Cattle, other ruminants, and horses require roughage through grazing or provision of hay. In an ideal world, there would always be green fields of grass to graze. More often than not, most producers require hay to provide the necessary roughage and nutrition.
In many parts of Texas, rains have been plentiful this winter and spring, leading to lots of grass, wet pastures and narrow windows to cut, rake and bale. Hay shortages may cause producers to dig deep into lower quality stores of hay. Once pastures and weather forecasts give way to harvesting pastures for hay, the maturity of the plants may lead to further reduced quality. It is recommended to test the nutritive value of the hay each cutting, season, or load.
Knowing the value of the nutrition provided by the hay provides good insight into balancing the diet your livestock needs. Quality of the hay should also be assessed in terms of the health risk that it may bring. Unwanted plants, toxins and molds can impact the value of the hay.
Mature plants have tougher, thicker stems that can cause scrapes and abrasions in the animal's mouth. Incomplete chewing of rougher forages can cause impactions further down the digestive tract. Some aberrant plants in the field such as needle grasses and spearhead grasses may cause severe lacerations in the mouth.
Nitrate toxicity is a common concern of livestock producers. Typically, it is an increased concern when fields are fertilized heavily and when weather conditions don't allow for plant growth to utilize the nitrogen provided. As they say, timing is everything, while plants a growing well with plenty of water, nutrients, and warming conditions, some fields may be at risk, though conditions are good for properly applied fertilizer to utilized well by the plants for growth.
Prussic acid -- also known as cyanide -- poisoning is another common concern, particularly with sorghum type grasses such as Johnsongrass. The recent cool/warm/cool cycle of weather with young plants may pose a risk factor, however, for those plants baled into hay, proper raking and drying should dissipate most of the toxin. As an aside, those grazing pastures at risk of prussic acid poisoning can visit with their veterinarian or local Extension personnel for strategies to utilize the pasture. More cattle benefit from the nutrition available in those pastures than those that are at risk.
Wet conditions during baling predispose the hay to mold growth. Aspergillus is fungus commonly found in rotting vegetation. Wet hay warms inside the bale creating an ideal environment for Aspergillus growth. As cattle eat into the bale, they are exposed to the mold. Affected cattle develop a respiratory syndrome.
Hay, namely alfalfa hay, that is fed to horses should be screened carefully for blister beetles that contain cantharadin, which can cause colic-like symptoms, increased urination, recumbency and death.
Hay conditions may make for challenges for livestock producers. Beyond the nutritive value, being aware of other risks may help keep livestock healthy.
Texas A&M AgriLife Extension photo
Prussic acid poisoning is a common concern, particularly with sorghum type grasses such as Johnsongrass.