Extended lactations could work for EU herds
Extending dairy cow lactations could not only boost profitability, but it could also offer improved levels of health and welfare for European herds.
That was the conclusion of a study, carried out by Chris Knight from the University of Copenhagen, which set out to answer the question of whether extended lactation could work for European dairy producers.
“For a 100-cow herd, extending lactations would incur costs of £22,000, but generate £42,000 in extra revenue, resulting in £20,000 in extra profit,” he told delegates at the British Society of Animal Science’s international conference entitled: Fertility in dairy cows – bridging the gaps.
“And trials and data show that increasing the voluntary waiting period between calvings does not increase disease incidence per lactation and this means that, on an annual or lifetime basis, disease is reduced,” added Mr Knight.
He said that modern dairy cows could lactate for at least 18 months in the US, but cautioned that the US data was possibly influenced by BST. “Persistency is key here if we’re to extend lactation length and there are three strategies to help improve this: breeding for increased persistency, identifying individual cows within the herd that are persistent and delaying their re-breeding, and/or managing the whole herd for increased persistency.”
The latter, without the assistance of BST, would require a combination of more frequent milking and more appropriate nutrition, according to Mr Knight. In an experimental study at the Hannah Research Institute, involving 24 cows, the effect of milking frequency, nutrition and calving season were monitored during two consecutive 18-month lactations and persistency was altered by management.
“And rebreeding results were similar to non-extended lactation cows, although the reproductive problems at nine months were different to the ‘usual’ two-month problems. We think they may be less intractable,” added Mr Knight.
Extended lactation: could it work for UK dairy farmers? C H Knight, University of Glasgow, Faculty of Veterianry Medicine, Division of Cell Sciences, Institute of Comparative Medicine, Glasgow, UK Email c.knight@vet.gla.ac.uk
summary(pdf) Presentation_032_knight_orig (pdf)
PDF of Powerpoint presentations available at http://www.bsas.org.uk/Members_Area/_
Full paper available through BSAS members area or http://journals.cambridge.org/action/displayIssue?jid=ANM&volumeId=2&issueId=08
All summaries from conference http://www.bsas.org.uk/downloads/animalbytes/Dairycow_Fertility.pdf
