The Effect of Silage and Concentrate Type on Intake Behavior, Rumen Function, and Milk Production in Dairy Cows in Early and Late Lactation

• Published in: Journal of dairy science 2008-12, Vol.91 (12), p.4778-4792
• Main Authors: Abrahamse, P.A., Vlaeminck, B., Tamminga, S., Dijkstra, J.
• Format: Article
• Language: English
• Subjects: absorption; acetic acid; Animal Feed - analysis; Animal productions; Animals; Biological and medical sciences; cattle; Cattle - metabolism; Cattle - physiology; corn silage; cow feeding; dairy cow; dairy cows; Dairying; dietary carbohydrate; Dietary Carbohydrates - metabolism; diets; drinking; dry matter intake; Eating - physiology; feed concentrates; feed intake; feed intake behavior; feed rations; feeding behavior; Female; Food industries; Fundamental and applied biological sciences. Psychology; Gastrointestinal Contents - chemistry; grass silage; Lactation - physiology; lactation stage; Milk - secretion; Milk and cheese industries. Ice creams; milk composition; milk fat percentage; milk protein percentage; milk yield; neutral detergent fiber; particle size; patterns; perennial ryegrass; propionic acid; Rumen - metabolism; rumen fermentation; rumen fluids; Silage; temporal variation; Terrestrial animal productions; transition period; Vertebrates
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.2008-1350

The objective of this experiment was to evaluate the effect of feeding total mixed rations (TMR) that differ in structural and nonstructural carbohydrates to dairy cows in early and late lactation on short-term feed intake, dry matter intake (DMI), rumen fermentation variables, and milk yield. A 5×5 Latin square experiment with 15 dairy cows was repeated during early and late lactation. The 5 treatments were a TMR with (all on dry matter basis) 55% roughage (a 50:50 mixture of corn silage and grass silage) and 45% concentrate (a 50:50 mixture of concentrate rich in structural carbohydrates and concentrate rich in nonstructural carbohydrates; treatment CON), a TMR with the concentrate mixture and 55% grass silage (RGS) or 55% corn silage (RCS), and a TMR with the roughage mixture and 45% of the concentrate rich in structural carbohydrates (CSC) or the concentrate rich in nonstructural carbohydrates (CNS). Meal criteria, determined using the Gaussian-Gaussian-Weibull method per animal per treatment, showed an interaction between lactation stage and treatment. Feed intake behavior variables were therefore calculated with meal criteria per treatment-lactation stage combination. Differences in feed intake behavior were more pronounced between treatments differing in roughage composition than between treatments differing in concentrate composition, probably related to larger differences in chemical composition and particle size between corn silage and grass silage than between the 2 concentrates. The number of meals was similar between treatments, but eating time was greater in RGS (227 min/d) and lesser in RCS (177 min/d) than the other treatments. Intake rate increased when the amount of grass silage decreased, whereas meal duration decreased simultaneously. These effects were in line with a decreased DMI of the RGS diet vs. the other treatments, probably related to the high neutral detergent fiber (NDF) content. However, this effect was not found in CSC, although NDF content of the TMR, fractional clearance rate of NDF, and fractional degradation rate of NDF was similar between CSC and RGS. Rumen fluid pH was lesser, and molar proportions of acetic acid and of propionic acid were lesser and greater, respectively, in RCS compared with all other diets. Milk production did not differ between treatments. There was no effect of type of concentrate on milk composition, but diet RCS resulted in a lesser milk fat content and greater milk protein content than diet RGS