Mammary Growth Response of Holstein Heifers to Photoperiod
نویسندگان
چکیده
منابع مشابه
Response of body weight and clearance and secretion rates of growth hormone to photoperiod in Holstein heifers.
Effects of photoperiod on growth, eating patterns and clearance rate, secretion rate and half-life of growth hormone in serum were assessed in Holstein heifers. Sixty-four prepubertal heifers (avg body wt 102 kg) were blocked by weight into four groups of 16. Within block, each animal was randomly assigned to one of four photoperiod treatments: 16 h of cool-white fluorescent light:8 h dark (CW-...
متن کاملLong-day photoperiod that enhances puberty does not limit body growth in Holstein heifers.
Previous research has demonstrated that extended photoperiod accelerates pubescence in dairy heifers thereby limiting time for mammary development, which could be detrimental to future milk yield. We hypothesized that the potential negative effects of rapid growth and puberty through long-day photoperiod (LDPP) exposure could be overcome with a greater supply of metabolizable protein in dairy h...
متن کاملPrevalence and antimicrobial susceptibilities of coagulasenegative Staphylococci isolated from mammary secretions in pregnant Holstein heifers
Mammary secretions of 913 quarters from 229 pregnant Holstein heifers were obtained aseptically to determine the prevalence of coagulase-negative Staphylococci isolated during periparturient period. Quarter samples were collected 14 to 10 days before expected parturition. Analysis of culture data indicated that 78.5% (717/913) of samples were negative, 20.5% (187/913) contained coagulase-negati...
متن کاملGrowth of Holstein dairy heifers in the United States.
Data were collected on the heart girth (n = 8,565; a measure of body weight) and height at withers (n = 8,568) of Holstein dairy heifers from 659 dairy farms as part of the National Dairy Heifer Evaluation Project during 1991 and 1992. Means and standard deviations for weight and height were determined for ages .5 to 23.5 mo. Third-order polynomial regression equations were derived to study the...
متن کاملprevalence and antimicrobial susceptibilities of coagulasenegative staphylococci isolated from mammary secretions in pregnant holstein heifers
mammary secretions of 913 quarters from 229 pregnant holstein heifers were obtained aseptically to determine the prevalence of coagulase-negative staphylococci isolated during periparturient period. quarter samples were collected 14 to 10 days before expected parturition. analysis of culture data indicated that 78.5% (717/913) of samples were negative, 20.5% (187/913) contained coagulase-negati...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 1985
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(85)80801-8