Lactation stages modulate the hematological, serum biochemical, and endocrinological profiles and oxidative stress markers in crossbred cows under tropical humid island ecosystem of Andaman and Nicobar Islands.

The present study was designed to assess the interrelationship between hematological, serum biochemical, and endocrinological profiles and oxidative stress markers and lactational stages in crossbred (CB) dairy cows of Andaman and Nicobar Islands (ANI). Healthy (n = 6) CB cows (50-62.50% exotic inheritance; Holstein Friesian × Andaman local) of 4th parity with age of 7-9 years and body weight of 350-400 kg were selected from Cattle Breeding Farm, ICAR-Central Island Agricultural Research Institute (ICAR-CIARI), Port Blair, ANI. These experimental cows were synchronized with Ovsynch protocol, and parturition was planned to happen in the month of May-June. Lactation was allowed for 305 days. Hematological profiles, serum biochemical profiles, oxidative stress markers and endocrinological profiles were measured at a 15-day interval from day 07 to 305 of lactation (after 6 days of colostrum). The lactation period was divided into first (day 07 to 90), second (day 91 to 180), and third (day 181 to 305) stage of lactation. Average daily milk yield (L) did not vary among the stages of lactations; however, first (8.56 ± 1.26) and second (9.79 ± 0.87) stages had higher milk yield compared to third (7.93 ± 0.79) stage of lactation. Hematological profiles did not vary among the stages of lactation; however, these values were within the range of bovine species at lactation. Serum glucose, triglyceride, total cholesterol, total protein, globulin, and blood urea nitrogen (BUN) increased (P < 0.05) and albumin and creatinine decreased (P < 0.05) gradually as lactation stages advanced. Activity of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) and concentration of calcium, phosphorous, and magnesium were nearly similar among the stages of lactation. Similarly, triiodothyronine (T3), and thyroxine (T4) increased and prolactin and cortisol decreased (P < 0.05) gradually as stages of lactation advanced. Total antioxidant capacity (TAC) increased and malondialdehyde (MDA) decreased (P < 0.05) as lactation stages advanced. The results of the present study indicated that the lactating CB cows suffered nutritional stress (deficiency of protein, carbohydrate, lipids, and minerals), physiological stress (higher cortisol), oxidative stress (higher MDA and deficiency of total antioxidant capacity), and hormonal imbalance (higher prolactin and cortisol and deficiency of thyroid hormones) during the early stages of lactation. Thus, the first and second stages are more stressful events compared to the third stage of lactation in the CB cows in ANI. Therefore, regular monitoring of blood components and accordingly suitable feeding strategies with balanced nutrients and minerals, supplementation of suitable antioxidants, and appropriate management practices need to be implemented to mitigate these stresses and to prevent metabolic disorders with maximum milk production during different stages of lactation in CB cows under humid tropical island ecosystem of Andaman and Nicobar Islands.

Serological evidence of Japanese encephalitis virus infection in pigs in a low human incidence state, Goa, India.

Japanese encephalitis (JE) is a mosquito-borne zoonosis caused by Japanese encephalitis virus (JEV). It is a leading cause of encephalitis in humans especially children in Asia. Aquatic wading birds are the reservoirs and pigs serve as amplifying hosts for JEV. Humans and horses are dead-end hosts. JE is endemic in several states of India. Goa, a small state on the west coast of India, had witnessed JE outbreaks in the past and as on date human JE cases are reported sporadically. Although human JE cases are well documented in Goa, the status of JEV exposure of pigs has not been well documented. Hence the present study was undertaken with an objective of identifying JEV exposure in the pig population of Goa state in the light of declining human JE cases. To achieve the objective, between January 2017 and May 2019, serum samples from 666 pigs were screened using enzyme-linked immunosorbent assay (ELISA) for the detection of anti-JEV IgG. The apparent prevalence of anti-JEV IgG in pigs was found to be 7.1 % (95 % confidence interval 5.3 %-9.3 %) and true prevalence was 4.6 % (95 % confidence interval 2.7 %-7.1 %). The seroprevalence of JE recorded in pigs of Goa state was low compared to other endemic states in India, which may also be one of the reasons for the lower prevalence of human JE cases in Goa state. Univariate analysis revealed that the age of the pigs and district did not significantly influence the JE seroprevalence in pigs of Goa state. However, in multivariable logistic regression, the North Goa district was found to significantly (p = 0.017) influence the JE seroprevalence in pigs. The study identified that JEV is still circulating in the Goan pig population and hence constant vigil is required to monitor the intensity of JEV circulation in pigs. Besides forewarning possible human outbreaks in the locality, evidence of JEV exposure in pig population provides valuable data on the magnitude and extent of geographical spread.

Toll-like receptors TLR1, TLR2 and TLR4 gene mutations and natural resistance to Mycobacterium avium subsp. paratuberculosis infection in cattle.

Toll like receptors (TLRs) are a class of pattern recognition receptors belonging to the innate immune system. Mutations in the protein coding region of TLRs are associated with altered responsiveness to pathogen-associated molecular patterns (PAMPs). A search was performed for novel mutations in bovine TLR1, TLR2 and TLR4 genes associated with the Mycobacterium avium subsp. paratuberculosis (MAP) infection. The work was also focused on the assessment of linkage between well known mutations in TLR genes (TLR2: Arg677Trp, Pro681His and Arg753Gln; TLR4: Asp299Gly and Thr399Ile), and the susceptibility of cattle to MAP infection. Detection of MAP infection in cattle population (n=711) was based on IS900 PCR, which revealed 22.50% (n=160) MAP positivity. Known mutations in TLR2 and TLR4 genes were not found in cattle population. A novel mutation Val220Met was associated (Odd's ratio, OR-3.459) with increased susceptibility to MAP infection. Toll/interleukin-1 receptor (TIR) domain of TLR2 was screened for the presence of mutations, wherein a novel Ile680Val mutation was linked with MAP infection. In silico analysis of the bovine TLR4 ectodomain (ECD) revealed the polymorphic nature of the central ECD and irregularities in the central LRR motifs. LRR11 of the TLR4 showed five missense mutations possibly linked with the increased susceptibility to MAP infection. The most critical position that may alter the pathogen recognition of TLR molecule was 4th residue downstream to LRR domain. Two such missense mutations in TLR4 (Asp299Asn downstream to LRR11, and Gly389Ser downstream to LRR15) were associated with MAP infection. Briefly, the work describes novel mutations in the bovine TLRs and presents their association with the MAP infection.