Singh, Sikh TejinderKaur, Navneet2019-05-072019-05-072017http://krishikosh.egranth.ac.in/handle/1/5810102190The present study was aimed to assess metabolic and oxidative status of periparturient crossbred cattle (HF×Sahiwal; n=30) in the tropical environment in relation to season (summer: THI>72; winter: THI?72), animal genetics (GEN1: 75% HF; GEN2: 75-82.5% HF), stages of transition viz. far off dry (FOD: >10 days following dry off and not < 30 days prior to calving), close up dry (CUD: 3-21 days prior to calving), fresh 1 (F1: 7-10 days in milk) and fresh 2 (F2: 30-45 days in milk), post-partum disease incidence, calf birth weight, colostrum quality and milk composition. There was significant effect of season ( 2=2.937, p<0.05) and animal genetics ( 2=8.523, p<0.01) on post-partum disease incidence, which was higher in summer and GEN2. Metabolic profile (serum NEFA, BHBA, Pi, Mg, creatinine), oxidative stress (erythrocytic LPO, GSH), rectal temperature and respiration rate were significantly higher and serum Ca, glucose and body condition score were significantly lower in the summer calving cattle. The level of exotic inheritance significantly influenced the energy metabolism (NEFA, BHBA). The metabolic health and oxidative status of cattle differed significantly during various stages of the transition. Higher NEFA, BHBA, LPO, creatinine and lower BCS, glucose and albumin in pre-partum period; and higher NEFA, BHBA, LPO and lower BCS, back fat thickness and calcium in post-partum period were associated with higher incidence of post-partum metabolic diseases. Higher concentrations of BHBA, BUN, creatinine and lower glucose, total proteins and albumin in the pre-partum period were associated with the birth of underweight calves (<24 kg). Colostral total immunoglobulins concentration was significantly higher in winter while the somatic cell count was significantly higher in summer. There was no effect of season on milk fat, while SNF, protein and lactose contents were significantly higher during winter season.ennullThesis