MILK SYNTHESIS AND SECRETION RATES IN COWS WITH MILK-COMPOSITION CHANGED BY OXYTOCIN

被引:44
作者
ALLEN, JC [1 ]
机构
[1] LOUISIANA STATE UNIV,DEPT DAIRY SCI,BATON ROUGE,LA 70803
关键词
milk composition; milk yield; oxytocin;
D O I
10.3168/jds.S0022-0302(90)78755-3
中图分类号
S8 [畜牧、 动物医学、狩猎、蚕、蜂];
学科分类号
0905 ;
摘要
Supraphysiological doses of oxytocin were used to investigate the association among milk composition, secretion rates, and cell electrolyte concentrations. Groups of 8 Holstein cows were injected i.v. with 1, 10, 100, or 1000 IU oxytocin after a normal milking. Milk yield over the following 12-h period declined 5.5, 8.1, 17.0, and 43.7% respectively. Milk Na increased in proportion to oxytocin dose. Yield and concentration of lactose and protein declined with increasing oxytocin doses, but milk fat yield remained unchanged. To determine whether the decreased milk lactose secretion was caused by a decline in synthesis or leakage into blood plasma and subsequent renal clearance, milk and urine were collected for 24-h periods before and after 100 IU oxytocin. Urinary lactose accounted for 2.7 ± 3.19 and 12.9 ± 8.9% of the total collected on the days before and after oxytocin. This increase (46.7 g/d) was only one-fifth of the 25% decline in total lactose recovery, suggesting that reduced mammary lactose synthesis is primarily responsible for lower milk yield. Measurement of Na and K in biopsied mammary tissue suggests that a high Na:K ratio in milk will increase that ratio in secretory cells, which may be part of the mechanism for lower milk yield under circumstances that increase permeability of mammary tight junctions. © 1990, American Dairy Science Association. All rights reserved.
引用
收藏
页码:975 / 984
页数:10
相关论文
共 25 条
[11]   EFFECTS OF OXYTOCIN AND MILK REMOVAL ON MILK SECRETION IN GOAT [J].
LINZELL, JL ;
PEAKER, M .
JOURNAL OF PHYSIOLOGY-LONDON, 1971, 216 (03) :717-&
[12]   DAY-TO-DAY VARIATIONS IN MILK COMPOSITION IN GOAT AND COW AS A GUIDE TO DETECTION OF SUBCLINICAL MASTITIS [J].
LINZELL, JL ;
PEAKER, M .
BRITISH VETERINARY JOURNAL, 1972, 128 (06) :284-&
[13]   INTRACELLULAR CONCENTRATIONS OF SODIUM, POTASSIUM AND CHLORIDE IN LACTATING MAMMARY GLAND AND THEIR RELATION TO SECRETORY MECHANISM [J].
LINZELL, JL ;
PEAKER, M .
JOURNAL OF PHYSIOLOGY-LONDON, 1971, 216 (03) :683-&
[14]   EFFECTS OF PROLACTIN AND OXYTOCIN ON MILK SECRETION AND ON PERMEABILITY OF MAMMARY EPITHELIUM IN RABBIT [J].
LINZELL, JL ;
PEAKER, M ;
TAYLOR, JC .
JOURNAL OF PHYSIOLOGY-LONDON, 1975, 253 (02) :547-563
[15]  
Neville M. C., 1983, Lactation. Physiology, nutrition, and breast-feeding, P49
[16]  
NOSTRAND S D, 1987, Journal of Dairy Science, V70, P228
[17]  
Peaker M., 1977, Symposia of the Zoological Society of London, P113
[18]   EFFECTS OF ESTRUS AND EXOGENOUS ESTROGENS ON MILK SECRETION IN GOAT [J].
PEAKER, M ;
LINZELL, JL .
JOURNAL OF ENDOCRINOLOGY, 1974, 61 (02) :231-240
[19]   LYMPHOCYTE STIMULATION - EFFECT OF OUABAIN ON NUCLEIC ACID AND PROTEIN SYNTHESIS [J].
QUASTEL, MR ;
KAPLAN, JG .
EXPERIMENTAL CELL RESEARCH, 1970, 62 (2-3) :407-&
[20]   RATES OF SYNTHESIS AND DEGRADATION OF NA+-K+-ATPASE DURING CHRONIC OUABAIN TREATMENT [J].
RAYSON, BM .
AMERICAN JOURNAL OF PHYSIOLOGY, 1989, 256 (01) :C75-C80