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

This Article 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 Petitclerc, D. Articles by Tucker, H. A. Search for Related Content PubMed PubMed Citation Articles by Petitclerc, D. Articles by Tucker, H. A.

Body Growth, Growth Hormone, Prolactin and Puberty Response to Photoperiod and Plane of Nutrition in Holstein Heifers¹

Michigan State University³, East Lansing 48824

Abstract

Effects of photoperiod and plane of nutrition on growth, serum concentrations of prolactin (PRL) and growth hormone (GH) and puberty were assessed in Holstein heifers. Sixty prepubertal heifers were assigned to one of four treatment groups arranged in a 2 X 2 factorial. The two main effects were photoperiods of 8 h light: 16 h dark (8L:16D)vs 16L:8D, and a low vs high plane of nutrition. Heifers on the low plane of nutrition were fed a diet formulated to achieve a body growth rate of approximately .7 kg/d. Daily feed intake was restricted and similar in both groups of low plane heifers subjected to either 8 or 16 h of light daily. Heifers on the high plane of nutrition were fed ad libitum to achieve a growth rate > 1 kg/d. Body weight was recorded every month for 5 mo. The PRL and GH concentrations were measured at d 9, 5 3 and 132 in serum collected every 30 min for 6 h from five heifers in each treatment group. Progesterone was monitored biweekly in all heifers as an index of puberty (> 1 ng/ml). Heifers subjected to 8L:16D-low plane, 16L: 8D-low plane, 8L:16D-high plane or 16L:8D-high plane gained .61, .72, .98 and 1.08 kg/d, respectively. In the same treatment order, averaging across all bleedings, concentrations of PRL were 32, 37, 38 and 46 ng/ml serum, and GH averaged 10.9, 9.3, 9.8 and 9.0 ng/ml serum. Similarly, body weight at puberty averaged 268, 257, 278 and 268 kg, respectively. Results suggest that 16L:8D stimulates rate of body weight gain, increases feed efficiency, hastens puberty and increases serum PRL regardless of whether heifers are fed moderately restricted or ad libitum planes of nutrition. We conclude that manipulation of photoperiod may be a useful management practice in cattle production.

¹ Michigan Agr. Exp. Sta. Journal Article No. 10789. This research was supported in part by USDA Grant 901-15-2 and 59-2261-0-2-012-0.

² On leave from Lennoxville Res. Sta. Agriculture Canada, Lennoxville, Quebec.

³ Dept. of Anim. Sci.

This article has been cited by other articles:

				P. K. Chelikani, D. J. Ambrose, D. H. Keisler, and J. J. Kennelly Effects of dietary energy and protein density on plasma concentrations of leptin and metabolic hormones in dairy heifers J Dairy Sci, April 1, 2009; 92(4): 1430 - 1441. [Abstract] [Full Text] [PDF]

				V. R. Osborne, N. E. Odongo, A. M. Edwards, and B. W. McBride Effects of Photoperiod and Glucose-Supplemented Drinking Water on the Performance of Dairy Calves J Dairy Sci, November 1, 2007; 90(11): 5199 - 5207. [Abstract] [Full Text] [PDF]

				M. R. Garcia, M. Amstalden, S. W. Williams, R. L. Stanko, C. D. Morrison, D. H. Keisler, S. E. Nizielski, and G. L. Williams Serum leptin and its adipose gene expression during pubertal development, the estrous cycle, and different seasons in cattle J Anim Sci, August 1, 2002; 80(8): 2158 - 2167. [Abstract] [Full Text] [PDF]