended dose (2.5 mg/kg body weight). Pigs from TUL and CV groups were vaccinated at 8 and 10 weeks of age. The specific humoral and cellular immune response against swine influenza virus (SIV) was evaluated. The results of present study showed that humoral postvaccinal response after vaccination against SIV can be modulated by treatment with tulathromycin. In pigs from TUL group, the significantly higher titers of anti‐SIV‐specific antibodies were observed 4 and 6 weeks after booster dose of vaccine. Simultaneously, T‐cell‐mediated immune response against SIV was not affected by tulathromycin. Our recent study confirmed the importance of defining the modulatory activity of tulathromycin because of its influence on the immune response to vaccines. Since the antibodies against hemagglutinin are crucial for the protection against SIV, the present observations should prompt further studies on the practical significance of recent results in terms of clinical implications (postvaccinal protection) in the field conditions.     

Yield potential and salt tolerance of quinoa on salt‐degraded soils of Pakistan

Quinoa is recently introduced to Pakistan as a salt‐tolerant crop of high nutritional value. Open field trials were conducted to evaluate its performance on normal and salinity/sodicity‐degraded lands at two locations of different salinity/sodicity levels, S₁ (UAF Farm, Normal Soil), S₂ (Paroka Farm UAF, saline sodic), S₃ (SSRI Farm, normal) and S₄ (SSRI Farm, saline sodic) during 2013–2014. Two genotypes (Q‐2 and Q‐7) were grown in lines and were allowed to grow till maturity under RCBD split‐plot arrangement. Maximum seed yield (3,062 kg/ha) was achieved by Q‐7 at normal field (S₁) soil which was statistically similar with yield of same genotype obtained from salt‐affected field S₂ (2,870 kg/ha). Furthermore, low yield was seen from both genotypes from both S₃ and S₄ as compared to S₁ and S₂. Q‐7 was best under all four conditions. Minimum yield was recorded from Q‐2 (1,587 kg/ha) at S₄. Q‐7 had higher SOD, proline, phenolic and K⁺ contents, and lower Na⁺ content in leaves as compared to Q‐2. High levels of antioxidants and K⁺/Na⁺ of Q‐7 helped to withstand salt stress and might be the cause of higher yields under both normal and salt‐affected soils. Seed quality (mineral and protein) did not decrease considerably under salt‐affected soils even improved seed K⁺, Mg²⁺ and Mn²⁺.     

Dietary roughage sources affect lactating Holstein x Zebu cows under experimental conditions in Brazil: a meta-analysis

Tropical Animal Health and Production - To reduce costs, lactating cows are often fed a higher proportion of roughage and alternative feeds; however, such protocols may not lead to optimal milk...     

Nutritional Contribution of Biofloc within the Diet of Growout and Broodstock of Litopenaeus vannamei,Determined by Stable Isotopes and Fatty Acids

The relative contributions of feed sources were determined through the isotopic signal (δ¹³C and δ¹⁵N) and fatty acid profile of feed items, shrimp muscle, and eggs of Litopenaeus vannamei reared in a biofloc system. In the growout phase, the isotope analysis showed the biofloc particle size class ≥250 μm contributed 55–100%; size ≥50 < 250 μm contributed 0–22%; and artificial feed contributed 0–45%. Principal component analysis applied to fatty acid profiles showed that biofloc ≥250 μm and artificial feed were the most important items in shrimp growout. For the egg production, isotope analysis suggested that the most important feed sources according to their relative contributions were polychaetes (0–100%), followed by artemia biomass (0–86%) and semi‐moist feed (0–66%), with lower contributions from squid, mussel, and the muscle of L. vannamei broodstock that had been cultured in biofloc. In terms of fatty acids, the most important items were artemia, polychaetes, and semi‐moist feeds. This work clarified the importance of feed sources for shrimp during culture in biofloc systems and during reproduction. Analysis of stable isotopes and fatty acids can be successfully used to trace the assimilation of nutrients during the nutrition of shrimp.     

The Effect of Kefir as a Dietary Supplement on Nonspecific Immune Response and Disease Resistance in Juvenile Rainbow Trout,Oncorhynchus mykiss (Walbaum 1792)

In this study, juvenile rainbow trout fed with commercial pellets containing kefir provided increased nonspecific immune response and improved disease resistance against lactococcosis and yersiniosis. Kefir was used as a feed supplement at 2, 5, and 10% inclusion rates and several nonspecific immune parameters were observed at day(s) 1, 7, 14, 21, 28, and 35 following the treatment. A total of four experimental groups, including control, was established. The various parameters including hematocrits, nitroblue tetrazolium positive neutrophils, total leukocytes, serum lysozyme activity, total serum protein, and immunoglobulin M (IgM) levels were examined. As a result of this study, kefir‐fed fish had an increase in measured nonspecific immune parameters, especially in the group received the 10% kefir treatment. The challenged fish fed with kefir‐supplemented diet showed a better survival rate against Lactococcus garvieae than Yersinia ruckeri. Kefir supplementation reduced fish mortality significantly against L. garvieae.     

Evaluation of the flukicide treatment policy for dairy cattle in Galicia (NW Spain)

Fasciola hepatica infection is an important cause of lost productivity in livestock worldwide. Effective control of fasciolosis is difficult, especially in milking cows, which can only be treated during dry periods, a control strategy that has not been yet evaluated. In this cross-sectional study, we investigated the effect of the type of flukicide treatment on the prevalence and intensity of infection in dairy cattle from Galicia, an area where fasciolosis is endemic and which is also the main milk-producing region in Spain. Faecal samples were taken from 5188 dairy cows on 275 randomly selected farms for measurement of the concentration of F. hepatica coproantigens by a monoclonal antibody based immunoassay (MM3-COPRO ELISA). On the same day as the sampling, each farm owner/manager was questioned about the types of treatment used on the farm. Three groups of farms were considered according to the fasciolicide treatment: (A) flukicides were not used, (B) an anthelmintic effective against mature stages of flukes was used (albendazole or netobimin) and (C) a fasciolicide effective against immature and mature stages was used (triclabendazole: TCBZ). Results indicated that 16.0% (832/5188) cows from 61.1% (168/275) herds were infected by F. hepatica. The mean coproantigen concentration in infected herds was 13.0ng/ml (range 0.9-112.6ng/ml). The highest individual concentration recorded was 496.6ng/ml. Herd and within-herd prevalences of F. hepatica were similar in all three groups, but surprisingly, individual prevalence and antigen concentration were higher in Group C (p<0.05). The percentage of farms with within-herd prevalences >25% was very high in all three groups, and no significant differences were observed. In contrast, the percentage of herds with mean antigen concentrations >20ng/ml was significantly lower (p<0.05) in Groups A and B (14.4% and 14.9%, respectively) than in Group C (50.0%). The proportion of herds that exceeded both limits (25% for prevalence and/or 20ng/ml for coproantigen concentration) was also significantly higher (p<0.05) in Group C than in untreated animals (Group A). The survey showed that most dairy farmers are unaware of the existence of F. hepatica infection on their farms, and treatments, when given, are administered without prior diagnosis. Treatment with TCBZ administered only at drying off did not show advantages over other measures including no treatment, or treatment with other benzimidazoles. Consequently, TCBZ should only be used to treat individual animals after correct diagnosis of the infection, and correct management measures taken to control re-infection.     

Identification of coagulase-negative staphylococci from bovine mastitis using RFLP-PCR of the groEL gene

Coagulase-negative staphylococci (CNS) have become the predominant pathogens causing bovine mastitis in many countries. CNS infections are associated with damage to milk secretory tissue of the mammary gland by increased connective tissue stroma, moderate increases of somatic cells count in milk and significant production decreases. These consequences impose serious economic losses for the farmers and the dairy industry. Routine veterinary laboratories do not usually identify CNS at the species level. Thereby, the aims of this study were to identify the most common staphylococcal pathogens involved in bovine mastitis using PCR-restriction fragment length polymorphism (RFLP) analysis of a partial groEL gene sequence and to compare our results with the identification carried out by the conventional method. A total of 54 isolates of Staphylococcus, involved in bovine mastitis, were analyzed by this method. The size and number of the fragments obtained by either AluI or HindIII/PvuII digestions made possible to form clear patterns differentiating, among the isolates, 11 of the most common species of animal staphylococcal pathogens. Most of the isolates clustered together with the reference strain of Staphylococcus chromogenes (28) and the type strain of Staphylococcus epidermidis (8). Besides, some isolates clustered together with the type strain of Staphylococcus aureus (5). All patterns were confirmed by the conventional biochemical method, showing concordant results. Thus, the PCR-RFLP of the groEL gene constitutes a reliable and reproducible molecular method for identification of CNS species responsible for bovine mastitis.     

Real-time PCR-based prevalence study, infection follow-up and molecular characterization of canine hemotropic mycoplasmas

Hemotropic mycoplasmas (hemoplasmas) have been reported in several mammalian species including dogs. Infections may lead to hemolytic anemia, but investigations in the dog had been hampered by the lack of adequate diagnostic methods. Only recently sensitive PCR-based assays were reported for the two canine hemoplasmas, Mycoplasma haemocanis and Candidatus Mycoplasma haematoparvum. By applying these assays, 15.4% of 460 dogs from the south of France tested hemoplasma positive. It was hypothesized that this high prevalence may be associated with the presence of Rhipicephalus sanguineus, a proposed vector for canine hemoplasmas. To address this hypothesis and expand the PCR-based knowledge on canine hemoplasmosis, we investigated dogs in a climatic zone that does not allow for the permanent establishment of R. sanguineus. Blood samples were collected throughout a year from 889 dogs in Switzerland: 1.2% of the dogs tested real-time PCR positive. The infection status was not significantly associated with anemia, age or gender. Phylogenetic analyses of Candidatus M. haematoparvum and M. haemocanis isolates revealed > or =99.8% identity to published sequences. All samples collected from three infected dogs throughout a follow-up period of < or =13 months tested PCR positive. Interestingly, the majority of the infected dogs either had been imported from or had visited regions where R. sanguineus is indigenous. Thus, canine hemoplasma prevalence was found to be low in a country with a climate incompatible with frequent occurrence of R. sanguineus. Nonetheless, veterinarians may expect hemoplasma infections in dogs with a travel history and/or after potential tick vector exposure.