There are five factors that influence a superb dining experience for cattle, including ration uniformity, feed availability, diet composition, cow comfort and other cow-related factors. While all impact feed intake, ration uniformity and feed availability are of the utmost importance in developing a dining experience cattle crave.
David Carlson and Paulina Letelier, both of Vita Plus, spoke of these factors during their presentation, “5 stars … would recommend! What would your cows say about their dining experience?” at the Vita Plus Midwest Dairy Conference June 13.
“Why do we care?” Letelier asked the audience. “Because we know the effects of variation on milk production. One study showed a decrease of just half a percentage point of variation in dietary energy was associated with greater milk production.”
Letelier also mentioned that feed costs are often the largest investment on a farm. For farms with 500 to 999 cows, purchased feed accounts for 55% to 65% of the costs of the dairy.
“Keep this in mind because we also want to get the most out of our money,” she said.
Ration uniformity
Ration uniformity looks at the machine used and methodology, such as facing, mixing time, load size and levelness of the mixer.
“There are a lot of ways to deliver formulated rations to cows,” Carlson said. “To know if it’s effective, compare what is happening and should be happening.”
Carlson suggested taking multiple samples from the largest load of TMR, equally spacing the samples throughout the bunk, and using the Penn State Particle Separator to find a coefficient of variation among the samples in the middle screen and pan. The goal should be 5% or less, ideally 3%.
In examining refusals and comparing those values to fresh feed for sortability, the goal is to be within 7 percentage points. If greater than that value, it is an indication cows are sorting the TMR.
Machinery wear has a large influence on ration uniformity.
In both vertical and horizontal mixers, augers are often the most worn part of the machine. Kicker plates, leading edges and knives of vertical mixers also have a large impact on ration uniformity when worn, whereas damaged paddles affect the ration in horizontal mixers.
“It’s really crazy to think how much metal wears off on a daily basis,” Carlson said.
The method and mixing process also greatly affect ration uniformity.
After defacing, both corn silage and haylage show variation, Letelier explained. To combat that, the defaced forage should be mixed with a bucket or in a mixer to create a more homogeneous feed ingredient. Industry guidelines indicate horizontal-auger mixers should run for about five minutes, while horizontal reel-auger mixers and vertical mixers should run for three to five minutes, all after the last ingredient has been added and the machine’s rpm is greater than 30.
When determining the mixer’s load size, volume should be the primary criteria and can be calculated by evaluating the ration’s density. As a rule of thumb, the ration density for lactating animals should be 20 to 25 pounds per cubic foot and 15 to 20 pounds per cubic foot for dry cows and heifers.
Carlson said an easy way to determine ration density is to take a 5-gallon bucket (weighing about 2.2 pounds) and fill it with the selected ration so the feed is level with the top of the bucket. Smack the bucket on the ground and add more feed to top it off. Weigh the ration and multiply that value by 1.5, then subtract 2.2 pounds to get the estimated ration density.
“It’s a worthwhile test when evaluating a mixer,” Carlson said. “Will the volume meet your needs?”
A minimum load size should cover the flighting of the machine as the mixing action will work the feed off the auger. The load size in a horizontal auger should be kept within the walls, whereas a vertical auger can vary greatly, so the feed should fall about 2 feet above the top of the auger.
The struck volume of a mixer is level full, or the maximum load size. Carlson suggested horizontal mixers maintain 75% of struck volume and vertical mixers 90% to 95% of struck volume.
Other factors that influence ration uniformity include levelness of the mixer on the ground, loading location and loading sequence of feed ingredients – first beginning with dry forages in vertical mixers and concentrates in horizontal mixers.
Feed availability
Delivering feed at the same time every day and keeping that feed available throughout the day to maximize dry matter intake is crucial in creating a five-star feeding experience. Feed availability also looks at push-up frequency and Mother Nature events that may influence quality of feed and refusals.
Letelier suggested that dairies have no more than 30 minutes per day when the bunk is empty.
“If you feed too early, that increases refusals,” she said. “If you feed too late, that decreases feed intake and creates bunk competition. Find the sweet spot where refusals are between 1 to 3 percent.”
The benchmark for refusals does vary from farm to farm and to which animals are being fed. Letelier said steers can manage a clean bunk, but lactating cows need fresh feed after milking and for it to be in front of them all day to minimize aggressive behavior at the bunk.
“Change the refusal amount to one that will work for your farm,” she said. “You need to build a push-up schedule that maximizes production potential.”
While there are other factors that influence feed intake, leading to improved production and components, ration uniformity and feed availability are top on the list in creating a five-star dining experience cows crave.
