Genome-wide association study and genomic heritabilities for blood protein levels in Lori-Bakhtiari sheep

Serum protein levels are related to physiological and pathological status of animals and could be affected by both genetic and environmental factors. This study aimed to evaluate genetic variation of serum protein profile in sheep. Blood samples were randomly collected from 96 Lori-Bakhtiari ewes, a heavy meat-type breed. Total protein, albumin, globulin, α1, α2, β and γ globulins and IgG levels were measured in blood serum. The samples were genotyped using the Illumina OvineSNP50 BeadChip. The studied traits adjusted for age, birth type, birth season and estimate of breeding value for body weight were considered as pseudo-phenotypes in genome-wide association analysis. In the GWAS model, the first five principal components were fitted as covariates to correct the biases due to possible population stratification. The Plink, R and GCTA software were used for genome-wide association analysis, construction of Q-Q and Manhattan plots and estimation of genetic variances, respectively. Noticeable genomic heritabilities ± SE were estimated for total and γ globulins (0.868 ± 0.262 and 0.831 ± 0.364, respectively), but other protein fractions had zero or close to zero estimates. Based on the Bonferroni adjusted p values, four QTLs located on 181.7 Mbp of OAR3, 107.7 Mbp of OAR4, 86.3 Mbp of OAR7 and 83.0 Mbp of OAR8 were significantly associated with α1, β, β and γ globulins, respectively. The results showed that the PKP2, IGF2R, SLC22A1 and SLC22A2 genes could be considered as candidate genes for blood serum proteins. The present study showed significant genetic variations of some blood protein fractions.

Protein Electrophoresis and Haptoglobin Values for Captive Bongo (Tragelaphus eurycerus)

Serum samples collected from 37 clinically normal bongo (Tragelaphus eurycerus) and 13 abnormal bongo were tested using assays for acute-phase proteins (APPs) and by protein electrophoresis. Abnormal bongo samples (n = 27) had significantly higher levels of fibrinogen (FIB) (p < 0.001) and trending but not significantly increased haptoglobin (HP) (p = 0.07) vs. samples from normal bongo (n = 37). There were no significant differences in values for total white blood cell counts or for any of the fractions determined by protein electrophoresis. Clinically normal female bongo (n = 19) had significantly lower levels of FIB than normal males (n = 18) (p = 0.014), and this observation was also made with samples from the clinically abnormal group (p = 0.004). Many weak to moderate significant correlations were observed with increasing age, including increased globulins, FIB, and HP and decreased albumin-to-globulin (A/G) ratio and albumin. In clinical cases reviewed in this study, mild HP changes categorized this reactant as a minor APP, which contrasts with the major APP classification of HP in the related species of the cow. The preliminary data indicate that the quantitation of these APPs may offer value in assessing inflammation in this species, but additional studies are needed.

Acute phase response and clinical manifestation in outbreaks of interdigital phlegmon in dairy herds

Several Finnish dairy herds have suffered from outbreaks of interdigital phlegmon (IP). In these new types of outbreaks, morbidity was high and clinical signs severe, resulting in substantial economic losses for affected farms. In our study, we visited 18 free stall dairy herds experiencing an outbreak of IP and 3 control herds without a similar outbreak. From a total of 203 sampled cows, 60 suffered from acute stage IP. We demonstrated that acute phase response of bovine IP was evident and therefore an appropriate analgesic should be administered in the treatment of affected animals. The response was most apparent in herds with high morbidity in IP and with a bacterial infection comprising Fusobacterium necrophorum and Dichelobacter nodosus, indicating that combination of these two bacterial species affect the severity of the disease.