title: Short communication: Feeding red clover cut in the afternoon or morning to late-lactation dairy cows.
abstract: Forages cut in the afternoon (p.m.) generally yield a higher concentration of nonstructural carbohydrates (NSC) than those cut in the morning (a.m.). We aimed to compare the effects of p.m.-cut red clover baleage (p.m.-RC) versus a.m.-cut RC baleage (a.m.-RC) on milk yield, concentrations and yields of milk components, and apparent total-tract digestibility of nutrients in late-lactation Holstein cows. Twelve multiparous and 2 primiparous Holstein cows received a total mixed ration containing, on a dry matter (DM) basis, 65% p.m.-RC or a.m.-RC plus 35% concentrate in a crossover design with 14 d for diet adaptation and 7 d for data and sample collection. One RC field was split in 2 with the first half cut in the afternoon (1600 h) and the second half in the following morning (0600 h). The p.m.-RC and a.m.-RC contained (% of DM): 12.6 versus 9.43% NSC in samples collected before the beginning of the experiment and 7.49 versus 7.79% NSC in samples collected during the sampling periods (i.e., d 14 to 21). The total mixed rations averaged 18.2 and 17.5% NSC for the p.m.-RC and a.m.-RC, respectively. Feeding p.m.-RC or a.m.-RC did not improve feed intake or milk yield and composition in late-lactation dairy cows. However, milk urea N and plasma urea N were both lowest in cows offered p.m.-RC. With the exception of the apparent total-tract digestibility of DM, which was highest in cows fed p.m.-RC, no other changes in nutrient digestibility were observed. Similarly, no treatment effect was observed for the urinary excretion of N and purine derivatives. Further research is needed to better understand NSC losses during storage and the associated effects on baleage quality and animal performance.
authors.affiliation: Department of Biological Sciences, University of New Hampshire, Durham 03824.
authors.forename: N T
authors.initials: NT
authors.lastname: Antaya
authors.affiliation: Valacta, Dairy Production Centre of Expertise Quebec-Atlantic, Sainte-Anne-de-Bellevue, QC, Canada H9X 3R4.
authors.forename: R
authors.initials: R
authors.lastname: Berthiaume
authors.affiliation: Agriculture and Agri-Food Canada, Soils and Crops Research and Development Centre, Quebec City, QC, Canada G1V 2J3.
authors.forename: G F
authors.initials: GF
authors.lastname: Tremblay
authors.affiliation: Department of Biological Sciences, University of New Hampshire, Durham 03824. Electronic address: andre.brito@unh.edu.
authors.forename: A F
authors.initials: AF
authors.lastname: Brito
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle / Q000502:physiology*; D003612:Dairying / Q000379:methods*; D004032:Diet / Q000662:veterinary; D004063:Digestion; D005260:Female; D007774:Lactation; D008892:Milk / Q000737:chemistry* / Q000378:metabolism*; D013997:Time Factors
keywords: baleage; dairy cow; diurnal cutting management; red clover