Risks to the calf

Calves are at risk of broken bones, especially ribs and limbs if chains are placed incorrectly, and internal organ damage.

When the calving jack makes sense

A calving jack is a useful tool for mild to moderate dystocias when a person is working alone, especially if they have strength or physical limitations. Before pulling any calf, check to make sure the calf is in the normal birthing position. You should feel a nose and two front feet.

Before pulling, determine if the calf is likely to fit through the pelvic canal. You should be able to fit one hand on either side of the calf’s shoulders as it is entering the canal. If your hand does not fit or if the calf’s front legs are crossing, it is unlikely the calf will fit. Remember, the widest part of the calf is the hips. If the shoulders of the calf are already wedged into the pelvic canal, then the hips can’t make it through.

Why patience matters

Even if the calf is in normal presentation and presumed to fit through the birth canal, the calf jack should not be the first choice of intervention. When a calf is born, the entire process of pushing the calf through the birth canal (stage two of labour) can take 30 minutes to two hours. This allows the cow’s cervix to fully dilate, her vagina to stretch, and facilitates the safer progress of the calf to reduce tearing. A calf jack will expedite the process, preventing the cow’s body from naturally adapting and increasing unnecessary trauma to cow and calf.

If a cow or heifer is not progressing after 20 to 30 minutes of active labour, it is appropriate to intervene. There are several techniques that can be used to leverage the cow’s natural physiology during labour as an alternative to the calf jack.

Alternatives to the calving jack

Cervix not dilated

If the calf is unable to fully enter the birth canal because the cervix is not fully dilated, it can be manually dilated. Place your hands through the cervix and clasp them on the uterine side. Push outwards with your forearms to encourage dilation of the cervix. The cervix should slowly dilate as you continue to push for several minutes.

Vagina not dilated

If the cervix is dilated but the vagina is preventing passage of the calf, use the same technique above with your arms to stretch the vagina. This helps to prevent tearing of the perineum, the separation between the vagina and the rectum.

Calf stuck in birth canal

If there is concern that the calf is too large to fit through the birth canal, there are a couple of tips to try before resorting to veterinary intervention. First, apply lots of lubricant. Mix in a bucket and use a drench tube and pump to get sufficient lubrication inside the birth canal. If possible, avoid J-Lube, as this brand is irritating to the abdomen if the dystocia leads to a C-section. Second, cast the cow down so she is lying instead of standing when you pull the calf. When a calf is lying down her pelvis is naturally tilted on a 45 degree angle. Since the birth canal is an oval shape, this rotation allows the hips of the calf to pass through on a diagonal, naturally creating extra space for it to pass.

For in-depth instructions on how to safely and easily cast a cow, search for videos of the Rueff or Burley method for casting cows with rope.

When to stop pulling

Keep in mind that as long as the umbilical cord is intact, the calf is receiving oxygen from the cow, and there is time to perform these manipulations. There is one related scenario where a calf jack is especially useful: backwards calvings with larger calves. When the calf passes through the birth canal backwards, the pelvis puts pressure on the umbilical cord, limiting oxygen delivery to the calf. If the calf runs out of oxygen, its instinct is to inhale, and it may breathe amniotic fluid into its lungs. Once the decision has been made to pull the calf, it is important to get the calf’s hips and abdomen through the pelvic canal as quickly as possible to prevent this.

If progress is not being made after 20 minutes, move on to the next option. Some calvings will only end successfully in a C-section or fetotomy. Making this decision promptly will improve the success rate for both calf and cow.

The post When should you use a calving jack — and when should you stop? appeared first on Canadian Cattlemen.

Vacinnating and treating livestock is a given for any beef operation. In this interview, Erika Stewart, the VBP+ coordinator for Saskatchewan, shares tips for choosing an injection site, giving multiple injections to the same animal and maintaining your vaccine’s effectiveness.

For more resources on beef cattle health, visit our Herd Health page.

The post AUDIO: Tips on vaccine placement in cattle appeared first on Canadian Cattlemen.

First let’s review how cattle meet their protein needs. Feed consumed by the animal enters the rumen and is subject to fermentation by rumen bacteria. This fermentation results in the breakdown of the carbohydrate and protein fractions of the feed. Fermentation of the carbohydrate fraction (i.e. starch, fibre) provides energy to the animal and concurrently to the rumen bacteria. The protein fraction is broken down to its constituent parts, specifically amino acids. These released amino acids are used by the bacteria to synthesize bacterial protein or are further broken down to ammonia, which in turn is used by the rumen bacteria to resynthesize amino acids, which are then incorporated into bacterial protein.

Critical to the use of ammonia for bacterial protein synthesis is an available energy supply, which as discussed above is derived from fermentation of the carbohydrate fractions of the ingested feed. If this energy is lacking or available at the wrong time, the efficiency of bacterial protein synthesis drops dramatically.

Finally, when the bacteria flow out of the rumen, they enter the small intestine of the animal and are subject to normal digestive processes. In particular, the bacterial protein and the high-quality amino acids it contains become available to the animal for its protein needs.

How does urea feeding relate to this process? First, remember that urea is strictly a nitrogen source; it is not a source of pre-formed amino acids as is the case with feed protein. The nitrogen content of urea is approximately 45 per cent. This equates to a crude protein value of approximately 280 per cent, based on a conversion factor of 6.25 (i.e. the nitrogen content of feed protein). While 280 per cent crude protein seems impressive, remember it is solely a nitrogen source. Urea is rapidly broken down in the rumen to ammonia. As with ammonia released from the fermentation of feed protein, ammonia released from urea breakdown needs to be converted to bacterial amino acids and then into bacterial protein to be used by the animal. If not used in this fashion, it is wasted.

The key to efficient use of urea-nitrogen by rumen bacteria is feeding a ration that is high in available energy, typically grain-based rations. These rations are readily fermented in the rumen, supplying both the animal and the bacteria with a readily available energy supply. In the case of the bacteria, this energy is used to incorporate urea-nitrogen into amino acids and ultimately bacterial protein. In situations where urea is fed without a readily available source of energy (i.e. poor-quality forage-based diets), much of the urea-nitrogen is wasted as there is no available energy for the bacteria to incorporate it into microbial protein.

With this background, let us try to answer the questions raised by producers regarding urea feeding. First, let’s look at using urea as the primary protein source in supplements (i.e. pelleted supplements, loose minerals or tubs) for mature cows fed poor-quality forage (i.e. poor hay, straw). It should be obvious from the above discussion that unless the supplement is fortified with an energy source such as molasses or the ration with grain, the urea in these supplements will be poorly utilized, as the forage consumed by these animals does not supply sufficient energy for the rumen bacteria to efficiently synthesize protein.

A similar situation applies to backgrounding rations. Such rations are primarily forage-based with a relatively low grain content. In such cases, protein/mineral supplements where urea supplies most, if not all of the protein should be avoided, as there is not sufficient energy released from the fermentation of these high-forage diets to make efficient use of the urea-nitrogen.

In contrast, urea can be used very effectively when high-grain rations are fed as the fermentation and release of energy from these diets nicely matches the release of ammonia from the urea. Such synchronization optimizes the ability of rumen bacteria to incorporate urea-nitrogen into protein. A good rule of thumb to follow in these high-grain feeding situations is that protein from urea comprises no more than one-third of the total ration crude protein.

In addition to ensuring the right “feeding situation,” there are several other important considerations when using urea as a protein source. Most importantly, keep in mind that urea can be toxic if fed in excess. As such, ensure that urea-based supplements are fed at recommended levels and thoroughly mixed in the ration. Do not feed multiple sources of urea. As well, rations need to be balanced for all essential nutrients, including the macro and micro minerals. Finally, from both a palatability and efficiency-of-use perspective, urea should not be fed to light-weight calves.

The post Revisiting the use of urea as a protein supplement appeared first on Canadian Cattlemen.

First a bit of chemistry: mineral elements exist in various ionic states that can have either positive or negative charges. Positively charged elements are referred to as cations (i.e. calcium, phosphorus, copper and zinc). Negatively charged elements are called anions (i.e. chloride, sulfur). Elements with opposite charges tend to attract each other, while those with similar charges tend to repel each other. It is through these ionic interactions that different combinations of minerals in feed and water sources restrict the absorption of specific minerals and by so doing, influence animal health and/or productivity.

The first example I will give is milk fever, which is a metabolic disease that affects beef cows at or near the time of calving. Symptoms include muscle weakness and twitching, abnormal gait/staggering, hyperexcitability, failure to stand and, in some cases, loss of consciousness and death. The most consistent clinical sign is low serum calcium, a condition known as hypocalcaemia. Low serum calcium levels can result from inadequate dietary sources, failure to absorb dietary calcium and/or failure to mobilize body calcium reserves.

Factors which predispose an animal to milk fever include age, parity number (number of times she’s calved) and diet. For example, milk fever is relatively rare in heifers. However, as the animal ages and increases in parity number, milk production typically increases, which increases the cow’s calcium requirement. Compounding this increased demand, older cows do not mobilize body calcium reserves as readily as younger animals and thus are at increased risk of low serum calcium levels at times of peak demand, such as the onset of lactation.

The effects of diet are somewhat more complicated. Feeding excess calcium to a prepartum beef cow might seem like a logical solution to low serum calcium levels at or near the time of calving. Unfortunately, such a strategy can have the opposite effect in that high dietary calcium intake tends to shut down or impede the body’s ability to regulate serum calcium. Specifically, mechanisms for calcium absorption and/or mobilization from bone are down-regulated in situations where dietary calcium levels are excessive.

Historically with dairy cattle, the approach was to feed low dietary calcium before calving in order to activate mechanisms for regulating serum calcium, an approach that was not always successful. A dietary approach that has proven successful, particularly with dairy cows, is manipulation of the dietary cation-anion balance (DCAB). Nutritionists calculate the DCAB from the sum of the sodium and potassium ions (i.e. the cations) minus the sum of chloride and sulfur ions (i.e. the anions) with the concentration of each element expressed in milliequivalents. Most importantly for our discussion, diets that have a surplus of anions relative to cations promote bone mobilization of calcium and help to prevent milk fever, while those with a surplus of cations have the opposite effect. In the dairy sector, it is common to see prepartum diets formulated with a negative DCAB to help minimize issues with milk fever. Unfortunately, with beef cattle, there has been very little research. But when one considers the relatively high potassium levels of some of our common forages, it would be extremely valuable to know the optimal DCAB for prepartum beef cows.

A second example is grass tetany or grass staggers. Symptoms are similar to milk fever but the condition is a result of low serum magnesium levels. As with milk fever, advancing age and parity number increases the animal’s risk. In terms of diet effects, low forage magnesium levels can induce the condition as well as an imbalance in the ratio of dietary potassium to that of magnesium and calcium (concentrations again measured in milliequivalents). Known as the “Tetany Ratio,” Australian research has shown that ratios greater than 2.2 are associated with an increased frequency of tetany symptoms in cattle. High ratios can be associated with forages that are high in dietary potassium and/or low in magnesium. Agronomic factors that can lead to high forage potassium levels include stressors on plant growth such as drought and the use of manure as a fertilizer, particularly with cereals grown for green feed.

A final example is the interaction that occurs between macro minerals such as sulphur and molybdenum and trace minerals such as copper. Feed and/or water sources that are high in sulfur and/or molybdenum can induce a copper deficiency in cattle despite adequate copper intake. This is because sulphur and molybdenum separately or together can form insoluble complexes with copper and markedly reduce its availability to the animal. To counteract this effect, many nutritionists will look at the copper/molybdenum ratio of the ration, as well as total sulfur intake when making decisions on mineral formulation.

As you can see from above, mineral nutrition is a complex subject; advice from your nutritionist and/or feed company can pay big dividends.

The post Milk fever, minerals and chemistry: It’s just one big interaction! appeared first on Canadian Cattlemen.

“We need to do studies looking at long-term implications of ingesting this material. Our study was a short-term look at what happens to it in the rumen,” he says.

Six types of material were evaluated: sisal twine, biodegradable twine, three different kinds of net wrap, and hay (bromegrass). The hay was a control sample, for comparison. Each material was cut into small pieces, and a two-gram sample put into nylon bags and placed in the rumen of two forage-fed Holstein steers.

“The nylon bags would not degrade in the rumen, yet the rumen fluid could come into the bag and bacteria action could occur in the bags. We kept some of these samples inside the cattle for 14 days,” says Dahlen.

After being in the rumen for various amounts of time (four, seven and 14 days) the bags were taken out and rinsed, drained and dried, then weighed.

“Nothing was disappearing. After 14 days in the rumen, none of the three types of net wrap or the biodegradable twine samples disappeared. Most of the hay sample was digested and gone, and more than 70 per cent of the sisal twine disappeared over the 14-day period. Biodegradable twine breaks down in UV light, but there is no UV light in the rumen, so it doesn’t break down in there,” he says.

“We did another study, feeding steers net wrap. One group was fed net wrap until harvest and another was fed net wrap up until 14 days before harvest. That group would have 14 days to continue eating and not have any new net wrap coming into their rumen. We wanted to see if the net wrap might go on through and if the rumen could clear itself of this material, or if this material would still be there after 14 days,” says Dahlen.

“This study looked at what might happen in the rumen if the net wrap is floating free in there while the animal burps, chews its cud, etc. It could come up with the other material, get chewed more — and the rumen is churning/pulling everything around inside it during the digestive process. We wondered if this might clear net wrap out of the system,” he explains.

“We opened those cattle up and there was still net wrap all through the rumen, even in the steers that hadn’t been fed any more net wrap for 14 days. That shows it is staying in there and may just keep accumulating.”

That wasn’t all they found. The rumens also held rocks and little pieces of plastic from the covering of a silage pile.

“These objects can either block on the front end, which would lead to bloat (hindering ability to burp) or block the other end, and the material can’t leave the rumen as readily.” This would create lingering effects like impaction, or weight loss because the rumen is full.

The post NDSU studies net wrap, twine ingestion in cattle appeared first on Canadian Cattlemen.

Initially beta-agonists were incriminated but numerous studies have essentially proven it was not due to beta-agonists but a combination of other factors that precipitated this condition. Coming out of this discovery were a number of preventive measures feedlot operators could use to prevent this condition from arising.

Dr. Dan Thomson of Kansas State University and a team of researchers in production animal medicine determined several stressors lead to fatigued cattle syndrome (FCS).

FCS has some characteristic symptoms but of course they can be confused with other syndromes such as acute laminitis due to grain overload, and selenium/vitamin E deficiencies. Symptoms of FCS include a strained pattern of breathing as well as very slow movements leading to non-ambulatory cattle. In severe cases there has been sloughing of the hooves.

Contributing factors to FCS are possibly preventable. The heat load definitely contributed as the initial cases appeared in temperatures around 35 C. The specific findings in our upcoming Canadian transportation code revision may lead to specific recommendations, but obviously we need to be extra careful handling, transporting and butchering cattle in the summer heat. Depending on distance travelled or number of cattle moved and sorted, perhaps a maximum temperature will be found that is safe. We also know that hide colour has a lot to do with heat stress and tolerable temperatures may go down as the percentage of black-hided cattle go up. A good percentage of the cattle we see today in Western Canada are black hided.

I was privy to a very descriptive video showing heat stress in a pen of mainly black-hided cattle. While the majority of the cattle were in the shade of a porosity fence and breathing heavily, the minority red and white cattle were up at the feed bunk eating. Of the few cattle I have treated for heat stress over the years, all have been black hided. Cattle handling, the distance to be loaded, the distance traveled and the related stress during movement all contribute to FCS.

These may all seem like common-sense observations, and they are, but until this specific syndrome appeared there was no reason to suspect we had a problem.

The researchers also performed tests to determine muscle enzyme levels in the blood. In affected cattle the levels get very high. It is the same with downer cattle as they attempt to rise or calves with white muscle disease.

Dr. Thomson and his group found that aggressive handling produced the same muscle lactate levels as running a seven or eight-minute mile or walking for about 20 minutes. We can all identify with this. If we run too far when we’re not used to it, our muscles can become extremely sore for a few days due to the buildup of lactic acid.

Feedlot cattle these days are getting bigger, and when they are in prime condition for butchering they are not athletic enough to be running around for any amount of time. In some large feedlots the home pen may be more than a mile from the load-out area and that had a bearing on the incidence of FCS, so changes may need to be made in lot design. It may require staged moving or more load-out areas.

It would be nice to have parameters that are easily measurable and tied in with temperature.

FCS was even more critical at the packing plants. Some common factors contributing to FCS at the plants were the time the cattle remained in the pens before slaughter and whether shade and cooling were available, particularly in areas with very hot climates. Cattle density in the pens was another factor. When holding pens get crowded the cattle cannot properly dissipate heat.

Animal handling practices and facilities were also looked at. Stress, exertion and rough handling can often be reduced by better facilities or better training of staff. Flooring was another factor. Some surfaces resulted in injuries to the feet.

In the U.S. discovering the causes of FCS has lead to a training and monitoring protocol termed the “FCS Stewardship Program.” The goal is to minimize or eliminate FCS by removing or reducing these risk factors across the industry.

Investigating all suspected cases should identify the areas that need improvement. Although the incidence of FCS may never have been as high in Canada as in the U.S. with our more temperate climate we still gets very hot summer days in southern areas of the country. So it makes sense to be aware of the potential ramifications of how we sort, process, load and transport cattle, especially with heavy marketweight, black-hided cattle on hot summer days.

The post Steer clear of fatigued cattle syndrome appeared first on Canadian Cattlemen.

I saw that two of these steers had each something wrong with one eye; one animal had an inflamed dripping eye that was closed shut, while the other steer had a visibly cloudy eye. The manager took their ear-tag numbers and treated them that afternoon for pinkeye.

By now, I understand that the patches used to protect their infected eyes have fallen off and both animals are up to the bunk with the rest of the cattle, like nothing happened.

This story is a good reminder that early detection, rapid treatment and a good prevention program should halt the advancement of pinkeye in most cattle herds. We should also be reminded that untreated cattle that go blind in one diseased eye consume less feed and don’t gain as well compared to cattle with acceptable two-eye vision. For example, mid-American research (SDSU, 2013) states spring calves diagnosed with pinkeye weigh about 20 pounds less than normal, which translated in hard cash is about $30 of lost revenue at weaning time.

Even with a pinkeye program in place, some people are shocked when a string of their cattle come down with this highly contagious and painful disease caused by Moraxella bovis bacteria. In itself, the healthy bovine eye has adequate defense mechanisms to prevent M. bovis growth, but a number of factors particularly during the summer months come together that breakdown this natural protection and cause a pinkeye outbreak.

I find it surprising that pinkeye can literarily start with one animal; one eye for whatever reason starts to tear, which underlies the perfect environment for the M. bovis bacteria to thrive. The initial source of eye irritation can come from anywhere such as abrasive pasture grass, dust, wind, or excessive sunlight, yet by far the primary source of cattle eye irritation is the common face fly.

Flies are leading culprits

Face flies are naturally attracted to the head of cattle on pasture, and specifically attracted to the discharges of the eye. These flies have abrasive spongy mouthparts that stimulate the eye to tear, so they can feed off the secretions. Inadvertently, they fly from one individual transferring m.bovis from animals with clinical pinkeye or recovered pinkeye carriers (still harbour bacteria in inner eyelid surface) to healthy cattle. These flies also cause small scratches on the conjunctiva and corneas of the eyes when they feed, which makes it much easier for the M. bovis organisms to attach to the eye tissue and thrive.

Treating cattle infected with pinkeye can be straightforward, but nobody should wait for it to appear before medical action is taken. A sound program for pinkeye prevention may start with insecticidal and non-chemical control, which focuses around the head of the animal as well as takes into account that face flies spend only about 10 per cent of their adult life on the face of cattle. Face flies are usually found spending most of their time on fences, trees and other objects. In the fall, face flies tend to overwinter in cattle buildings.

Pinkeye control program

The underlying foundation of a good pinkeye control programs are:

• Ear tag protection. Plastic ear tags are impregnated with either organophosphates or pyrethroids. One tag per season is recommended per animal. Most people should be aware that the efficacy of the insecticide in ear tags is good for up to about five months of control.
• Strategic rotation of insecticides. It’s also common practice for producers to alternate organo- and pyrethrin-based tags every other year to reduce the chance of face-fly resistance. Note: a new ear tag has come out in recent years that contains both of these insecticides.
• Non-chemical and animal management. Some producers keep their cattle out of tall grass pasture and overgrown bush, which is not always practical, but reduces the incidence of eye irritation. In drylots, excessively dusty areas are controlled by various means. Ideally, infected animals should be isolated from the rest of the herd, because they are highly contagious.
• Nutrition prevention. Make sure nutrients that promote good eyesight and a functioning immune system (such as vitamin A, vitamin E, zinc, copper and selenium) are fed.
• Feed management. I know of one feedlot producer who adds water to his beef grower diet to keep the dust down. Another producer quit emptying dusty feedlot ration on the heads of the cattle during feeding time to avoid irritating feed getting in the cattle’s eyes.

Such methods to halt pinkeye in cattle are important because of the serious economic losses when an animal loses sight of even one eye. Pinkeye might be a summertime disease because of the associated risks involved, but implementing the proper treatment and prevention programs can help producers combat the effects of pinkeye, all year round.

This article first appeared in the June 7, 2016 issue of Grainews magazine

The post Untreated pinkeye in cattle can be costly appeared first on Canadian Cattlemen.

As the temperature/humidity chart illustrates, beef cattle like the ones that I saw are susceptible and suffer from one of three Bs (baked, broiled or barbecued) of summertime heat stress. It starts to occur in cattle at any time when the temperature-humidity index (THI) of 72 is exceeded.

As cattle enter the ‘baked’ zone, because they don’t sweat like us (cattle have a 10 per cent capacity to do so), they must rely on panting to dissipate heat to maintain a normal body temperature of 101.5 F (38.6 C). As the weather gets hotter and/or more humid, these cattle figuratively move into the ‘broiled’ zone, where they significantly increase water consumption and lose much interest in eating.

Finally, under extreme heat-stress conditions, cattle are visibly uncomfortable and often foam from the mouth from excessive salvation. Beyond this point, cattle are literarily ‘barbecued’ to death.

Luckily, heat stress fatalities are rare in Western Canada, yet I would expect heat-stressed cows to slow down any significant grazing during the hottest parts of the day. If they don’t catch up at night, overall nutrient intake could be reduced and milk production could be irreversibly compromised. Also, slightly heat-stressed calves usually do not nurse as well and are less likely to use the creep feeders. Cow-calf loss of nutrition leads to significant lower spring calf weaning weights, which could mean lower revenues coming off pasture.

Losses add up

Just consider a 300-cow-calf operation with spring calves that traditionally gain 2.0 lbs. per day, only to stall out during a 21-day heat-stress period in August. When these calves are sold in the fall (assumed at the same time of the year); my calculation for their failure to gain weight/subsequent decreased income is as follows:

300 spring calves x 2 lb./head/ x 21 days x $2.25 (demonstration autumn price — weaned 600-lb. steers) = $28,350. That’s nearly a loss of $30,000 revenue directly due to heat stress.

Overall research supports that heat-stressed cows are more likely to remain open, because they are less likely to ovulate, have irregular estrus cycles, may have poor conception rates, and suffer from a high rate of early embryonic deaths at two different times of pregnancy. Cows that experience early embryonic loss during the first week of pregnancy appear as repeat breeders (return to cycling), while cows that experience fetal death later on come back to cycling at the end of the breeding season.

Late-breeding season bulls (re: breeding bull still out on pasture) might also become temporarily infertile due to heat stress.

Managing heat stress

Producers can’t change the weather, but there are many proactive steps that can help reduce hot weather’s negative impact upon the comfort and performance of the beef herd:

1. Lots of cool, clean water must be provided. The water surface area should be sufficient for a large number of cattle to drink at the same time, and the water flow within the waterers and tanks should be replenished, quickly.
2. Cows and calves should access to trees and other forms of shade. Open buildings and pole sheds with light-coloured roofs can be used to provide shade. Windbreaks will provide shade, but they reduce air movement and sometimes contribute to heat-stress.
3. Adjust pasture management. Under rotational grazing systems; rotate the cattle through pastures more quickly. This change allows cattle to graze more digestible pasture forages which lowers their internal generation of heat from fiber fermentation.
4. Feed a nutritious and palatable creep feed to nursing calves. It is also a good idea to frequently check the creep feeders, and not allow them to go empty.
5. Provide salt and a good commercial mineral at all times. Pasture studies suggest cattle need more sodium, potassium, and magnesium under heat stress.
6. Implement a good fly-control program. Many producers implement insecticide ear tags and use cattle back-rubbers, dusters and oilers. Eliminate shallow pools, muddy areas and other fly-breeding spots.

We can help grazing cattle and calves hit hard by the three Bs of heat stress by implementing these coping techniques. It’s my experience that they do work. A few years ago, I took a beef management course at Texas A&M University. One afternoon, I was walking down the street in College Station and the temperature was 40 C with a relative humidity of about 80 per cent (THI = 99). The rest of the day, I spent in the hotel pool, in the shade and drinking diet Pepsi. I felt much better.

The post Tips to help cattle cope with summertime heat stress appeared first on Canadian Cattlemen.

Bovine tuberculosis affects the lungs of cattle and bison, and wild species such as deer and elk. It also can be transmitted to humans. While more prevalent in the developing world, where it causes annual losses of about $3 billion, managing the disease also carries a multi-million-dollar price tag in Canada. Johne’s disease, caused by a related species of bacteria, results in chronic inflammation of the intestinal tract in cattle. It is a particular problem for dairy herds, causing the animals to sicken and sometimes die.

VIDO-InterVac researchers and their collaborators in Canada and Ireland aim to deliver two new vaccines for these costly mycobacterial diseases. The funding, awarded through Genome Canada’s Genomics and Feeding the Future program, is part of a $7.4-million project over four years.

The team, which includes collaborators at the University of British Columbia (UBC) and the Agri-Food and Biosciences Institute in Northern Ireland, will use a genomics-based approach called ‘reverse vaccinology’ to identify disease proteins that the cattle immune system will recognize as foreign and react to. Identification of these proteins is the first step in developing novel vaccines. The project will use VIDO-InterVac’s state-of-the-art containment Level 3 facility.

“We have the only facility in Canada with the capacity to conduct vaccine development and testing of this magnitude,” said VIDO-InterVac director Andrew Potter. “Our team will take full advantage of VIDO-InterVac’s containment infrastructure to develop vaccines that will not only improve the health of cattle, but will also enhance Canada’s reputation as a major agri-food producer.”

Project co-lead, Robert Hancock, director of the Centre for Microbial Diseases and Immunity Research from UBC, agreed.

“This grant is further evidence that our long term collaboration with VIDO-InterVac produces outstanding results that solve economically-important problems,” said Hancock.

The researchers plan to develop and bring to market vaccines for these costly diseases within two years of the project’s end.

The post VIDO-InterVac awarded funding for new cattle vaccines appeared first on Canadian Cattlemen.

In Canada, when we think of environmental stress, we generally think of those mid-winter days where below-zero temperatures and/or wind combine to increase the maintenance energy requirements of cattle. In other parts of North America, particularly the southern U.S. and Mexico, heat stress is an equally serious threat to productivity. To understand how extremes in environmental conditions impact the animal and how it adapts to such stress, it is necessary to explore how an animal regulates its body temperature. Normal body temperature in cattle is 38.5 C and must be maintained within relatively tight limits for normal physiological function. One of the challenges to maintaining a constant body temperature is the need to dissipate heat generated from normal metabolism and digestion, particularly rumen fermentation. The ability of cattle to dissipate such heat is influenced by a number of internal and external factors. Heat is lost from the body via radiation (loss to atmosphere), evaporation (respiration, sweating) or by convection and conduction (air/water movement across or in contact with skin).

• More ‘Nutrition’ with John McKinnon: Focus on your yearlings this breeding season

Under “normal” environmental conditions, dissipating this body heat is not a large issue and the energy required to do so is considered a part of normal maintenance requirements. However, when environmental temperatures rise to a point where the animal has difficulty dissipating body heat, steps must be taken to actively lose that heat (i.e. seek shade, increase water intake, decrease feed intake, increase respiration rate). Conversely, when the environmental temperature falls, at some point the body heat produced by the animal is no longer sufficient to maintain its core body temperature and steps are taken to generate heat (i.e. shivering, increase feed intake, seek shelter). The range of environmental temperatures where cattle do not have to expend energy to maintain normal body temperature is known as the thermal neutral zone. The points where cattle must actively lose or generate heat are referred to as the upper and lower critical temperatures, respectively.

It is not possible to precisely define the temperatures that define the thermal neutral zone for any group of cattle, as both the upper and lower critical temperatures are a result of complex interactions between environmental (i.e. ambient temperature, wind speed, humidity), animal (i.e. hide thickness, summer versus winter hair coat) and management (i.e. windbreaks; muddy pens, bedding) factors. To understand how these factors interact, let’s look at heat stress. If we use 25 C as a starting point, as the ambient temperature rises and approaches/exceeds 30 C, the animal will experience greater difficulty in dissipating heat. When these high temperatures are combined with humid conditions, the animal’s ability to shed body heat is greatly reduced and the result is heat stress. The higher the humidity and/or ambient temperature, the greater the impact! Heat-stressed cattle show a range of symptoms. In mild cases, cattle will seek shade, or water sources to cool themselves, change or reduce eating/grazing patterns and alter their herd behaviour. Physiologically they will increase their respiration rate. In more severe cases cattle will exhibit very rapid rates of respiration to the point where they are actively panting in order to increase heat loss.

For many Canadian producers, heat stress is not high on their radar, however, it has obvious implications on production, animal welfare and ultimately on economic return. In the feedlot, it will lead to reduced dry matter intakes, lower gains and extended days on feed. In breeding cattle, milk production drops off with implications on weaning weights and breeding programs can be extended, particularly if your bulls are overconditioned. In severe cases, death can result. Alberta Agriculture has an excellent fact sheet that provides practical advice on minimizing heat stress in cattle. As we move into the dog days of summer, it is worth reading.

Cold stress is a much more familiar concept to Canadian producers. Like heat stress, the point where cattle actively take steps to increase heat production to maintain core body temperature is influenced by a number of interacting environmental, animal and management factors. However, since it is only June, it does not seem appropriate to be writing on winter feeding and management strategies. As such, I will save this discussion for a future article. In the meantime, keep your eye on the horizon (or the weather channel) as you never know what system is moving in next.

The post A Colorado low you say – only in Manitoba appeared first on Canadian Cattlemen.