title: Effects of supplemental chromium propionate and rumen-protected amino acids on productivity, diet digestibility, and energy balance of peak-lactation dairy cattle.
abstract: Chromium (Cr) feeding in early lactation increased milk production in some studies, but responses to dietary Cr during peak lactation have not been evaluated. Furthermore, interactions of essential amino acids (AA) and Cr have not been explored. Our objective was to evaluate responses to CrPr (KemTRACE chromium propionate 0.04%, Kemin Industries Inc., Des Moines, IA) and rumen-protected Lys (LysiPEARL, Kemin Industries Inc.) and Met (MetiPEARL, Kemin Industries Inc.) and their interaction in peak-lactation cows. Forty-eight individually fed Holstein cows (21 primiparous, 27 multiparous, 38 ± 15 d in milk) were stratified by calving date in 12 blocks and randomly assigned to 1 of 4 treatments within block. Treatments were control, CrPr (8 mg/d of Cr), RPLM (10 g/d of Lys and 5 g/d of Met, intestinally available), or CrPr plus RPLM. Treatments were premixed with ground corn and top-dressed at 200 g/d for 35 d. Diets consisted of corn silage, alfalfa hay, and concentrates, providing approximately 17% crude protein, 31% neutral detergent fiber, and 40% nonfiber carbohydrates. Dry matter intake (DMI) significantly increased with the inclusion of CrPr (22.2 vs. 20.8 ± 0.67 kg/d), and energy-corrected milk (ECM) yield tended to increase. In addition, CrPr increased milk protein yield and tended to increase DMI in primiparous cows but not in multiparous cows. A CrPr×week interaction was detected for milk lactose content, which was increased by CrPr during wk 1 only (4.99 vs. 4.88 ± 0.036%). As a proportion of plasma AA, lysine increased and methionine tended to increase in response to RPLM, but the inclusion of RPLM decreased N efficiency (milk protein N:N intake). Digestible energy intake, gross energy digestibility, and energy balance were not affected by treatments. We observed no treatment effects on feed efficiency or changes in body weight or body condition score. In summary, feeding CrPr increased DMI and tended to increase ECM in cows fed for 5 wk near peak lactation, with primiparous cows showing greater responses in DMI and milk protein yield than multiparous cows.
authors.affiliation: Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506.
authors.forename: C F
authors.initials: CF
authors.lastname: Vargas-Rodriguez
authors.affiliation: Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506.
authors.forename: K
authors.initials: K
authors.lastname: Yuan
authors.affiliation: Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506.
authors.forename: E C
authors.initials: EC
authors.lastname: Titgemeyer
authors.affiliation: Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506.
authors.forename: L K
authors.initials: LK
authors.lastname: Mamedova
authors.affiliation: Kemin Industries, Des Moines, IA 50317.
authors.forename: K E
authors.initials: KE
authors.lastname: Griswold
authors.affiliation: Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506. Electronic address: bbradfor@ksu.edu.
authors.forename: B J
authors.initials: BJ
authors.lastname: Bradford
mesh_terms: D000596:Amino Acids / Q000097:blood; D000818:Animals; D001835:Body Weight; D002417:Cattle; D004032:Diet / Q000662:veterinary*; D004043:Dietary Fiber / Q000008:administration & dosage; D019587:Dietary Supplements; D005260:Female; D007774:Lactation; D007785:Lactose / Q000032:analysis; D008239:Lysine / Q000008:administration & dosage* / Q000097:blood; D008715:Methionine / Q000008:administration & dosage* / Q000097:blood; D008892:Milk / Q000737:chemistry; D008894:Milk Proteins / Q000032:analysis; D011422:Propionates / Q000008:administration & dosage*; D012417:Rumen / Q000187:drug effects* / Q000378:metabolism; D012820:Silage / Q000032:analysis; D003313:Zea mays
chemical_list: D000596:Amino Acids; D004043:Dietary Fiber; D008894:Milk Proteins; D011422:Propionates; D008715:Methionine; D007785:Lactose; C029658:propionic acid; D008239:Lysine
keywords: chromium; essential amino acid; lysine; methionine