Georgia Farm Bureau News - August 2016

Page 10

Lab of thousands of samples

By Jay Stone __________________________________________________________________________


he hay submitted in Georgia Farm Bureau’s annual Quality Hay Contest will take on many forms between the field and the results being announced. Once it leaves the farm, it comes under the watchful eye of Dr. Uttam Saha, program coordinator of the University of Georgia’s Feed and Environmental Water Laboratory (FEW), which focuses on nutrition for animals. The FEW lab is one of three labs in UGA’s Agricultural & Environmental Sciences Laboratories. The others are a soil, plant and water lab, and a crops and environmental quality lab. Saha and his team have analyzed tens of thousands of forage and animal feed samples including the GFB Hay Contest samples, samples for similar contests, for-

Details for entering the GFB Quality Hay Contest are on page 14. age samples producers send in themselves and pet food submitted by pet owners. “The model we are using now has been developed over many years,” Saha said. “Initially we had some issues to solve and we moved forward. It is now in a stage that we are very confident in what we’re getting.” Hay producers know they can submit a sample in a plastic bag, and they get back an 10 / August 2016

RFQ number for that sample. RFQ stands for “relative forage quality,” a one-number measure of whether livestock will eat a certain forage material and if they do, how well it will meet their nutritional needs. Saha puts that sample through a rigorous set of steps. It arrives at FEW in Athens as everything from straw to seeds. At the lab, it is ground into powder with particles no more than 1 millimeter in thickness, then packed into a cell with quartz-glass sides. The quartz ensures there is no light interference with the sample, which, once packed into the cell, is inserted into a nearinfrared spectrophotometer, an instrument that sends light to the cell and measures reflected light from the particles. The wavelengths of the reflected light return as different colors, and these colors correspond to specific chemical bonds. Each scan produces more than 100,000 data points, which is automatically fed into a computer compiled into a visual chart. The GFB Hay Contest always has great prizes, but the report detailing the nutritional quality of their hay is the product hay producers pay for with their $20 contest entry fee. From the report, they know how much dry matter (which indicates palatability for livestock), as well as food protein, acids, non-starch carbohydrates and nonfibrous carbohydrates (all measures of digestibility) were in their sample.

Photo by Jay Stone

Photo by Jay Stone

UGA Feed & Environmental Water Lab Program Coordinator Dr. Uttam Saha holds a raw hay sample and a cell containing hay that has been ground into 1 millimeter particles.

The dry matter is added to the digestibility number to reach the RFQ score. UGA Extension Forage Specialist Dr. Dennis Hancock said the average RFQ in Georgia is 95. By way of comparison, Hancock said the target RFQ is 140 or more for dairy cows, 120-125 for stocker cattle, 115 or more for cows producing milk and 100 or more for cows no longer producing milk. “We can take a lower number and feed it as long as we’re mixing it with something else to bring up that nutrition,” Hancock said. “As a rule of thumb we want it to be 100 or better so we minimize the amount we have to supplement.” Supplemental feed like corn or soybean meal means increased costs. Hancock said hay might cost as low as six cents per pound, while corn is about seven cents per pound and soybean meal around 20 cents per pound. A single cow needs more than 20 pounds of feed per day, and those costs escalate quickly when multiplied by dozens or hundreds of cows. The testing also measures elements that could be harmful to livestock if ingested in sufficient quantities. Of particular concern is nitrate levels, which can result in animal death. In the GFB contest, samples with nitrate levels more than 4,500 parts per million are disqualified. If that number surpasses 5,000, Saha contacts the producer who submitted it. “There is risk associated with that, and they need to know as soon as possible,” Saha said. If that step saves the producer several cows, the $20 lab fee pays for itself many times over.

The cell containing the ground sample goes into the near-infrared spectrophotometer for analysis. Georgia Farm Bureau News