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Aim:The aim of this study is to test the potency of bovine serum albumin (BSA) conjugated ampicillin (AMP) and enrofloxacin (ENR) antigens in eliciting an immune response in rats using indirect competitive enzyme-linked immunosorbent assay (icELISA).Materials and Methods:AMP and ENR antibiotics were conjugated with BSA by carbodiimide reaction using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) as a cross-linker. The successful conjugation was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Sprague-Dawley rats were immunized with the conjugates and blood samples were collected serially at 15 days time interval after first immunization plus first booster, second booster, third booster, and the fourth sampling was done 1½ month after the third booster. The antibody titres in the antisera of each antibiotic in all the four immunization cycles (ICs) were determined by an icELISA at various serum dilutions ranging from 1/100 to 1/6400.Results:Analysis of antibiotic-BSA conjugates by sodium dodecyl sulfate polyacrylamide gel electrophoresis and coomassie blue staining revealed high molecular weight bands of 85 kDa and 74 kDa for AMP-BSA and ENR-BSA respectively when compared to 68 kDa band of BSA. Both the antibiotic conjugates elicited a good immune response in rats but comparatively the response was more with AMP-BSA conjugate than ENR-BSA conjugate. Maximum optical density 450 value of 2.577 was recorded for AMP-BSA antisera, and 1.723 was recorded for ENR-BSA antisera at 1/100th antiserum dilution in third IC.Conclusion:AMP and ENR antibiotics proved to be good immunogens when conjugated to BSA by carbodiimide reaction with EDC as crosslinker. The polyclonal antibodies produced can be employed for detecting AMP and ENR residues in milk and urine samples.

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Background: Milk production is one of the most important economic traits in dairy cattle. Crossing of zebu cattle (Bos indicus) with temperate cattle breeds (Bos taurus) was undertaken to improve the milk production in India. Crossbreeding has resulted in improved production performance of the dairy animlas over the past few decades. Methods: Data on 50 purebred Sahiwal cows from the Livestock Farm Complex, College of Veterinary Science, Rajendranagar, Hyderabad and 50 Holstein Friesian × Sahiwal crossbred cows maintained at the Military Dairy Farm, Secunderabad were utilized to study the influence of breed and parity on various production and reproduction traits. The various traits studied were: Total lactation milk yield (TLMY) Lactation length (LL), Peak yield (PY), Age at first service (AFS), Age at first calving (AFC), Gestation period (GP), Service period (SP), Dry period (DP) and Calving interval (Cl). Result: In the present study, significant effect of breed was found on the TLMY and PY with the crossbreds recording higher values for both the traits. The means for TLMY, PY, LL, GP, SP, DP and CI were 1768.32±109.67 kg, 10.17±0.50 kg, 304.41±13.00 days, 277.71±2.24 days, 182.60±15.51 days, 167.47±10.68 days and 430.23±13.46 days in Sahiwal and 2983.45±78.32 kg, 14.92±0.36 kg, 324.71±9.29 days, 275.34 days, 181.09±10.91 days, 127.01±7.51, 413.61±9.47 days in crossbred cows respectively. It may be concluded that the productive performance of crossbred cows was better than that of indigenous cows.

Background: Cellular tolerance to heat stress is mediated by heat shock proteins (HSPs). The HSPs act as molecular chaperones and are transcribed in response to stress. Among different families of these proteins, HSP70 is considered to be related to the development of temperature tolerance. Unraveling polymorphism in heat shock protein genes could be a step towards the identification of genetic markers for selecting heat-tolerant cattle. Methods: The present study was carried out in Sahiwal (n=50) and Crossbred cows (n=50) with the objective to identify polymorphisms in HSP70 gene. Two fragments (295 and 220 bp) of HSP70 gene were subjected to Polymerase Chain Reaction-Single-Strand Conformation Polymorphism (PCR-SSCP) technique. Statistical analysis was performed to study the association of each SSCP genotype on physiological, production and reproduction traits in Sahiwal and crossbred cows using the univariate GLM model of SPSS 25. Result: The PCR-SSCP of 295 bp fragment of HSP70 gene revealed two genotypes AA and AB in Sahiwal cows and two genotypes AA and AC in crossbred cows. The association analysis revealed that genotype AA had higher peak milk yield in Sahiwal cows while the same genotype had higher total lactation milk yield, lower service period and calving interval in crossbred cows. The 220 bp fragment was found to be monomorphic in both Sahiwal and crossbred cows.