Source: Manitoba Agriculture Food, and Rural Initiatives
Although thumb rules cannot be expected to replace sound nutritional advice, they do serve as guidelines to which you can compare your own rations. If your ration differs significantly from the following thumb rules, or if you’re not sure how your ration compares, discuss it with your feed company representative or Manitoba Agriculture and Food nutritionist. Recommended nutrient levels are given for the total ration, on a 100% dry matter (DM) basis.
- Cows should be eating at least 4% of body weight per day at peak intake. Example: 600 kg cow X 4% = 24 kg dry matter.
- Provide 18-19% crude protein in your top cow ration.
- Bypass (undegradable) protein should be 35-40% of crude protein.
- Soluble protein should not exceed 30% of crude protein.
- Provide a minimum of 19% ADF in the total ration dry matter. o Provide 25-30% NDF in the total ration dry matter.
- Maximum NDF should be about 1.25% of body weight.
- Forages should provide about 65-75% of total NDF.
- Rations for top cows should contain at least 1.74 mcal NEL/kg.
- Grain intake should not exceed 60% of ration dry matter.
- Grain fed per feeding should not exceed 3.0-3.5 kgs.
- Provide a variety of non-fibre carbohydrate sources to optimize rumen balance.
- Grain/milk ratios (Holstein):
- Feed supplemental fat to cows producing over 32 kgs milk/day.
- Rations for cows producing over 32 kgs should contain at least 0.75% calcium and 0.5% phosphorus.
- Increase the calcium to 0.9-1.0% if supplemental fat is fed.
- Rations should contain 0.3 mg selenium/kg dry matter.
- Minimum levels of copper, zinc and manganese are 10, 40 and 40 mg/kg, respectively.
- Feed 85-112 g (3-4 oz) trace mineralized salt/cow/day.
- Provide 3,960 IU vitamin A/kg DM. Example: 24 kgs DM X 3,960 IU = 95,000 IU/day.
- Provide 1,000 IU vitamin D/kg DM.
- Provide at least 15 IU vitamin E/kg DM. Example: 24 kgs DM X 15 IU = 360 IU/day. Higher levels (500-600 IU/day) may be required.
- Clean, fresh water must be available at all times – about 3-4 L per kg of milk produced.
For further information contact:
Farm Production Extension, Animal Nutritionist
Manitoba Agriculture Food, and Rural Initiatives
204-545 University Crescent
Winnipeg, MB R3T 5S6