Watch for Heat Stress in Livestock as Temps Climb
OKLAHOMA – The heat of summer is setting in, and after a cool spring, livestock are not yet fully acclimated to warmer temperatures. In a recent edition of the Oklahoma State University Extension Cow-Calf Corner newsletter, Paul Beck, Extension beef nutrition specialist, said cattle could suffer from heat stress.
“In hot summer conditions, heat transfer failures cause accumulation of body heat resulting in heat stress, reduced performance, animal discomfort or death,” he said. “When animals experience discomfort from heat stress, their behaviors change to reduce heat load.”
These reactive behaviors include increased water consumption, decreased feed intake, seeking shade and standing in water. Beck said water intake per unit of feed intake is twice as high during the summer than in the winter. During heat stress, the linear water space in a body of water or stock tank increases from 1 inch per head to 3 inches per head to allow for sufficient water access.
Cattle alleviate their excess heat load through panting, which is the evaporation of moisture from the respiratory tract. Livestock owners can help animals lower their body temperatures by providing shade, especially for feedlot cattle. Shade relieves and prevents heat stress for cattle in the finishing stage in the following ways:
• Lower respiration rates and body temperatures when external temperatures increase
• Increased average daily gain, hot carcass weights and dressing percentage
• Improved feed efficiency “Providing shade, if designed correctly, is an effective strategy to reduce heat load by lowering heat accumulation from direct solar radiation and has animal welfare benefits that can improve performance,” Beck said.
Effective shade structures include:
• At least 1.8 to 9.6 square yards of space per head of cattle
• Efficient thermal properties of the shade material
• Sturdy ground cover under the shade
• A height of at least 12 feet to reduce direct solar radiation and increase the shelter’s air movement
• Proper ventilation Beck said metal shades effectively block direct solar radiation but can gather heat and radiate it onto the animal. Shade cloth is a better option because it allows more air movement and heat dissipation.
Glenn Selk, OSU Extension cattle specialist, discusses how heat stress in cattle can affect reproductive cycles in a 2019 segment of OSU Agriculture’s SUNUP television show. Watch for a new SUNUP segment on cattle and heat stress this weekend, June 18 and 19, on OETA.
Honey Bees are Famous, but Native Bees are Powerful Pollinators
The world’s fascination with honey bees is linked to a population decline during the past decade that threatens the production of fruit, nut, forage, vegetable and other crops that rely on pollination. The permanent disappearance of pollinators would be detrimental to society.
Researchers at the U.S. Department of Agriculture report not only bees but also wasps, butterflies, other insects and birds are all responsible for pollinating more than 100 crops in the U.S. while contributing to healthy ecosystems of clean air and viable soil. When worker bees abandon their hives due to pests, diseases, pesticides, pollutants, stress and heat, the result is Colony Collapse Disorder.
“Commercial bees that are worth millions of dollars were dying off, and that jumped the public’s awareness of bees in general,” said Andrine Shufran, an Oklahoma State University Extension specialist in entomology and plant pathology and director of the OSU Insect Adventure. “We’re trying to take advantage of that kind of excitement in bees and insects.”
Shufran stressed the differences between honey bees raised for commercial pollination services and honey production and those that live in the wild as native pollinators.
“In the U.S., there are 4,000 different species of native bees; those are the pollinators,” Shufran said. “Then there are non-native species of bees, and those are the European honey bees that don’t pollinate as well as our native pollinators. Keeping European honey bees is not the peaceful pastoral activity it used to be 30 or 40 years ago.”
From chemical and pest problems to mite infestations, beekeeping is hard work that requires hive checks every two weeks. Startup costs involve at least a few hundred dollars.
RNA Research
Students in the Ferguson College of Agriculture as well as the College of Arts and Sciences are studying honey bees and other pollinators. Camila Armas, an animal and food sciences graduate student, began researching them in the lab of assistant professor Darren Hagen.
“I’m focused on the identification of RNA modifications in bees to better understand gene expression between castes, such as pupae, nurses and foragers,” Armas said. “The information that will be generated in my project can be used by other scientists as a reference to continue developing conservation strategies from a genomic approach.”
Bees have impressive genetics, Armas said. All hive members have similar genomes but differ in gene expression due to chemical tags. These tags are important and can influence how the pupae, larvae, queen, nurses, drones and foragers behave and fulfill specific roles in their society.
“For example, when pupae develop into adults, they start as nurses taking care of larvae, and after two to three weeks, they go outside the hive to collect pollen,” she said. “It’s amazing how this behavior and others can be explained by looking at the information stored in DNA and/or RNA.”