Welcome to the Nutritionist e-Network, published by Dairy Herd Management® magazine. This issue is sponsored by Arm & Hammer Animal Nutrition, Elanco Animal Health, Kemin Industries, Lallemand Animal Nutrition, Land O'Lakes Purina Feed, Milk Specialties Global Animal Nutrition, Novus International, Nutrition Physiology Company and Soy Best.
Sponsored by Lallemand Animal Nutrition
Are distillers grains responsible for milkfat depression? Is milkfat depression the result of too much corn distillers grains in the diet, the cows’ reaction to a knee-jerk dietary change, or something else? “There is a big concern in the industry about milkfat depression when you feed distillers grains,” Kononoff, associate professor of animal science at the University of Nebraska, said during a presentation last month at the American Dairy Science Association’s annual meeting in Phoenix, Ariz. “We did not observe a statistical effect,” Kononoff says of his own research involving diets containing up to 30 percent distillers grains. “In fact, what we observed is total yield of milk fat increased.” Kononoff points to other recent articles from the Journal of Dairy Science that note similar observations. “None of them show milkfat depression when you feed distillers grains to dairy cattle,” he says. So, why is there a discrepancy between published research findings and what producers observe on farm? Kononoff believes one of the reasons is that treatment diets are specifically formulated to include distillers grains, but on-farm diets often include distillers on a whim, so-to-speak, when the price of corn goes up or the price of milk goes down. To accommodate the inclusion of distillers, people find themselves swapping one or two ingredients haphazardly, “and in those cases perhaps we see milkfat depression,” Kononoff says. Another potential cause is rumen biohydrogenation. Rumen microorganisms are very powerful, he says, “and when we feed distillers grains, this is potentially something that is working against us.” Biohydrogenation produces an array of conjugated linoleic acids (CLA) in the rumen. Even in small concentrations, some of them have been shown to have dramatic effects on milkfat.“There are really two big risk factors that can cause this cascade of milkfat depression,” Kononoff says.
Increased fat supply. In situations where you’re bringing a lot of distillers grains into the diet, you can drive up linoleic acid levels and contribute to milkfat depression.
Low rumen pH. Distillers grain is very fermentable, so if you’re not dropping dietary starch levels when you add it to the diet, you can run into low pH issues which put cows at risk for milkfat depression.
Click here to read abstract No. 338 from Kononoff’s presentation in Phoenix.
Researchers compare corn silage harvest practices Researchers from the University of Wisconsin-Madison examined 24 peer-reviewed journal articles published over an 11-year period to determine the effects of different corn silage harvest practices on dry matter intake and lactation performance of dairy cows. Results from their meta-analysis were published this year in the Professional Animal Scientist journal, as well as presented in poster format at the 2012 Joint Annual Meeting of the American Dairy Science Association, held July 15-19, in conjunction with four other animal science societies. Results show starch digestibility and milk yield were decreased for dairy cows fed diets containing corn silage with very high dry matter (greater than 40 percent dry matter), says Randy Shaver, University of Wisconsin-Madison extension dairy nutritionist. Starch digestibility and milk yield also were reduced for dairy cows fed diets containing corn silage with insufficient kernel processing. Click here to read ADSA abstract No. M102. A summary of the research also can be found in the 2012 Tri-State Dairy Nutrition Conference proceedings. Click here to read that paper, or view Shaver's Tri-State presentation here.
Sponsored by Milk Specialties Global Animal Nutrition
Q: What impact is ethanol having on corn prices and, ultimately, the dairy industry?
The following answer was provided by Alvaro Garcia, professor and extension dairy specialist at South Dakota State University.
A: The recent history of U.S. ethanol for fuel can be divided in two periods: the last decade of the 20th century and the first decade of the current century. During these two decades, ethanol production grew by 60 and 780 percent, respectively. Estimated production in 2011 was 13,900 million gallons of ethanol. According to the Renewable Fuels Association (2012), U.S. farmers harvested in 2011 almost 12.4 billion bushels of corn. In the same publication, the demand for ethanol production was estimated at 40 percent of the crop or roughly five billion bushels. During a recent news conference held by the RFA, however, it was suggested that this 40 percent does not take into account the distillers grains co-product, which goes back into the marketplace as animal feed, and that ethanol only utilizes 14.5 million acres of the total 88.2 million acres of corn planted, ending up with 16 percent net corn acres used up by ethanol. During the last decade, corn prices have increased by nearly three-fold. Other factors that influenced corn prices were energy prices, exchange rates, and adverse weather. In the U.S., diets for dairy cows in confinement consist largely of forage and concentrates. Before the recent expansion of the corn-to-ethanol industry, diets were formulated to contain approximately 50:50 forage-to-concentrate ratio on a dry basis.
(Continue by clicking below) [To read the rest of Garcia's answer or leave a comment, click here]
Sponsored by Soy Best
Prices reported the week of Aug. 13-16 by professional dairy nutritionists or commodity brokers in five key dairy regions.
Corn, fine ground or steam-rolled
Soybean meal (48%)
Premium alfalfa hay (170-185 RFV)
Truckload quantities delivered to the dairy ($/ton)
a Fine ground shelled corn b Steam-rolled or steam-flaked corn c 46 percent to 48 percent soybean meal d 47.5 percent soybean meal
PRACTICE BUILDER: Get accurate readings when checking cows’ mineral status
Sponsored by Arm & Hammer Animal Nutrition
Editor’s note: The following information is provided by Mike Socha, research and nutritional services manager with the Zinpro Corp.; Jerry Torrison, veterinarian with the Zinpro Corp., and Neil Michael, veterinarian and technical field consultant with the Vita Plus Corp.
When dairy cattle health and performance fall below expectations, dairy consultants often begin looking at blood and tissue samples to provide a snapshot of the nutritional status of the herd. Consultants are cautioned to not confuse results from individual diseased animals when attempting to make whole herd assessments of nutritional status. Several factors contribute to accurate assessments, including type and number of cattle sampled, sample type, mineral evaluated and sample handling. Following are five key recommendations for pulling blood and tissue samples to assess the mineral adequacy of the diet.
The type of tissue sampled is dependent on the mineral being analyzed (see chart below). For example, blood samples are a poor indicator of zinc and copper status because blood concentrations will not drop until these minerals are depleted.
When sampling for mineral adequacy, at least 20 cows or 10 percent of the herd (whichever is less) should be sampled. Ideal candidates are cows 75 to 175 days in milk that are healthy and metabolically stable. Cows that are sick or stressed will not give accurate measurement of mineral status and should not be included in the sampling process.
Collecting a clean sample is critical to the accuracy of the results. Possible sources of contamination include dirt or other foreign materials for tissue and, surprisingly, collection tubes for blood samples. For example, the red rubber stoppers on blood collection tubes typically use a lubricant containing zinc that can result in erroneously high zinc concentrations when the sample is analyzed.
Proper handling of blood samples is crucial in obtaining a valid sample. Freezing whole blood samples increases the risk of hemolysis and results in elevated concentrations of iron, manganese, potassium, selenium and zinc in the serum. In addition, serum should be separated from the red blood cells within one to two hours of collection to avoid artificially high concentrations of potassium and zinc.
Once a sample is accurately prepared, it is important to use the appropriate reference range to assess the mineral status. Animal parity, as well as life cycle stage of the animal, can affect the validity of the sample analysis. For instance, copper concentrations vary with age — older cows have higher concentrations than young cows — and the copper status of cows is generally lowest right around calving due to the transfer of copper from the cow to the calf. Vitamin B12, an indicator of cobalt supply, drops throughout lactation while selenium concentrations vary depending on the source of selenium in the diet, whether organic or inorganic.
FEED UPDATE: Analysis: Forget drought; 'demand rationing' is corn's new master
Sponsored by Novus International
Editor's note: The following Feed Update was written by Karl Plume, Reuters News Service When all is said and done, predicting the damage done to U.S. corn and soy crops from the worst drought in half a century may have been the easy part. With the harvest imminent and plants mature, most traders are fairly confident they have a handle on this year's supply. Whether corn yields are 120 bushels an acre or 130, it's clear that demand will outstrip supply, possibly by a wide margin. Demand, in trade parlance, will have to be "rationed.” What's far less clear — and harder to discern now than ever before — is just how much less food, feed or fuel will be made from corn as buyers cut back. From food companies to livestock ranchers to ethanol plants, the calculations are complex: Can end consumers withstand higher prices? Can they sustain production with cheaper grain alternatives? For traders, that complexity is multiplied. The unpredictability of dry weather is nothing compared to the vagaries of consumption by livestock producers, exporters, ethanol makers and other industrial users that turn corn into scores of products including plastics, adhesives, explosives and pharmaceuticals. So after two months of relatively steady price gains as every passing hot, dry day withered the crop a little more, some are bracing for a bumpy spell in which traders attempt to second-guess the price point at which demand is rationed. "Demand occurs in so many different categories that it's a little hard to get your hands around," said Darrel Good, a respected agricultural economist with the University of Illinois and a foremost authority on the topic. "The thought process is pretty clear, but quantifying things is pretty subjective." USDA cut its 2012/13 U.S. corn crop forecast by 4.011 billion bushels, or 27 percent, over the past two months and slashed its estimate of corn use across all demand segments by 2.55 billion bushels, or 19 percent. U.S. inventories at the end of next summer are now expected to fall to 650 million bushels, a 17-year low and considered near the bare minimum required to prevent an unprecedented scramble for the last kernels. As recently as June, the USDA had forecast 2 billion bushels. Few traders expect those numbers to be final, with the agency fine-tuning for months to come. Read the full story.
CASE STUDY: This farm needed help in making the transition
Editor's note: The following case study was handled by Bob Corbett, nutritionist and veterinarian with Dairy Health Consultation in Spring City, Utah.
A 5,000-cow dairy in Mexico had been experiencing a number of issues with metabolic disease and infectious disease in fresh cows and heifers. Bob Corbett, a nutritionist and veterinarian from Spring City, Utah, was called in to see what he could do about it. It became apparent that much of the problem had to do with the way the transition cows were being handled prior to calving. The farm had expanded and many of the close-up pens were filled to capacity. Cows that were over-conditioned going into calving were placed in a special pen. In that particular pen, and in some other pens, as well, the cows weren’t given the benefit of a close-up ration for a full three weeks. This can happen on a lot of farms, Corbett points out. The farm may set its computer to flag cows at 259 or 260 days of a 280-day gestation period. But if the farm is only moving cows once a week, some of the cows that miss the cut may have to wait up to six more days before moving into the close-up pens. In addition, up to 20 percent of the cows can calve 10 days early — day 270 vs. day 280, Corbett says. As a result, many cows aren’t getting the full benefit of a close-up ration, which is meant to prepare them for lactation. Indeed, it is probably the most critical ration on the farm, Corbett says. At this dairy in Mexico, the managers decided that the over-conditioned cows should only be in the close-up pens for two weeks to try and prevent more weight gain. And, with the vagaries of moving them once a week, that meant some of the cows were only in there for a week or so. On top of that, they were fed a lower-quality ration than the other transition cows. Read the full story.
CALENDAR OF EVENTS
Sponsored by Land O'Lakes Purina Feed
Minnesota Nutrition Conference Sept. 18-19, Holiday Inn in Owatonna, Minn. More information.
World Dairy Expo Oct. 2-6 at the Alliant Energy Center campus, Madison, Wis. More information.
Arizona Dairy Production Conference Oct. 11 at The Waterfront in Tempe. Ariz. Cornell Nutrition Conference for Feed Manufacturers Oct. 16-18 at the Doubletree Hotel Syracuse in East Syracuse, N.Y. More information. Submit an upcoming event (all events listing subject to approval).
WHAT'S NEW IN THE LAB: Drought has made it important to test for nitrates
Sponsored by Kemin Industries
Editor’s note: The following information was provided by Rock River Laboratory, Inc., in Watertown, Wis.
Nitrate analysis is nothing new at Rock River Laboratory, Inc. However, the 2012 corn silage harvest season has brought these analysis results to the forefront, since greater than 60 percent of the U.S. has been affected by drought. Rock River Laboratory has gone from analyzing an average of 20 samples per week for nitrate levels to now analyzing more than 200 samples per week due to the abundance of drought-stressed corn. There is a silver lining, though. Based on our nitrate analysis, there has been a decline in average nitrate levels on a weekly basis over the past month. The average nitrate level from July 9 through July 13 was 918 ppm. From July 23 through July 27, the level decreased to an average of 613 ppm. Finally, Aug. 6 through Aug. 10, the average nitrate level was 560 ppm. Below is a table that breaks down nitrate results for samples analyzed from July 2 through Aug. 10:
Total % of Samples
1000 – 1500
1500 – 2000
2000 – 3000
3000 – 4000
It is important to remember that a large percentage of nitrates are found in the lower portion of the stalk. If your results confirm that you have high nitrates, raising the cutting height of your corn will help to avoid some of those nitrates in your feed. Allowing the corn silage to ferment for three to four weeks may also allow the nitrate levels to drop, as fermentation causes a decrease in nitrate levels by 25 to 40 percent. Naturally occurring bacteria may be low in drought-stressed corn. Adding an inoculant is recommended to improve fermentation. However, be sure to always test the forage before feeding.