Basic Nutrition for Dairy Cattle

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Source: Cornell University

The goal of a dairy nutrition program is for the Milk to Feed Ratio to be greater than 1.50
or
Energy Corrected Milk (ECM) / Dry Matter Intake (DMI) > 1.50

ECM = ((0.325 X milk yield) + (12.86 X milk fat yield) + (7.04 X milk true protein yield))

  • Milk yield = average pound per cow per day
  • Milk fat yield = (milk yield X percent milk fat)
  • Milk true protein yield = (milk yield X percent milk protein)

DMI = ((feed offered – feed refused) X Dry matter of feed)) / Number of cows in group

Milk to Feed ratio = ECM / DMI with a goal of >1.50

**If milk to feed ratio is <1.50 then more investigation is warranted:

  1. Forage Quality – Digestibility, Composition, Preservation quality, and Silo management
  2. Feed Management – Particle size, Accuracy of mix, Equipment cleanliness and maintenance, and Feed bunk management
  3. Diet – Ration formulation, and Forage analysis

Forage Quality Goals

Characteristic of silage Alfalfa Goal Grass Goal Corn Goal
Neutral detergent fiber (NDF) % 39 – 43% 48 – 55% 40 – 45%
Dry matter, % bunker  34 – 40%  28 – 38% 30 – 35%
Dry matter, % upright (stave) 34 – 42% 34 – 45% 32 – 38%
Dry matter, % bag 34 – 45% 30 – 40%  32 – 38%
  • The odor of silage should be little or none at a distance, slightly sharp and pleasant up close.
  • Lactic Acid level – Wet (<35% DM) 6 – 8%; Wilted (>40% DM) 3 – 4%
  • Acetic Acid level – <1– 2% with a ratio of at least 3:1 lactic: acetic
  • Butyric level < 0.1%
  • Total VFA < 10%
  • Particle length in TMR, Penn State Separator: 8 – 10% on top screen and >40% on middle screen
  • Particle length of forage, Penn State Separator: 15 – 20% of TMR on coarse screen
  • Iron level < 200 ppm

Feed and Diet Management Best Practices:

  • Maintain feed records
  • All feed components are weighed according to formulated ration
  • Calibrate scales at least monthly
  • Diet is adjusted based on dry matter of feed
  • Feeding management should be consistent among all persons feeding? Consider weekends, holidays, vacations, etc.
  • Rations should be reviewed at least monthly
  • Rations should be formulated according to nutrient recommendations
  • Rations should be based on current and accurate forage analysis
  • Animals should have adequate access to clean water
  • Feed refusals are removed daily
  • Particle size of refused feed should resemble particle size of fresh feed
  • Cows should have 24-hour access to feed. Consider amount of feed offered and frequency of feed being pushed up.

**Goal is having no less than 2% of total refusal feed just prior to feeding and fresh feed offered within one hour of removing refusal feed.

Best Management Practices for Dry and Fresh Cows

  • Pen Moves – During the dry period two moves would ideally entail a move from the far-off dry cow area to the close-up dry cow area and a move from the close-up area to the individual pen for active calving (feet out). Target one pen move during the fresh period. It is preferred to move cows in a group instead of individually with the exception when the cow/heifer is actively calving.
  • It is preferred to house heifers separately from cows during the close-up dry period and the fresh period if there are adequate facilities for both groups.
  • Bunk space:
    • Far off dry cows 18″–24″
    • Close up dry cows 24″–30″
  • Stalls stocking rate:
    • Far off dry cows of 100%
    • Close up dry cows goal of 80%
  • Space/cow on a pack:
    • Far off dry cows 80–100 sq ft
    • Close up dry cows 80–100 sq ft
  • There should be adequate ventilation to control moisture, stale air, and flies.
  • There should be adequate heat abatement in place using fans and soakers over feed bunks.
  • Stalls/packs for dry cows and fresh cows are well bedded to provide comfortable areas that allow cows to rest as much as possible. 70% of cows should be lying down at all times except when having just been fed.
  • Adequate bedding for cows to keep them dry and free of manure.
  • Floors should be non-slip.
  • Have protocols in place for monitoring and assisting with calving.
  • Have protocols in place for monitoring and treating fresh cows.
  • Fresh cows should not be restrained for more than 1 hour for exams or treatments.

Dry Cow Nutrition and Management

  • Feed a balanced ration in consultation with a nutritionist and/or veterinarian to ensure all nutrient requirements are met.
  • Target a body condition score of 3 – 3.5 for cows at dry off and for heifers prior to calving.
  • For far off dry cows (dry off to 3 weeks prepartum) feed a high-forage, low energy diet with 0.57 to 0.61 Mcal NEL, per pounds of dry matter. Reduce energy intake by adding 20-30% chopped straw or hay to the diet. Feeding the diet as a TMR is better to ensure adequate protein and minerals.
  • For close up dry cows (3 weeks prepartum to calving) feed should be available 24 hours/day. Ration should be balanced to provide 27-28 pounds of dry matter intake per cow per day containing approximately 0.68Mcal NEL per pound. The ration should provide <1.3% potassium, 0.9 – 1.0% calcium, 0.40 – 0.42% magnesium and 0.30 – 0.35% phosphorus. If DMI is over 30 pounds per cow per day and the herd is experiencing issues with DA’s and ketosis post calving, the feed can be supplemented with lower energy forage that is bulky and has low potassium content (<1.5%).
  • If using one dry cow ration, the diet should provide 0.65 – 0.66 Mcal NEL/lb, 28 lbs DMI, <1.3% potassium, 0.9 – 1.0% calcium, 0.40 – 0.42% magnesium, 0.30 – 0.35% phosphorus.