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Factors affecting levels of volatile 4-alkyl branched-chain fatty acids in sheep milk from 2 contrasting farming systems in New Zealand

journal contribution
posted on 2023-05-03, 19:44 authored by Fei Teng, Mariza Gomes Reis, Marita Broadhurst, Kirill Lagutin, Linda SamuelssonLinda Samuelsson, Ying Ma, David StevensDavid Stevens, Li DayLi Day
Knowledge of factors influencing the levels of 4-alkyl branched-chain fatty acid (vBCFA), and consequently the “sheepy flavor” intensity of New Zealand sheep milk, is currently limited. In this study, we investigated the effects of 2 contrasting farming systems (fully housed/mid-lactation or pasture-grazed/late lactation) on the levels of vBCFA in sheep milk on a commercial farm in the North Island of New Zealand. Fully housed/mid-lactation ewes were housed 24 h/d and fed a total mixed ration. Pasture-grazed/late-lactation ewes were grazed 24 h/d and offered approximately 40% supplements because of poor pasture growth resulting from dry and hot climatic conditions. Any effects of genetics, age, lactation stage, feed composition, lambing date, or the environment in the housing barn or outdoors were confounded. The results obtained in this study were descriptive rather than definitive, because of the limitations of the experimental design. Levels of 4-methyloctanoic acid and 4-methylnonanoic acid in milk from fully housed/mid-lactation ewes increased during the trial period, but remained low in milk from pasture-grazed/late-lactation ewes. Levels of 4-ethyloctanoic acid in milk from the 2 groups of ewes were comparable throughout the trial. Increases in levels of 4-methyloctanoic acid and 4-methylnonanoic acid in sheep milk were associated with lactation stage and the proportion of lucerne silage fed to ewes. The level of free-form 4-ethyloctanoic acid was positively correlated with the proportion of soy meal in the diet and negatively correlated with the proportion of barley. Milk from fully housed/mid-lactation ewes had a higher flavor values than milk from pasture-grazed/late-lactation ewes because of its higher total amounts of vBCFA.

History

Rights statement

© 2020 Elsevier Ltd. All rights reserved.

Language

  • English

Does this contain Māori information or data?

  • No

Publisher

Elsevier

Journal title

Journal of Dairy Science

ISSN

0022-0302

Citation

Teng, F., Reis, M. G., Broadhurst, M., Lagutin, K., Samuelsson, L., Ma, Y., … Day, L. (2020). Factors affecting levels of volatile 4-alkyl branched-chain fatty acids in sheep milk from 2 contrasting farming systems in New Zealand. Journal of Dairy Science, 103(3), 2419–2433. doi:10.3168/jds.2019-17192

Funder

Blue River Dairy||Ministry of Business Innovation & Employment||Waituhi Kuratau Trust

Contract number

A20185

Job code

11565x02

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