Abstract #154

# 154
Effects of environmental enrichment on behaviors, growth, and stress in limit fed Holstein heifers.
K. M. Kelly*1, S. H. Ward1, J. H. C. Costa2, G. W. Smith1, A. J. Geiger3, 1North Carolina State University, Raleigh, NC, 2University of Kentucky, Lexington, KY, 3Zinpro Corporation, Eden Prairie, MN.

The objective of this study is to determine if the addition of environmental enrichment will prevent the negative behaviors exhibited by limit-fed heifers. Twenty-four Holstein heifers (161.9 ± 33d of age) were randomly assigned to a split-plot design and housed in 2 sets of 3 pens containing a brush (BR), ball (BA) or no enrichment (NO). Within each pen, 4 Calan gates were used to individually feed heifers with control (CON, n = 2) or limit-fed (LIM, n = 2) diet. LIM heifers were fed 85% of the NRC (2001) DM % recommendation and the CON was fed 100% of NRC (2001) DM% recommendations. Both diets were balanced to provide the same nutritional content. Weekly rumen samples, blood samples, and body measures were taken. Rumination events were recorded every 5 min over 6 h after feeding. Individual heifer behaviors such as feed aggression, feeding, use of enrichment, and social play behavior were recorded for 24 h each week. Lying time was recorded every hour for 6 weeks using an accelerometer. A linear regression in MIXED procedure of SAS was used to analyze the effects of treatment, date, and all 2-way interactions for all models on social play, object interactions, rumination events, and lying time. Pen was included in the random statement. Enrichment or diet did not affect the average daily gain. LIM heifers consumed less (0.68 kg/d DM, P = 0.003). CON heifers with a BR or NO had 4 and 2.8 more rumination events than the LIM in those groups (respectively, P < 0.001). Providing a BA increased social play by 8 min per day (P = 0.01). Heifers, regardless of diet, spent 30 min more using the BR then heifers using the BA (P = 0.03). Treatment did not affect feed aggression or visits to the feed bunk. When the pen was enriched with a BA, LIM heifers laid 72 more mins/day compared with CON (P = 0.01). BR did not affect lying time. Enrichment use in limit fed heifers shows some improvement in lying times and social play.

Key Words: limit feeding, environmental enrichment