Dairy Nutrition, An Issue of Veterinary Clinics of North America: Food Animal Practice (eBook)

Robert J. Van Saun (Autor)

eBook Download: PDF | EPUB

2014 | 1. Auflage
100 Seiten
Elsevier Health Sciences (Verlag)
978-0-323-32689-6 (ISBN)

Infos

Dr. Robert Van Saun has assembled an expert panel of authors on the topic of dairy nutrition. Articles include: Feed analysis and its interpretation, Management and evaluation of ensiled forages, Feeding, evaluating and controlling the rumen, Control of energy intake and partitioning through lactation, Protein feeding and balancing diets for amino acids, Lipids feeding and milk fat depression, Dietary management of macrominerals in preventing disease, Trace mineral feeding and assessment, Transition cow feeding and management to prevent disease, Monitoring total mixed rations and feed delivery systems, and more!

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Management and Assessment of Ensiled Forages and High-Moisture Grain

William J. Seglar, DVM, PASa∗[e-mail] and Randy D. Shaver, PhD, PASb,     aGlobal Nutritional Sciences, Global Forages division, DuPont-Pioneer, Northwest 62nd Avenue, Johnston, IA 50131, USA; bDepartment of Dairy Science, University of Wisconsin, 1675 Observatory Drive, Madison, WI 53706, USA

∗Corresponding author.

Various forage and grain crops are grown, harvested, and fed to dairy cattle as ensiled forages or high-moisture grains. Although the nutritional value of hybrids and varieties is influenced by genetic inheritability, the crop growing environment dictates the outcome of forage quality, affecting nutrient digestibility. How the crop is managed based on its stage of harvest maturity and dry matter, along with key ensiling management factors, also determine the nutritional quality of fermented forages and grains. Veterinary practitioners can implement silage quality evaluations as part of a nutritional consultation service to help dairy clients maximize dairy performance and efficiencies.

Keywords

Silage quality

Forage quality

Ensiled forage

Forage and grain crops

Nutritional value

Fermentation

Digestibility

Evaluation

Key points

• Forage crop options affect dairy cow performance and health.

• Environmental growing conditions, more than seed genetic selection, determines the final forage quality fed to dairy cattle.

• Forage digestibility is influenced by growing conditions and length of time in silo storage.

• Harvest and ensiling management determines success of forage fermentation process and silage feeding value.

• On-farm tests and forage laboratory samples are available for determining forage quality of ensiled forages and grains.

Forage and grain crops ensiled for dairy production

The diversity of geographies and growing environments dictate the types of ensiled forages that are used for dairy production. Feed cost represents the largest single expenditure on most livestock operations. The production of high-quality silages can help reduce the cost associated with feeding concentrates and supplements. For dairy producers, whole-plant corn, high-moisture corn, alfalfa, cereal, and a variety of grass species are the silages of most economic significance.

Specific forage crop hybrids and varieties and impact of the growing environment

Forage Production Considerations

• Decisions on forage product options based on genetic nutritional traits are important; however, environmental and management factors have the greatest influence on forage quality.

• Corn silage quality at time of harvest is primarily influenced by harvest maturity, kernel processing (PROC), theoretical length of chop, and length of storage time in silos.

• Corn offers a diversity of feeding options, which include corn silage, high-moisture shelled corn, high-moisture ear corn (HMEC), snaplage (SNAP), dry corn (DC), and stalklage.

• Legume, grass, and cereal forage quality is contingent on stage of maturity at time of harvest and wilting time to achieve proper dry matter (DM) content at time of ensiling the crop.

• Temperature and moisture are 2 environmental variables during plant growth that highly influence forage quality of corn, legumes, grass, and cereal forage crops.

Forage categories

Plants are classified as C3 and C4 carbohydrate producers, and the primary difference is within plant cells in which photosynthesis for carbon fixation events occur. C3 plants are cooler season crops that have a longer growing season and higher water demands (Table 1). In contrast, C4 plants are warm season crops that are water efficient and drought tolerant. Table 2 compares water usage requirements for several C3 with C4 crops; alfalfa is a C3 crop that has the highest water demand, whereas C4 sorghum crops use about one-third of the water required by alfalfa.1

Table 1

Characteristics of cool and warm season grasses

Cool Season Grasses (C3)

Warm Season Grasses (C4)

Optimal growth at cooler temperature (70°F)

Optimal growth at higher temperature (95°F)

More digestible and higher in crude protein

Less digestible and lower in crude protein

Longer growing season

More drought tolerant

Higher water demands

More efficient at using water

Data from Teutsch C. Using mixtures of summer forages for improved forage yields in dry conditions. J Anim Sci 2013;91(E-Suppl 2)/J Dairy Sci 96(E-Suppl 1):406. [abstract 358].

Table 2

Water use in forage crops

Alfalfa (C3)

844

100

Bennett & Doss, 196363

Bromegrass (C3)

828

98

Martin et al, 197664

Wheat (C3)

505

60

Martin et al, 197664

Orchardgrass (C3)

418

50

Bennett & Doss, 196363

Sudangrass (C4)

380

45

Martin et al, 197664

Corn (C4)

372

44

Martin et al, 197664

Sorghum (C4)

271

32

Martin et al, 197664

Data from Teutsch C. Using mixtures of summer forages for improved forage yields in dry conditions. J Anim Sci 2013;91(E-Suppl 2)/J Dairy Sci 96(E-Suppl 1):406. [abstract 358].

Crop scientists monitor growth rates with calculators based on ambient temperature where using corn for example, growth starts at 7.2°C, maximizes at 22–30° C range, and ceases at 46°C. A Growing Degree Unit (GDU) calculation is used in the United States that is based on a linear relationship of growth to temperatures in the 10–30°C range. The GDU formula along with an example for corn is shown in Table 3. Using alfalfa in contrast, this crop starts growing at 5°C compared to corn at 10°C. Using the calculation for alfalfa and same daytime and night time temperature inputs as showing in the table, there would be 15.0 GDU accumulated for that day.2

Table 3

GDU calculations for corn and alfalfa

Corn

[(Daily maximum temperature + daily minimum temperature)/2] – 10

[(30°C+10°C)/2] – 10

10.0

Alfalfa

[(Daily maximum temperature + daily minimum temperature)/2] – 5

[(30°C+10°C)/2] – 5

15.0

Corn utilization as ensiled forage or grain

Corn is the predominant cereal crop grown throughout the world, because compared with all cereal crops, corn is unique in its ability to outyield the other crops on a ton/acre and nutrients/acre basis.2 Corn growth and development are typically categorized by a staging system that divides plant development into vegetative (before flowering) and reproductive grain development (after flowering) stages. The reproductive stages are key growth periods for capturing crop harvest opportunities intended for (1) whole-plant corn silage (WPCS), (2) high moisture ear corn (HMEC) or snaplage (SNAP), high-moisture shelled corn (HMSC), and (4) dry corn (DC). The reproductive maturity of corn is assessed by plant moisture, as shown in Table 4. WPCS is based on whole-plant moisture content, whereas high-moisture and dry grains are based on kernel moisture content.

Table 4

Corn harvest opportunities for corn silage and grain

Corn Use

% Moisturea,b

Plant Part Moisture

Corn silage

63–68

Whole plant

HMEC/SNAP

26–33 32–39

Kernel HMEC/SNAP product

High-moisture corn (HMC)

25–32

Kernel

DC grain (shelled corn)

<15

Kernel

a% Moisture is used by crop producers, whereas cattle producers use % DM...

Produkt-Details

• Erscheint lt. Verlag: 5.11.2014
• Sprache: englisch
• Themenwelt: Medizin / Pharmazie
• Themenwelt: Veterinärmedizin ► Großtier
• Themenwelt: Weitere Fachgebiete ► Land- / Forstwirtschaft / Fischerei
• ISBN-10: 0-323-32689-7 / 0323326897
• ISBN-13: 978-0-323-32689-6 / 9780323326896