Influence of Precalving Feed Allowance on Periparturient Metabolic and Hormonal Responses and Milk Production in Grazing Dairy Cows

• Published in: Journal of dairy science 2005-02, Vol.88 (2), p.677-689
• Main Authors: Roche, J. R, Kolver, E. S, Kay, J. K
• Format: Article
• Language: English
• Subjects: 3-Hydroxybutyric Acid - blood; Animal Feed; Animal Nutritional Physiological Phenomena; Animal productions; Animals; Biological and medical sciences; Blood Glucose - analysis; Body Composition; Body Weight; Calcium - blood; Cattle - metabolism; cow feeding; dry matter intake; dry period; early lactation; Fatty Acids, Nonesterified - blood; Feed and pet food industries; feeding level; Female; Food industries; Fundamental and applied biological sciences. Psychology; Growth Hormone - blood; Hormones - blood; Insulin-Like Growth Factor I - analysis; Lactation - physiology; Leptin - blood; Lipids - analysis; Magnesium - blood; Milk - chemistry; milk fat yield; Parturition; pasture; Postpartum Period; Pregnancy; Prenatal Care; Terrestrial animal productions; transition cow; Vertebrates
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.S0022-0302(05)72732-6

Fifty-two multiparous dairy cows were allocated to 4 treatments consuming 5.4, 8.2, 10.0, or 11.0 kg/d of pasture dry matter per cow for 27±9.6 d precalving. This equated to 1.3, 1.9, 2.4, and 2.6% of body weight (BW; not including the conceptus weight). Following calving, all cows were fed ad libitum on pasture. Blood was sampled 17 d precalving, on day of calving, and on d 1, 2, 3, 4, 7, 14, 28, and 35 postcalving. Results suggest that the near-term grazing dairy cow requires 1.05 MJ of ME/kg of BW0.75 and that previous estimates of energy requirements were underestimated. Precalving plasma concentrations of glucose, insulin-like growth factor-1, and leptin increased quadratically with increasing pasture intake. This was associated with precalving plasma concentrations of growth hormone that declined linearly, and concentrations of nonesterified fatty acids and β-hydroxybutyrate that declined quadratically with increasing dry matter intake (DMI). Postcalving plasma concentrations of these metabolites showed no lasting effect of precalving feeding. The effect of precalving nutrition on milk production was small, and other than milk fat, was confined to wk 1 postcalving. Milk fat yield increased with increasing precalving DMI and calving body condition score until wk 3 post-calving, after which treatment effects were not evident. These results indicate that the level of feeding in grazing dairy cows during the last month before calving has only small effects on cow metabolic and hormonal status, and on milk production in the first 5 wk of lactation.