If you find yourself reading the title of this [article] twice, wondering what “space” has to do with the diet of a dairy cow, you are not alone. Nutritionists and producers regularly discuss terms like pounds of dry matter intake (DMI) or percent protein or how many megacalories of energy or grams of calcium or what is the ratio of calcium-to-phosphorus. None of these discussions even comes close to mentioning space as an important consideration when planning or troubleshooting a milking cow’s diet.

The basic premise used by all nutritionists when formulating rations is that each mouthful of the diet is balanced with respect to the known nutrient requirement of the target animal. The diet must contain the necessary nutrients to support maintenance, growth, production and health. Feed additives should be present to provide the appropriate level of protection from disease and other maladies. In all cases, the levels must be controlled so as to be neither deficient nor toxic.

The science surrounding protein and energy nutrition, no matter the livestock species, is a couple of generations ahead of mineral nutrition – particularly trace mineral nutrition. Yet finally there are signs that mineral nutrition science might one day catch up. One sign of progress is industry and academic interests using ‘organic’ minerals in lieu of inorganic forms of zinc, manganese, copper and selenium. The initial focus is on reproductive issues and on enhancing immune response and milk quality – areas where trace mineral availability may be limiting. Another issue is environmental accumulation of minerals in manure spread on cropland.

The ability of dairy cows to convert feedstuffs into products for human consumption is generally referred to as feed efficiency and is expressed as pounds of milk produced per pound of dry matter (DM) consumed. This expression represents a gross measure of feed efficiency and does not account for nutrients partitioned to reproduction, growth and tissue deposition. Thus, interpretation of the value obtained should consider stage of lactation, age and stage of gestation for the herd in question.

Nutritionist Jess Argyle of Jerome, Idaho, says despite higher prices for rolled corn and regionally imported ration components, dairy producers should push for more milk and higher components, being careful not to lose milk production while looking for good buys on commodities. “Don’t short-change the cows. Push for production,” Argyle says. “I’ve never been able to cut out or cut back on feed and save money. We always lose more in production than what we can save in cutting back on feed.”

Are your feed costs high? The most expensive feeds are those with high levels of protein (greater than 20 percent protein). Testing for MUN (milk urea nitrogen) in the milk can help you determine the correct level of protein in the feed. There are other reasons for testing for MUN:

For dairy producers wishing to improve their profitability, the first feed investment that needs to be made in improving milk production is dry matter intake (DMI) conversions, says Marvin Hoekema, president of Dairy Decisions Consulting, LLC, in Visalia, California. The reason is these conversions are 40 to 50 percent of a dairy operation’s budget, “meaning there is real money on the table.”

Milk fat depression (MFD) syndrome is a prevalent problem in many dairy herds feeding high-yielding dairy cows. A significant increase in understanding of MFD syndrome occurred in the last several years, and, clearly, different factors may be acting individually or together to result in a lower milk fat content. This article is focused on some of the possible dietary factors involved with MFD. One of the first steps nutritionists evaluate when they face a MFD problem is the dietary effective neutral detergent fiber (efNDF). Penn State University developed a method to evaluate the dietary efNDF which is based on the particle size of the forages or the total mixed ration. A minimum dietary efNDF guideline of 22 percent is required to provide a healthy rumen environment and maximize a cow’s intake, milk yield and composition.

Selenium (Se), like the other trace minerals, is necessary to sustain life and is essential for basic physiological functions in both animals and humans. While the daily requirement for these minerals is obviously small, their importance to and impact on the health and well-being of livestock and humans are well documented in research. Fortunately, the difference between deficiency and toxicity with most of these trace minerals is believed to be fairly broad, allowing for the wide range of supplemental regimes used around the world.

With drought and heat-stressed corn [...], mycotoxin levels could be elevated leading to animal health risks. Corn grain may exhibit signs of fungi growth and kernel damage. Mycotoxins are toxic byproducts produced by fungi that infect feed crops due to insect damage or stressed plants. These fungi produce mycotoxins that can include aflatoxin, zearalenone, T-2 and DON (deoxynivalenol) that can impact dairy cattle performance for several reasons, including: