Int.J.Curr.Microbiol.App.Sci (2017) 6(8): 1264-1270 1264 Original Research Article https://doi.org/10.20546/ijcmas.2017.608.153 Study of Lactation Length and Milk Yield of F 1 (Tharparkar X Holstein Friesian) Crossbred Cow During Three Consecutive Lactation Bajarang Lal Choudhary 1* , Mahesh Datt 1 and Basant Kumar Bhinchhar 2 1 Department of livestock production management, SKNAU, Jobner, Jaipur, India 2 Department of Animal Husbandry and Dairying, IAS, BHU, Varanasi, India *Corresponding author ABSTRACT Introduction India is endowed with the largest livestock population in the world. Women constitute about 70% of the labor force in livestock farming. As the ownership of livestock is more evenly distributed among landless laborers and marginal farmers, the progress of these results is in a more balanced development of the rural economy. In global context, the performance of the Indian dairy sector appears impressive in term of livestock population and total milk production but extremely poor in term of productivity. Low milk production in India is probably due to low genetic potential for milk production, poor nutrition management and adverse agro climatic condition. Indian arid zone, where International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 6 Number 8 (2017) pp. 1264-1270 Journal homepage: http://www.ijcmas.com S.K.N. College of Agriculture, Jobner dairy farm was purposively selected for the study. The selection of cows was done randomly. The data of 18 F 1 crossbred cows (Th x HF) those had completed three consecutive lactation at the college dairy farm was collected for carrying out the present study. This herd is being maintained at S.K.N. College of Agriculture, Jobner dairy farm under semi-arid condition. Data was collected from the record of college dairy farm over a period of eight years (1994-2001). The production performance of 18 F 1 crossbred cows maintained in S.K.N. College of Agriculture, Jobner was studied for total lactation milk yield during first, second and third lactation and corresponding lactation length during first, second and third lactation. To estimate the production traits in F 1 crossbred cows in least square estimation method was used for statistical analysis of data to arrive the conclusions. In general, total F 1 crossbred (Th x HF) cows are presented on the college dairy farm. The average milk yield during first, second and third lactations were 2631.91±62.83, 2562.09±59.57 and 2592.39±54.04 in liters respectively. The average lactation length during first, second and third lactations were 373.13±15.09, 363.19±32.19 and 372.50±32.91 in days respectively. The milk yield during first, second and third lactation varied among different cows. The mean values for third lactation were higher than second lactation but lower than first lactation. The first lactation was highest milk yield and lactation length. Milk yield increases with increasing lactation length. Least square analysis of variance showed that lactation length had significant influence upon lactation milk yield in all crossbred cows. The performance of the F 1 Tharparkar x HF crosses can possibly be the best during first lactation. This could be done to the influence of hybrid vigour that reflected in crossbred cows maintained in tropical climatic condition. Keywords Lactation length, Milk production, and Crossbred cows. Accepted: 17 June 2017 Available Online: 10 August 2017 Article Info