Responses of Lactating Holstein Cows to Chilled Drinking Water in High Ambient Temperatures D. L. WILKS, C. E. COPPOCK, J. K. LANHAM, K. N. BROOKS, C. C. BAKER, and W. L. BRYSON Department of Animal SCience R, G. ELMORE Department of Large Animal Medicine and Surgery
R. A. STERMER USDA-ARS Texas A&M University College Station 77843 ABSTRACT
In Experiment 1. 12 lactating Holstein cows were provided drinking water of either 10.6 or 27.0·C for 24 hid in a changeover design to examine the effects of water temperature on feed intake, water intake, respiration rate, rectal temperature, plasma thyroid hormone concentration, and milk yield. The 1st wk of each 3-wk treatment period was for adjustment and the next 2 wk were comparison periods. Least squares means for DM intake as a percentage of body weight were 3.68 and 3.57 for 10.6 and 27.0·C treatment groups. Water intakes in liters per kilogram of dry feed consumed as a percentage of body weight were 21.3 and 20.3. Respiration rates were 70.5 and 81.0 breaths per minute; rectal temperatures were 39.7 and 39.9·C, Triiodothyronine averaged .88 and .75 ng/ml; thyroxine, 42.4 and 39.2 nglml; cortisol, 3.03 and 2.06 ng/m}; and progesterone in milk, 4.58 and 3.15 ng/ml for the 10.6 and 27.0"C treatment groups. Milk yield averaged 25.9 and 24.7 kg/d and FCM averaged 25.6 and 23.6 kg/---.--..---'-ewere identical and contained similar amounts of I~ ~ 25 \Min. Temp water-one with lO'C water, the other with wa15 ter of about 30"C. The two containers were 9/2 9/9 placed side by side in place of the feed manger. 8126 7/22 8/12 8/19 7129 8/5 4 Std. 5 Adj. I 6 2 3 The amounts offered exceeded the amount drunk in all cases. The positions of the two Figure 1. Weekly averages of daily ambient temperacontainers (right side vs. left side) were rotated twes and of relative humidities. Journal of Dairy Science VoL 73,
No.4, 1990
1094
WILKS ET AL.
TABLE 1. Chemical composition of drinking water. J ,2 Composition Cations Calcium Magnesium Potassium Sodium Total cations
3.6 1.0
3.0 208.3 215.9
Anions Carbonate Bi-carbonate Sulfate Chloride Total anions
59.8 462.1 16.6
60.7 599.2 815.1 8.9
Total solids
pH
tWater was from the Texas A&M University water system. 2Average of three samples.
cows consumed less chilled water than ambient water (2, 5, 6, 10, 12, 15). The amount of heat absorbed per cow per day from the chilled and ambient water was 2153.31 and 898.27 kcal. This value was calculated by taking the difference between body temperature and drinking water temperature and multiplying it by the average liters of water consumed by each group. Chilled drinking water absorbs more kilocalories of heat than ambient water, but there is an additional cooling effect for the treatment cows in this experiment, because they consumed more of the chilled water than the ambient water. This agrees with previous ex-
periments with cattle (2, 11) in which a greater amount of heat was absorbed by chilled water even though less was consumed. Cattle with chilled drinking water ate more (P
R. A. STERMER USDA-ARS Texas A&M University College Station 77843 ABSTRACT
In Experiment 1. 12 lactating Holstein cows were provided drinking water of either 10.6 or 27.0·C for 24 hid in a changeover design to examine the effects of water temperature on feed intake, water intake, respiration rate, rectal temperature, plasma thyroid hormone concentration, and milk yield. The 1st wk of each 3-wk treatment period was for adjustment and the next 2 wk were comparison periods. Least squares means for DM intake as a percentage of body weight were 3.68 and 3.57 for 10.6 and 27.0·C treatment groups. Water intakes in liters per kilogram of dry feed consumed as a percentage of body weight were 21.3 and 20.3. Respiration rates were 70.5 and 81.0 breaths per minute; rectal temperatures were 39.7 and 39.9·C, Triiodothyronine averaged .88 and .75 ng/ml; thyroxine, 42.4 and 39.2 nglml; cortisol, 3.03 and 2.06 ng/m}; and progesterone in milk, 4.58 and 3.15 ng/ml for the 10.6 and 27.0"C treatment groups. Milk yield averaged 25.9 and 24.7 kg/d and FCM averaged 25.6 and 23.6 kg/---.--..---'-ewere identical and contained similar amounts of I~ ~ 25 \Min. Temp water-one with lO'C water, the other with wa15 ter of about 30"C. The two containers were 9/2 9/9 placed side by side in place of the feed manger. 8126 7/22 8/12 8/19 7129 8/5 4 Std. 5 Adj. I 6 2 3 The amounts offered exceeded the amount drunk in all cases. The positions of the two Figure 1. Weekly averages of daily ambient temperacontainers (right side vs. left side) were rotated twes and of relative humidities. Journal of Dairy Science VoL 73,
No.4, 1990
1094
WILKS ET AL.
TABLE 1. Chemical composition of drinking water. J ,2 Composition Cations Calcium Magnesium Potassium Sodium Total cations
3.6 1.0
3.0 208.3 215.9
Anions Carbonate Bi-carbonate Sulfate Chloride Total anions
59.8 462.1 16.6
60.7 599.2 815.1 8.9
Total solids
pH
tWater was from the Texas A&M University water system. 2Average of three samples.
cows consumed less chilled water than ambient water (2, 5, 6, 10, 12, 15). The amount of heat absorbed per cow per day from the chilled and ambient water was 2153.31 and 898.27 kcal. This value was calculated by taking the difference between body temperature and drinking water temperature and multiplying it by the average liters of water consumed by each group. Chilled drinking water absorbs more kilocalories of heat than ambient water, but there is an additional cooling effect for the treatment cows in this experiment, because they consumed more of the chilled water than the ambient water. This agrees with previous ex-
periments with cattle (2, 11) in which a greater amount of heat was absorbed by chilled water even though less was consumed. Cattle with chilled drinking water ate more (P
