Feed Efficiency and Profitability
by Michael F. Hutjens, Department of Animal Sciences, Urbana, IL, 61874
Feed efficiency can be defined as pounds of milk produced per pound of dry matter (DM) consumed. Beef, swine, fish, and poultry industries have used feed efficiency (feed to gain ratios) as a benchmark for profitability. Monitoring feed efficiency (also referred as dairy efficiency) in the dairy industry has not been used as a common benchmark for increasing profitability and evaluating dry matter intake relative to milk yield.
Economics of Feed Efficiency
With lower milk prices, one way to maintain profitability without sacrificing milk production or herd health is by enhancing feed efficiency. Table 1 is an example of how improving feed efficiency impacts the bottom line. Herd A produced 80 pounds of milk consuming 57 pounds of DM for a feed efficiency of 1.40. Herd B produced the same amount of milk, but the cows consume only 50 pounds of dry matter, for a feed efficiency of 1.60. Assuming feed costs of $0.07 per pound of dry matter, Herd B has a lower feed cost of $0.49 per cow per day compared to Herd A. In addition, Herd B with the lower feed intake and higher feed efficiency will have lower nutrient excretion as manure. This will be important as manure regulations for whole-farm nutrient management are enforced by local, state, and national government groups.
Optimizing feed intake is the “in” term; not maximizing DMI (dry matter intake). Higher nutrient demand for higher milk production led to the reasoning that maximum DMI must be achieved to meet these requirements. The more DM the cow eats, the more she will milk. For Holstein cows, each additional pound of DM consumed could lead to an additional two pounds of milk. If one pound of dry matter costs seven cents, two pounds of milk can be worth 25 to 30 cents more income or 18 to 23 cents more income over feed costs. This guideline assumes two points.
- Ration digestibility is constant (digestibility declines with increased DMI).
- All the nutrients consumed are converted to milk production after maintenance needs have been met (no growth or weight gain for example).
Composition of the diet (forage to grain ratio) and dry matter intake (multiples of maintenance) has marked effects on digestibility and energy values. Diets that do not promote optimal ruminal fermentation will result in an over-estimation of energy values.
Factors Impacting Feed Efficiency
Feed efficiency (FE) values in the field can vary from 1.1 to 1.8. High producing herds fed a one group TMR will range from 1.4 to 1.6. Early lactation mature high groups of cows can approach 1.8. If cows lose body weight, FE values will increase as nutrients from body weight mobilization contribute to milk yield. The following factors will shift FE values.
- Reducing days in milk can lead to higher FE values as cows direct more nutrients to milk production at the expense of growth and weight gain.
- Age or lactation number (first lactation cows) can lower FE values as young cows divert nutrients to growth in mid and late lactation.
- Pregnancy requirements reduced FE values as the fetus requires additional nutrients.
- Cows gaining body weight will have lower FE values as nutrients are stored as body condition or fat.
- Digestible forages will enhance FE values as more nutrients are available for productive functions.
- Stimulating rumen fermentation while stabilizing the rumen environment will improve nutrient and fiber digestibility. Rumen acidosis will reduce FE.
- Excessive heat and cold stress will reduce FE values as more nutrients are needed for maintenance requirements.
- Feed additives (such as rumen buffers, yeast cultures, and fermentation/digestion aids) and silage inoculants can improve FE values by improving digestion and/or nutrient availability.
- Using BST may improve FE values as cows divert more nutrients to milk production.
Research on Feed Efficiency
Tennessee workers monitored 13 dairy herds over a 14 month time period evaluating feed efficiencies as the environment and feed changed. Variables measured included temperature (< 21 degrees C and > 21 degrees C, days in milk, dry matter intake, milk yield, milk fat percentage, acid detergent fiber, neutral detergent fiber, and forage level). Season, days in milk, dry matter intake, percent forage in the ration, neutral detergent fiber, and acid detergent fiber lowered feed efficiency (negative correlation). Cool weather favored high feed efficiency (1.40) compare to warm weather conditions (1.31). Dairy efficiency and milk yield were positively correlated (more milk resulted in higher efficiency). Fiber intake and level reduced feed efficiency. The variation in these rations was limited reducing the impact on feed efficiency.
Genetics may also play a role in dairy efficiency. Daughters from high genetic merit bulls produced more milk than lower genetic merit bulls even though feed intake was not different. The F1 Holstein-Jersey crosses demonstrated greater net efficiency than did the purebred Holstein or Jersey. It might be possible to select for more economic efficiency by focusing on dry matter intake, live animal weight, and/or other variables.
Fine Tuning Feed Efficiency
The following guidelines can be used to refine FE values measured on dairy farms.
- Correct for milk components as more nutrients are needed as milk fat and protein content increases. Values reported in this paper are based on 3.5 percent fat corrected milk (3.5%FCM). The following formula can be used to convert milk components:
3.5% FCM = (0.4324 x lb of milk) + (16.216 x lb of milk fat)
- On the dairy farm, use the thumb rule of adding or subtracting one pound of milk for every one-tenth percentage point change above or below 3.5 percent fat test. For example, if a herd averages 70 pounds of milk with a 3.9 percent milk fat, the estimated pounds of 3.5% FCM would be 74 pounds.
- Dry matter intake must be corrected for weigh backs or feed refusals. For example, a herd manager delivers 50 pounds of dry matter per cow with a four percent feed refusal. The number to use in calculating FE is 48 pounds, not 50 pounds.
- Another approach to FE is the “13 pound tax” for Holsteins (adjustment for maintenance requirements). The “13 pound tax” for Holsteins reflects the initial 10 megacalories (Mcal) of net energy needed for maintenance functions (higher tax or needs for cows on pasture and experiencing heat/cool stress).
Milk yield: (DMI consumed - 13 pounds of DM) x 2
For example, a herd consuming 50 pounds of dry matter could support 74 pounds of milk (50 lb -13 lb for maintenance equals 37 lb of DM times 2). One pound of DM could support two pounds of milk. For Jersey cows, use 10 pounds of dry matter for maintenance or “10 lb tax”.
Table 1. Impact on feed costs in two herds with different FE (Casper, 2003)
|Milk Income @ $12/cwt
|Feed Costs @ $.07/lb dry matter
|Income of over feed costs
|Cost to produce 100 lbs milk