Effect of feed restriction on reproductive and metabolic hormones in dairy cows
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Date
2014-02
Authors
Ferraretto, Luiz F.
Hackbart, Katherine S.
Nascimento, Aníbal Ballarotti
Dalla Costa, F.
Bender, Robb W.
Guenther, Jerry N.
Shaver, Randy Duncan
Wiltbank, Milo Charles
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
The objective of this trial was to evaluate the effects of feed restriction (FR) on serum glucose, nonesterified fatty acids, progesterone (P4), insulin, and milk production in dairy cows. Eight multiparous Holstein cows, 114 +/- 14 d pregnant and 685 +/- 39 kg of body weight, were randomly assigned to a replicated 4 x 4 Latin square design with 14-d periods. During the first 8 d of each period, cows in all treatments were fed for ad libitum feed intake. Beginning on d 9 of each period, cows received 1 of 4 treatments: ad libitum (AL), 25% feed restriction (25FR), 50% feed restriction (50FR), and 50% of TMR replaced with wheat straw (50ST). Daily feed allowance was divided into 3 equal portions allocated every 8 h with jugular blood samples collected immediately before each feeding through d 14. In addition, on d 12 of each period, blood samples were collected before and at 60, 120, 180, 240, 300, 360, 420, and 480 mm after morning feeding. The conventional total mixed ration and total mixed ration with straw averaged 15.1 and 10.8%, 32.1 and 50.5%, and 26.8 and 17.0% for concentrations of crude protein, neutral detergent fiber, and starch, respectively. Cows that were feed and energy restricted had reduced dry matter intake, net energy for lactation intake, circulating glucose concentrations, and milk production, but greater body weight and body condition score losses than AL cows. Circulating concentrations of insulin were lower for cows fed 50FR (8.27 p,mu IU/mL) and 50ST (6.24 mu IU/mL) compared with cows fed AL (16.65 mu IU/mL) and 25FR (11.16 p,mu IU/mL). Furthermore, the greatest plasma nonesterified fatty acids concentration was observed for 50ST (647.7 mu Eq/L), followed by 50FR (357.5 mu Eq/L), 25FR (225.3 mu Eq/L), and AL (156.3 mu Eq/L). In addition, serum P4 concentration was lower for cows fed AL than cows fed 50ST and 25FR. Thus, FR reduced circulating glucose and insulin but increased P4 concentration, changes that may be positive in reproductive management programs.
Description
Keywords
Feed restriction, Reproductive hormones, Dairy cow, Nonesterified fatty-acids, Postpartum follicle wave, Neutral detergent fiber, Portal-drained viscera, Liver blood-flow, Milk-production, Metabolic hormones, Early lactation, Energy-balance, Postfertilization development, Agriculture, Food science & technology, Bos, Triticum aestivum
Citation
Ferraretto, L. F. vd. (2014). "Effect of feed restriction on reproductive and metabolic hormones in dairy cows". Journal of Dairy Science, 97(2), 754-763.