Effect of Environment on Nutrient Requirements of Domestic Animals (1981) / Chapter Skim
Currently Skimming:
WATER-ENVIRONMENT INTERACTIONS
WATER-ENVIRONMENT INTERACTIONS
Pages 39-50
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 39... ...
Most estimates of water needs are based on free water consumed under ad libitum offerings. WATER SOURCES The water needs of livestock are filled from three major sources: (1)
|
From page 40... ...
The ability to reabsorb water in the lower gut and excrete drier fecal pellets instead of wet, loose feces is presumably one mechanism of water conservation. Water loss from the respiratory tract is extremely variable, depending on relative humidity and respiration rate.
|
From page 41... ...
10 1.70 6.55 0.166 0.251 0.417 20 1.66 5.09 0.201 0.277 0.478 30 1.69 4.43 0.323 0.482 0.805 35 1.67 5.27 0.597 1.561 2.158 40 1.65 5.33 0.995 3.443 4.438 a Adapted from van Kampen, 1974. FACTORS AFFECTING WATER INTAKE There are numerous factors that influence the intake of free water, such as animal species, physiological condition of the animal, level of dry matter intake, physical form of the diet, water availability, quality of water, temperature of the water offered, and ambient temperature.
|
From page 42... ...
When corrected for water content of milk, lactating ewes consume 100 to 164 percent more water than dry ewes (Forbes, 1968~. Weanling pigs will consume approximately 20 kg water daily per 100 kg of body weight, but those near market weight much less, 7 kg/100 kg of FIGURE 13.
|
From page 43... ...
However, at 31°C maximum daily temperature there was no effect of cooling the water for finishing cattle (Harris et al., 1967~. When heated water TABLE 6 The Effect of Water Availability on Water Consumption by Lactating Grazing COWS Treatment Water Consumed (kg)
|
From page 44... ...
Under two ambient temperatures, 3°C and 12°C, water temperatures of 1, 14, 27, and 39°C did not have a detectable effect on digestion of Holstein cows even though ingestion of 21 kg of water at 1°C depressed lower, middle, and upper rumen temperatures by 13, 6, and 1°C within 10 min (Cunningham et al., 19641. Air Temperature The concept that water intake of livestock is related to air temperature is well recognized.
|
From page 45... ...
For average daily temperatures around 8°C in Britain, water intake of lactating cows was significantly correlated with daily milk yield and dry matter content of the forage but was not significantly related to either air temperature or relative humidity. Average intake was 3.70 kg/kg DM consumed after adjustment for water in the milk (Castle and Macdaid, 19751.
|
From page 46... ...
When maximum daily temperature exceeds 30°C, free water intake tends to rise more rapidly than from 25 to 30°C, but variation among individuals increases markedly. It is, therefore, difficult to characterize water needs because of confounding with changes in animal behavior and the possibility that animals may use high water intake to maintain a sensation of fill that may result in lowered feed intake (McDowell, 19724.
|
From page 47... ...
Up to approximately 38°C daily maximum temperature, water intake appears positively related to temperature, but at 40°C or higher, water intake may decline or rise rapidly, as in Figure 15 for cattle (Daws and Squires, 19741. When temperature declines to-12°C, the temperature of the rumen, rectum, and subcutaneous tissues decreases, resulting in a decline of about 50 percent in water intake from the 15°C level (Bailey et al., 19624.
|
From page 48... ...
It has also been suggested that type of body covering may influence water needs with hair sheep having the least need, followed by coarse wool sheep and fine wool sheep (Hafez, 1968~. Swine Experiments under controlled temperature conditions have shown an inconsistent relation between ambient temperature and water intake.
|
From page 49... ...
Thus, rising ambient temperatures increase the need for water. Water is lost from poultry as a fluid (excretory water loss through urinary and digestive systems or as a vapor (respiratory water loss)
|
From page 50... ...
Most likely, the quick rise in water consumption at high temperature is used by animals as a stopgap measure to maintain heat balance until physiological processes can adjust to the new environment. No doubt ingested water is used as a heat sink in the rumen and may also be used by animals under acute thermal stress to replace feed at least on a temporary basis.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.