title: Short communication: Effects of feeding sweet sorghum silage on milk production of lactating dairy cows.
abstract: The objective of this study was to determine the feeding value of sweet sorghum silage (SS) for dairy cows compared with alfalfa silage (AS). Two diets were formulated with a 50:50 forage:concentrate ratio. Sweet sorghum silage and AS constituted 70% of the forage in each diet (dry matter basis). Twelve lactating Holstein cows in early lactation were used in a crossover experiment. Relative to AS, SS contained 58% more neutral detergent fiber and 36.6 and 72.7% less acid detergent lignin and crude protein, respectively. Milk yield (33.0 vs. 36.7 kg/d) was lower for cows fed SS than for those fed AS. However, dry matter intake, energy-corrected milk, and feed efficiency were similar for both dietary treatments. Replacing AS with SS increased concentrations of milk fat (4.44 vs. 3.80%) and total solids (13.31 vs. 12.88%) and reduced concentrations of milk lactose (4.55 vs. 4.61%), milk solids-not-fat (8.88 vs. 9.08%), and milk urea nitrogen (10.0 vs. 14.0 mg/dL). We concluded that replacing AS with SS had negative effects on milk yield, whereas dry matter intake, energy-corrected milk, and milk efficiency were similar.
authors.affiliation: Department of Animal Science, Macdonald Campus, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada H9X 3V9.
authors.forename: S
authors.initials: S
authors.lastname: Amer
authors.forename: P
authors.initials: P
authors.lastname: Seguin
authors.forename: A F
authors.initials: AF
authors.lastname: Mustafa
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D002417:Cattle; D004032:Diet / Q000662:veterinary; D005260:Female; D007774:Lactation / Q000187:drug effects / Q000502:physiology*; D008892:Milk / Q000378:metabolism; D012820:Silage / Q000032:analysis; D045868:Sorghum / Q000737:chemistry