El Nino and the Effects on Cattle

February, 2016
James McWhorter, Highlands County Livestock Extension Agent This year being an El Nino year, we are experiencing a wetter than normal year, but I do not believe we thought we would receive this much rain. In January, according to weather.com we received 8.02 inches of rain. Looking back to 2013 and 2014 in Hardee county, rainfall was .5 and 3.8 inches respectively. The predictions for higher than average temperatures have been correct so far. The lowest temperature recorded in Sebring was 37F, but areas of the county have seen some frost. We still have plenty of time to see temperature fall below freezing, but so far we have had a pretty mild winter. The three month forecast from NOAA, issued on January 21st, predicts temperature should fall back to the averages, but rainfall will remain greater than average. If the forecast holds true, we should expect more rain in the coming three months.

Looking at this weather through the eyes of a cattlemen may seem like a blessing and, in some ways, it is. Any winter forages should be doing relatively well unless they are in low lying areas that may be underwater when we experience large amounts of rain in a short time period. However, the other side of the coin is high moisture in pasture forages can lead to reduced dry matter intake. This can cause cattle to lose body scores especially this time of year when our warm season grass have the lowest nutritive value. Feeding hay can make up for this deficient in dry matter intake. It may seem counter-intuitive to feed hay when the pasture looks like it has a lot of forage, but they may not be able to get enough dry matter from the moisture packed forage in the pastures. Standing water around feeders can affect the intake of cattle as well. Not meeting the cow’s nutritional need at this time of the year could lead to lower reproductive rates if your breeding season has started or is about to start.

Pasture weeds may also present a problem with our current weather. Without freeze events and higher rainfall this winter, many pasture weeds like tropical soda apple may become a problem this summer. Without cold weather to suppress weed populations, livestock producers may have to be more aggressive with their weed control programs this year. Many areas of the county still have tropical soda apple germinating in pastures. Getting a head start controlling pasture weeds this year may lead to a lot less work controlling weeds this spring and summer.

The last point I want to briefly point out is fly and external parasites. Warmer temperatures this winter will reduce the winter kill off of flies and external parasites. Early fly control may be appropriate this year to maximize the impact of your fly control program. Controlling the flies and parasites early can reduce their ability to reproduce. If we do continue to have warm temperatures the fly population could be large problem this summer.

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