Abstract #M32

# M32
Effect of calf hutch type on calf performance and calf hutch temperature humidity index.
Kimberly J. Reuscher*1, Barbara W. Jones1,2, Ellen R. Jordan3, 1Tarleton State University, Stephenville, TX, 2Texas A&M AgriLife Research, Stephenville, TX, 3Texas A&M AgriLife Extension, Dallas, TX.

The objective of this study, conducted at a heifer grower operation in the Texas panhandle from July 10 to October 12, 2017, was to evaluate 4 different calf hutch designs to determine if differences exist in calf performance. Female Holstein calves (n = 120) sourced from 3 different operations were housed in 4 types of Calf-Tel polyethylene hutches (Hampel Corp., Germantown, WI). Eleven calves initially enrolled were removed due to low IgG absorption levels or death. Hutch A (n = 31) had vents on the top of the rear wall. Hutch B (n = 27) had an adjustable rear ventilation door. Hutch C (n = 25) was similar to Hutch B but had 2 added circular vents on the rear wall of the hutch. Hutch D (n = 26) was the same design as Hutch A but was elevated 15.24 cm in the rear by a custom lift. A HOBO external data logger (Onset, Bourne, MA) was placed inside one of each hutch type as well as one placed at calf level outside to record ambient temperature and relative humidity every 10 min. Average calf weight entering hutches was 31.31 ± 2.65 kg and average weight leaving hutches was 96.14 ± 9.20 kg. The MIXED procedure of SAS (Cary, NC) was used to evaluate fixed effects of hutch type, farm origin, and initial calf weight and their 2-way interactions on weight gain. The GLM procedure in SAS was used to evaluate the fixed effect of hutch type on THI. Stepwise backward elimination was used to remove non-significant interactions (P ≥ 0.05). All main effects were kept in the model regardless of significance. No significant differences (P ≥ 0.05) existed for weight gain between hutches A, B, C, and D (60.32 ± 1.76, 59.93 ± 1.93, 57.09 ± 1.95, and 57.31 ± 1.98 kg, respectively). No significant differences (P ≥ 0.05) existed for weight gain between farm 1, 2, and 3 (59.69 ± 1.39, 58.28 ± 2.79, and 58.01 ± 1.28 kg, respectively). When outside temperature humidity index (THI) was above 77, the THI was significantly different (P < 0.05) between hutches A, B, C, and D (80.38 ± 0.06, 78.78 ± 0.09, 79.21 ± 0.06, 78.33 ± 0.07, respectively). Results indicate no differences in calf weight gain when housed in different calf hutches.

Key Words: heat stress, hutch, calf