two hornless calves on mowed grass
Hornless calves (named Buri and Spotigy) produced by gene editing. Photo from Carlson et al. 2016 Nature Biotechnology 34:479-481

We know that hornless cattle are safer for people, their herdmates, and themselves. Unfortunately, the combination of polledness and elite genes for other, more critical traits (like milk yield and productive life) don’t often appear in the same animals. We could spend several decades using polled sires to introgress the POLLED allele (allele = version of a gene) into the broader dairy population, but we would sacrifice gains in other traits, because along with the POLLED allele, the calves would get other stretches of less desirable DNA. (However, the nice thing about the POLLED allele is that it’s dominant, meaning that only one POLLED allele is required. At that same location on the other paired chromosome, there can be the horned allele, but we would still have a polled cow.)

You may have heard of gene editing, particularly with a system called CRISPRs. These CRISPR molecules can be introduced into target cells and are capable of recognizing a particular stretch of DNA and cutting at that location. If pieces of DNA containing the desired sequence for that location (e.g., the POLLED sequence) are made available to the cell at the same time, the cell’s DNA repair machinery will use that “new” DNA to repair the break in the chromosome. Voila! That repaired chromosome now contains the DNA sequence we want at that location, instead of the sequence that was originally there.

This type of gene editing has been successfully done in cattle embryos. In this case, the researchers used a more primitive version of CRISPRs called TALENs, but they do the same thing. In embryonic cells from horned cattle, the targeted section of DNA on chromosome 1 was replaced with the POLLED DNA sequence. In this proof-of-concept experiment, clones were created from these cells. And they grew no horns! The rest of the DNA in these animals remained the same as it was in the original genetic source, only the horned/polled location was altered. The two bulls produced (pictured above) will be used in breeding experiments to confirm that their offspring will also be polled.

This precise gene editing technique could be used to introduce polledness into elite dairy sires. In one generation, we could nearly eliminate the need to dehorn/disbud calves. That’s assuming there are no regulatory setbacks regarding the gene editing technology. (Ah, the potential sticking point.)

If you’d like some additional explanation accompanied by video of the polled bulls—currently residing at UC Davis—Science Friday has that here. The paper can be found here on page 479 (Carlson et al. 2016 Nature Biotechnology 34:479-481). I’ve glossed over some of the details, so if you’d like any additional explanation, please post a question via the “Leave a reply” link or email me.

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.)

Nelson et al. 2016. Vitamin D status of dairy cattle: Outcomes of current practices in the dairy industry. Journal of Dairy Science 99:10150-10160.

line graph showing blood vitamin D levels of six groups of calves across six weeks
(Modified) Figure 4 from Nelson et al. 2016. Serum 25-hydroxyvitamin D [25(OH)D] of Holstein dairy calves according to various housing and nutrition practices. Each point represents the mean and 95% CI of samples from at least 6 calves. The samples collected at 0 wk of age were collected after colostrum consumption. Open triangles (△) and dashed line represent calves from a herd in Idaho fed pasteurized waste milk with no supplemental vitamin D3 limited sun exposure (calves were housed in either hutches or barn and samples were collected in winter). Open circles (○) and dashed line represent calves from a herd in Florida fed pasteurized waste milk with no supplemental vitamin D3 and no direct sun exposure. Filled circles (●) and solid line represent calves in the same herd that received 150,000 IU of vitamin D3 at birth via injection and pasteurized milk supplement that provided 5,000 IU/d. Filled diamonds (◆) and solid line represent calves fed whole milk 3 times/d and kept outdoors in Florida (samples collected in mid-April). Filled squares (■) and solid line represent calves from a herd in Georgia fed milk replacer containing 6,600 IU/kg of DM. The calves received 0.8 kg/d of milk replacer from 0 to 14 d and 1.2 kg/d milk replacer from 15 to 42 d and raised under shade. Filled triangles (▼) and solid line represent calves from a herd in Florida kept outdoors in a group pen and fed ad libitum milk replacer containing 11,000 IU of vitamin D3/kg of DM.

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 eversm@oregonstate.edu or call (503) 758-6695.

A Holstein calf stands in a round calf hutch with several inches of snow.
At least the sun is shining? (Photo: Zweber Family Farms)

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?

Photo of a Holstein cow licking her newborn calf.
Photo: Carla Wardin, Truth or Dairy

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.

outline of a cow with detailed labeling of the digestive tract: mouth, esophagus, reticulum, rumen, omasum, abomasum, small intestine, large intestine
Figure 1 – Illustration of the digestive system in a cow.

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.

bar graph showing numbers of bacteria, protisis, fungi, mycoplasma, and viruses in a rumen. Also shown is the number of humans on earth for comparison. Data courtesy of Mel Yokoyana, Michigan State University.
Figure 2 – Illustration of microbe populations typically found in the rumen. The scale on the left is logarithmic.

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 jobs@crv4all.us by December 23, 2016.

Details are in the pdf links below.

crv-usa-2016-2017-marketing-intern-job-description

crv-usa-2017-dairy-genetics-intern-job-description

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.)

WHERE: Oldfield Teaching Center (on west side of OSU campus)

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 shelby.filley@oregonstate.edu 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.