Identification of genomic regions associated with resistance to gastrointestinal parasites in an indigenous sheep by single- and multiple-locus methods.

We investigated the association between 157 SNPs located in 75 candidate genes involved in the immune system and proxy traits for resistance to gastrointestinal nematodes in sheep. A total of 211 lambs from eight flocks were sampled. Nematode eggs per gram were counted and classified as: (i) Strongyles, (ii) Nematodirus spp., (iii) Trichuris spp. and (iv) Marshallagia marshalli. Single- and multiple-locus models were used to test the marker-trait associations. Seven significant SNPs were identified on chromosomes OAR6, 15, 16, and 19. These findings provide insights for breeding nemarode-resistant traits in low-input production systems. General linear model, fixed and random model circulating probability unification, and Bayesian-information and linkage-disequilibrium iteratively nested keyway analyses identified a significant association between the eggs per gram of Strongyles nematodes and a specific variant of the PRLR gene.

Effect of arginine supplementation on growth performance, lipid profile, and inflammatory responses of broiler chicks challenged with coccidiosis.

Avian coccidiosis causes inflammation and decreases growth performance in poultry. Arginine alleviates inflammation and improves growth performance. This study aimed to evaluate the effects of different levels of arginine on growth performance, lipid profile, and inflammatory responses in broiler chicks challenged with Eimeria spp. A total of 384 one-d-old broiler chicks were assigned into eight groups and six replications per group. At 21 days of age, a mixture of Eimeria species was used for induction of challenge in the broiler chicks. Broiler chicks were divided into infected and uninfected groups and received arginine at 85, 100, 125, and 150 % of recommended level. Growth performance, serum nitric oxide (NO), pro-inflammatory cytokines, lipid profile, and faecal oocyst were further assessed. Broiler chicks challenged with coccidiosis showed lower growth performance compared to non-challenged broiler chicks in grower and finisher periods; however, those fed diets containing 125 and 150 % arginine showed better growth performance compared to broiler chicks fed with 85 and100 % levels. The challenged broiler chicks showed higher concentrations for serum NO, lipid profile, and pro-inflammatory cytokines in comparison to uninfected ones. Nevertheless, adding arginine into diet at 125 and 150 % levels increased the levels of serum NO and decreased the concentration of pro-inflammatory cytokines. In conclusion, higher levels of arginine caused anti-inflammatory effects in broiler chicks challenged with coccidiosis.

Study on outbreak of Neospora caninum-associated abortion in dairy cows in Tabriz (Northwest Iran) by serological, molecular and histopathologic methods.

OBJECTIVE: To determine Neospora caninum (N. caninum) as a cause of bovine abortion in dairy cows by ELISA, PCR and Pathological methods in Tabriz, Northwest of Iran. METHODS: For study of outbreak of neosporosis, blood samples were collected from 76 Holstein aborted dairy cows in Tabriz (Northwest Iran). Antibodies to N. caninum were assayed by using a commercially ELISA kit (IDEXX, USA). IgG against N. caninum were found in 14 (18.4%) cases. Aborted fetuses of these seropositive dams were proposed for histopathological and molecular investigations. Brains, spinal cords and placentas of the fetuses were fixed in 10% buffered formalin for histopathology. Also 5-10 g of brain tissue was sampled for DNA extraction. In 6 out of 14 (42.8%) fetuses, brain tissue was positive in PCR. All dams of these fetuses were serologically seropositive in ELISA test. RESULTS: Histopathologically, the lesions consistent with N. caninum were observed in brains, spinal cords and placenta of all fetuses. Lesions in CNS included severe congestion, perivascular and perineuronal edema, status spongiosis, perivascular cuffing, focal gliosis, nourophagy and focal necrosis. There were some Neospora-like cysts in brain. In placentas, severe congestion, perivascular infiltration of mononuclear cells, vascular thrombosis, focal placentitis and necrotic foci in cotyledons were noticed. CONCLUSIONS: The results of present study agreed the results of similar studies about serological, histopathological and molecular results of other studies about neosporosis and it seems to support the outbreak of N. caninum-associated abortion in dairy cows in Tabriz (Northwest Iran).