6Goswami. Effect of meterological factor and seasons on luteinizing hormone, testosterone and semen of zebutanrus bulls. Indian J anita sci. 1991,61 (6), 579-583.
7Aearden.H J, Fuquay.J W. Applied animal reproduction. Prentice-Hall Inc. 2000.
8Singh D V. Factors affecting seminal attributes of Mehsana bulls.Indian Veterinary Journal of Science. 1994, (12): 1185-118.
9SalahH.M.Esmail.Keep it down! The effects of noise on poultry[J].国畜牧学:猪与禽,2006,26(3):36-37.
10David.O. Fertility in South Australian commercial Merion Flocks relationship between reproductive traits and environmental cues. Theriogenoiogoy.2005,63 ( 9 ) :2416-2433.