Masters Theses

Date of Award

5-2018

Degree Type

Thesis

Degree Name

Master of Science

Major

Animal Science

Major Professor

Peter D. Krawczel

Committee Members

Helen A. Baghdoyan, Gina M. Pighetti

Abstract

The objective of the study was to determine the effects of sleep or lying deprivation on the behavior, production, metabolism and immune function of dairy cows. Data were collected from 8 multi- and 4 primi-parous cows (DIM = 199 ± 44 (mean ± SD); days pregnant = 77 ± 30). Each cow experienced: 1) 24 h sleep deprivation implemented by noise or physical contact and 2) 24 h lying deprivation imposed by a wooden grid placed on the pen floor that prevented a recumbent position. An 11-d collection period (from 2 d before the first treatment (trt) to 8 d after trt) was followed by 12-d washout periods. Study days were organized from 2100 to 2059. During habituation (d -2 and -1 before trt), baseline (d 0), and trt (d 1), housing was individual stalls (mattress with no bedding). After trt, cows returned to sand-bedded freestalls for a 7-d recovery period (d 2 to 8). Lying behaviors were recorded by accelerometers attached to the hind leg. Milk yield was recorded 2× daily. NEFA and glucose concentrations were evaluated from serum sampled at 0300, 0900, 1500, and 2100 on d 1 and 2. Data were analyzed using a mixed model in SAS including fixed effects of trt, day, and their interaction with significant main effects separated using a PDIFF statement (P ≤ 0.05). Lying time decreased during trt and increased on the first day of recovery for lying deprivation compared to sleep deprivation (d 1: 1.9 vs. 8.4 ± 0.7 h/d (mean ± pooled SE); P < 0.001; d 2: 16.8 vs. 13.6 ± 0.7 h/d; P = 0.002). Milk yield decreased during lying deprivation compared to sleep (P = 0.002). NEFA and glucose varied by time (P ≤ 0.03). IL-1β and TNF-α were higher during trt, compared to baseline for both treatments (day: P = 0.04 and P = 0.004, respectively). Collectively, this suggests, lack of access to resting resources rather than the relative comfort of that resource, may have greater long-term effects on the welfare of dairy cows.

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