Determining Water Consumption Levels

The first essential nutrient for living organisms is water. Whereas an animal can survive for days without food, a lack of water can cause death within a matter of hours. In the case of cattle and sheep, an animal can stay alive for up to 3 weeks without food but can live for two or at most three days if not provided with drinking water. High temperatures, as are often experienced during dry periods, increase stress related to a water shortage.

The data in the table below provides a guideline to water requirements of livestock based on a number of assumptions, including:

• environmental temperatures are not excessively high
• the water provided is relatively clean
• the water is palatable
• animal activity is average
• dry matter intakes (and consequently growth rates) are average.

In the case of cattle, the European breeds have a slightly higher daily water need than indigenous breeds. European cattle will consume 3 kg of water per kg of dry matter consumed at an environmental temperature of 5°C and will drink about 8 kg of water per kg dry matter intake at an ambient temperature of 32°C. With sheep, the voluntary consumption of water is two to three times the intake of dry matter. The daily water intake of sheep can be 12 times greater in summer than in winter. The data in Table 16 should therefore be used as a guide only. Local conditions, including temperatures, wind speed and water quality, could change these figures substantially.

Where livestock are fed concentrates, water is contaminated by feed adhering to the muzzles of the animals. Contaminants enhance the growth of microbes in the water, which reduces the palatability of the water and can lead to diseases. For example, some algae growing in water cause photosensitivity in cattle. It is therefore essential that animals have constant access to clean water ensured by regular cleaning of water troughs. For efficient water utilization, drinking troughs must be correctly designed (See previous learning unit).

It is recommended that water troughs are cleaned at least once every three days, but in the feedlot situation, to encourage feed intake, daily cleaning is warranted. Water should be tested for salt content as the most common reason for the poor palatability of water is a high content of salts.

To ensure that a water shortage does not adversely affect animal performance, livestock must have constant access to water. Drinking troughs must be checked daily and, as a precaution, a backup system is important. With a large water reticulation system, the primary reserve should contain at least 8 days’ supply and the secondary reserve (between the main water reserve and the drinking points) at least a 2-day supply of water. It is useful to keep water carts on standby for emergencies.

Table. Water requirements of livestock, excluding waste, and assuming that the water is clean and palatable.

Feedlots are places where cattle are forced to live in close proximity to each other in an unnatural environment for them. This close proximity of cattle from, often, a range of sources creates ideal circumstances for the spread of sickness and diseases. To lessen the risk of the diseases and sicknesses spreading a thorough and well-designed cleaning programme must be implemented within each feedlot.

Research has also shown that the weight gains of cattle fed spoilt feed decline rapidly. This gives us another reason to make sure that cleaning is done regularly and in a set manner. Clumps of feed leftover in the bunkers are likely to spoil and create conditions that can negatively affect the weight gaining process. Similarly, dirty water can create ideal conditions where diseases can spread and multiply with astonishing speed throughout the entire feedlot.

To determine the collective water consumption of the cattle in a feeding pen or a feed bunker one needs to be firstly aware of how much water was given to the cattle in each pen. Normally water troughs are refilled once a day after cleaning and a feedlot manager should be well aware then of how much water was left in each trough before cleaning and how much water each trough contains.

Many producers overlook the importance of water availability as it relates to bunk management, including the amount of water, space provided, and the location of water sources. Problems that limit water intake also can limit feed intake, and this, in turn, limits overall animal performance. Poor water quality or lack of water can cause cattle to go off feed quickly. Feed callers need to recognise this problem before making any drastic changes in the amount of feed offered. In free-stall barns, 3 inches of linear space per cow and one watering space (or 2 feet of tank perimeter) for each 15 to 20 cows are recommended. A water depth of 6 to 8 inches is suggested to help keep the water fresh and easier to clean because less debris accumulates. As temperature and humidity go up, more water is required. During months of hot weather, water supply becomes an important issue. Adding water tanks for the summer can help in the feedlot.

The following table gives an indication of the amount of water needed per head of cattle per day at different temperatures.

Water requirements for feedlot cattle (Litres/Day)