By SUSAN MYKRANTZ
Ohio Correspondent 

ALTON, Ohio — Better cows mean better profitability on today’s dairy farms, according to Dr. Bennett Cassell, dairy science professor emeritus of Virginia Polytechnic Institute in Blacksburg. He was also a presenter at the 2015 North Central Ohio Dairy Grazing Conference in Dalton.

Cassell said some dairy producers may not be concerned about importance of genetics in their herd, "but, you have to get those cows bred and you have to breed them to something." Does it matter what bull a producer uses? He noted there are many resources available to help producers make the right decisions when mating their animals, whether using a system that analyzes the strengths and weaknesses of each animal and identifies bulls that will correct the faults or using set criteria to select bulls to use in the herd.

"The bottom line is that it doesn’t cost any more to use a good bull than a mediocre bull," he said. "And those genetics in that calf will be passed on and continue to improve your herd."

Today’s cows have been bred to be specialized, according to Cassell. In the 1940s there were fewer than 200 million people in the United States and more than 25 million dairy cows. Today, there are roughly 320 million people and the dairy cows have dropped to about 9.2 million; fewer cows are producing more milk for more people.

The advent of DHI has helped dairy producers make genetic improvements in their herds, as access to individual cow performance has helped farmers as well as the artificial insemination (AI) industry identify superior animals. Cassell said producers need to keep good records on their animals because it will help them make better management decisions.

He said breed associations are also using this information to identify important conformation and performance traits to enhance their breed improvement programs.

Modern agriculture focuses on producing food economically and efficiently, and dairy cattle are no exception. Today, cows are fed and managed differently than they have been in the past and genetics have changed. "Individual cows have become valuable enough to justify a greater investment in feed and management," he said.

Cassell explained using genetic evaluations can help producers make good choices for their herds. But one drawback to current evaluations is the fact performance data have been dominated by confinement operations. Performance information from grass-based operations has not been included in the U.S. evaluations – Cassell said New Zealand and Ireland use genetic evaluations based on grass, but they also have management systems unique to their environment.

He pointed out consumers are interested in how their food is produced and this could be beneficial to grass-based dairies.

Cassell said knowledge and control of the nutritional and environmental needs of dairy cows has grown tremendously and milk yields have responded, as a result. But without the genetic improvement in cows, the advancements in nutrition and management would have little impact. Cassell contends that nutrition, management and genetics form the trifecta for success as better genetics increase with better management.

Management plays a critical role in helping young stock reach their full genetic potential, but many times calves and heifers get shortchanged with poor-quality forages. If dairy herds are trying to get heifers in the milking herd at a younger age, the heifers need to be well grown, so they cycle and are bred on time. Cassell said production is higher on first-lactation animals than it has been in the past in part because of improved genetics.

"We have seen steady progress to improve milk yields in all breeds," he said. "But we have seen a decline in productive life, and a lot of that is due to how dairy operations manage their cows."

He said there has also been a negative trend in daughter pregnancy rates over the past couple of years, but new options and techniques available to help get cows bred has seen that trend starting to reverse. "The genetic ability of cows to stay in the herd has improved."

Cassell said producers can look at Predicted Transmitting Ability statistics to help make breeding selections for the next generation of their herd. The PTA is a measure of the average genetic merit transmitted to the offspring of animals being evaluated. He said some traits respond more quickly than others and selecting to improve individual traits may result in success in some areas, but setbacks in others. For example, production traits respond more quickly than fertility traits.

In addition to selecting for milk, producers are also looking at health and fitness traits, which probably matter more in grazing than confinement operations. "We have made progress in developing cows that function well in confinement operations," he said. "The needs of grass-based dairies probably didn’t shape current confinement systems, but for traits such as udders and feet and legs, genetic progress has worked pretty well for grass-fed cows."

Right now, much of the genetic progress in dairy herds has been driven by selecting better bulls in each successive generation, according to Cassell. "Sire selection is the key, but only if you are making good, sound, informed decisions using the best information that you have available."

He added he won’t argue that producers need to be on official test so the industry had access to accurate data. Instead, he said they need to have data that benefits them, such as calving dates, breeding information and milk records. Tools such as Net Merit indices use economic values for traits to avoid double-counting the value of a trait expressed in other, similar traits.

"The more you know, the more money that cow will make you," he explained. "If you do your best to breed every cow and heifer that you plan to keep a replacement heifer from to the best AI bull you can afford, you are going to make genetic progress at the fastest rate possible for your herd."

Many herds are starting to use tools such as genomics to help identify genetically superior animals to use as replacements, especially if they are using sexed semen. "If producers cull animals based on their pedigree, they can make mistakes," he said. "But genomics change the game."