Pasture Management, Part 2

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Del curso dictado por The Pennsylvania State University

Dairy Production and Management

278 calificaciones

The Pennsylvania State University

Dairy Production and Management

278 calificaciones

With the world's first MOOOOO-C, you will gain a broad and comprehensive understanding of all aspects of dairy management such as genetics, nutrition, reproduction, animal health, farm economics, and sustainability of dairy production systems. There's something here for everyone whether you are just looking for the basics or have years of experience in the dairy industry. This is an eight-week course. Each week consists of four to nine video lectures, additional reading materials, and a multiple-choice questions quiz. Estimated study time is between three and five hours per week. Learners have the option to purchase a Course Certificate for 49.00 USD. The certificate can be purchased at any time, but you must verify your identify before taking the course quizzes in order to be eligible. For those who cannot afford the certificate fee, financial aid is available through Coursera. Why is producing milk efficiently and sustainably so important? Milk provides humans with over 16 essential nutrients, such as: Energy, Protein and Essential Amino acids, Vitamin A, Vitamin D, several B vitamins, including B12, Pantothenic and Folic acids, and essential minerals such as Calcium, Magnesium, Phosphorus, Potassium, Zinc, as well as other minerals. Did you know that one glass of milk provides a 5-year old child with 21% of his/her daily protein requirements and 8% of their energy needs? Most milk in the world, about 85%, is produced from cattle. However, water buffaloes, goats, sheep, and camel are also dairy animals. The United States, India, the European Union, Brazil, and New Zealand are among the largest dairy producers in the world. Yet among these dairy-producing countries there are varied methods to generate milk with highly variable productivity and efficiency. Dairy production is vital for the survival of billions of people. Globally, around 150 million small-scale dairy households, equivalent to 750 million people, are engaged in milk production. The number and size of dairy farms varies among countries, but in India alone, there are estimated 78 million dairy farms! In the United States, one of the leading milk-producing countries in the world, total milk production has been steadily increasing in the last decades, reaching over 205 billion pounds (93 billion kilograms) in 2014. This was accompanied by a steady increase in average milk yield per cow, reaching 22,260 lb (over 10,100 kg) per lactation in 2014. How has this efficiency been achieved? What methods are necessary to ensure production of high quality milk? How do we balance milk production efficiency with animal health and environmental protection? This course will provide the student with information to better understand dairy production systems and their role in feeding the world population. In this MOOOOO-C, you will learn about the dairy enterprise from internationally recognized dairy science professors who have delivered highly regarded dairy education programs within the United States and internationally. Course lectures are translated into Portuguese and Chinese; PDF files of these translations can be found under each course week. The Dairy MOOC team thanks Dr. Antonio Branco (Universidade Estadual de Maringá, Brazil) and Ms. Yuanyuan Zhang (Pennsylvania State University) for translating the lecture materials. Course Sponsors This course was supported by the generous contributions of Innovation Center for US Dairy at Silver Level and Pancosma North America, RP Nutrients, Inc. and Arm and Hammer, which provided funding support at a Bronze Level. The Pennsylvania State University has final responsibility for the academic content of this course.

De la lección

Forage Production and Pasture Management

This week you will learn about what forages are, why they are important and the multiple roles they play on the dairy farm. We will also review some of the basic management considerations that are involved in the establishment, production and harvesting of these crops. The first lecture will focus on the multiple roles that forages play on the farm on considerations that are necessary to develop an effective forage production system. In the second lecture we will discuss some common perennial forage crops and their management. This will include alfalfa, alfalfa grass mixtures and grasses. In the third lecture, we will discuss the annual forages commonly used on dairy farms: corn, sorghums and small grains. You will learn how to utilize pastures in dairy production systems. The fourth lecture will discuss grazing and pasture management, including challenges of grazing systems, how grazing management has evolved, and proper grazing management for optimum forage and animal productivity. The fifth lecture will focus on nutrition for grazing herds, including nutrient content of pasture relative to the nutrient requirements of lactating dairy cows and strategic supplementation strategies for optimal animal health and milk production. Those of you, who would like to get more engaged in discussions and are interested in completing the Course Certificate requirements, can participate in discussion forums and take the weekly quiz. Enjoy this week's material and the entire course!

Pasture Management, Part 17:53

Pasture Management, Part 210:53

Conoce a los instructores

Alexander N. Hristov
Professor of Dairy Nutrition
Animal Science
Troy L. Ott
Professor of Reproductive Biology and Associate Director
Huck Institutes of the Life Sciences
Bhushan Jayarao
Resident Director
Penn State Animal Diagnostic Laboratory (ADL)
Greg Roth
Professor of Agronomy
Plant Science
Gabriella A. Varga
Distinguished Professor of Animal Science
Dairy and Animal Science
Chad Dechow
Associate Professor of Dairy Cattle Genetics
College of Agricultural Sciences
Robert Van Saun
Professor of Veterinary Science and Extension Veterinarian
Department of Veterinary and Biomedical Sciences
Kathy Soder
Research Animal Scientist
USDA-Agricultural Research Service, Pasture Systems and Watershed Management
James Dunn
Professor of Agricultural Economics
Agriicultural Economics, Sociology and Education
Lisa A. Holden
Associate Professor of Dairy Science
Animal Science

[MUSIC]

Hello, my name is Kathy Soder.

I am a research animal scientist with the USDA Agricultural Research Service.

Today, I will be presenting the second of two lessons on grazing

management from the dairy production and management MOOC series.

In the last lesson, we focused on pasture management.

Today, we will focus on the animal,

to look at the nutritional aspect of dairy grazing systems.

While grazing cows is a low cost resource for feeding dairy cows,

intensive grazing systems present challenges to nutritionists and farmers.

The forage quality of pastures is usually higher than

the same forage harvested as silage or dry hay due to maturity level of harvest.

Seasonal variation, species composition such as legumes mixed with grass species,

fertilization management and grazing preferences by animals makes supplemental

feeding with pasture based systems more difficult

than with confinement systems where forage quality is known.

High quality pastures are key to optimal milk production in grazing dairy herds.

However, there are many questions regarding what defines a high quality

pasture and how we can develop and

maintain high quality forages in sufficient quantities

to meet the dry matter and nutrient needs of lactating dairy cows.

High quality pasture has many positive attributes for lactating dairy cows, but

it also has nutritional imbalances and deficiencies.

Total protein is usually high in frequently exceeds crude protein needs

of the lactating cow, especially if nitrogen fertilization or

legumes are part of the pasture management.

This protein is highly degradable in the rumen.

This rumen degradable protein,

or RDP, is rapidly broken down by the rumen microbes into ammonia.

Ideally, this ammonia is recaptured into more microbial protein to maintain rumen

function and provide protein to the animal further down the digestive tract.

However, if energy is lacking in the diet, which can be the case with pasture

based diets, this ammonia cannot be recaptured into microbial protein.

Rather it is converted to urea, a less toxic form, and

excreted in urine and milk.

Not only is this a potential environmental issue with additional nitrogen excreted in

urine, and can have negative effects on cow productivity through elevated milk

urea nitrogen or MUN levels, but the conversion of ammonia to urea

requires energy that otherwise could have been used to produce additional milk.

For high producing cows, producing greater than 70 pounds of 32 kilograms of

milk per day on pasture, rumen undegradable or bypass protein,

also known as RUP, may be inadequate and a supplemental source of rumen

undegradable protein may be necessary to maintain optimal milk production.

The fiber content of high quality pasture may be too low,

particularly in the spring and fall.

To stimulate adequate cud chewing and rumination.

This may result in reduced milk fat content and

metabolic issues such as acidosis.

Some grazing dairies will allow some pastures to get a bit more

mature to increase the fiber content of the diet.

However, this will also result in reduced protein and energy of the pasture forage,

so supplemental feeding may be needed to meet those nutrient needs.

Other farms will supplement with hay or baleage to provide long fiber.

The amount of several minerals including calcium, phosphorus, magnesium,

sulfur, zinc, and salt are usually inadequate in pasture.

In general, these minerals should be added to the supplemental feeding program or

to a free-choice trace mineral mix.

Potassium and

phosphorous may be too high in some regions relative to nutrient needs,

particularly in areas that historically have had heavy lumen application.

High potassium diet can result in milk fever, or

hypocalcemia, while high phosphorous is an environmental concern as it is excreted in

the minora and it can get into the water supply.

Vitamins A and E are high in fresh pasture forages and

vitamin supplementation is often not needed during the grazing season, but

may be necessary during the non-grazing season when conserved forages are fed.

In addition to the high protein content, the other notable nutrient imbalance is

a relatively low fermentable carbohydrate content.

The major source of energy for both the rumen microbes, and

the cow, in most pastures compared to the needs of the cow.

Therefore, strategic supplementation with grain or other energy sources may be

desirable to maintain milk production, milk components, and animal health.

Research at Penn State University has shown that high quality pastures in

the Northeastern United States can support 18-23 kg or 40-50 lb of milk production.

However, this was a short-term study that did not account for

long-term effects on body condition or reproduction.

In addition, many grazing farms target higher levels of milk production or

need supplemental feeds to fill in gaps in forage production such as summer slumps or

poor quality forage.

Therefore, strategic supplementation of grazing dairy cows is often

needed to maintain animal productivity and farm milk production goals.

The most common supplementation strategies are grains for

energy, effect the fiber from forage or high fiber feed ingredients, and

minerals that are deficient in pastures.

In addition, some very high producing herds may supplement with fat or

rumen bypass protein source to improve production and components.

Before we discuss supplementation,

the first step in a successful grazing system is to provide adequate quantities

of high-quality pasture, which is the cheapest feed source available.

If pasture availability is limited,

cows cannot maintain adequate dry matter intake.

In addition, they will spend more time walking around searching for more to eat.

The energy spent walking could have been used to produce more milk.

Therefore, we want to make sure the cows get the most

high quality forages possible in every bite taken.

When deciding how much area to give cows,

the farmer must consider the following options.

How much time with the cow spend in this pasture will she be out half a day,

one day, or longer on the same pasture?

How many cows are on the pasture?

How big is that pasture?

Estimated dry matter intake of group.

How much forage is available?

And how much will cows actually consume versus what they will waste or

leave behind?

This last point is important.

Cows will not eat every single bite of grass available in a pasture.

Some forage will be wasted due to rejection, manure and urine spots and

preference for other plants.

It is important to allocate more pasture than is expected to be consumed

probably 50 to 100% over and above expected requirements.

For cows to maintain dry matter intake, select the highest quality forages,

avoid manure and urine patches and

allow enough forage residual to maintain plant regrowth.

Even with sufficient quantities of high quality pasture,

the nutrient needs of lactating cows are often not met, especially energy.

Therefore, strategic supplementation is a crucial part of dairy nutrition

in most grazing herds.

Any type of supplement will reduce the cows' intake on pasture.

If forage is supplemented,

you can expect an approximate one to one substitution rate.

That is, for every pound or kilogram of supplemental forage fed,

on a dry matter basis, you can expect pasture intake to decrease by one pound or

kilogram of dry matter.

This results in no change in total dry matter intake.

One pound or kilogram of concentrated grain on a dry matter basis

will reduce pasture intake by ony one-half a pound or kilogram of dry matter.

Supplementing with grain or concentrate will not ony result in greater total dry

matter intake due to a lower substitution rate, but greater nutrient intake,

especially energy, due to the increased nutrient density of the grains.

Substitution rates for biotic feeds may vary depending on source and

nutrient content.

Another factor that can influence pasture intake and

grazing behavior is when supplemental feed is fed in relation to the grazing period.

Some farms will feed supplemental feed in the milking parlour or

immediately after milking.

The cows are then turned out to pasture.

Other farms will turn cows out on pasture after milking and

feed supplemental feed later in the day.

When cows are fed supplements prior to grazing,

appetite will be reduced when turned out on pasture.

And just like humans,

when they are less hungry, cows get pickier about what they eat.

They may only nibble on the tips of the forage plants or select certain species of

plants which result in decreased pasture intake and utilization.

When cows are turned out hungry with no supplemental feed prior to grazing,

appetite is high.

Grazing is more aggressive and cows will be much less selective about what plants

and plant parts they eat, thereby increasing pasture intake and utilization.

Grazing dairy farmers can use this behavior to meet their farm goals,

whether it is to maximize pasture intake or

stretch pasture resources with supplemental feed.

Due to grain prices and availability, farm philosophy and

milk markets, some grazing dairies have gone no grain.

Feeding only forages to their cows in the form of pasture or conserve forages but

not corn silage.

While this can be successfully done, it does take a higher level of management and

adaptation to go no-grain.

High forage quality is a must at all times,

as there is no grain to fall back on if forages are not of sufficient quality.

Cows must be adapted to a no-grain diet, as well.

It is not advisable to put cows with high milk production potential

on a no-grain diet.

They will continue to try to produce high quantities of milk at the expense of their

body condition and health and eventually fall out of the system.

Cows should be of moderate body frame, moderate milk production,

with enough body capacity to process high forage diets.

Farmers must also make adjustments.

Milk production will likely drop but must be maintained at profitable levels.

There are some premium markets for grass-fed milk, but

at this time, they are limited to the United States.

Farmers must keep a close eye on pasture quality and availability and

often be thinking weeks or months ahead to insure there's adequate pasture available

as well as have a backup plan in place in the event of adverse weather conditions

such as drought or flooding.

Management of a profitable grazing system requires higher and

different management skills compared with confinement systems.

Successful grazers acquire these skills with experience, education and

mentorship from other grazers.

Keeping adequate amounts of high quality pasture is one of the most important

aspects of nutritional management of raising dairy herds.

Thank you for joining us for the grazing management section.

More information will be provided in the lesson resources on the MOOC website.

[MUSIC]

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