Agriculture officials in parched Texas said Wednesday there are no hard numbers on how many head of cattle have died but reports of deaths from too much water or too little are showing up across the nation's leading cattle production state.
"They over drink because they're thirsty," said Dr. Robert Sprowls of the Texas Veterinary Medical Diagnostic Laboratory in Amarillo. "Once they fill up on water it happens pretty quickly."
Producers are losing cattle after moving them from withered pastures where water tanks have dried up. Once in new pastures, cattle that die take in too much water too quickly. The animals die within minutes and their carcasses are found near the stock tanks from which they were drinking, Ted McCollum, a beef cattle specialist with Texas AgriLife Extension Service in Amarillo, said.
Texas is coming off its driest nine-month period ever and its hottest June on record. More than 90 percent of the state is in the two most severe drought stages. The cattle deaths are occurring earlier, in part because of lack of forage growth in pastures.
"We are seeing more incidents of heat stress in cattle," he said. "More incidents of death and problems with health."
As with humans, water intoxication can occur when there's too much water in the body, which disrupts electrolyte balance in cells. Death can occur.
Typically an average cow grazing green forage consumes as much as 8.4 gallons of water a day from it. This year, because drought precluded forage growth and there's been a relatively low intake of dry forage, daily water consumption is around 0.6 gallons.
"The cow's `jug of water' is relatively empty this year and the risk of heat stress and water-elated problems are greater," he said.
In addition to too much water, ranchers also must watch for dehydration in their animals and should regularly check on the quality of water from stock tanks that cattle use.
"They're all interrelated," McCollum said.
Cattle will drink out of tanks where water quality suffers from high concentrations of salt, nitrates and other organic materials, but they're taking in less water because of the mix. Either the animal cannot or will not consume enough water when the water quality drops.
"Water quality can indirectly affect performance and health by reducing water consumption which exacerbates heat stress and can lead to water intoxication once cattle locate or can access palatable water."
Also, hot, sunny days can warm stagnant water and produce blue-green algae blooms, some species of which are toxic. Ingesting the algae or the toxins from them can be fatal. The dead animals are usually found close to the watering site.
The situation isn't likely to improve any time soon. Weather forecasters predict the drought in Texas won't diminish until at least the end of September. Ranchers, many of whom are culling their herds, are either providing supplemental fed to their cattle or taking them to other states to graze.
