Dairy Goat Nutrition – The Fundamental Nutrients

Published on Wed, 10/12/2022 - 3:02pm

Dairy Goat Nutrition – The Fundamental Nutrients.

 By Jennifer A Bentley - Iowa State University Extension and Outreach.

 When raising dairy goats, nutrition lays the groundwork for good health and in reaching their full genetic potential. Nutrition also has a large effect on reproduction, lactation, and growth. In managing dairy goats, feed makes up over half of the production costs. Knowing the importance of the fundamental nutrients will help in understanding the productivity and profitability of managing a dairy goat operation. Let’s get back to the basics and review these nutrients.

While water is the cheapest and most basic, essential nutrient, it often becomes the most overlooked. Like all livestock, dairy goats require high quality water offered free choice, that is routinely sampled to determine quality and safety of consumption. A goat weighing 100 pounds will need 1-3 gallons of water depending on age, diet, weather, and production factors. A lactating doe will need an additional 0.5 gallon of water for every 2 pounds of milk produced. For example, if a doe is producing 8 pounds of milk, she will require an additional 2 gallons of water. Restricting high quality water consumption will affect feed intake and performance more than any other nutrient deficiency. Take into consideration weather elements, as water intake will increase when temperatures are above 70 degrees, while winter conditions can freeze water accessibility.

Most of the goat’s energy needs come from carbohydrates (sugars, starch, and fiber). Digestibility and energy content will range from high to low depending on the maturity of the plants; young plants having the highest level of energy and most digestible fiber, while older, mature plants will have less energy and many times poorly digested. Evaluating fiber sources can be done through a hay analysis or reading the feed tags, taking into consideration that at least minimum fiber levels are met. Feeding too high of a grain diet (greater than 60%) and not enough roughage will affect how the rumen works and can cause nutritional disorders such as acidosis. The volatile fatty acids (VFAs), produced during rumen fermentation are important to the energy needs, milk production, and overall health of the lactating doe. To stimulate rumination, fiber length greater than 1” is appropriate for most of the forage. Excess energy will be stored as fat; however, too little energy can affect body condition, causing pregnancy toxemia, one of the most common metabolic disorders in goats.

While fats are important for the absorption of fat-soluble vitamins, they provide a lot of energy that needs to be balanced appropriately in the diet to avoid suppression of fiber digestion and intake. Fat usage is typically limited due to cost but can be of benefit particularly in early lactation when the doe may be experiencing a negative energy balance.  With forages being fed, ruminant diets are generally lower in fat. Sources of fat that can be added to the diet include whole cottonseed, roasted soybeans, and vegetable oils.

Protein is required for growth and maintenance in all stages of life but decreases as the animal ages. Protein is a fundamental nutrient for the rumen bacteria to breakdown, as they use the amino acids as bacterial protein to feed the rumen bugs (microbes). High protein (>20%) can be found in oilseed meals like soybean or canola, moderate protein (15-25%) is found in pasture or legumes, and by-products such as distillers’ grain, and low protein (<15%) is found in grain silage or grass hay, and by-products such as soy or oat hulls. Most feedstuffs contain protein but have varying differences in what gets used by the rumen microbes and what gets digested in the small intestine as by-pass protein. Crude protein is most used to balance dairy goat rations.

Vitamins and Minerals
Lack of appropriate vitamins can affect the goat’s metabolic process, resulting in symptoms of deficiency. Fat soluble vitamins are generally adequate in diets that contain a high-quality forage; however, it is common to add supplementation. Water soluble vitamins such as Thiamin or vitamin B are synthesized in the rumen and can become deficient, causing polio. This can happen when feeding a high concentrate diet, particularly with high sulfur or when consuming water high in sulfur. Early lactation goats may benefit from additional vitamins to prevent metabolic disorders.

Mineral supplementation can be expensive, so it’s important to supplement only what is deficient in the diet. A forage analysis along with knowing how much the goat is consuming will help in mineral balancing. Lactating does need adequate levels of calcium for milk production, particularly in early lactation when hypocalcemia (milk fever) can occur due to a shortage of blood calcium. Urinary calculi can occur when there is an imbalance of calcium to phosphorous in the diet. A 2:1 ratio calcium and phosphorous is recommended.  

There are other vitamins and minerals that should be evaluated. It’s best to consult with a nutritionist or veterinarian on which ones to add based on soil mineral deficiencies in the region as overfeeding can cause toxicity issues.

Remaining factors or tips to consider
• When determining nutrient requirements, factor in age, body weight and condition, stage of lactation or production level, weather elements and housing conditions. These play a critical role in the goat’s ability to consume and absorb fundamental nutrients.  
• Routinely observing body condition score can be a way to evaluate the nutritional status of a herd. Using a scale of 1-5, with 1 being emaciated, 3 as average, and 5 being obese, optimum scores for dairy goats include:
  ° 2 - Maintenance
  ° 3 – Breeding
  ° 2+ - Early Gestation
  ° 3 – Late Gestation
  ° 3+ - Kidding
  ° 2 – Weaning
• Make changes slowly to the diet, particularly when trying something new or increasing the amount of concentrates or forages as they have varying rates of passage and could cause digestive upset, leading to poor performance or health.  Sample forages for nutrient analysis before feeding.
• Ration balancing software can help in determining nutrient needs based on the availability and quality of feedstuffs, cost, and factors mentioned above. Work with a consulting nutritionist or try a university ration balancing tool, for example Langston University Nutrient Calculator or Iowa State University Brands Software

References used: Dairy Goat Production Handbook, Langston University and Maryland Small Ruminant Page