Effects of Altering the Energy and Protein Supply to Dairy Cows During the Dry Period. 2. Metabolic and Hormonal Responses

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Effects of Altering the Energy and Protein Supply to Dairy Cows During the Dry Period. 2. Metabolic and Hormonal Responses. / Moorby, Jon; Dewhurst, Richard J.; Tweed, John; Dhanoa, M. S.; Beck, Neil.

In: Journal of Dairy Science, Vol. 83, No. 8, 2000, p. 1795-1805.

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Moorby, Jon ; Dewhurst, Richard J. ; Tweed, John ; Dhanoa, M. S. ; Beck, Neil. / Effects of Altering the Energy and Protein Supply to Dairy Cows During the Dry Period. 2. Metabolic and Hormonal Responses. In: Journal of Dairy Science. 2000 ; Vol. 83, No. 8. pp. 1795-1805.

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@article{f61d7f4716b4477fbb594894d4e901b9,
title = "Effects of Altering the Energy and Protein Supply to Dairy Cows During the Dry Period. 2. Metabolic and Hormonal Responses",
abstract = "We offered 48 multiparous Holstein-Friesian cows one of three different dry-period diets for 6 wk before predicted calving: A) a grass silage and barley straw mix (60:40 on a dry-matter basis), with a low protein content; B) grass silage only (medium protein); or C) grass silage plus 0.5 kg of high protein corn gluten meal (high protein)/d. A standard grass silage-based diet was offered to all cows following calving. All animals were blood sampled at weekly intervals during the dry period, and at wk 1, 3, 5, 7, 13, 17, and 21 of lactation. Nitrogen balance was measured in a subset of 12 cows (four per treatment) at 3 wk before calving, and at wk 8 and 18 of lactation. Nitrogen balance in the dry period increased significantly as dietary protein supply increased [9, 34, and 50 g of N/d (SED 8.8) for the three diets, respectively]. We measured no residual effects of dry-period treatment on N balance during lactation. Plasma concentrations of growth hormone became significantly higher in the late dry period in cows offered the silage and straw diet, although treatment differences disappeared after calving. Insulin concentrations were significantly affected by treatment throughout the dry period and indicated inadequate nutrient supplies from the low protein diet, leading to losses in body reserves of energy and protein. The results indicate that animals offered the low protein diet accumulated less N per day than is required for fetal development, suggesting that protein must have been repartitioned from maternal tissues.",
keywords = "nitrogen balance, dry period, dairy cows",
author = "Jon Moorby and Dewhurst, {Richard J.} and John Tweed and Dhanoa, {M. S.} and Neil Beck",
year = "2000",
doi = "10.3168/jds.S0022-0302(00)75050-8",
language = "English",
volume = "83",
pages = "1795--1805",
journal = "Journal of Dairy Science",
issn = "0022-0302",
publisher = "Elsevier",
number = "8",

}

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TY - JOUR

T1 - Effects of Altering the Energy and Protein Supply to Dairy Cows During the Dry Period. 2. Metabolic and Hormonal Responses

AU - Moorby, Jon

AU - Dewhurst, Richard J.

AU - Tweed, John

AU - Dhanoa, M. S.

AU - Beck, Neil

PY - 2000

Y1 - 2000

N2 - We offered 48 multiparous Holstein-Friesian cows one of three different dry-period diets for 6 wk before predicted calving: A) a grass silage and barley straw mix (60:40 on a dry-matter basis), with a low protein content; B) grass silage only (medium protein); or C) grass silage plus 0.5 kg of high protein corn gluten meal (high protein)/d. A standard grass silage-based diet was offered to all cows following calving. All animals were blood sampled at weekly intervals during the dry period, and at wk 1, 3, 5, 7, 13, 17, and 21 of lactation. Nitrogen balance was measured in a subset of 12 cows (four per treatment) at 3 wk before calving, and at wk 8 and 18 of lactation. Nitrogen balance in the dry period increased significantly as dietary protein supply increased [9, 34, and 50 g of N/d (SED 8.8) for the three diets, respectively]. We measured no residual effects of dry-period treatment on N balance during lactation. Plasma concentrations of growth hormone became significantly higher in the late dry period in cows offered the silage and straw diet, although treatment differences disappeared after calving. Insulin concentrations were significantly affected by treatment throughout the dry period and indicated inadequate nutrient supplies from the low protein diet, leading to losses in body reserves of energy and protein. The results indicate that animals offered the low protein diet accumulated less N per day than is required for fetal development, suggesting that protein must have been repartitioned from maternal tissues.

AB - We offered 48 multiparous Holstein-Friesian cows one of three different dry-period diets for 6 wk before predicted calving: A) a grass silage and barley straw mix (60:40 on a dry-matter basis), with a low protein content; B) grass silage only (medium protein); or C) grass silage plus 0.5 kg of high protein corn gluten meal (high protein)/d. A standard grass silage-based diet was offered to all cows following calving. All animals were blood sampled at weekly intervals during the dry period, and at wk 1, 3, 5, 7, 13, 17, and 21 of lactation. Nitrogen balance was measured in a subset of 12 cows (four per treatment) at 3 wk before calving, and at wk 8 and 18 of lactation. Nitrogen balance in the dry period increased significantly as dietary protein supply increased [9, 34, and 50 g of N/d (SED 8.8) for the three diets, respectively]. We measured no residual effects of dry-period treatment on N balance during lactation. Plasma concentrations of growth hormone became significantly higher in the late dry period in cows offered the silage and straw diet, although treatment differences disappeared after calving. Insulin concentrations were significantly affected by treatment throughout the dry period and indicated inadequate nutrient supplies from the low protein diet, leading to losses in body reserves of energy and protein. The results indicate that animals offered the low protein diet accumulated less N per day than is required for fetal development, suggesting that protein must have been repartitioned from maternal tissues.

KW - nitrogen balance

KW - dry period

KW - dairy cows

UR - http://hdl.handle.net/2160/36480

U2 - 10.3168/jds.S0022-0302(00)75050-8

DO - 10.3168/jds.S0022-0302(00)75050-8

M3 - Article

VL - 83

SP - 1795

EP - 1805

JO - Journal of Dairy Science

JF - Journal of Dairy Science

SN - 0022-0302

IS - 8

ER -

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