title: Short communication: Effects of prepartum diets supplemented with rolled oilseeds on Brix values and fatty acid profile of colostrum.
abstract: The objective of this study was to evaluate effects of oilseeds supplemented in prepartum diets on colostrum quality. Thirty-nine dry pregnant Holstein cows (14 primiparous and 25 multiparous cows) were blocked by body condition score and parity and assigned to 1 of 3 experimental diets containing rolled oilseeds at 8% of dietary dry matter (canola seed or sunflower seed) or no oilseed (control) at 35 d before the expected calving date. Canola seed is high in oleic acid and sunflower seed is high in linoleic acid content. Colostrum samples were collected at the first milking after calving, and concentrations of nutrient composition, fatty acid profile, and Brix value (an indicator IgG concentration) were determined. Cows fed sunflower seeds before calving produced colostrum with greater crude protein content (15.0 vs. 12.9%), colostral Brix values (24.3 vs. 20.3%), and conjugated linoleic acid concentration (18:2 cis-9,trans-11; 0.64 vs. 0.48%) compared with those fed canola seed. Positive effects of feeding sunflower seed might be mediated by ruminal metabolism of linoleic acid and subsequent enhanced production of conjugated linoleic acid. Oilseed supplementation in prepartum diets of dairy cows also altered fatty acid profile of colostrum in a way to reflect fatty acid profile of the supplemented oilseeds except for oleic acid. In conclusion, prepartum feeding of sunflower seed increased colostral Brix value, an indicator of colostral IgG concentration, compared with that of canola seed, but its mode of action and effects on health and productivity of calves need to be investigated.
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Salehi
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada; Livestock Research Branch, Alberta Agriculture and Rural Development, Edmonton, Alberta, T6H 5T6, Canada.
authors.forename: D J
authors.initials: DJ
authors.lastname: Ambrose
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada. Electronic address: moba@ualberta.ca.
authors.forename: M
authors.initials: M
authors.lastname: Oba
mesh_terms: D000818:Animals; D002417:Cattle; D003126:Colostrum; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D005227:Fatty Acids; D005260:Female; D007774:Lactation; D019787:Linoleic Acid; D008892:Milk
chemical_list: D005227:Fatty Acids; D019787:Linoleic Acid
keywords: Brix; canola seed; colostrum; fatty acid profile; sunflower seed