By John Lovett
One percentage point of feed conversion loss in large-scale poultry production can cause millions in lost revenue, so even small improvements like fine-tuning a single nutrient in feed can make a big difference.
Calcium plays a key role in poultry feed conversion. In addition to bone density, enzyme activation, muscle contraction and other critical functions, calcium affects the efficiency of turning food into weight gain. But in broilers, it's not just the amount of calcium that matters. What really counts is bioavailability: how much of that nutrient the bird can actually use.
Accurately measuring calcium bioavailability has been tricky for poultry scientists.
"The biggest challenge we have is analytically picking up the calcium content of our samples accurately," said Ben Parsons, an assistant professor of poultry nutrition with the Arkansas Agricultural Experiment Station, the research arm of the University of Arkansas System Division of Agriculture, and the Dale Bumpers College of Agricultural, Food and Life Sciences. "Our main calcium sources dicalcium phosphate and limestone are rocks. You may get a big piece or a little one in the sample, and it causes variability."
A new study by Parsons and his colleagues in the Center of Excellence for Poultry Science compared the results of two calcium availability tests a classic approach and a newer, speedier test and found that both tests offer reliable results that can help poultry producers optimize calcium digestibility.
Arkansas has consistently ranked as the third-largest producer of broiler chickens in the nation, producing more than 7.4 billion pounds of broiler meat in 2023, according to the latest Arkansas Agricultural Profile. Bringing in $6.5 billion, broiler production represents about 45 percent of all agricultural cash farm receipts in Arkansas.
In the quest to formulate optimum-performance poultry feed, poultry nutritionists have been looking at not just how much calcium is in the feed but how much is digested and absorbed by the bird.
Currently, the feed is formulated to meet a total calcium requirement in the diet, which does not account for differences in calcium availability among sources. Even among different sources of the same ingredient, calcium availability can vary due to factors such as solubility and particle size.
Source : uark.edu