Optimizing efficiency with isoacids

Andrew LaPierre Zinpro Corporation

SIOUX FALLS, S.D. — Supplementing the dairy ration with isoacids can help drive efficiency, Andrew LaPierre said.

LaPierre is a dairy technical specialist at Zinpro Corporation, based in eastern New York. He spoke during the seminar, “Optimizing Feed and Nitrogen Efficiency in Dairy Cattle Diets by Feeding Isoacids,” March 18 at the Central Plains Dairy Expo in Sioux Falls.

“We want to be able to squeeze the most out of what we have available to us,” LaPierre said.

Isoacids are 4- and 5-chain carbons that are the fermentative end products produced by the breakdown of proteins and amino acids. LaPierre said isoacids are similar to acetate, propionate and butyrate, but they show up in a lower proportion relative to these volatile fatty acids.

Focusing on what happens in the microbial ecology of the rumen to ensure cows have good levels of fermentation is important, LaPierre said. By driving VFAs levels, cows are fermenting the ingredients to maximize acetate, butyrate and propionate production.

“I think we miss the mark, at least here recently, that we can have perfect diets on paper,” LaPierre said. “We can feed these animals to the best of our abilities, but they’re not the only ones that are in the buffet line. The bacteria tend to be the first in that line to try to get at these nutrients that we are feeding these animals. We are driving a more competitive rumen environment where all of these bacterial and microbial populations are competing for nutrients.”

LaPierre said he recognizes diets that have more non-forage fiber sources allow for a greater passage rate within the rumen.

“We may be under-serving these guys (rumen bacteria) who may be more metabolically inactive relative to their counterparts,” LaPierre said. “We need to be able to feed them appropriately.”

If cows are making more protein and energy, they have a greater amount of energy corrected milk, and farmers are driving better energy conversion out of these animals by letting the rumen work in the cows.

“Let the ruminant be a ruminant,” LaPierre said. “If we’ve got ingredients that are highly fermentable, we’re trying to get that into our diets. Obviously, we need to be aware of costs, but greater fermentability drives more productivity out of these ruminants.”

When the supply of rumen-degradable protein is lower, there is lower potential for isoacids to be supplied endogenously by the diet, leading producers to supplement it in the ration, LaPierre said.

RDP is broken down into peptides, then into amino acids. Starch and sugar digesters take amino acids and break them down into isoacids, he said. The fermentative end products that happen from starch and sugar digesters are utilized by fiber digesters to improve fiber digestibility in the rumen and drive more microbial protein out of the rumen.

LaPierre said there are some situations where cows’ diets may be underserving fiber digesters in the rumen, and only partially meet our demands for VFAs. So, supplementing isoacids also allows farmers to bridge the gap in the rumen.

Balancing RDP and fermentable carbohydrates allows producers to maintain stability within the diet, LaPierre said.

If cows receive a lot of fermentable carbohydrates and minimal RDP, farmers may see some muted responses. Having more fermentable ingredients allows the cows to have more bacterial yields, he said.

When supplementing isoacids, LaPierre suggests starting at 42 days before calving.

As producers are feeding isoacids they are capturing a better upswing in a pre-peak response, bringing that into the lactation curve.

Primarily in late lactation, producers are putting protein back onto the cows as they get ready for the next lactation, LaPierre said.

“If we didn’t mobilize that tissue in the early stages of lactation, it means less nutrients need to be diverted to the backs of that animal and more available to milk production throughout that lactation curve.”

If cows have better nutrient conversions, producers can lower beta-hydroxybutyrate, which helps prevent ketosis. Cows have higher glucose levels, lower body weight maintenance and metabolic incidents, which drives nutrients towards milk production.

LaPierre has done research with a product called IsoFerm, a supplement that adds isoacids to the ration. In his research, he has collected data from 70,000 cattle across the U.S. Energy-corrected milk has increased upwards of 4.3% and feed efficiency has improved by about 5.5%. LaPierre found that dry matter intake was reduced about 2% and is most evident in  mid- to late-lactation animals.