title: Performance, metabolic, and endocrine responses of periparturient Holstein cows fed 3 sources of fat.
abstract: The objective of this study was to examine the effect of feeding diets containing fat supplements enriched in either saturated fatty acids (n = 10), Ca salts of trans-octadecenoic fatty acids (tFA, n = 10) or Ca salts of safflower oil fatty acids (SFL, high in linoleic acid, n = 9) on performance, metabolic, and endocrine responses of periparturient Holstein cows. Dietary treatments were initiated at approximately 28 d before calculated calving dates and continued through 49 d postpartum. Blood samples for metabolite and hormone analyses were collected weekly beginning 1 wk before estimated calving date through 7 wk postpartum. Incorporation of tFA or SFL into the peripartum diet had no detectable effects on body weight or body condition score. Cows fed the SFL-enriched diet produced less milk fat and established a positive energy balance sooner after calving than those fed the tFA supplement. Analysis for individual fatty acids resulted in increased concentrations of trans 18:1 fatty acid and conjugated linoleic acid isomers in milk fat from cows supplemented with SFL. Across weeks, the average nonesterified fatty acids concentration in plasma was lower in cows fed the SFL-enriched diet than in those consuming the tFA-supplemented diet. Mean concentrations of plasma glucose, insulin-like growth factor-I, and progesterone were greater in cows fed the SFL-enriched diet compared with those fed the saturated fatty acid-supplemented diet. Feeding fat supplements that can suppress milk fat production during the early postpartum period may help minimize negative energy balance, reduce adipose tissue mobilization, and improve circulating concentrations of insulin-like growth factor-I and progesterone. Whether the SFL supplement would have similar effects without a decrease in milk fat production remains to be determined and warrants further investigation.
authors.affiliation: Department of Dairy Science, Virginia Tech, Blacksburg, VA 24061, USA.
authors.forename: C
authors.initials: C
authors.lastname: Caldari-Torres
authors.forename: A L
authors.initials: AL
authors.lastname: Lock
authors.forename: C R
authors.initials: CR
authors.lastname: Staples
authors.forename: L
authors.initials: L
authors.lastname: Badinga
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001786:Blood Glucose; D002118:Calcium / Q000737:chemistry; D002417:Cattle / Q000097:blood / Q000502:physiology*; D004032:Diet / Q000662:veterinary*; D004041:Dietary Fats / Q000032:analysis; D019587:Dietary Supplements; D004734:Energy Metabolism / Q000502:physiology; D005227:Fatty Acids / Q000008:administration & dosage*; D005260:Female; D007774:Lactation / Q000502:physiology; D008892:Milk / Q000737:chemistry; D009829:Oleic Acids / Q000008:administration & dosage*; D058725:Peripartum Period; D011374:Progesterone / Q000097:blood; D012450:Safflower Oil / Q000008:administration & dosage*; D012492:Salts; D013002:Somatomedins / Q000032:analysis
chemical_list: D001786:Blood Glucose; D004041:Dietary Fats; D005227:Fatty Acids; D009829:Oleic Acids; D012492:Salts; D013002:Somatomedins; D011374:Progesterone; D012450:Safflower Oil; D002118:Calcium