Current Progressive Dairy digital edition
Advertisement

0706 PD: Water quality for calves

Timothy R. Johnson Published on 07 August 2006

Physiology of the preruminant calf
Water makes up 85.8 percent of the bodyweight (BW) of a neonatal calf. Prior to birth, the developing fetus is surrounded by amniotic fluid that is 92 percent water. In the uterus, the developing calf is supplied with water by diffusion from maternal plasma, and at birth the calf is at its greatest water content, having developed in a water-based media where water has borne the nutrients required to allow rapid growth and development.

The uterus supplies an environment where water-containing fluids shelter the fetus, mitigating the effects of jolting and gravity on the developing fetus. Upon birth, the mammal is suddenly exposed to light, temperature extremes and wind, beginning the processes of drying and dependence on water contained in milk and the intake of free water by the calf.

advertisement

advertisement

While milk is the primary source of water for the calf, consumption of additional free water is required to support optimal growth and health in the bovine. Feeding supplemental water to preweaned calves is of particular importance to encourage consumption of dry feed.

Kertz et al. demonstrated that when supplemental water was not provided, this resulted in a 31 percent decrease in dry matter (DM) intake and a 38 percent reduction in weight gain. For each extra liter of water consumed, there was a corresponding increase of 82 grams per day of dry feed intake and an increase in weight gain of 56 grams per day. These data powerfully emphasize the importance of providing access to supplemental water of high quality for young calves from a very early age.

Mineral content in water
Mineral content of well water has been shown to be variable across and within regions of the United States. A database of more than 5000 water samples from rural areas across the United States has been developed by Zinpro Corporation (Eden Prairie, Minnesota), with assistance from Agri-King, Dairy One (Ithaca, New York) and Dairyland Laboratories, Inc. (Arcadia, Wisconsin). The most basic measure in this database is that of total dissolved solids (TDS). This, in addition to total soluble salts (TSS) and pH, is the initial consideration in determining the suitability of drinking water for calves.

Water hardness is a physiochemical property of water based primarily on calcium, magnesium and iron concentrations. Water turbidity, partially dissolved solids, acid-base balance and mineral content are all factors that may affect water acceptance, palatability and final intake of free water. Minerals of particular concern when in high concentrations are cobalt, copper, iron, hydrogen sulfide, manganese and sulfur.

The form in which sulfur is present depends on water pH and the concentrations of anions and cations present in the water. Hydrogen sulfide, which is the rotten egg odor that some water contains, is volatile, and no accurate measure of it can be made without special equipment that allows a sample to be taken without exposure to air prior to determination. Hydrogen sulfide has been shown to decrease water palatability, acceptance and intake in adult cattle, but in my reading, I was not able to find a specific reference to the effects of hydrogen sulfide concentration on free water intake of preweaned calves. On the other hand, total sulfur in water of less than 500 milligrams per liter has been recommended for calves from research.

advertisement

High but still safe concentrations and maximum tolerable concentrations of minerals for dairy cattle are shown in Table 1*. These values are based on nutrient recommendations made by the National Research Council (NRC) and from several other sources.

Mineral interactions and associated metabolic problems
Elemental copper interacts with manganese and several other elements. Acid-base balance and the anion-to-cation ratio influence the magnitude of these interactions. In the state of New York, the influence of elevated magnesium in veal calf diets was investigated by supplementing veal milk replacer with magnesium oxide to mimic problems seen in the field with calves developing kidney stones when fed milk replacers reconstituted with water containing high levels of magnesium. Four diets were fed containing 0.1, 0.3 or 0.6 percent magnesium and the fourth diet, 0.6 percent magnesium plus 2 percent sodium chloride.

The 0.6 percent concentration of magnesium supplementation resulted in 70 percent of the calves developing renal calculi (kidney stones). Addition of 2 percent sodium chloride to the 0.6 percent magnesium replacer diet, over the 112-day feeding period, reduced presence of kidney stones to 30 percent, as determined by autopsy after euthanasia. Increased free water intake prompted by the addition of sodium chloride was suggested to have been the causative factor in reducing stone formation.

Iodine is used as a disinfectant for dairy equipment, as an ingredient in teat dips, and as a compound to allow sterilization of the umbilical cord of calves. Jenkins and Hidirglou investigated the effect of adding 0.57, 10, 50, 100 or 200 parts per million (ppm) iodine to calf milk replacer from 3 to 38 days of age. This study revealed typical signs of iodine toxicity at 100 and 200 ppm of iodine, including nasal discharge, excessive tear formation and saliva production.

While digestibility of milk protein was reduced only at the two highest doses of iodine, even 50 ppm of supplemental iodine resulted in greater iodine in blood plasma, bile and nonthyroid tissues after a five-week feeding period. This led researchers to set 10 ppm of iodine as the practical limit, as is reflected in the NRC (2001).

Milk replacer diets fed to rapidly-growing veal calves are a good example. The NRC (2001) states the copper requirement for calves is 0.2 ppm; however, practical water and replacer diets for rapidly-growing veal calves are often limited to 0.05 ppm copper because of clinical copper toxicity problems which occur when the water and replacer mixture contain greater copper concentrations.

advertisement

The solubility of minerals and microminerals in the calf digestive system is important for absorbability. An example is the element aluminum. Experimentally, aluminum chloride added to calf diets, even at low levels, has been shown to decrease dry matter intake (DMI), weight gain, bone ash weight and bone phosphorus composition. In addition, these authors mentioned soil aluminum content and ingestion of aluminum containing soils by grazing ruminants in New Zealand has been shown to reduce phosphorus digestibility.

However, the practical importance of this toxicity or mineral interaction in the United States is unknown. Solubility of the aluminum fraction is so poor that little practical problem with aluminum toxicity is seen.

Temperature
The influence of milk or supplemental water temperature on health and performance of dairy calves has been reviewed by Davis and Drackley. Veal calves fed cold milk replacer without restraints or limits decreased intake of milk as compared to veal calves fed replacer at room temperature. In several studies with female dairy calves, restricted amounts of replacer and dry calf starter were fed; calves fed the cold milk replacer exhibited similar performance to calves fed warm replacer.

Seasonal dairy producers often practice mob feeding of grouped dairy calves. Nipples of hardened rubber are put midway on the outside of 55-gallon drums, and tubes to the nipples are kept at the bottom of the barrel to increase suckling activity and saliva production by the calf.

Nipple barrel calf feeding systems work best if calves are fed milk or replacer twice each day. Using this system, milk is usually consumed in 20 to 30 minutes; after the milk is consumed, water is fed by placing about 20 gallons of fresh water in the drum. This allows partial drum cleaning and gives the calves access to free water which, as in more traditional calf feeding systems, provides the calves extra water that promotes maximum DM intake and growth. Data from many feeding systems have shown an extremely strong positive correlation between intake of water and intake of DM from replacers and from supplemental concentrates and forages.

Organic contaminants
Presence of E. coli, coliform and total bacteria, as well as presence of organic toxicants, in water on Ohio dairy farms was reviewed by Mancl and Eastridge. In addition, the presences of bacteria (E. coli, coliform and salmonella), as well as protozoal and fungal contaminants, have undergone an extensive survey on dairy operations in the Pacific Northwest.

The most readily available source for testing of fecal coliform bacteria is measurement by local health departments. Fecal coliform levels are reported in colony forming units (CFU) per milliliter. Bacterial numbers are reported on a log 10 scale per milliliter of the liquid sample. It should be noted this number only predicts the present number of microbial CFU and ignores potential growth under different environments and temperatures. It is possible that even low levels of coliform, E. coli or salmonella bacteria (less than 10 CFU per milliliter) can quickly and exponentially increase to dangerous levels.

Organic contaminants also include nonliving organic compounds, such as pesticides, fuel tank discharge, paints, sealants and other contaminates. Several commercial laboratories offer analytical services to test for some of these contaminants through high-pressure liquid chromatography (HPLC), gas liquid chromatography (GLC) and liquid chromatography (LC).

Some rarely encountered contaminants, such as organophosphates, may require testing by highly specialized laboratories. Dr. Jeffery Pyle and his associates with North Manchester Veterinary Clinic work with some small and several very large veal growers in northern Indiana. Veal producers have a great sensitivity to water quality problems. The preferred sources for mixing milk replacer on small operations is water treatment by long-term storage of chlorinated water in raised tanks. Frequent sampling is performed to confirm complete bacterial kill.

On very large commercial veal operations, operators often take mineral content of well water out of the picture by using distilled water and by the use of citric acid to reduce pH of water to near neutral (pH 7.0). Nearly neutral pH is preferred on veal operations because coagulation of casein (milk clot) in the abomasums of calves can be limited if water pH and buffering capacity is not modified.

On these veal operations, distilled water is often used to closely control mineral concentrations, particularly of iron and copper. Iron concentrations in water and replacer are limited for two reasons. First, because salmonella bacteria thrive in water with a high iron content; and, second, there is need to produce the pale coloration and meat quality for a traditional veal product. Veal calves receive needed iron by injection rather than by an oral route.

The potential for explosion of coliform bacteria in milk replacer has prompted many veal growers to further treat previously chlorinated water with an in-line supply of ultraviolet radiation to reach the goal of zero CFU of bacteria in the final replacer delivered to calves.

While the lengths taken to control inorganic and organic components in water used on veal operations may seem too costly and time-consuming for use with dairy calves, lessons can be learned and new ways of controlling water quality for calves can be implemented by learning from veal growers who are striving to bring healthy calves from about 100 pounds of initial bodyweight to a well-finished 550 pounds of final bodyweight in less than 19 weeks (133 days).

Take-home messages
•Ensure consistently having clean, fresh water readily available for calves

•Suggest that producers supply [nutritionists] with current water test information which includes TDS, pH, mineral and micromineral concentrations and information on presence, CFU per milliliter and speciation of bacteria.

•Know the least expensive and most efficient methods available to modify mineral and microbial concentration of water fed to calves. PD

References omitted due to space but are available upon request.

*Table omitted but is available upon request to

—From 2005 Tri-State Dairy Nutrition Conference Proceedings

Timothy R. Johnson, Department of Animal Sciences, Purdue University

LATEST BLOG

LATEST NEWS