@conference {41686,
	title = {Effects of conjugated linoleic acid on bioenergetics and milk production parameters in grazing dairy cows offered ad libitum or restricted pasture},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {66},
	year = {2006},
	month = {Jan},
	pages = {423-428},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Napier},
	abstract = {Conjugated linoleic acids (CLA) reduce milk fat synthesis in grazing dairy cows and often improve net energy balance (EBAL). Study objectives were to determine if CLA-induced milk fat depression (MFD) could be utilised during times of feed shortage (i.e drought) to improve bioenergetic and milk production parameters. Twelve multiparous mid-lactation rumen-fistulated Holstein cows were offered ad libitum (AL) or restricted (R) pasture and abomasally infused twice daily with 0 (0) or 50 (50) g/d CLA in a cross over design. Treatment periods lasted 10 d and were separated by a 10-d washout period. Milk and plasma samples were averaged from d 9 and 10, and EBAL was calculated from d 6-10, of the infusion periods. Pasture restriction reduced (P<0.05) the yield of milk and milk components. CLA reduced (P<0.01) milk fat yield by 45 and 46 \% in AL and R, respectively. There was no effect of CLA on milk yield nor milk lactose content or yield, however milk protein content increased (P<0.05) in both AL and R, resulting in an increased (P<0.05) protein yield of 6 and 9\% respectively. The CLA-induced changes to milk fat and protein increased (P<0.01) protein:fat ratio by approximately 2-fold in both AL and R. Calculated EBAL improved following CLA infusion (-1.84 vs. 11.22 and 1.59 vs. 13.77 MJ/cow/d for AL and R respectively; P<0.05), however CLA did not alter plasma bioenergetic markers (including insulin, non-esterified fatty acids, {\^a}-hydroxybutyrate, urea and glucose). Data indicate that during short periods of nutrient restriction, CLA may provide an alternative management tool to improve milk protein:fat ratio and calculated EBAL, however further studies are required to determine if CLA is effective at improving bioenergetic parameters during more severe nutrient restriction. },
	issn = {1176-5283},
	author = {Kay JK and Mackle TR and Bauman DE and Thomson NA and Baumgard LH}
}
@conference {41533,
	title = {Regulating milk fat synthesis: potential on-farm applications of basic science},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {65},
	year = {2005},
	month = {Jan},
	pages = {33-39},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {  This review covers results from numerous trials evaluating conjugated linoleic acid (CLA) effects on milk fat  synthesis and its potential as an on-farm management tool to improve dairy cow performance. Supplemental CLA reduces  milk fat synthesis in numerous animal models, and in grazing dairy cows can improve energy balance as well as increase  milk and milk protein yield.  Mammary lipid metabolism effects are thus far specific to  trans-10,  cis-12 CLA, and we  demonstrated trans-10, cis-12 CLA reduces mRNA expression of enzymes required for de novo fatty acid synthesis, fatty  acid uptake and intracellular transport, and triglyceride formation. The amount of CLA required to reduce milk fat synthesis  in lactating cows has little or no effect on circulating basal bioenergetic metabolites and hormones or stimulated responses  to homeostatic signals.  We hypothesized CLA can be utilized to stimulate milk fat depression when milk synthesis and  other physiological processes are limited by energy availability, as is the case in early lactation, during heat stress and  occasionally in pasture based dairying. Our research focuses on identifying the mechanisms of action and potential use of  CLA as an on-farm management tool to increase farm profit via increased milk production, improved reproduction and  decreased metabolic disorders.},
	issn = {1176-5283},
	author = {Baumgard LH and Kay JK and Moore CE and Roche JR and Vanbaale MJ and Rhoads RP}
}
