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Thursday, December 23, 2010

DAIRY FARM .VIT-E NEGATIVE EFFECTS

THE NETHERLANDS - In a field study of 300 Dutch dairy cattle, Doctoral Candidate Ruth Bouwstra unexpectedly found a negative effect caused by vitamin E supplements.

In the study, the dairy cattle that were temporarily not producing milk and that had received vitamin E supplements had a significantly higher chance of developing mastitis than cattle that received less vitamin E.

Vitamin E is a powerful antioxidant. Normally, antioxidants prevent oxygen radicals from harming the body, and it is generally assumed that antioxidants have a positive health effect. For that reason, supplements containing antioxidants intended for consumption by humans and animals are very popular. The study was originally conducted to illustrate the positive effect of vitamin E, but the results of the study showed that extra vitamin E in the cow’s diet had a negative effect on the health of the cow’s udders. The researchers were very surprised at this unexpected result of their study.

One possible cause of this negative effect could be that some cattle that received extra vitamin E displayed an increase in the damage caused by oxygen radicals, instead of the expected decrease, and a high level of this type of damage seems to be linked to a higher risk of mastitis. Some cows that already had higher levels of vitamin E in their blood before they stopped giving milk, and which then received vitamin E supplements during their dry period, were observed to have more damage due to oxygen radicals.

From this, Ruth Bouwstra concluded that not every dry cow requires vitamin E supplements. According to her, the animal’s vitamin E levels should be tested before it is given any extra vitamin E.

Friday, December 10, 2010

HERD MANAGEMENT

MU Grazing-Dairy Herd Now Bred With Timed AI; Calves Come Early, Milking Starts Sooner In Spring

09/14/2010 09:23AM

MOUNT VERNON, Mo. - Getting cows to calve early in the milking year produces more milk in a seasonal dairy. Timed artificial insemination (TAI) makes grouped early calving possible.

That was just one research report given on the dairy tour at the 48th field day at the University of Missouri Southwest Center, Sept. 10.

At breeding time, 36 of 49 heifers conceived on the same day when bred with TAI, said Scott Poock, MU Extension veterinarian who bred the herd.

At the first stop, Chris Davis, MU dairy herdsman, mentioned that getting heifers bred was one of the biggest challenges on a dairy farm.

With TAI, the new heifers entering the herd were synchronized and bred without heat detection, a labor-saving method. The cows were synchronized, but were visually heat detected to determine when to breed.

In conventional dairies without synchronization, heat detection and breeding becomes almost a year-round chore. With TAI, all breeding can be done in one day. The resulting calves will be grouped to be born just ahead of the grazing season, another labor saver.

The grazing dairy at the MU research farm is operated as a seasonal milking herd. Milking season begins in early February, as the calves are born. The cows are dried off in December, which gives the cows and the milking crew a break in the daily milking chores.

"From the name, you can guess where the Show-Me Synch timed AI protocol was developed," Poock told visitors. The protocol, which uses a CIDR insert, was developed from basic research and field testing at the University of Missouri-Columbia.

To synchronize cow breeding, the CIDR, a vaginal insert, delivers naturally occurring progesterone, which controls the cow's breeding cycle.

The Show-Me Synch protocol has been tested on thousands of heifers in beef herds across Missouri, Poock said. Long-term average for the new protocol, now adopted nationally, has been about 62 percent conception on the first day of the breeding season.

"We're extremely pleased with the 73-percent conception in the dairy herd," Poock added.

With grouped calving, the cows reach peak lactation and their highest energy demand at a time when cool-season grass paddocks reach peak of spring growth. The cow nutritional demand matches forage production. More of the milk from the herd can be produced on low-cost forages instead of purchased supplemental feed.

At his stop on the dairy farm tour, Ted Probert, MU Extension dairy specialist, said a major advantage of AI breeding is access to the best genetics in a cow breed. "You can select from the best proven sires in a breed, whether Holstein or Jersey," Probert said. "The sire books provide lots of information on projected production. You can select what you need for your herd."

The basic breeds in the milking herd at the MU dairy are Holstein and Jersey. Most are crossbred, giving advantages of both breeds through hybrid vigor. Heterosis typically gives a 10-percent bump in reproduction efficiency, Probert said.

Over time, genetic selection in U.S. dairy cattle has centered on milk yield, Probert said. In a seasonal grazing dairy, ability to rebreed on time becomes the No. 1 concern.

Current MU dairy breeding concentrates on building a herd of about half U.S. dairy genetics and half New Zealand genetics. "At the Southwest Center we want to see if imported genetics result in improved herd fertility," Probert said. "Those have developed in an environment where breed-back is important."

In forage research, studies are underway comparing tall fescue containing a novel endophyte with a perennial ryegrass, said Stacey Hamilton, MU Extension state dairy grazing specialist. In the first year, the toxin-free fescue came on stronger, earlier. However, that advantage was lost as temperatures increased in the grazing season.

Hamilton said research at the farm is directed by a panel of farmer advisers. "We try to answer questions they need answered."

This fall, new research paddocks are being seeded west of the airport at the farm. These will compare five kinds of ryegrass to determine suitability for local climate and soils.

Besides dairy, the field day gave tours on beef, forage, fence, horticulture and grape research. The MU Southwest Center is part of the Missouri Agricultural Experiment Station, Columbia

HERD MANAGEMENT

Relationship Between Cow Weight, Milk Production, & Nutrient Needs

09/15/2010 09:21AM

Calf prices appear to be strong this fall. Because of high input costs, margin of profit for the cow/calf producer will again be narrow. Producers that continue to match genetics (mature weight and level of milk production) with feed resources, environment, and management system will be the ones that continue to enhance their profit potential. If moderation is your goal in terms of cow weight and milk production, it may be an increasing challenge to find the genetics to meet this goal. Breed sire summaries indicate that the genetic trends for growth traits, carcass weight, and milk production have increased over the years. It is hard to see how milk production and mature weight of commercial cow herds has not continue increased over time. In addition, it hard to see how nutrient needs of the commercial cow herd haven’t increased over time as well. McMurray (Feedstuffs article, 2008) suggested that average cow weight had increased 322 pounds between 1975 and 2005. McMurray indicates that average cow weight (weight for cows at body condition score 5) in 2005 was 1,369 pounds compared to 1,047 pounds in 1975.

Maintenance feed intake is proportional to the animal’s metabolic body weight. Metabolic body weight is defined as body weight to the 3/4 power (body weight3/4) which also describes the surface area and is representative of the active tissue mass or metabolic mass of an animal. So as cow weight increases, maintenance feed intake increases because metabolic body weight increases. Cows partition energy that they consume to body maintenance and growth, then lactation, and finally reproduction. In a low feed environment, cows with a high production potential would have limited energy left over for reproduction because they would shunt energy to maintenance and lactation and finally reproduction. In contrast, cows with low production potential (described as lower mature weight and daily milk production) in a low feed environment in theory would be able to shunt energy to body maintenance, lactation, and reproduction. A solution to increase energy intake for high producing cows in a low feed environment on a fixed resource base would be to reduce cow numbers (cow inventory). In a high feed environment, low production potential cows have enough energy to partition to maintenance, lactation, reproduction, and will likely put on condition. In this low feed environment and a fixed resource base, to limit energy intake of low production potential cow so they don’t get over-conditioned would be to increase cow numbers.

If cow mature weight were fixed at 1,200 pounds and milk production varied from 10 pounds/day to 30 pounds/day, annual maintenance energy needs increase. As milk output per day increases from 10 to 20 pounds/day, annual maintenance energy needs increase by 8% (7,815 Mcal per year compared to 8,427 Mcal per year). The increase in annual maintenance energy of a 1,200 pound mature cow producing 10 pounds of milk daily is 16% less than the same cow producing 30 pounds of milk daily.

If milk output per day is fixed at 10 pounds per day and cow mature weight changes from 1,000 to 1,200 pounds or 1,400 pounds, annual maintenance energy needs increase 14% going from a 1,000 pound cow (6,803 Mcals annually) to a 1,200 pound cow (7,728 Mcals annually). Likewise, maintenance energy needs increase 27% between a 1,000 pound cow compared to a 1,400 pound cow (8,637 Mcals annually).

If a ranch unit has a fixed set of resources, the effect of mature cow weight and daily milk production can be used to determine the number of cows at the same milk output with cows differing in mature weight that could be managed on the unit. If par was annual maintenance needs in Mcals for cows with a mature weight of 1,200 pounds and daily milk production was 20 pounds, we could calculate the number of 1,400 pound cows producing 20 pounds of milk daily on a fixed resource base. Likewise, using similar information, we could calculate the number of 1,000 pound cows producing 20 lb of milk daily that could be managed on the same set of resources. If 100 head of 1,200 pound cows producing 20 pounds of milk daily could be managed on a fixed resource base, using the annual maintenance energy needs, about 90 head of 1,400 pounds cows producing 20 pounds of milk daily or 112 head of 1,000 pound cows could be managed on the same fixed resource base. If cows in each weight group had a weaning rate of 85%, 85 calves, 77 calves, and 95 calves would be weaned from cows that weighed 1,200, 1,400, and 1,000 pounds respectively.

This is only part of the profit equation. Profit of an enterprise is a complex set of relationships. Net income or profit is gross income dollars generated minus total annual expenses. Gross income in a cow/calf enterprise is pounds of calf sold times price ($/cwt). Pounds of calf sold is a function of weaning weight and the number of cows weaning a calf. Nutrition impacts both of those factors.

Breed differences allow producers to design genetic packages that best fits the feed resources of the operation. In turn, this should increase the profit potential of the enterprise. The next question is what is the difference in costs as cow mature weight and daily milk production are varied. You’ve got over half the battle whipped when you have a genetic package of your cow herd fitting the resources they are to be managed in, especially feed resources. If the genetic trends continue in the direction they have been, how do producers maintain the genetic package that they have worked so hard to fit their resources and environment? The focus of the article isn’t to say light mature weight cows are better than heavy cows and high milk output is less desirable than low milk output. The idea is to help you keep your eye on the target of what genetics package fits your environment and to remind you of the major items that impact of the nutrient needs of your cow herd.

Source: Dr. Rick Rasby, Professor of Animal Science, University of Nebraska - Lincoln

HERD MANAGEMENT

Transition Cows: What Are Some Of The Basics?

09/16/2010 15:48PM

The transition period discussed here is defined as 3 weeks before calving to 3 weeks after calving - the most stressful in the life of a cow. Cows need the best care they can get during this period if producers want to have a successful dairy enterprise.

Basics in managing transition cows include adequate nutrition and environment. During the transition period nutrient needs increase whereas feed intake decreases. Very challenging, isn’t it? But cows can do it with some help. Nutrition is key, but a lot of the problems we sometimes see on dairy farms are non-nutritional and involve management, such as cow comfort.

During the transition period, the cow is going from the pregnant, non-lactating stage to the non-pregnant, early lactation stage. During the last weeks of pregnancy, feed intake decreases by about 30%, but at the same time, nutrient requirements are increasing. It is important to feed a nutrient dense diet to compensate for this lower intake. The rumen needs to be adapted to the higher grain lactation diet, and this should be done gradually. It is strongly recommended that herds have a close-up dry cow group (last 3 weeks of pregnancy) and a fresh cow group (2 to 3 weeks after calving). Reasons are not only nutritional, but management related. Heifers can benefit from a longer close-up period of about 4 to 5 weeks and large herds could have close-up and fresh heifer groups.

Transition Program Goals
Iowa researchers identified four physiological goals that the transition cow program needs to achieve:

1. Adapt the rumen for the higher energy lactation diet.
2. Maintain normal blood calcium concentration.
3. Build and stimulate the immune system.
4. Maintain a positive energy balance to avoid fatty acid build-up and subclinical ketosis.

Close-up Cows
Some of the feeding strategies needed during the close-up period to achieve these goals were outlined by Drackley, Goff, Grummer, Reneau, Shaver (summary from various articles):

1. Body condition score at dry-off should be 3.25 to 3.75 (BCS scale 1 to 5). Condition should be maintained during the dry period. Excessive body condition at calving can increase incidence of ketosis and fatty liver.
2. Increase grain feeding to 0.5 to 0.75% of body weight.
3. Target 35 to 40% nonfiber carbohydrates as a % of DM.
4. Feed high quality forages with sufficient effective fiber.
5. Limit fat to 1/4 to 1/3 lb per day.
6. Feed low potassium forages; balance for potassium concentration less than 1.5% of diet DM (get close to 1% as possible).
7. Provide adequate magnesium (0.4% of diet DM) and calcium (1 to 1.2% of diet DM).
8. Feed adequate selenium (0.3 ppm) and vitamin E (2000 IU per day).
9. Supply extra trace minerals such as copper, manganese and zinc to account for decline in feed intake.
10. Feed adequate crude protein (cows need 12 to 13%, heifers 15% of diet DM).

Fresh Cows
Calving and the change to lactating status are very stressful in the life of a cow. They need a lot of care. Assign your best employee/person to monitor this group of cows.

Maternity facilities must be clean, dry, well lit, well ventilated and comfortable. After leaving the maternity pens, cows should ideally be moved to a fresh cow group. There is also benefit in having a separate heifer group, because heifers are smaller and do not compete as well at the feed bunk.

The first 1 to 2 weeks after calving set the stage for the entire lactation. Studies have shown that for each 1 lb increase in peak milk, there is a 220 lb milk production increase for the entire lactation.

Monitoring Progress
After calving, it is important to optimize dry matter intake as soon as possible. Hutjens suggests monitoring feed intake by rating how the cow consumes fresh feed on a scale of 1 to 4 (1 = 0 to 33% consumed; 2 = 33 to 66% consumed; 3 = 66 to 90% consumed; 4 = all consumed). Cows off-feed will require special treatment. Observe chewing and rumination activity. Rumen movements should be monitored using a stethoscope – healthy cows have about 1.5 to 2 rumen movements per minute.

Body temperatures should be recorded daily. The goal is to be below 103º F for mature cows and 102.5º F for heifers. Uterine discharges should be checked and a ketone test on the cow’s urine or milk is recommended.

Ration Recommendations
Fresh cow rations should be intermediate between the close-up and the high group rations. Cows should be fed ad libitum – that means a 5 to 10% feed refusal. If concentration of energy and protein are somewhat low in the ration fed right after calving, it is important not to leave the cows in this group for too long of a time.

Rations should have at least 21% neutral detergent fiber (NDF) from forage and enough particle size to support good chewing activity and rumen fill. Shaver recommends diets have 8 to 10% of particles on the top screen of the Penn State Particle Size Separator for both prefresh and fresh cows. Hutjens suggests feeding 3 to 5 lb of high quality long forage to maintain rumen function.

Forage quality is very important in the transition period. High digestibility forages allow for increased intake and provide more energy in the ration. Satter and co-workers at the Dairy Forage Research Center observed an increase in milk yield of 4.5 lb per cow per day during the first four weeks of lactation when they were fed a brown midrib (BMR) corn silage compared to conventional silage. BMR silage has greater NDF digestibility than conventional silage. Cows were also fed the two silages 3 weeks before calving.

Recommended concentration of crude protein is 17 to 18% of the ration DM with 10.5% rumen degradable protein. Try to use a palatable source of bypass protein. It is important not to reduce feed intake. This might be a time to use rumen-protected amino acids, such as lysine and/or methionine. Goff warns that excess protein is counterproductive as it takes energy to eliminate the excess nitrogen in the form of urea. Synthesis of urea means that some glucose will be used for that purpose instead of being used for milk production.

As for the close-up group, it is important to feed adequate levels of copper, zinc, manganese, selenium and vitamin E. Horst suggests 2000 IU of vitamin E per day for fresh cows.

Water should always be available, clean and easily accessible. Water is the single most important nutrient. Waterer space should be a minimum of 3 inches per cow.

Nutrition is certainly important for the success of a transition cow program, but management is equally important.

Feeding Management Considerations
Feed bunk management is especially important for fresh cows and a risk factor for laminitis and displaced abomasums. How transition cows are fed is probably as important as what they are fed. Early fresh cows should have adequate feed bunk space (minimum of 2 linear ft per cow) and stall space. We should not crowd this group!

Forages should be analyzed for nutrient content. Use of table values is not recommended. Sampling of forages needs to result in a representative material of the forage that is going to be fed. Minerals should be analyzed by wet chemistry methods and not NIR.

Adequate ration particle size provides enough effective fiber to promote chewing and rumination. Sorting in the feed bunk should be avoided. Shaver suggests that an on-farm evaluation of sorting should include particle size determination of the TMR and refusals. Sorting can be caused by high ration dry matter, particle size of the forages, cobs in the silage, amount and quality of hay added to the ration, how often cows are fed, bunk space and time available to eat the ration (Shaver).

Properly mixing the ration is crucial to the success of the dairy operation. Any scale errors should be fixed and the person feeding the cows should be properly trained on ration mixing and delivery.

Cow Comfort and Environmental Stress
Cows are physiologically at the most stressful time of their lives during the transition period. They do not need any extra stressors such as, crowded stalls, not enough feed bunk space, competition from bossy cows, not enough waterer space, poor walking surfaces, small stalls, poor bedding, poor ventilation.

Overcrowding is common on most freestall barns. Greenough, a veterinarian from the University of Saskatchewan, Canada, suggests that there be 25% more stalls available than there are cows. Fresh cows need to have their space. Comfort of stalls should be maximized. Cows will lie as many as 14 hours in the most comfortable stalls. The minimum amount of time spent lying or resting should be 10 hours per day (Grant and Albright).

Surfaces should not be slippery. It is necessary to roughen smooth concrete or add grooves on a quadrilateral pattern. Manure should not accumulate on walking surfaces. It can reduce sure footing and contribute to lameness by softening the claw.

Grouping of transition cows can affect feeding behavior and incidence of metabolic disorders. Heifers can benefit from separate grouping because of their smaller size and lower position in the pecking order.

The effect of many stressors affecting the cow at the same time is additive. Stress takes energy from the body and can predispose the cow to developing diseases.

Take-home Message
For a successful transition cow program, attention should be given to proper formulation of rations to avoid metabolic problems and get cows to a good start. It is also important to have proper feeding management and grouping strategies. Last, but not least, cow comfort and reduction of environment stressors are critical during the transition period.

Source: Marcia I. Endres, Assistant Professor and Extension Dairy Scientist, Department of Animal Science, University of Minnesota, St. Paul 

HERD MANAGEMENT

At the request of the four co-chairmen of the Congressional Dairy Farmer Caucus, Congressman Joe Courtney, Congressman Timothy Walz, Congressman Devin Nunes, and Congressman Peter Welch, the Food and Agricultural Policy Research Institute at the University of Missouri (FAPRI-MU) has analyzed the impact of adopting the current California fluid milk standards throughout the U.S.
Milk as it comes from the cow contains water, nonfat solids and butterfat. Nationally, the average annual composition of milk is 8.72 percent nonfat solids and 3.67 percent butterfat, with the remainder being water.
Food and Drug Administration (FDA) regulations allow fluid processors to affect the composition of milk by adding or removing butterfat or by blending milk of varying compositions to achieve a particular fluid product. Fluid milk processors cannot add water to adjust the butterfat content of milk. Minimum standards for fluid milk are established by the FDA. States can also establish standards for fluid milk marketed within the state.
Imposing California fluid standards in the U.S. has been a policy alternative that has been debated many times over the past several years. When the dairy industry was burdened by large surpluses of nonfat dry milk, many believed it was a way to eliminate those surpluses. Today, with some nonfat solids entering export markets the potential for exports of nonfat solids to grow, the effects of imposing California fluid standards results in a slightly different outcome than was found in a period of surplus nonfat solids.
Imposing California fluid standards increases producer milk prices and consumer fluid milk prices. These effects become less over time as the industry adjusts to the changing standards. Fortification allowances could work to minimize these effects depending on how they would be implemented. The increase in producer milk prices would reduce Commodity Credit Corporation dairy outlays but the effect is small against the current FAPRI baseline.
There is the potential for some differing regional effects depending on the availability of condensed skim to meets the needs of fluid processors who need product to meet the new minimum standards.
The effect of imposing California fluid milk standards is lessened over time as supplies of milk increase in response to higher milk prices.
Source: Food and Agricultural Policy Research Institute at the University of Missouri