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A rumen unprotected conjugated linoleic acid supplement inhibits milk fat synthesis and improves energy balance in lactating goats.
J Anim Sci. 2013 Jul; 91(7):3305-14.JA

Abstract

Feeding trans-10, cis-12 CLA supplements in a rumen-protected form has been shown to cause milk fat depression (MFD) in cows, ewes, and goats. Methyl esters of CLA were shown to be as effective as FFA in inducing MFD when infused postruminally, but their efficacy as a feed supplement has not been addressed in studies with lactating ruminants. In the present study, we investigated the effects of an unprotected trans-10, cis-12 CLA supplement as methyl esters on performance, milk composition, and energy status of dairy goats. Eighteen multiparous Toggenburg goats were randomly assigned to dietary treatments in a crossover experimental design (14 d treatment periods separated by a 7 d washout interval): 30 g/d of calcium salts of fatty acids (Control) or 30 g/d of a rumen unprotected CLA supplement containing 29.9% of trans-10, cis-12 CLA as methyl esters (CLA). Lipid supplements were mixed into a concentrate and fed individually to animals 3 times a day as a total mixed ration component. The DMI, milk yield, milk protein and lactose content and secretion, and somatic cell count were unaffected by CLA treatment. On the other hand, milk fat content and yield were reduced by 19.9 and 17.9% in CLA-fed goats. Reduced milk fat yield in CLA-fed goats was a consequence of a lower secretion of both preformed and de novo synthesized fatty acids. The CLA treatment also changed the milk fatty acid profile, which included a reduction in the concentration of SFA (2.5%), increased MUFA and PUFA (5.6 and 5.4%, respectively), and a pronounced increase (1576%) in milk fat trans-10, cis-12 CLA. Consistent with the high milk fat trans-10, cis-12 CLA content, all desaturase indexes were reduced in milk fat from CLA-fed goats. The MFD induced by CLA reduced the energy required for milk production by 22%, which was accompanied by an improvement in the estimated energy balance (P < 0.001), greater blood glucose concentration (P < 0.05), and a trend for increased BW (P = 0.08). Approximately 7.2% of trans-10, cis-12 CLA was estimated to escape from rumen biohydrogenation and indirect comparisons with data obtained from other studies suggest equivalent MFD between dietary CLA in the methyl ester form and rumen protected sources. Thus, despite the apparent low degree of rumen protection, our results suggest that methyl esters of CLA could be an alternative to rumen protected CLA supplements due to manufacturing and cost advantages.

Authors+Show Affiliations

Department of Animal Production, Santa Catarina State University, Lages, Santa Catarina, 88520-000, Brazil.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Randomized Controlled Trial
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

23798520

Citation

Baldin, M, et al. "A Rumen Unprotected Conjugated Linoleic Acid Supplement Inhibits Milk Fat Synthesis and Improves Energy Balance in Lactating Goats." Journal of Animal Science, vol. 91, no. 7, 2013, pp. 3305-14.
Baldin M, Gama MA, Dresch R, et al. A rumen unprotected conjugated linoleic acid supplement inhibits milk fat synthesis and improves energy balance in lactating goats. J Anim Sci. 2013;91(7):3305-14.
Baldin, M., Gama, M. A., Dresch, R., Harvatine, K. J., & Oliveira, D. E. (2013). A rumen unprotected conjugated linoleic acid supplement inhibits milk fat synthesis and improves energy balance in lactating goats. Journal of Animal Science, 91(7), 3305-14. https://doi.org/10.2527/jas.2012-5766
Baldin M, et al. A Rumen Unprotected Conjugated Linoleic Acid Supplement Inhibits Milk Fat Synthesis and Improves Energy Balance in Lactating Goats. J Anim Sci. 2013;91(7):3305-14. PubMed PMID: 23798520.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - A rumen unprotected conjugated linoleic acid supplement inhibits milk fat synthesis and improves energy balance in lactating goats. AU - Baldin,M, AU - Gama,M A S, AU - Dresch,R, AU - Harvatine,K J, AU - Oliveira,D E, PY - 2013/6/27/entrez PY - 2013/6/27/pubmed PY - 2014/2/20/medline SP - 3305 EP - 14 JF - Journal of animal science JO - J Anim Sci VL - 91 IS - 7 N2 - Feeding trans-10, cis-12 CLA supplements in a rumen-protected form has been shown to cause milk fat depression (MFD) in cows, ewes, and goats. Methyl esters of CLA were shown to be as effective as FFA in inducing MFD when infused postruminally, but their efficacy as a feed supplement has not been addressed in studies with lactating ruminants. In the present study, we investigated the effects of an unprotected trans-10, cis-12 CLA supplement as methyl esters on performance, milk composition, and energy status of dairy goats. Eighteen multiparous Toggenburg goats were randomly assigned to dietary treatments in a crossover experimental design (14 d treatment periods separated by a 7 d washout interval): 30 g/d of calcium salts of fatty acids (Control) or 30 g/d of a rumen unprotected CLA supplement containing 29.9% of trans-10, cis-12 CLA as methyl esters (CLA). Lipid supplements were mixed into a concentrate and fed individually to animals 3 times a day as a total mixed ration component. The DMI, milk yield, milk protein and lactose content and secretion, and somatic cell count were unaffected by CLA treatment. On the other hand, milk fat content and yield were reduced by 19.9 and 17.9% in CLA-fed goats. Reduced milk fat yield in CLA-fed goats was a consequence of a lower secretion of both preformed and de novo synthesized fatty acids. The CLA treatment also changed the milk fatty acid profile, which included a reduction in the concentration of SFA (2.5%), increased MUFA and PUFA (5.6 and 5.4%, respectively), and a pronounced increase (1576%) in milk fat trans-10, cis-12 CLA. Consistent with the high milk fat trans-10, cis-12 CLA content, all desaturase indexes were reduced in milk fat from CLA-fed goats. The MFD induced by CLA reduced the energy required for milk production by 22%, which was accompanied by an improvement in the estimated energy balance (P < 0.001), greater blood glucose concentration (P < 0.05), and a trend for increased BW (P = 0.08). Approximately 7.2% of trans-10, cis-12 CLA was estimated to escape from rumen biohydrogenation and indirect comparisons with data obtained from other studies suggest equivalent MFD between dietary CLA in the methyl ester form and rumen protected sources. Thus, despite the apparent low degree of rumen protection, our results suggest that methyl esters of CLA could be an alternative to rumen protected CLA supplements due to manufacturing and cost advantages. SN - 1525-3163 UR - https://www.unboundmedicine.com/medline/citation/23798520/A_rumen_unprotected_conjugated_linoleic_acid_supplement_inhibits_milk_fat_synthesis_and_improves_energy_balance_in_lactating_goats_ L2 - https://academic.oup.com/jas/article-lookup/doi/10.2527/jas.2012-5766 DB - PRIME DP - Unbound Medicine ER -