Cattle, like people, can get vitamin D from food and from exposure to the sun. Specifically, vitamin D2 is acquired from plants, while vitamin D3 is synthesized by cells in sun-exposed skin. Vitamin D availability within the body is often measured as the concentration of 25(OH)D in the blood (serum). 25(OH)D is a product of metabolism of both vitamins D2 and D3. With summer sun exposure and no exogenous vitamin D, cows will have 40-100 ng/mL serum 25(OH)D. For cows without the opportunity to graze out on the range all summer, alfalfa hay can provide pretty significant amounts of vitamin D2, and even corn silage contains some. Additionally, vitamin-mineral supplement mixes usually contain vitamin D3, which is metabolized more efficiently than D2.
In a study published last year (full citation below), the investigators compared various management practices with 25(OH)D levels across several herds. Levels of vitamin D in the cows and heifers looked pretty good: all herds had 25(OH)D averages above 30 ng/mL, which is considered the minimum for vitamin D sufficiency. However, the herd that was supplementing at only 20,000 IU/day (rather than the 30,000-50,000 IU/day of the others) did have 22% of their cows below that sufficiency threshold.
The situation for calves in this study wasn’t quite so rosy. Now, newborn calf levels of serum 25(OH)D are typically much lower than in older animals—in this study they averaged 15 ng/mL. In the six herds examined, 25% of newborn calves had serum 25(OH)D concentrations below 10 ng/mL. If left uncorrected, these calves in particular could suffer impaired health. If we look at the figure below, we see distinct differences across farms as the calves age. (We’re looking exclusively at the pre-alfalfa-eating stage here.) Spring/summer sun exposure or supplemental vitamin D in the diet would seem to make a significant difference in a calf’s vitamin D level.
Given that vitamin D is associated with growth, development, and immune function, this nutrient is required starting with a calf’s first days. Most milk replacers contain adequate vitamin D. If raising calves on milk, one should provide supplemental vitamin D3 at a rate of 6000-10,000 IU/kg of dry matter. Additionally, giving calves a 50,000-100,000 IU bolus of vitamin D3 at birth may also be helpful.
(Before initiating a new treatment or nutrition regimen, you should consult your veterinarian/nutritionist.)
The OSU Dairy Club’s biannual Beaver Classic Sale is Saturday, February 4. The silent auction and dinner start at 5:30 pm with the sale to follow at 7 pm. Proceeds from the events will go to support the Dairy Club activities and its future industry leaders.
The sale catalog can be found here.
Location: Oldfield Animal Facility – 35th Street and SW Campus Way in Corvallis.
Questions: Contact Mitch Evers at email@example.com or call (503) 758-6695.
Being prepared for subfreezing weather is key to getting farm chores done safely and effectively. (In addition to getting to the farm!) While this short article was written for South Dakota’s harsh winters, the author’s point about newer employees who may never have lived and worked through cold weather is useful for us, too. The article includes a link to a Spanish/English brochure about winter preparedness.
Dystocia (difficulty calving) is hard on a cow, especially when the calf (or calves, blasted twins!) has to be pulled. That trauma to the reproductive tract can cause pain and inflammation that can last for several days. As we know, cows that don’t feel good often don’t spend as much time at the feed bunk, and cows that eat less than they should, make less milk than they could. When we humans feel achy, we often take an NSAID (nonsteroidal anti-inflammatory drug, like ibuprofen). Maybe we should do the same for our cows around calving?
In a study just published in the January 2017 Journal of Dairy Science, the investigators gave flunixin meglumine (Banamine®) immediately precalving and then again 18-36 hours later. As it turned out, that was a bad idea! The precalving dose was discontinued after the first week of the study (72 animals) because the treated group had 26% stillbirths vs. 5% in the control group. For the rest of the study (~1200 animals) the treatment group only received doses of flunixin at ~1 hour and ~24 hours post calving. The results: through 14 days in milk, cows treated with flunixin produced significantly less milk (3.5 lbs./day) than the untreated cows. Additionally, flunixin-treated cows had an increased likelihood of retained placenta. Bottom line: it is inadvisable to give periparturient cows flunixin meglumine (Banamine®).
So are there other NSAIDs that could help out cows after calving?
A few years ago, the same research group looked at meloxicam as a pain reliever for cows that had needed assistance calving. Animals in the treatment group received a single injection of meloxicam approximately 24 hours after calving. They found that meloxicam-treated cows had the same dry matter intake and milk production as their untreated herdmates. The treated cows did spend a little more time at the feed bunk, which may indicate that the NSAID was reducing pain.
The post-calving use of ketoprofen was explored in a study published in 2009. Each cow received a dose of ketoprofen as soon as possible after calving and then a second 24 hours later. Treated cows tended to have fewer cases of retained placenta than control cows, but the difference was quite small. Ketoprofen treatment did not result in a difference in early-lactation milk yield or subsequent fertility. So like meloxicam, ketoprofen doesn’t seem harmful (unlike flunixin), but it’s probably not particularly helpful either.
Something simpler than an NSAID?
Interestingly, an older study (1997) found that ingestion of amniotic fluid at calving seemed to have a pain-dampening effect. That study was prompted by similar findings in rats. Allowing a cow to lick her baby clean may have benefits beyond a dry and stimulated calf.
Future investigations into pain relief for calving, especially dystocia, will hopefully give us more effective options for getting our cows feeling better quickly.
(Before initiating a new treatment regimen, be sure to consult your veterinarian and observe any drug use restrictions.)
It is estimated that the world’s population is around 7.4 billion people. The US population recently climbed past 300 million people, as we continue to add a new person every 7 seconds. The United Nations projects that the world population will increase to 7.9 billion people by 2020. The huge majority of this growth (95%) will be in developing countries, where 77 percent of the world’s population already lives. These developing countries are also increasing their per capita consumption of meat, milk, and eggs. Thus, the demand for animal products is expected to increase more rapidly than the total population.
I have listened to people debate the issue of feeding this ever increasing population and have wondered what needs to be done to continue to provide nourishment for all these people. Many argue we have no food shortage currently; we just have populations that are too poor to grow or purchase food. Regardless, I think feeding the world’s residents is a major challenge in years to come. I am convinced ruminant animals have a significant role to play in the solution.
I know my children have questioned for years why I get so excited about cattle and grass. I have tried to explain the unique role ruminants play in our lives, but I still am not sure they are excited as I am. Globally, around 55% of the world’s land is classified as pasture, grasslands, meadows, or forest-pastures that have the potential to produce 5.8 trillion Mcal of metabolizable energy. Around 50% of the 1.9 billion acres in the US is classified as range or pastureland. This is an extremely large resource that already is or can be used for food production.
Grazing ruminant animals is an efficient way to produce food for humans. Grazing animals on land that is unsuitable for crop production more than doubles the land area in this country that can be used to produce food. Ruminant animals can use plant cell walls as a major source of dietary fiber and energy. The polysaccharides in plant cell walls cannot be degraded by mammalian enzymes, which is why humans cannot effectively use grass as food. However, ruminants are uniquely adapted mammals that depend on microbial fermentation in one of their stomachs, the rumen. With this adaptation, ruminants are especially capable at using plant fiber for energy. Fiber, measured as neutral detergent fiber (NDF), usually accounts for 30-80% of the organic matter in forage crops. The remaining organic matter is almost completely digestible by a ruminant’s own enzymes. It is this unique digestive system that allows ruminant animals to consume poor quality forages and transform them into high quality meat and milk. And because so much of the world is covered with range and pasture lands, it only makes sense that sustainable communities and sustainable agriculture include grazing animals.
Over the years, critics of animal production have argued we should be feeding human-edible foodstuffs (grains, protein sources, etc.) to only humans and not include these in ruminant diets. Too often the opponents of animal agriculture evaluate the desirability of animal production on gross calorie or protein intake/output values, with an assumption that all animal feed could or would be eaten by people. However, in many cases the feeds used in animal production are not consumed nor consumable by humans, and in order to properly evaluate animal production, only human-edible consumable energy and protein intake should be used for efficiency comparisons.
Many studies and evaluations have been conducted looking at the efficiency of livestock in converting plant based protein and energy into animal products. Non-ruminant animals like swine and poultry, cannot utilize low quality forages like ruminants can, but they are really efficient in their ability to gain weight eating grains. Ruminants, on the other hand, are less efficient in converting grains to animal protein. However, they can maintain and produce on a diet of 100% forage or by-product feeds if necessary. In fact, dairy cattle and goats are quite exceptional in being extremely efficient in converting plant-based protein/energy sources into high-quality animal fats and proteins. I believe the evidence that ruminant livestock belong in sustainable livestock production systems is convincing.
Ruminants have served and will continue to serve a valuable role in sustainable agricultural systems. They are particularly useful in converting vast renewable resources from rangeland, pasture, and crop residues or other by-products into food readily eaten by humans. With ruminants, land that is too poor or too erodible to cultivate becomes productive. Nutrients in all kinds of by-products are utilized and do not become a waste-disposal problem. In Oregon, waste products from the grass seed, vegetable, nut, tree fruit, and berry industries as well as brewing wastes are being fed to livestock. It is clear to me ruminants are essential components in food production systems now and in the future.
Lactating cows can eat upwards of 55 pounds of feed a day on a dry matter basis. How do they do that? Ruminants produce large quantities of saliva every day. Estimates for adult cows are in the range of 25 to 38 gallons of saliva per day. Aside from its lubricating qualities, saliva serves at least two additional very important functions in the ruminant. It plays a major role in buffering the pH in the foregut and provides fluid for the fermentation activities in the rumen. Boluses of preliminarily chewed forage are regurgitated from the reticulorumen and re-chewed: the process we refer to as rumination or cud chewing. The grinding action of the teeth mechanically breaks down the plant fibers into smaller particles, providing additional surface area for digestive enzymes to “attack”. Animals on pasture or range typically graze for around 8 hours a day, providing a steady stream of feedstuffs to the reticulorumen. Contractions mix the feed around and between the rumen and reticulum. See Figure 1 for a diagram of a typical ruminant digestive tract.
The rumen is essentially a fermentation vat. We have often heard cows have four parts to their stomach, the rumen in the largest section in this stomach series and tend to get most the attention because of its unique capabilities. It provides an anaerobic environment, constant temperature and pH, and thorough mixing that allow the microbes to digest forages. Bacteria, protozoa, and fungi are the three major types of microbes. Figure 2 illustrates the types and approximate numbers of microbe types in a rumen (and the number of humans on Earth, just for comparison). Mammals don’t produce enzymes that can digest plant fibers like cellulose. Cattle and other herbivores rely on the digestive enzymes produced by their gut microbes in order to get the majority of nutrients out of forages.
The rate of flow of solid material through the rumen is quite slow and dependent on feedstuff size and density. However, water flows through the rumen rapidly and appears to be critical in flushing particulate matter downstream. As fermentation proceeds, feedstuffs are reduced to smaller and smaller sizes and microbes constantly proliferate. Ruminal contractions constantly flush lighter solids back around the reticulorumen while denser particles (feedstuffs that have been there longer) proceed to the omasum.
The function of the omasum is rather poorly understood. It may function to absorb residual volatile fatty acids and bicarbonate. The tendency is for fluid to pass rapidly through the omasal canal, but for particulate matter to be retained between the omasal leaves. Periodic contractions of the omasum knock flakes of material out of the leaves for passage into the abomasum.
The abomasum is a true, glandular stomach which secretes acid (significantly lowering the pH) and otherwise functions very similarly to the stomach of a monogastric. One fascinating specialization of this organ relates to its ability to process large masses of bacteria. In contrast to the stomachs of non-ruminants, the abomasum secretes lysozyme, an enzyme that efficiently breaks down bacterial cell walls. Much of the protein need of the ruminant is actually satisfied by digesting bacteria that have traveled from the rumen.
CRV USA is looking for qualified university students for two paid internships: a Dairy Genetics Intern and a Marketing Communications Intern. The Marketing Communications Intern will begin work as soon as January 2017 and the Dairy Genetics Intern during the summer of 2017.
To apply, submit a cover letter, resume, and sample work/project to firstname.lastname@example.org by December 23, 2016.
Details are in the pdf links below.
OSU Calving School, Willamette Valley class
WHEN: Thursday, December 8, 2016, 4 pm to 8 pm
WHAT: This program will consist of presentations, educational videos, and simulated calving assistance. Topics covered will include The Calving Process, Nutritional and Management Strategies to Prevent Calving Problems, Designing Calving Facilities, Dystocia and Calving Assistance, Diseases and Injuries Associated with Calving, and Managing Newborn Calves.
(The program will have a beef cattle slant, but dairy cattle have calves the same way.)
COST: $20 per person (includes program, the calving school handbook, and pizza dinner)
PRESENTERS: Reinaldo Cooke (Beef Cattle Specialist), Shelby Filley (Regional Livestock and Forage Specialist), and Charles Estill (Extension Veterinarian)
For more information on the program, please contact email@example.com or 541-236-3016
For on-line registration and payment, go to http://bit.ly/LinnCalvingSchool
If you need help registering, please contact the Linn County OSU Extension Service at 541-967-3871
Calving School will also be held in other locations:
December 9, 2016 (4 pm to 7 pm) Myrtle Point, OR
December 12, 2016 (2 pm to 5 pm) Fossil, OR
December 13, 2016 (4 pm to 7 pm) Heppner, OR
December 14, 2016 (11 pm to 2 pm) Enterprise, OR
For more information on those classes, please contact Reinaldo Cooke (541-573-4083) or your local Extension Office.
Welcome to the new Oregon State University Extension Service dairy blog, Dairy Bearing. The blog’s title might seem odd at first reading, but there’s a little more to it than the way it rolls off the tongue. Dictionary.com (this is an internet-based medium, so forgive me for not pulling the print dictionary off the shelf), lists multiple definitions for bearing. They include
- The manner in which one conducts or carries oneself
- The act or capability of producing
- The act of enduring
- Reference or relation (e.g., having bearing on a problem)
- Holding up or supporting
- Moving in a particular direction
These definitions seem rather fitting if we think about them in the context of dairy farming.
The purpose of this blog is for us at OSU to share research results, techniques, resources, announcements, and other items that might be of interest to those involved in dairy production. Up above, there are permanent links that connect to various web pages that might be useful. This section that you’re currently reading will scroll along in typical blog fashion, with the most recent post at the top. Feel free to comment or post queries. Note that any comments not in the spirit of respectful discourse will be deleted.
And in the humor of the season: