HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Reed, J. J. Articles by Caton, J. S. Search for Related Content PubMed PubMed Citation Articles by Reed, J. J. Articles by Caton, J. S.

Effect of creep feed supplementation and season on intake, microbial protein synthesis and efficiency, ruminal fermentation, digestion, and performance in nursing calves grazing native range in southeastern North Dakota¹

Department of Animal and Range Sciences, North Dakota State University, Fargo 58105

² Corresponding author: joel.caton{at}ndsu.edu

Nine ruminally and duodenally cannulated (172 ± 23 kg of initial BW; Exp. 1) and 16 intact (153 ± 28 kg of initial BW; Exp. 2) crossbred nursing steer calves were used to evaluate the effects of creep feed supplementation and advancing season on intake, digestion, microbial efficiency, ruminal fermentation, and performance while grazing native rangeland. Treatments in both experiments were no supplement or supplement fed at 0.45% of BW (DM basis) daily. Supplement consisted of 55% wheat middlings, 38.67% soyhulls, 5% molasses, and 1.33% limestone. Three 15-d collection periods occurred in June, July, and August. In Exp. 1, ruminal evacuations were performed and masticate samples were collected for diet quality analysis on d 1. Duodenal and fecal samples were collected from cannulated calves on d 7 to 12 at 0, 4, 8, and 12 h after supplementation. Ruminal fluid was drawn on d 9 and used as the inoculate for in vitro digestibility. On d 11, ruminal fluid was collected, and the pH was recorded at –1, 1, 2, 4, 8, 12, and 24 h postsupplementation. In Exp. 1 and 2, milk intake was estimated using weigh-suckle-weigh on d 15. Steers in Exp. 2 were fitted with fecal bags on d 6 to 11 to estimate forage intake. In Exp. 1, supplementation had no effect (P = 0.22 to 0.99) on grazed diet or milk composition. Apparent total tract OM disappearance increased (P = 0.03), and apparent total tract N disappearance tended (P = 0.11) to increase in supplemented calves. Microbial efficiency was not affected (P = 0.50) by supplementation. There were no differences in ruminal pH (P = 0.40) or total VFA concentration (P = 0.21) between treatments, whereas ruminal NH₃ concentration increased (P = 0.03) in supplemented compared with control calves. In Exp. 2, supplementation decreased (P = 0.02) forage OM intake (OMI; % of BW) and increased (P = 0.06) total OMI (% of BW). Supplementation had no effect on ADG (P = 0.94) or G:F (P = 0.35). Supplementation with a wheat middlings and soybean hull-based creep feed reduced forage OMI but improved total tract OM and N digestion and had minimal effects on ruminal fermentation or performance. Supplementation with a wheat middlings and soybean hulls-based creep feed might improve OM and N digestion, but might not produce significantly greater BW gains compared with no supplementation.

Key Words: calf • creep feed • digestibility • forage • intake • supplementation

This article has been cited by other articles:

				S. F. Liao, E. S. Vanzant, J. A. Boling, and J. C. Matthews Identification and expression pattern of cationic amino acid transporter-1 mRNA in small intestinal epithelia of Angus steers at four production stages J Anim Sci, March 1, 2008; 86(3): 620 - 631. [Abstract] [Full Text] [PDF]

				J. C. Marini, D. G. Fox, and M. R. Murphy Nitrogen transactions along the gastrointestinal tract of cattle: A meta-analytical approach J Anim Sci, March 1, 2008; 86(3): 660 - 679. [Abstract] [Full Text] [PDF]