by Sally Colby
While some cattle producers are interested in ways science has helped change the way beef cattle are fed, Dr. Dan Moser is fascinated with how much cattle genetics information has changed. “It will never be less complicated than it is today,” he said. “It’s only going in one direction.”
Moser is president of Angus Genetics Inc., and discussed the use of genetic information with cattle producers at a field day held at Penn State University.
“We have moved from initial performance testing and weaning/yearling rates to herd rates to the early EPDs,” said Moser. “With new biotechnology tools, we’ll have more tools in the future. Some of those tools are for looking at new traits such as genetic predictions for health traits, and aren’t that far away. Think about how that could change your business if you could provide bulls or sell feeder calves that have a genetic advantage for health characteristics.”
Moser explains that EPDs, or expected progeny differences, are the language of genetics. EPDs are tools that describe genetic levels of animals but don’t take into consideration the environment. “We know that any trait has environmental influence,” he said. “The fact that a calf weighs 670 pounds is partially because of genetics and partially because of their environment.”
It’s important to understand that EPDs do not predict actual performance. Moser said he’s often asked questions such as “What EPD do I need to get 75 pound calves?”
“There’s no way to know that because it depends on so many things,” he said. “It depends on what kind of cow you’re breeding bulls to, what part of the country you’re in, polled versus horned, spring versus fall calving and climate.” Moser explained further that he usually answers that question with the Dr. Phil question: “What have you been doing and how is that working for you?”
“If you have been using a bull with (x) EPD and getting calves that are too big, you need to use a lower birth weight bull,” said Moser. “If you like the calves you’ve got, stay the course.”
Is it that simple? Moser said that since the inception of the American Angus Association in the 1860s, there’s been a strong focus on reporting pedigrees. “Pedigree information is useful in describing cattle and the probability of traits,” said Moser, “and with performance records, producers have even more information.”
Early Angus archives show that sire information was limited to measurements such as birth weight, weaning weight and yearling weight. Over time, values for other traits were calculated and made available to producers. For example, CED, or calving ease direct, uses birth weight data to determine the percentage of unassisted births. Higher values represent calving ease in first calf heifers. “If one bull is at 12 and the other is 8, that’s 4 percent difference,” said Moser. “If I breed some heifers to a bull that’s a 12, and other heifers to the bull that’s an 8, I would expect to assist more calves from the bull that’s a lower number. Higher numbers mean higher ease, less difficulty.”
Another useful value is CEM, or calving ease maternal, which predicts a bull’s daughters’ ability to calve. “If I pay attention to CED, I would also pay attention to calving ease maternal,” said Moser. “Over time, I wouldn’t have to worry about mating females that are harder calving.”
Values for feed efficiency are useful but can be confusing. DMI, or dry matter intake, refers to feed intake and not efficiency. “Some Angus bulls are high for intake, some are low for intake,” said Moser. “That says how much their calves eat. To know whether they’re efficient, you need to also know how much they gain.” Moser explained that the value for RADG, or residual average daily gain, is more useful. “RADG asks if cattle eat the same, which one gains the most? They don’t eat the same amount, but we adjust the data. If they all eat exactly the same, which one would gain more weight on more feed?”
Docility scores are important to many breeders – a higher number indicates more docility. Moser says that some cattle in the 1980s and ‘90s had disposition problems, but by examining the genetic component of that trait, docility has improved. Angus breeders provide disposition or temperament scores for individual animals, and over time there’s been a notable improvement in docility. Moser noted that many genetic traits, including docility, aren’t stand-alone and should be considered along with environmental influences.
Moser explained that every EPD has an accuracy number. “If a bull is highly proven and has thousands of progeny in the database, his accuracy for traits is going to be close to 1.0,” he said. “Some bulls in the semen catalog are 0.9 accuracy, which means we have a lot of data on them, and we’re confident in that prediction. With a young animal, we can’t be as confident because we don’t have enough information yet.” Moser added that data on young animals tends to change slightly, but less now than in the past due to improvements in genomics. “If you see a young bull in a catalog and his accuracy is 0.3, that’s very useful information. A lot of breeders have made tremendous genetic progress buying yearling or two-year-old bulls.”
Some traits can be evaluated in relatively young animals. “For carcass traits, we still do a lot of ultrasound, and that’s still very important data to collect,” said Moser. “A calf at weaning is too young to ultrasound so we’re working with pedigree only. Hundreds of thousands of animals have been scanned with ultrasound, and we can use information from that database to apply to the calf that hasn’t been scanned.”
Moser said that breeders can purchase a (tested) bull, turn it out into a commercial herd and know as much about calving ease and birth weight genetics if there was already one calf crop on the ground, measured, weighed and submitted against a reference sire. For embryo transfer work, genomic values allow more timely evaluation of females for the program.
“Genomics is a risk-reduction tool,” said Moser. “It’s the ability to describe a young animal earlier – you can take a DNA test on a month-old calf if you want to. The real value is knowing more, and being more confident in your animals.”