Dairy cattle nutrition is a critical factor in the success of a dairy herd. There are many factors to consider when feeding your herd and it is best to discuss with your veterinarian to make sure you are providing them with the right foods to ensure they remain healthy.
Contents
Non-structural carbohydrates
Carbohydrates are the main source of energy for dairy cows and are the precursors for protein and fat. Although the composition of the carbohydrates can vary, they can be classified as structural and nonstructural.
Non-structural carbohydrates (NSC) and non-fibrous carbohydrates (NFC) are the most important drivers of microbial protein production in the rumen. These are usually included in lactation diets. However, it is important to note that the levels of NSC and NFC are not interchangeable.
The presence of high levels of NSC and NFC in the diet can inhibit fiber intake and limit rumen fermentation. Hence, it is vital to ensure that the ration contains adequate levels of “adequate effective fiber” that promotes stable rumen fermentation.
Fat
Dairy cattle use their body fat for energy. During the early stages of lactation, cows mobilize their fat reserves to produce milk. But, the high production demands put an enormous stress on the body.
Fortunately, a peripartum ration of dairy cows should contain adequate protein, fibre, and viscera. This ration should also include glucose, amino acids, and fatty acid precursors.
Several studies have investigated the effect of the adipose “lipolysis pathway” on milk production. The research focused on the role of adipose tissue in metabolizing fats and proteins and in the release of fatty acids from the fatty liver. The results indicated that the adipose “lipolysis” pathway was the major contributor to the increase in milk fat yield.
Protein
Dairy cows have high requirements for protein in their diets during lactation. They require amino acids for growth, reproduction, and milk protein synthesis.
Dairy cows have complex metabolic systems, which use protein as an energy source. They cannot store it. A dairy ration must be balanced to provide an adequate protein supply.
There are several types of dietary proteins. These are metabolizable and non-metabolizable proteins. Ruminant animals derive most of their amino acids from microbial protein. Soybean meal is an excellent source of amino acids. Other plant proteins can be mixed with urea to provide nitrogen. This is the preferred protein supplement for many dairy cows.
Potassium
During lactation, potassium is an essential nutrient for dairy cows. It affects many biological processes in the body, including cardiac function, smooth muscle function, and kidney function. The level of potassium required is dependent on a number of factors, including the body size and physiological status of the dairy cow.
During heat stress, potassium is especially important for lactating cows. The mineral is present at a high concentration in sweat, a byproduct of milk production. Therefore, a high potassium intake can decrease the rate of trans fatty acid oxidation and help to prevent losses from panting and urination.
There are a variety of forages that contain a high concentration of potassium. In a study at Washington State University, cows fed a diet with a higher proportion of potassium carbonate produced a greater proportion of milk fat.
Rumen-protected FA
Rumen-protected dairy cattle nutrition is a form of supplemental feed which circumvents the rumen fermentation process. Although some people call these “rumen bypass fats,” they can still be digested in the cow’s intestine.
Protected fats are best fed to high-yielding cows. They provide an energy-dense, palatable source of calories. They also coat the fiber in the rumen. However, they can only be used in small quantities by the rumen.
In addition to helping the cow increase dietary energy, fats can be used to help boost butterfat content. However, they do not have much impact on palatability. They are most often fed to early lactation cows.
Regulation of CD36
The regulation of CD36 in dairy cattle nutrition remains unclear. The protein may function as a lipid sensor and be involved in lipid absorption and cholesterol homeostasis. Its role in milk fat synthesis in ruminants has also been investigated.
Inactivation of the gene for CD36 suppresses spontaneous preference for lipid-enriched solutions in mice. Although the exact mechanism of action is unknown, it is likely to involve the orosensory system. Nevertheless, further experimental investigations are needed to explore the neural pathways responsible for dietary lipid digestion and behavioral physiology.
The expression pattern of CD36 in the rat and mouse is species-specific. Unlike other lipid-binding proteins, CD36 is expressed only in taste bud cells. It is therefore believed that CD36 is required for short-term preference for LCFA-rich beverages.
