Lecture 2- Feeds

Question 1

What is the most expensive economic input for a livestock producer?

Answer 1

-feeds

Question 2

What is malnutrition and what are its effects?

Answer 2

-either insufficient or over sufficiency in nutrient supply -Insufficient intake of nutrients results in decreased performance and possibly death (starvation) -Excessive nutrient consumption results in obesity, other metabolic dysfunction (and possibly death)

Question 3

What is a feed?

Answer 3

• Diet or ration • A mixture of feedstuffs (most diets will have multiple ingredients)

Question 4

What is a feedstuff?

Answer 4

• Ingredient in diet or ration

Question 5

What does a typical feed analysis look like?

Answer 5

• get proportions of the major macromolecules
• can tell if it is high in carbohydrate or protein and need to balance protein to energy

Question 6

What are the 3 categories of animals, in terms of their diets?

Answer 6

1.

Question 7

What are the 5 sources of plant based foods?

Question 8

What are the two categories of feed?

Answer 8

1. Concentrates 2. Roughages

Question 9

What are the characteristics of a concentrate feed?

Answer 9

– Low in fibre content (20% CP (e.g. soya)

Question 10

What are the characteristics of a roughage feed?

Answer 10

– High fibre content (> 18% crude fibre) – Bulky materials, with low nutrient density -lot of fibre, crucial for ruminants but also important in other animals, eg. in humans for colon health

Question 11

What are the by-products source of feed and the advantages and disadvantages?

Answer 11

-by products: from industrial production of food, most often cheap • Advantages -contain useful nutrients - frequently very inexpensive • Disadvantages - variable nutrient content from batch to batch - variable availability on a consistent basis -there are laws limiting what sort of feed you can give an animal depending on the particular digestive system it has

Question 12

What are the characteristics of energy feeds?

Answer 12

• High in starch: >70% • In grains, starch is mainly located in the endosperm • High digestibility: > 85% DMD • Low in protein: 8 to 14%. • In grains, embryo is the only source • Generally deficient in calcium and some vitamins (e.g. vitamin A) -lot of easily accessible energy -high in carbohydrates and low in proteins

Question 13

What is the cost evaluation of feeds like? (cents/MJ)

Answer 13

• feeds vary on season, rainfall
• cost per unit of energy or protein= to compare how much value you are getting in the feed
• have high energy feeds, or high protein
• forage ones= more expensive per unit of energy (lucerne= alfa alfa)

Question 14

What are the energy concentrates?

Answer 14

-

Question 15

What do you look at when evaluating grain?

Answer 15

-look at: • Seeds are not split or cracked • Seeds are of low-moisture content • Seeds have a good colour • Free from mould • Free from rodent and insect damage • Free from foreign material • Free from rancid odour

Question 16

What are maize distillers grains?

Answer 16

• grain by product, from making beer
• usually can get for free but have to beware of quality
• left: Low quality – poor toasting digestibility of crude protein reduced – high ADIN
• right: High quality high digestibility and low ADIN

Question 17

What does a cereal grain look like?

Answer 17

-embryo: where the protein is, the rest is carbohydrates

Question 18

What are the sugar refining by-products?

Answer 18

-Molasses (liquid) • By-product of sugar beets, sugarcane, citrus waste or wood products used to manufacture sugar • Very palatable and readily available energy source. Minimum content 46% sugar • Restricted to 2-5% of dry rations as a flavour/taste additive, binding agent, also controls dust • Levels approaching 8-10% may result in clumping of feeds in mixer or ingredients clumping together in sacked feed, increased risk of mould • Can be laxative at high levels • Inefficiency in utilisation can lead to high levels of methane production -all animals will eat sugar

Question 19

What is betaine?

Answer 19

-by-product of sugar refining, osmolite= good for hangover, effects on lipid metabolism, protects agains heat stress -used for muscle growth and fat loss in the bodybuilding community

Question 20

What are the feed blocks, licks and supplements?

Answer 20

-Until recently these supplements could just have water soluble ingredients, such as urea and molasses -Advances in technology now allows admixtures of most kinds of feeds. For instance we can now add dry supplements: soya, cottonseed, minerals, vitamins, additives -Delivery systems for feed additives: clay, xantham gum, xylan- based materials

Question 21

What are some more energy by-product feeds?

Answer 21

• Dried Bakery Products • Similar to composition of wheat except for ether extract content (12-16%) • Limited in diets to 20% due to high salt content • Vegetable and fruit wastes • Unmarketable or damaged commodities • Crop residues left in the field • Canning,juicing,orprocessingwastes • Use is restricted to areas where processing locations are found -lot of byproducts from mass production of bread and very high in carbs, can be used in feeds -ether= fat content -have to be limited as have high salt! almost all processed food has high salt content

Question 22

What about feeding oil and fat to animals?

Answer 22

-Residue remaining after extraction of oil from seeds is high in protein • Some heating is desirable for oil meals to destroy toxic/inhibitory compounds (e.g. lectins in soya oils) • Heating must be carefully controlled as to not reduce the digestibility of the proteins (heat damaged protein or ADIN)

Question 23

How are fats and oils utilised in feeds?

Answer 23

• Used extensively in commercially prepared diets (1-7% in pelleted concentrate) to: • Increase energy content (GE of fat = 39 MJ/kg DM) • Controls dust • Improve pelleting rate (improves consistency of mixture as it enters the die) • Improve palatability (too much reduces palatability) • Reduce machinery wear • Should be treated with an antioxidant (e.g. BHT) to prevent rancidity (oxidation products)

Question 24

What are the protein concentrates?

Answer 24

-

Question 25

What are the characteristics of protein feeds?

Answer 25

• Protein quality • Amino acid profile • Essential amino acids for monogastrics • Complementary amino acids that are deficient in basal feeds • lysine is most common limiting AA as base diets contain high levels of grain - generally protein feeds are used to complement the diet to prevent lysine deficiency • Tryptophan – grain low concentrations – maize deficient • Methionine - grains are marginal; legumes low; animal sources are generally good -cn know the AA profiles, how much of each -important lysine= the most common limiting AA, can be used to make other amino acids, then if do not have lysine cannot make other ones, so AAs that were non essential become essential

Question 26

Characteristics of protein feeds 2:

Answer 26

• Digestibility coefficient • usually highly digestible: >80 % • Ideally require protein that is utilised in the small intestine (so-called by pass protein in ruminant nutrition) • Heat damage: common problem with forages and processed (wet) protein ingredients; lysine or other S amino acids react with sugar • Protein (lysine) + sugars + moisture

Question 27

What is the cost of evaluation of feeds like when looking at the protein/kg values?

Answer 27

-

Question 28

What are seed extract sources?

Answer 28

• Residues from the extraction of oil from seeds • Oil is used primarily for cooking (human use) and the bouyancy of that market influences the price of the meal • As the oil is removed the protein concentration of the residue increases EE (%) CP (%) Whole cottonseed 24.0 23.6 Cottonseed meal 2.0 45.0