Animal Nutrition Training Manual - ATNESA

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Animal nutritiontraining manual********************************Dr. Alimuddin NaseriNational Animal Husbandry AdvisorAKF Kabul - Afghanistan [email protected] Mobile: 93 (0)79 211 047Animal nutrition, with emphasis on dairy cows. Submitted by Alimuddin Naseri, Afghanistan: [email protected] 1

CHAPTER 1COMPOSITION AND FUNCTION OF FEEDSTUFFSIntroduction: the Animal and its FoodFood consists of water and Dry Matter (DM). If the water content in food is 75%, the DMcontent is 25%. Although water is very important, the DM is crucial to the composition of aration. More food is needed when it contains more water. The main components of a foodsare: Water Food Dry Matter (DM) True Proteins Organic Matter (OM) Vit. B,C Inorganic Matter (IOM) minerals/ash N Compounds (CP) Undesirable Substances N Free compounds Energy Non Proteins (NPN) Degradable Lipids (EE) Vit. A,D,E,K Carbohydrate Degradable Undegradable Sugars, Starches (NFE) Cellulose Lignin (CF) Major Elements (Na,Ca,P,CL,K,S,Mg) Undesirable substances Trace Elements (I,Mn,F,Co,B,Zn,Fe,Cu,M)1.1 WaterWater is vital to any animal. The bodies of young animals may consist up to 80% of their liveweight. Older, and especially fat animals, have less water in their bodies (down to 50%).Feeds can contain both high and low water percentages. Examples of feeds with high watercontents are young grass ( 15% DM) and cabbage ( 10% DM). Hay and concentrates arefeeds with low water contents (85-90% DM).An animal obtains water from three sources: drinking water, water present in food andmetabolic water. The latter is formed during metabolism by oxidation of hydrogen (H)containing organic nutrients. Water leaves the body with urine, faeces, milk, and as vapourvia the lungs (respiration) and the skin (perspiration). There is no evidence that, under normalconditions, an excess of drinking water is harmful. If water is offered ad lib, animalsnormally drink what they require.Animal nutrition, with emphasis on dairy cows. Submitted by Alimuddin Naseri, Afghanistan: [email protected] 2

It is important to note that a lack of water in the diet results in a reduced appetite: a cow willeat less! This might affect DM intake which can have many consequences.Dairy cattle require water for: and swallowing (saliva)Transport of nutrients around the bodyFormation and maintenance of body tissuesDisposal of waste productsRegulation of the body temperatureMilk production1.2 Dry Matter (DM)All valuable feed substances are contained in the DM. If the DM% in a feed is known, it ispossible to calculate how many kg DM an animal obtains from the feedstuff (and how manykg concentrate is needed as a supplement according to the norms for the production level).The DM of a feedstuff can be divided into two groups:1.2.1Organic Matter (OM)Inorganic Matter (IOM)Organic Matter (OM)The OM in a feedstuff consists of:*Nitrogenous compoundsNitrogen-free compounds Crude Protein (CP) * EnergyIn reality, not all N compounds are CP, but it is convenient and almost universal for the N requirements ofanimals in the N status of foods to be stated in terms of protein. 30-40% Protein (CP)Proteins are the building blocks in an animal. Protein is needed for growth, maintenance,reproduction and lactation. In general, every animal must have a constant supply of protein inorder to remain healthy. A shortage will result in small calves at birth and/or slow-growingyoung stock (retarded growth). Other effects due to shortage of protein are: milk productionLess protein in the milkLoss of body weight in (early) lactationIncreased risk of infections and metabolic diseasesLow fertility (longer calving interval)CP is made up of true protein (chains of amino-acids) and of inorganic nitrogen salts, amidesand other substances. Amides can be seen as a substance which is to become true protein orAnimal nutrition, with emphasis on dairy cows. Submitted by Alimuddin Naseri, Afghanistan: [email protected] 3

as broken-down true proteins. In green, flushy products (e.g. young grass) a large part of theCP comes from amides. In full-grown vegetable products the amid content is normally low.The true protein can be divided into degradable and undegradable proteins.Nitrogen in a feed, which does not come from protein, is named non-protein nitrogen (NPN),which are all degradable.Ruminants, such as dairy cows, can very well utilize NPN (see Chapter 2). Hence, instead offeeding dairy cows expensive (true) protein, cheaper sources of nitrogen can be used as well.Urea which is relatively cheap chemical product, is such a non-protein nitrogen. However,certain precautionary rules must be observed when feeding non-protein nitrogen to dairycows. It should be realized, that NPN (urea) can only be used in low level production systemswith high amounts of poor quality roughage. In feeding high yielding dairy cows, this NPNdoes not play a significant role. In case the ration is deficient in energy, the cow will utilizepart of the proteins as an energy resource, which may lead to protein deficiency. so-called energy contents of a feedstuff can be subdivided into two groups:-CarbohydratesLipids (fats)CarbohydratesCarbohydrates are sugars and starches derived from cereals, tubers, roots, and othersubstances such as cellulose and lignin from plant cell walls, vessels and woody tissues.Carbohydrates do mainly provide energy for maintenance and production. A surplus ofenergy is stored as body fat.A part of the carbohydrates is crude fibre (CF), the remaining is nitrogen-free extract (NFE).The latter consists of sugars, starches and sugar-like substances. Sugars and starches aremuch easier to digest than CF. CF is very important for the functioning of the rumen and forproduction of milk rich in butterfat. Food for dairy cows should therefore contain a goodquantity of CF. In total, the ration should contain at least 30 % roughage (on DM base).Lipids (Fats) or Ether Extract (EE)Lipids also provide energy. In fact, lipids provide much more energy than the same amountof carbohydrates (multiplication factor: 2.25). The fat soluble vitamins A, D, E and K arefound in the lipid fraction. Because of the vitamins, some fat must be present in the feed.However, too much in the ration lowers feed intake of the ruminant and disturbs functioningof the rumen.Roughage have a low fat content. Feedstuffs derived from oilseeds (e.g. soya, cotton) have arelatively high fat content.Animal nutrition, with emphasis on dairy cows. Submitted by Alimuddin Naseri, Afghanistan: [email protected] 4

1.2.2Inorganic Matter (IOM)IOM is also called ash. IOM content is determined by burning samples until no carbon is left.A high level of ash in a sample often indicates contamination with soil. For example, over10% ash in roughage (silage) or concentrates indicates soil contamination or adulteration withe.g. chaff.Ash contains the minerals. Minerals are very important for building-up the body as in thebones and teeth. Minerals are needed as a part in proteins to make-up the soft tissues of thebody. Further more, numerous enzyme systems and osmotic regulation of the body requireminerals. Consequences of a shortage of minerals can be: fertilityPoor growthDiseasesDeformation of the skeletonLow productionGenerally speaking it is advisable to provide livestock with ad lib mineral blocks and/or witha mineral mixture included in concentrates. Another possibility is to correct mineraldeficiencies in the soil by application of appropriate fertilizers.Minerals are divided in major and trace elements. The only difference is that animals needlarge(r) quantities of the major-elements.1.3 MineralsThe important minerals in dairy cattle feeding are divided into two groups:-1.3.1Major MineralsTrace MineralsMajor MineralsCalcium (Ca)Ca is the most abundant mineral element in the body and a very important constituent of theskeleton and teeth, in which 99 % of the total body Ca is found. Substantial amounts of Caare released in the milk.Deficiency symptoms:- rickets (misshapen bones, lameness) especially in calves- milk fever (hypocalcaemia)Sources: bonemeal, shell meal, lime, meat meal, fish meal, milk, legumes, pulses, dicalciumphosphate.Ca utilization in the body is strongly associated with phosphorus (P) and vitamin D. Therequired Ca : P ratio for dairy cattle is in general 1½-2 : 1.Animal nutrition, with emphasis on dairy cows. Submitted by Alimuddin Naseri, Afghanistan: [email protected] 5

Phosphorus (P)P is used in bone formation, in close association with Ca and vit.D. In addition, P has moreknown functions in the animal body than any other mineral element. Deficiency symptomsare mainly related to P deficiency in soils and is the most important deficiency in grazinganimals.Deficiency symptoms:- rickets- chewing wood, bones, rags etc.- poor fertility- lower milk yieldSources: cereal grains, bonemeal, dicalcium P, milk, and fish meal.Note:di-CaP can not be distinguished from mono-CaP by the "naked eye". Howevermono-CaP cannot be absorbed/utilized by the animal.Potassium (K)K is very important for osmotic regulation of the body fluids and regulation of the acid-basebalance in the rumen, along with NaCl. Deficiency is very rare, although excess K mayinterfere with the absorption of magnesium (Mg), leading to hypomagnesia (grass staggers,grass tetany). K-contents in plants is generally rather high.Sodium Chloride (NaCl)NaCl is also known as common salt or kitchen salt. Functions in association with K in theacid-base balance (rumen pH) and the osmotic regulation of body fluids. This is veryimportant in the warmer climates (sweating). Deficiencies are usually indicated by a generalpoor performance (poor growth, infertility). Most feedstuffs, especially plant originated food,have a comparatively low NaCl contents (except meatmeal and foodstuffs of marine origin).The main source of NaCl is common salt which should be provided ad lib., either as a "lick"or in a special water trough with a 2-2.5 % salt contents (2-2.5 kg of salt in 100 litre ofwater).Sulphur (S)S occurs mainly in the proteins in the body. Deficiency indicates basically a proteindeficiency in the ration. Extra sources of S may have to be included in diets with substantialamounts of NPN (urea). Potential S sources are: protein rich sources (soya cake, cotton seedcake) or sodium sulphate.Magnesium (Mg)Mg is closely associated with Ca and P. 70 % of Mg is found in skeleton, the remainder beingdistributed in soft tissues and body fluids. Deficiency is not uncommon in milk fed calvesbetween 50-70 days of age. Symptoms are poor bone formation (calves) andhypomagnesemia (grass tetany). The absorption of Mg may be inhibited by high levels of Kfrom manured pasture grass. Sources are: wheatbran, legumes, plant protein cakes likecottonseed cakes (not suitable for calves; gossypol) and soya cakes.Animal nutrition, with emphasis on dairy cows. Submitted by Alimuddin Naseri, Afghanistan: [email protected] 6

1.3.2Trace MineralsIron (Fe)More than 90 % of the Fe in the body is combined with proteins, mainly haemoglobin.Deficiency is indicated by anaemia, especially in young calves which are only fed on milk.Deficiency is not common in adult cattle, as Fe is widely distributed in the feedstuffs (exceptmilk). Good sources are: green leaves, legumes, seed coats and meat, blood and fish meals.Copper (Cu)Cu is necessary for haemoglobin formation and pigmentation. Deficiencies are indicated byanaemia, dull coat colour (black hairs become brownish), infertility and scouring. Cu iswidely distributed in feedstuffs and under normal conditions the diet of dairy cattle containsadequate amounts of Cu. Seeds and seed by products are normally rich in Cu, provided thatthere is no Cu deficiency in the soil.Cobalt (Co)Co is important for the functioning of the rumen micro organisms (RMO's) in associationwith vitamin B12, which contains Co. Symptoms of deficiency are emaciation, anaemia,pining. Most foods contain traces of Co and normally deficiencies do not occur.Iodine (I)I plays an important role in the functioning of the thyroid gland. The main indication ofdeficiency is an enlargement of the thyroid gland, known as "endemic goitre" (big neck). Thedeficiency may result in breeding problems and birth of hairless, weak or dead calves. Feedof the Brassica family (kale, rape, rape seed, cabbage), but also soya beans, peas and groundnuts may contain goitrogenic substances causing goitre if given in large amounts. I occurs intraces in most foods. In areas where goitre is endemic (inland), precautions can be taken bysupplementing the diet with I, usually in the form of iodized salt.Manganese (Mn)Mn is an enzyme activator. Very little amounts are required. As Mn is widely distributed infeedstuffs (especially in wheatbran, ricebran and seeds), usually no problems areencountered.1.4 VitaminsVitamins are indispensable, but the animals need them only in very small quantities. Themost important vitamins are:-1.4.1Water soluble vitaminsFat soluble vitaminsWater Soluble VitaminsVitamin B (complex)This group of vitamins is produced by the animals themselves in the rumen and a shortage isnot likely in ruminants, except when the diet is short of cobalt. Bran, milk and brewers grainare rich sources of vitamin B for cattle.Animal nutrition, with emphasis on dairy cows. Submitted by Alimuddin Naseri, Afghanistan: [email protected] 7

Vitamin CAll farm animals can synthesize vitamin C and will not experience a shortage. Green leafyvegetables, citrus and potatoes are sources rich in vitamin C.1.4.2Fat Soluble VitaminsVitamin AA shortage of vitamin A causes a dry skin, infections of the skin and eyes, the digestive tract(diarrhoea) and the genitals (infer