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Feed Management, Feeding, Livestock Hygiene, and Biosecurity

Agriculture (SSW 2) · 農業(2号) · Written by Tokutei Pass based on the official study texts; not copied verbatim.

Roughage, Concentrates, Nutritional Metrics (TDN, CP), and TMR

Livestock feeds are divided into fiber-rich roughage essential for rumination and rumen health (pasture grass, hay, silage, rice straw) and energy/protein-dense concentrates (corn, soybean meal, wheat bran, formula feed).

Steam-flaked grains (corn or barley steamed and rolled flat) have gelatinized starch for higher digestibility. Feed nutritional value is evaluated primarily by Total Digestible Nutrients (TDN) and Crude Protein (CP).

Feeding cattle a Total Mixed Ration (TMR)—blending chopped roughage, concentrates, and minerals uniformly—prevents feed sorting (selective eating of concentrates) and stabilizes rumen pH.

Roughage, Concentrates, Nutritional Metrics (TDN, CP), and TMR

Key points


  • Grass, hay, and silage are roughages; corn, soybean meal, and formula feeds are concentrates.

  • TDN (energy) and CP (crude protein) are the primary nutritional metrics, and steam-flaking improves grain digestibility.

  • TMR blends roughage and concentrates evenly to prevent selective eating and rumen acidosis.
WordMeaning
roughage and concentrate feed
Total Digestible Nutrients (TDN)
Total Mixed Ration (TMR)
feed sorting / selective eating

Hay & Silage Preparation and Prevention of Feed Poisoning

Hay for long-term storage must be dried to 15% moisture or less to prevent mold and spontaneous combustion. Silage (including wrapped bale silage) is made by sealing forage at 50–70% moisture under anaerobic (airtight) conditions to promote lactic acid fermentation.

High-quality silage has a low pH (4.2 or below), a greenish-yellow to yellowish-brown color, and a pleasant sweet-sour aroma. Air infiltration causes aerobic secondary fermentation, heating, mold, and dark putrid spoilage; discard spoiled silage and immediately patch any film holes with repair tape.

Moldy feed can cause mycotoxin poisoning (such as aflatoxin) and milk residues. Also avoid heavy feeding of high-nitrate forage grown with excess nitrogen fertilizer under low sunlight, which causes acute nitrate poisoning (hypoxia) in cattle.

Key points


  • Dry hay to 15% moisture or below; seal silage tightly to ensure anaerobic lactic acid fermentation.

  • Good silage smells pleasantly sweet-sour; never feed moldy or dark, slimy spoiled silage.

  • Prevent mycotoxicosis from moldy feed and nitrate poisoning from high-nitrogen, low-sunlight forage crops.
WordMeaning
lactic acid fermentation and anaerobic condition
secondary fermentation (aerobic spoilage)
mycotoxin (fungal toxin)
nitrate poisoning

Rearing Hygiene Management Standards and Farm Biosecurity

To prevent devastating infectious diseases such as foot-and-mouth disease (FMD), classical/African swine fever (CSF/ASF), and highly pathogenic avian influenza (HPAI), farms strictly enforce Rearing Hygiene Management Standards under the Act on Domestic Animal Infectious Diseases Control.

Designate a biosecurity (hygiene management) area separated from the outside, disinfect vehicles at the gate, and restrict visitors. Workers must change into farm-dedicated clothes and barn-specific boots, disinfect hands, and step through footbaths.

Install perimeter fencing and bird-proofing nets (2 cm mesh or smaller) to exclude wild boars, wild birds, and rodents, restrict entry after overseas travel, and ban bringing meat products onto the farm. Immediately report any vesicular lesions, sudden deaths, or mass poultry mortality.

Key points


  • Maintain a designated hygiene management area with vehicle disinfection, dedicated clothing, barn-specific boots, and footbaths.

  • Use bird nets (≤2 cm mesh) and fences against wild animals, and never bring raw meat or meat products onto the farm.

  • If infectious disease is suspected (blisters, high fever, cluster deaths), halt animal movement and report immediately.
WordMeaning
Biosecurity / Rearing Hygiene Management Standards
biosecurity / hygiene management area
foot-and-mouth disease and swine fever
bird-proofing net (mesh ≤ 2 cm)

Vaccination Hygiene Principles and Veterinary Drug Withdrawal Periods

When injecting vaccines or medications, reusing a single needle across multiple animals transmits blood-borne pathogens such as Bovine Leukemia Virus (BLV) and PRRS; therefore, strictly practice 'one needle per animal (ittou-isshin)'.

If an injection needle accidentally breaks and remains inside an animal, immediately mark and identify the individual, record its ID and the injection site, and report to the supervisor and veterinarian to prevent broken needles in meat.

Furthermore, for livestock treated with veterinary drugs such as antibiotics, milk, meat, or eggs must never be shipped until the statutory 'withdrawal period (withholding period)' specified for each drug has fully elapsed.

Key points


  • Never reuse needles across animals; use a fresh needle per head (ittou-isshin) to prevent blood-borne diseases like BLV and PRRS.

  • If a needle breaks inside an animal, immediately mark the animal, record the details, and report to the supervisor and veterinarian.

  • Never ship milk, meat, or eggs from medicated livestock until the mandatory drug withdrawal period has passed.
WordMeaning
one needle per animal (fresh needle per head)
broken / retained injection needle
veterinary medicinal product
withdrawal period (withholding period)

Feed Nutrition and Biosecurity

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Official references