May 24, 2012
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Animal Health & Nutrition

RSS By: Rick Lundquist, Dairy Today

Rick Lundquist is an independent nutrition and management consultant based in Duluth, Minn. He provides livestock production advice.

Make the Most of Summer Grasses

May 21, 2012

Maximizing the use of forages suited for the local environment is both economical and sustainable. It’s not, however, without its challenges.

By Rick Lundquist, Ph.D.  
 
Dairies in the southern states have come a long way maximizing the use of summer grasses. We used to think we had to buy expensive imported alfalfa hay to get good production. Digestibility of warm season grasses has improved with better plant genetics and more intense management. Maximizing the use of forages suited for the local environment is both economical and sustainable. However, it’s not without its challenges.
 
I only need to dust off my favorite graduate school textbook by Peter Van Soest to remind me of what influences the digestibility of forages, especially in tropical and subtropical regions. From the plant’s perspective, its survival depends on the nutrients it stores (which are highly digestible) and the structural components that protect it against the environment and predation, such as lignin (which is not digestible).
 
The age of the plant, or time after re-growth in the spring or interval between cuttings, is the most important variable influencing the digestibility of warm-season grasses. Several factors influence the relative maturity of the forage at a particular age. Since corn and sorghum are also C4 grasses, these factors can affect their digestibility as well.

1. Temperature. Higher temperatures promote more rapid growth, but reduce digestibility due to increased lignification of the stem and the leaf midrib in grasses.

2. Light. Longer days and more light intensity promote better digestibility due to photosynthetic production of sugars and conversion of nitrates to amino acids. The sun is more intense in the southern states, but the nights are longer. Plants use up digestible nutrients during the night.  Angle of the sun and long days have much more influence on improved forage digestibility in northern latitudes during the growing season. Cloudy humid days, common during the rainy season in the South, generally lower forage quality.

3. Water. Lack of water retards the growth and maturity of forages, which tends to increase digestibility while decreasing yield. Alternatively, rain and humidity increase yield, but reduce digestibility.

4. Nitrogen. Nitrogen fertilization increases the yield and protein content of grasses. But the increase in protein content may displace soluble carbohydrates. So, other than what is needed for adequate growth, excessive nitrogen fertilization actually depresses forage digestibility.
 
Weather conditions can be a challenge during the summer. There’s not much you can do to control the environment. But you can try to balance yield and age of the forage, keeping in mind the factors that influence the growth rate and maturity of the plant. Adjusting cutting intervals will improve forage digestibility and milk production. 
 

A Quick Heat Stress Diagnostic Tool

Apr 23, 2012

It’s relatively easy to determine if the body temperature of your cows is in the heat stress zone.
 

Now that we’re entering the heat stress season, a simple heat stress diagnostic tool, which I have discussed before, bears repeating.

Body temperatures as low as 102.2 F are indicative of a heat-stressed cow. At this body temperature, detrimental effects on the developing embryo that may result in early pregnancy losses have been shown. 

It’s relatively easy to determine if the body temperature of your cows is in the heat stress zone. You don’t have to temp cows or use a recording device. Respiration rates are highly correlated to body temperature. Count respiration rate by watching the movement of the flanks or the nostrils. If cows are breathing with an open mouth, observe the movement of the cheeks. Check at least eight to 10 cows in a pen by counting for 20 seconds and multiplying by three to getrespirations/minute. Check a few cows before and after they go to the holding pen to see if the respiration rate has changed.

Heat stress usually peaks in mid to late afternoon. However, humidity is highest in the late evening and early morning. Cows have difficulty dissipating heat at this time due to a “sauna” effect. Early summer mornings in Florida and other humid climates are often the least comfortable time for a cow.

Use the following graph developed by Brouk to extrapolate body temperature from the respiration rate that you counted. Normal body temperature is 101.5 F and normal respiration is about 45 breaths per minute. From the graph, a quick reference is 60, 80 and 100 breaths/minute equates to a little over 102, 103 and 104 F.

Cows are most comfortable at temperatures between 40 F and 60 F. Add in humidity, and a temperature-humidity index (THI) above 65 can affect reproduction. Besides fans and sprinklers or misters, the most important nutritional consideration to prevent heat stress in your herd is an ample source of clean, easily accessible drinking water.


Lundquist chart 4 20 12

 

Got Heat Stress? Milk Camels

Mar 26, 2012

I recently visited a 2,000-head camel-milking farm in the United Arab Emirates, where camel milk is processed and sold throughout the region.

In the Dubai desert, the camels at Camelicious Dairy are unfazed by the 130-degree heat. In fact, their milk production often goes up in the summer.
Camel 1
I recently visited this 2,000-head camel-milking farm in the United Arab Emirates, where camel milk is processed and sold throughout the region. Dr. Peter Nagy, manager of Camelicious Dairy (Emirates Industries for Camel Milk and Products) conducted a tour of this state-of-the-art milking facility and processing plant. Flavored camel milk and camel milk chocolate are their primary products.

There are two types of camels: the less common two-humped variety (Camelus camello) and the much more widely distributed one hump (Camelus dromedario) or Dromedary, which Camelicious raises and milks. They have always had an important socio-economic bond with humans in the Middle East and Asia. They are companion animals used for racing and even beauty contests as well as for milk, meat and transportation. Camelicious Dairy is one of the first to expand their role to commercial milk production.

Camels are uniquely adapted creatures. They are ruminating animals but are classified in a different suborder than ruminants. They have a three-compartment forestomach. The compartments are just called C1, C2 and C3. The large C1 compartment is lined with a stratified epithelium in the dorsal part and a glandular mucosa in the ventral part. There are no papillae, like in a rumen. The C2 compartment is comparable to the reticulum, and C3 is an elongated tube-like compartment. Their digestive system is uniquely adapted to survive on low-protein, highly lignified browse from trees and bushes. Their ability to conserve water is imperative, since there basically is none in the deserts of the Arabian Peninsula.
Camel milk
The camels at Camelicious give an average of about 6-8 liters (1.5 – 2 gallons) of milk per day. They have a 20-month lactation but are with their calves for two months after freshening, before the milk is harvested. They are very persistent milkers, with a 90% persistency coefficient over their lactation. Camel milk is typically lower in solids than bovine milk (2.5% fat, 2.8% protein, 4.3% lactose). They don’t eat much for a 1,250 pound animal. They are offered 8 lb. of wheat bran and 13 lb. of alfalfa hay at Camelicious Dairy.

People like me have offered advice on how to increase milk production by feeding the camels more like dairy cows. Dr. Nagle tried increasing their energy by feeding more grain. It didn’t work. They still gave the same amount of milk. They just partitioned the extra nutrients as stored energy in their hump and they put on weight. You may have had a cow like that at one time. But that’s what they are supposed to do as camels. I suppose one would have to breed some of the camel out of them to try to change this. And I’m not sure if that is a good idea.

‘The Mammary Gland Is an Amazing Biological Factory’

Feb 27, 2012

The productive efficiency of the modern dairy cow is four times greater than it was in 1944. It’s one of the many reasons why dairy products will continue to have a major place in human diets.

 
The title is a quote from Dr. Dale Bauman of Cornell University. I spent last weekend with Dr. Bauman in a small group discussion of topics ranging from gene regulation of milk fat synthesis to sustainability and dairy production. Dr. Bauman is just as comfortable studying the cow from a microscopic view as he is standing back and looking at the big picture.
 
Not only is the mammary gland an efficient biological factory, but the productive efficiency of the modern dairy cow is four times greater than it was in 1944. This productive efficiency is one of the many reasons why dairy products will continue to have a major place in human diets. Two-thirds of these gains are estimated to be from genetics and one-third from nutrition and management.
 
What’s the genetic basis for this improvement in productive efficiency? Interestingly, we have not been able to improve upon the efficiency of milk synthesis in the mammary gland. Animals differ very little in the efficiency of nutrient use for milk synthesis, and Dr. Bauman states that there is no relationship between genetic merit and partial efficiency of nutrient usage for milk synthesis. Neither has genetic selection for milk yield altered the efficiency of digestion and nutrient absorption. The efficiency of nutrient use for maintenance is also similar for all mammals on a metabolic body weight basis and has not been affected by genetic selection.
 
So, then what does account for the huge improvements in productive efficiency? The main source of genetic gain is through nutrient partitioning; in other words, where the available nutrients are used. In the modern dairy cow, the body coordinates many tissues and body processes to direct and support the demand for nutrients by the mammary gland. This, in turn dilutes the mandatory nutrients for maintenance, making the cow more efficient. 
 
Our improvements in nutrition, management and cow comfort support these genetic gains in nutrient partitioning. Heat stress, for example, not only reduces feed intake but also redirects the nutrients available for milk production. The result is that milk yield decreases more than what can be explained by the reduction in dry matter intake. 
 
Dr. Bauman pointed out two other interesting concepts that need to be considered when discussing the efficiency of modern dairy production and its impact on the environment:
 
1.       The environmental impact of producing food should be measured by the nutrient contribution of that food, not just on the basis of weight or calories. On the basis of nutrient density per unit of green house gas emission, milk really shines.
 
2.       The dairy industry should get carbon credits for using byproducts that would otherwise have very little value. The majority of the nutrients used to produce milk are not from human usable sources. Milk production is even more efficient when you consider this.    
 
Dr. Bauman’s scientific approach to sustainability in dairy production and his understanding of the regulation of nutrient use in the cow is an asset to the dairy industry. His website is http://www.ansci.cornell.edu/bauman/.
 

Contact Lundquist at SiestaDog@aol.com.

Comparing Milk Yield: Apples to Apples

Jan 30, 2012

Fat-corrected milk and/or solids-corrected milk are really better benchmarks to help you decide how much milk you're getting. Here are two formulas you can use to accurately gauge milk production.

By Rick Lundquist, Ph.D.
 
How much milk are you getting? That’s how most of us compare production. Fat and protein are usually secondary. But to accurately gauge milk production, we should account for butterfat, protein and even lactose. Fat-corrected milk and/or solids-corrected milk are really better benchmarks.
 
With more Jersey blood and other colored breeds in many herds, higher components skew comparisons.  On the other hand, milk yield with low butterfat or protein should be discounted for comparison purposes.
 
Two formulas can be used, depending on whether you are in a fluid or a cheese market:
1.                   3.5% Fat Corrected Milk, lb. = (0.4324 x milk, lb.) + (16.218 x (milk, lb. x fat %)).
2.                   Solids Corrected Milk, lb. = milk, lb. x ((12.24 x fat %) + (7.1 x protein %) + (6.35 x lactose %) - .0345)
             
Fat, protein and lactose percent should be entered as decimals in these equations. Entering the equations into a spreadsheet will make the math easy.
 
If, for example, you have a Jersey x Holstein herd averaging 65 lb. of 4.2% fat milk: 3.5% fat corrected milk = ((0.4324 x 65) + (16.218 x (65 x.042)) = 72.38 lb.
 
If you have a Jersey herd giving 60 lb. of 5.2% fat, 3.8% protein, 5.0% lactose milk: Solids corrected milk = 60 x ((12.24 x .052) + (7.1 x .038) + (6.35 x .05) - .0345) = 71.35 lb.
 
It takes energy to produce fat, protein and lactose. Yet, we tend to look at just milk yield as long as components aren’t real low or real high.
 
When fat test in Holstein herds is high, I often hear the comment that we could get more milk if we fed for lower butterfat. And in some cases this may be true. However, I caution that feeding a ration that is potentially unhealthy is not the solution. The fat corrected milk equation can help you determine where your milk production could be if the available energy was partitioned for more volume and less fat. Using these formulas gives us a more accurate picture of production: apples to apples.  
 

Contact Rick Lundquist at siestadog@aol.com.

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