Influence of water temperature and heat stress on drinking water intake in dairy cows
Grazing animals are exposed to heat stress and there should be conditions to facilitate water intake. Three experiments were carried out to determine the relationship between water intake, water temperature, and heat stress for Holstein pastured dairy cows. Experiment 1: Drinking behavior of 13 cows...
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Published in | Chilean journal of agricultural research Vol. 70; no. 2; pp. 328 - 336 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English Portuguese |
Published |
Chile
Instituto de Investigaciones Agropecuarias, INIA
01.06.2010
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Subjects | |
Online Access | Get full text |
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Summary: | Grazing animals are exposed to heat stress and there should be
conditions to facilitate water intake. Three experiments were carried
out to determine the relationship between water intake, water
temperature, and heat stress for Holstein pastured dairy cows.
Experiment 1: Drinking behavior of 13 cows was evaluated (for 3
consecutive days) and four time periods were established according to
the temperature humidity index (TI-11): (H1:05:00 to 10:59 h, H2: 11:00
to 16:59 h, H3:17:00 to 22:59 h, and H4:23:00 to 04:59 h). The highest
mean percentage of drinking bouts (53.2%) was registered in H2 (THI:
74.91 to 83.95). Drinking bout means among time periods were different
(p < 0.05), thus showing that heat stress conditions influence
drinking behavior. Experiment 2: Three water troughs were placed in the
sun (S) and three under a 2.2 m high structure covered with shade cloth
(MS). Water temperature was registered at 10:00, 13:30, and 17:00 h,
twice a week for 6 weeks. Mean water temperatures at 17:00 h were 33.2
± 1.6ºC (S) and 25.3 ± 1.9ºC (MS) and showed
significant differences (p < 0.05), thus supporting the shade cloth
effect. Experiment 3: Five cows were offered water simultaneously at 18
and 31 ºC (Tl and T2), for 10 min, twice a day for 5 d. There were
no significant differences among treatments (p > 0.05). Recorded
water intake in Tl (18 L) was lower than in T2 (35.9 L), although body
heat dissipation was higher (Tl = 672.64 kJ d -1 , T2 = 620.76 kJ d -1
). |
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ISSN: | 0718-5820 0718-5839 0718-5839 |
DOI: | 10.4067/S0718-58392010000200017 |