Feed insights: Connection between nutrition, health & productivityFeed insights: Connection between nutrition, health & productivity
Nutritionists discuss feed management insights to protect energy levels and thus, immunity in livestock.
May 15, 2023
Have you ever been sick and felt like a routine walk from the couch to the kitchen required the stamina of a marathon runner? Did you know that cattle also experience the same kind of energy drain during sickness that keeps them from being as efficient as possible? The good news is there are steps we can take to support cattle nutritionally in their time of need.
When animals become sick or go through an inflammatory immune response, their appetite substantially decreases, which impacts their well-being and profitability through the feeding phase. Will Kayser, PhD, Beef Technical Consultant and Sara Kvidera, PhD, Dairy Technical Consultant with Elanco Animal Health discuss the science behind how nutrition and immunity intertwine during sickness as well as insights to bolster your beef operation’s gains. Dr. Kvidera’s shared insights are rooted in her pursuit to study the activated immune system in steers, and her research has been published in the Journal of Animal Science.1
How does the immune system’s response affect potential growth in ruminant livestock—ultimately impacting the animal’s health and a producer’s bottom line?
Dr. Kvidera: The immune system has a huge appetite for energy (glucose in particular) when an animal is sick. It also takes energy for healthy cattle to gain a pound of protein, so if there’s energy drain going elsewhere—in this case, if energy is needed to fight an infection—that animal has to reprioritize its energetic resources to put survival before growth.
It takes an animal around 10 kcals of energy to make 1 g of protein. The immune system of a sick 300-lb Holstein steer uses about 1 kg of glucose (~4,000 kcal) in a 24-hr period. That means the immune system is eating up around 4 Mcals of energy, the same amount that could have been used to synthesize 0.9 lbs of protein or 3 lbs of lean tissue.
That’s quite an energy drain on cattle.
This is all happening while experiencing a reduction in energy intake because of poor appetite, making what’s in the diet extremely important. We want to make sure we have a nutrient-dense diet that will support the needs of an active immune system when intake is limited. The immune system specifically has an appetite for glucose, so special attention needs to be paid to ensuring we set an animal up for success by having adequate glucose precursors. Having a better understanding of the energetic and nutrient requirements of the immune response helps us understand the importance of minimizing stress and poor environmental conditions which activate the immune system.
How does nutrition play a role in an animal’s ability to fight infection, specifically thinking about the timing for starting calves on feed?
Dr. Kayser: Nutrition is uniquely complex and requires just the right mixture of nutrients to support the animal’s performance, and stronger performance typically signifies better growing conditions and a healthier immune system.
When starting calves on feed, I recommend a combination of long-stemmed hay and a mixed ration. This helps calves get adjusted to feeding out of a bunk for their starter diet.
Next, I recommend slowly removing the hay once they’re comfortable at the bunk, which can help stabilize intake. Starter rations are not the time to skimp on feed quality—setting calves up for success has huge benefits in the long run. Reducing stressors and getting calves on feed in those initial 7-14 days is critical; after that, our focus is on caloric intake. We generally see that when calves start on feed quicker, there are fewer health problems down the road.
An animal that already has an adequate supply of nutrients will have a greater ability to prevent or proactively recover from infection if they get sick.
Dr. Kayser: Rumensin can be an intake-limiter in cattle on a finishing diet. However, we rarely see an impact when starting calves. Dose is also important, and I would suggest starting calves at half the dose of what you’re feeding the cattle on a finished diet. Rumensin improves the energetic efficiency of ruminants by increasing the propionate in the mix of other volatile fatty acids. The pathway from glucose to propionate is energetically efficient and essentially reduces the maintenance requirement of the animal. The rule of thumb based on peer-reviewed research is that every 100 mg increase in Rumensin results in about a 1% improvement in feed efficiency—incremental net returns are greater in seasons when feed costs are high.2
This is certainly meaningful when input resources are limited, as most of the industry has experienced drought conditions and hay shortages in recent times.
When you can support your calf/cow’s energetic requirements early on, they are able to more efficiently gain weight and have a well-supported immune system if an infection arises.
Rumensin improves the energetic efficiency of ruminants and can help support their growth throughout the feeding period.
To speak with a nutritionist technical consultant, contact your Elanco Animal Health representative to discuss immunology needs to support energetic productivity in your herd.
1 Kvidera SK, Horst EA, Abuajamieh M, et al. Technical note: A procedure to estimate glucose requirements of an activated immune system in steers. J Anim Sci. 2016 94(11): 4591-4599. https://doi.org/10.2527/jas.2016-0765. Accessed: December 2022.
2 Duffield TJ, Merrill JK, Bagg RN. Meta-analysis of the effects of monensin in beef cattle on feed efficiency, body weight gain, and dry matter intake. J Anim Sci. 2012 90(12): 4583-4592. https://pubmed.ncbi.nlm.nih.gov/22859759/. Accessed: December 2022.
Lalman D, Gross M, Beck P. OSU cowculator v2.0 beef cow nutrition evaluation software. Oklahoma State University Cooperative Extension Service. 2020. Accessed: December 2022.
The label contains complete use information, including cautions and warnings. Always read, understand and follow the label and use directions.
CAUTION: Consumption by unapproved species or feeding undiluted may be toxic or fatal. Do not feed to veal calves.
Growing beef steers and heifers fed in confinement for slaughter:
For improved feed efficiency: Feed 5 to 40 g/ton of monensin (90% DM basis) continuously in a complete feed to provide 50 to 480 mg/hd/day.
For the prevention and control of coccidiosis due to Eimeria bovis and Eimeria zuernii: Feed 10 to 40 g/ton of monensin (90% DM basis) continuously to provide 0.14 to 0.42 mg/lb of body weight/day, depending upon severity of challenge, up to a maximum of 480 mg/hd/day.
Growing beef steers and heifers on pasture (stocker, feeder, and slaughter) or in a dry lot, and replacement beef and dairy heifers:
For increased rate of weight gain: Feed 50 to 200 mg/hd/day in at least 1.0 lb of Type C Medicated Feed. Or, after the 5th day, feed 400 mg/hd/day every other day in 2.0 lbs of Type C Medicated Feed. The Type C Medicated Feed must contain 15 to 400 g/ton of monensin (90% DM basis). Do not self-feed.
For the prevention and control of coccidiosis due to Eimeria bovis and Eimeria zuernii: Feed at a rate to provide 0.14 to 0.42 mg/lb of body weight/day, depending upon severity of challenge, up to a maximum of 200 mg/hd/day. The Type C Medicated Feed must contain 15 to 400 g/ton of monensin (90% DM basis).
Type C free-choice medicated feeds: All Type C free-choice medicated feeds containing Rumensin must be manufactured according to an FDA-approved formula/specification. When using a formula/specification published in the Code of Federal Regulations (CFR), a Medicated Feed Mill license is not required. Use of Rumensin in a proprietary formula/specification not published in the CFR requires prior FDA approval and a Medicated Feed Mill License.
For improved feed efficiency when receiving supplemental feed: Feed continuously at a rate of 50 to 200 mg/hd/day. Cows on pasture or in dry lot must receive a minimum of 1.0 lb of Type C Medicated Feed per head per day. Do not self-feed.
For the prevention and control of coccidiosis due to Eimeria bovis and Eimeria zuernii: Feed at a rate of 0.14 to 0.42 mg/lb of body weight/day, depending upon severity of challenge, up to a maximum of 200 mg/hd/day.
For calves (excluding veal calves):
For the prevention and control of coccidiosis due to Eimeria bovis and Eimeria zuernii: Feed at a rate of 0.14 to 1.00 mg/lb of body weight/day, depending upon severity of challenge, up to a maximum of 200 mg of monensin/hd/day. The monensin concentration in Type C medicated feed must be between 10 and 200 g/ton.
Rumensin, Elanco and the diagonal bar logo are trademarks of Elanco or its affiliates.
© 2023 Elanco or its affiliates. PM-US-22-2610
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