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]
![]() |
PDF
503kB |
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 Name/Journal: | Acta Universitatis Agriculturae Sueciae | ||||||||||
Year of publishing : | 2012 | ||||||||||
Number: | 2012:80 | ||||||||||
Number of Pages: | 62 | ||||||||||
Papers/manuscripts: |
| ||||||||||
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 |
Repository Staff Only: item control page