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Effects of increasing the proportion of high-quality grass silage in the diet of dairy cows

Patel, Mikaela (2012). Effects of increasing the proportion of high-quality grass silage in the diet of dairy cows. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae, 1652-6880 ; 2012:80
ISBN 978-91-576-7727-3
[Doctoral thesis]

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Abstract

The Swedish dairy cow has almost doubled its annual milk yield over a few decades. This has simultaneously led to an increase in the dietary proportion of concentrate in
order to meet the increased nutritional requirement of dairy cows. The proportion of forage is often below 50% of dry matter (DM) intake in conventional dairy production
on an annual basis. However, the regulations for organic dairy production stipulate a minimum of 60% DM of forage in the diet, with a permissible decrease to 50% in early
lactation. The price of concentrate is currently high, so feed is a large expense for dairy farmers and has a large impact on total farm profits. Since the techniques for forage preservation have improved, enabling earlier harvesting, the nutritional quality of grass
silage has increased. This may allow partial replacement of concentrate by high-quality grass silage without any adverse effects on milk production.

This thesis examined the
effects of replacing concentrate with grass silage of high nutritional quality over the entire lactation. The effects were examined for milk production, enteric methane
emissions, milk fatty acid composition and profitability.
Over two consecutive years, a total of 92 dairy cows were randomly assigned to one of three diets that differed in the proportion of forage. After peak lactation, from
lactation month four, the proportion of forage was gradually increased over the entire lactation up to a maximum in late lactation of 50%, 70% or 90% on a DM basis.

Overall, increasing the dietary proportion of silage up to 70% in late lactation did not significantly affect milk yield compared with feeding 50% silage. Positive effects were shown in terms of milk fatty acid composition and profitability. Increasing in the dietary proportion up to 90% silage in late lactation significantly decreased milk production, but the positive effects on milk fatty acids persisted. Enteric methane emissions showed a tendency to increase with increasing proportion of silage in the diet. The overall conclusion was that there is great potential for increasing the proportion of high-quality grass silage in the diet of high-yielding dairy cows after peak lactation, up to 70% silage in late lactation.

Authors/Creators:Patel, Mikaela
Title:Effects of increasing the proportion of high-quality grass silage in the diet of dairy cows
Series/Journal:Acta Universitatis agriculturae Sueciae (1652-6880)
Year of publishing :2012
Volume:2012:80
Number of Pages:62
Papers/manuscripts:
NumberReferences
I.Patel, M., E. Wredle, E. Spörndly and J. Bertilsson. Replacing concentrate with high-quality grass silage in diets for dairy cows after peak lactation. (manuscript, submitted to Livestock Science).
II.Patel, M., G. Börjesson, R. Danielsson, A.D. Iwaasa, E. Spörndly, E. Wredle and J. Bertilsson. (2011). Enteric methane emissions from dairy cows fed different proportions of highly digestible grass silage. Acta Agriculturae Scandinavica, Section A - Animal Science 61:3, 128-136.
III.Patel, M., E. Wredle and J. Bertilsson. (In press). Effect of dietary proportion of grass silage on milk fat with emphasis on odd- and branchedchain fatty acids in dairy cows. Journal of Dairy Science (2012), doi:10.3168/jds.2012-5441.
IV.Patel, M., E. Wredle, E. Spörndly, J. Bertilsson and K.-I. Kumm. Profitability of organic and conventional dairy production with different dietary proportions of high-quality grass silage. (manuscript, submitted to Organic Agriculture).
Place of Publication:Uppsala
Publisher:Institutionen för husdjurens utfodring och vård, Sveriges lantbruksuniversitet
ISBN for printed version:978-91-576-7727-3
ISSN:1652-6880
Language:English
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:L Animal production > L02 Animal feeding
L Animal production > L51 Animal physiology - Nutrition
Subjects:(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 402 Animal and Dairy Science > Animal and Dairy Science.
Agrovoc terms:dairy cows, animal feeding, silage, concentrates, feed intake, proximate composition, fatty acids, milk yield, methane emissions
Keywords:milk yield, forage-to-concentrate ratio, feed utilisation, greenhouse gas, sulphur hexafluoride, fatty acid, economy, milk income over feed cost
URN:NBN:urn:nbn:se:slu:epsilon-e-723
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-723
ID Code:9233
Department:(VH) > Dept. of Animal Nutrition and Management
External funders:FORMAS and Swedish Board of Agriculture
Deposited By: Mikaela Patel
Deposited On:16 Nov 2012 08:24
Metadata Last Modified:02 Dec 2014 10:53

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