eChapters

Crude protein of feedscontain true proteinandnon-proteinnitrogen. Trueprotein is madeupaminoacids andforthemaximumefficiency, feed musthave essential amino acids in correct proportion, correct balance as well as non essential amino acids should also be in sufficient amounts. About digestion in simple stomached animals, the true protein is degraded to oligo peptides (less than ten peptides) in the stomach, subsequently to mono peptide and amino acids in the small intestine. Thereafter amino acids are assimilated in the small intestine. But in ruminants, the situation is complex in the sense that feed proteins get digested in the rumen but even amino acids are also broken down by microbes and thereafter, amino and carboxylic groups are released. Secondly, synthesis of new amino acids or proteins takes place for the formation of their own microbial body coat. Because of these reasons, the approach for protein evaluationor expressionisdifferent inruminant andnon-ruminant animal.Further, non-protein nitrogen portion of feed can not be utilized effectively by non – ruminants like swine and poultry. These animals are usually fed with oil cakes, cereals and cereal by-products, which are poor in non-protein nitrogen compounds, however, young succulent fodders, clover etc. are rich in such compounds.

The animal bodycan be imagined as a machine, which is gettinginput of desired or available feed given by the farmer and this animal body after processing through various metabolic activities, output of product is given off. Feed is composed of organic nutrients-carbohydrate, fat and protein and after reaching in the animal body, used for constructive work, for example synthesis of body tissues and other associated work. Later, milk or egg is produced as an output. Now putting the same perspective in terms of energy, that is, these organic nutrients of the feed contain chemical energy and after reaching in the animal body, used as mechanical energyin muscles or heat energyin metabolism. The energy in the body would be utilized for the synthesis of body tissues or other productive output, for example, draft work by bullocks. Therefore, energy is primarily required for the maintenance of the body and then, for the productive purposes :

• Growth for all the farm animals

• Milk from cow, buffalo, sheep, goat • Eggs from poultry, duck, turkey

• Wool from sheep

• Meatfromfatteninganimals under the law, for example– mutton, chevon, pork, chicken.

There are three types of systems for expressing the energy value of feeds and many examples have been depicted in each of these systems the world over but here, one example has been taken up in each of these categories.

Digestible Nutrient Type

For example, Total digestiblenutrients (TDN) system: Digestibility coefficients of various organic nutrients like carbohydrate, fat and protein are determined by digestibility trials, which can be utilized to be involved for total digestible nutrients as a measure of nutritive value of feeds. Here only faecal enegy loss has been considered barring losses from other channels. Hence roughages are overestimated bysuchcalculations.Otherwise, thismethodissimple, economical and has some basis for animals to be fed on such standard in India. The TDN value is expressed in percentage as following :

% TDN = % dig. C.P. + % dig. C.F. + % dig. N.F.E. + [% dig. E.E. X 2.25]

Thousands andthousands ofsamples ofvarious feeds andfoddersweresubjected to Weende analysis fortheir chemical composition have been depictedin various manuals. Such proximate principles of these feeds provide only the potential value forreference or consultationpurpose, but not theactualvalue of feedstuffs. Losses of nutrientsinfaeces(solids), urine (liquid), gasesetc.duringthe digestion, absorption andmetabolismof theanimal shouldalso be taken into consideration. Therefore, a need arises to conduct digestibilitytrial or experiment for the feeds in the ruminant animals. Major portion of the nutrients present in the feeds are not properly digested in the gastrointestinal tract (G.I.T.), hence not completely available to the animal body. Digestibility is that portion of a feed or any single nutrient of feed, which is not excreted in the faeces or dung and it is therefore, assumed to be absorbed by the animal. When this digestibility is expressed in percentage, it is termed as ‘digestibility coefficient (D.C.)’.

Mixture of nutrientscomprisingcarbohydrates, fats, proteins, minerals, vitamins and water are feed stuffs. From the intestinal wall, very few of such nutrients can pass directly to the body tissues, therefore they must be degraded down into simple compounds before they pass through the mucous membrane of the gastrointestinal tract (G.I.T.) intothe bloodand lymph. This degradation process is regarded as ‘digestion’. Thereafter, the movement of these simple compounds through the mucous membrane oftheG.I.Tract into the blood iscalled absorption. Metabolism is the utilization of these nutrients by the animal body and then excretion of the end products takes place from the body. The digestion of feeds is carried out by three means namely, mechanical action: mastication in the mouth and the muscular contraction of G.I.Tract; chemical action: this is carried out by enzymes secreted by digestive juices and microbial action: this is also enzymatic action, but the enzymes are secreted by microbes instead of host.

In ruminants, it is the rumen which harbours bacteria, protozoa and fungi (Fig. 1) ; whereas in non-ruminants, it is the large intestine (Fig. 2). There are four compartments in the stomach-reticulum, omasum, rumenand abomasums. Reticulumprovides ruminantadditionalspacefor storage.Also, if byanychance, foreign bodies like nails, wires etc. reach over here alongwith feed, they are retained for longer periods and thus, soft organs are protected. Omasum squeezes out water from the feed with the help of its strong muscular walls. In the suckling calves or lambs, the two compartments-rumen and its continuation reticulum are less developed and both are joined by a tube like structure -oesophageal or reticular groove, which directly opens into abomasum. That is why in these sucklings, milk reaches straight into the abomasum, which is the true stomach. Rumen develops at about six weeks of age in these young ones. As these sucklings begin to eat solid feed, both rumen and reticulum enlarge greatly and separate. Now oesophageal or reticular groove does not exist.

There are six nutrients which are very important to animal body and they are – Carbohydrates, Lipids, Proteins, Minerals, Vitamins and water.

Carbohydrates: These are polyhydroxy aldehyde or ketone as in monosaccharide or polymers in oligo or polysaccharides. The question arises whether carbohydrate is a dietaryessential !!! Carbohydratemay not be dietary essential but it is definitely metabolically essential. The organic compounds – fats, proteins are oxidized only in the presence of carbohydrates. Carbohydrates are the structural components of DNA, RNA, and some other vital organic molecules. Although less than 1% is present in the human body (because constantly being formed and broken down in metabolism), yet without the presence of this carbohydrate, the existence of living creature is at stake.

Carbohydrate in the form of glucose primarily provides energy in the body and excess amount of carbohydrate is stored as glycogen in the liver and muscle. More than fifty per cent of the energy value of the diet is provided by carbohydrate.

Glucose + 6O₂ → 6 CO₂ + 6H₂O + Δ E (675 k.cal)

They also exhibit protein sparing action because proteins are mainly required for tissue-building i.e. general wear and tear in the body. If there is any emergency, say animal is deficient in calories of the diet, then it will use adipose and protein tissues. It is said that proteins and fats are burnt or oxidized in the flame of carbohydrate.It means thatcertain intermediarycompounds of glucose oxidation through krebscycle are absolutely necessary for oxidation of proteins and fats. Again, in any emergency, if glucose level of the body goes down, fats and proteins take over and they get metabolized faster than the animal body

Livestock feeds have a variety of feed stuffs for feeding. Composition and characteristics differ even amongcloselyrelated feeds.Also, cost and availability of such feeds at a particular place, makes the farmer to choose for practical feeding. Therefore, it becomes imperative to learn about such classes. Feeds may generally be classified according to the amount of a specific nutrient they provide intheration. Theymayconvenientlybe divided intotwo general classes– roughages and concentrates. Roughages are bulky feeds containing more than 18 per cent crude fibre, but less than 60 per cent total digestible nutrients. Contrary to this, concentrates have less than 18 per cent fibre, but more than 60 per cent total digestible nutrients. Roughages may be further sub-divided intosucculent and drytypes.Whereas, concentratesare sub-dividedintoEnergy or basal feeds havingless than 20 percent crude protein and Protein supplements havingmorethan 20percent crude protein. Followingfeeds indicate theoutlines of classification [Flow chart 1] of the conventional feeds into broad categories with examples.

Nutrition involves various bio-chemical and physiological activities which transformfeed elements into bodyelements. These feed elements are nutrients which are digested, absorbed, utilized to build and renew the components of the animal body. As a result, animal grows and produces-milk, eggs, wool with the help of energy so produced in the body. Afterweaning, most of our farmanimals obtainall of their feedsupply from plants.Barringcarnivores, theplant kingdom is the original and essential source of all animal life, because plants are able to utilize the energy of the sun to build substances which nourishthe animal. Plants make use of carbon dioxide, water and mineral salts to form carbohydrates, fats and proteins which are utilized in the life processes of animal body. Thus plants store and animals dissipate energy.

Plants and their parts

Animal body and plants contain the same substances but they differ in relative amounts. There are also much larger compositional differences among species than do animals. Water is the principal constituent of living plants as well as animal body. With the maturity of seed, water content decreases. The dry matter of plants consists principally of carbohydrates, which serve as both structural and reserve material, while in animals, protein comprises the structure of the soft tissues and fat is the reserve. Thus, animal body contains only a trace of carbohydrate, though occurring as much less than 1 per cent at any given moment, because it is constantly beingformed and broken down in metablolism. Whereas, this is the principal constituent of most of the plant species. Protein is the main constituent of active tissues and thus leaves are much richer in this nutrient than are stems. Grass hays contain less protein than leguminous hays. When theplant matures, there isgradualmovementof protein fromthe vegetative parts to the seed. Thus, the seed contains a higher percentage of protein than the rest of the plant, as in grains and stovers.

A. Multiple choices (you have to choose most appropriate answer among 4 alternatives)

1.    Which of the following bacteria in rumen is not cellulolytic

a. Bacteroides succinogenes

b. Ruminococcus flavefaciens

c. Ruminococcus albus

d. Succinivibrio dextrinosolvens

2.    Which of the following bacteria does not interact with anaerobic fungi

a. R. albus

b. R. flavifaciens

c. Butrivibrio fibrisolvens

d. Fibrobacter succinogenes

A. Answer the following questions

1.    WhyvitaminAdeficiencyis far common in captive carnivores than free rangingwildlife?

Ans: Because they are fed exclusively on carcass meat without liver, cod liver oil or synthetic sources of vitamin A and moreover, thay can not convert ?-carotene to vitamin A.

2.    Why weekly off day feeding is practiced in tiger in all Indian zoos?

Ans: This ispracticed tostimulatetheintermittentfeedingbehavior of tiger in wild condition.

3.    Why metabolic bone diseases are very common in captive carnivores?

And: As the carcass meat provided in captivecondition is deficient in Ca and ratio of Ca: P (1:20) is very highly imbalanced.

4.    Write the extreme specializations in GItract seen in vampire bats?

Ans: Like blood sucking parasites, their GI tract is reduced to a tube since it feeds only on blood.

A. Answer the following questions

1.    Why protein requirement for maintenance in cat is high?

Ans: It is due to the inability of the nitrogen catabolic enzymes in the cat’s liver to adapt to changes in dietary protein intake.

1.    Why arginine is dietary essential in cat?

Ans: Because, cat is unable to synthesize ornithine which is an arginine precursorwithin theurea cycle. Aminoacid glutamic acid and proline is precursor of ornithine in the intestinal mucosa of all mammals.However, an enzyme thatis required in the pathway, proline-5-carboxylate synthatase is absent in cat’s intestinal mucosa. In the absence of dietary arginine, a high catabolism of protein generates a load of ammonia that cannot be detoxified by its incorporation to urea and hyper ammonia develops.

2.    Why taurine is dietary essential in cat?

A. Answer the following questions

1.    What is the DM consumption in adult guinea pig? Ans. An adult animal consumes @ 7-8% of body weight.

2.    Mention daily average feed consumption of guinea pigs?

Ans: Growing Guinea pigs: 20-30g, Adult maintenance: 30-50g, Pregnant and lactating: 40-60g.

3.    Write down the peculiarities of digestive system of guinea pig.

Ans. The entire stomach of guinea pig is lined with glandular epithelium and gastric mucosa does not have a keratinized portion.

4.    Why guinea pig cannot synthesize vitamin C?

A. Answer the following questions

1.    Why Oats are mostly preferred by horse?

Ans: Because oats are low in energy, rich in fibre (8-11%), very soft and easily ruptured duringmastication, highly palatable, rich in oil content (5%), better protein quality (high lysine), more readily digested in the S.I. than maize and barley and moreover it provides a more open textured material in the stomach due to high fibre and are thus least likely to cause colic compared to other cereals.

2.    Why wheat is most likely cereal to cause colic in horse?

Ans: Because of its high gluten content since gluten leads to the formation of doughy lump in the stomach. Hence wheat should not be used exceptin small quantities or in low levels.

3.    Why Excessive feeding of wheat bran leads to ‘Big head disease’ or ‘Millers disease’ in horse?

Ans: It is due to an imbalance ratio of Ca and P in this bran i.e high in P and low in Ca. So, due to a Ca deficiency, Ca is withdrawn from the bone and the bone is replaced by a proliferationof fibrous connective tissue whichismainlyfound in the skull or jaw.

A. Answer the following questions:

1.    What is flushing?

Ans: It means putting the sow on a more nutritious ration before breedingseasonto improvephysical condition of the female, prominent heat symptoms, increases ovulation rate, shortens period between weaning to successful conception, more uniform litter size and minimizes embryonic death, prompt post weaning estrus.

2.    What is piglet anaemia?

Ans: It is a condition occurs 2-4 weeks after birth when piglets do not have access to soil or pasture and are housed in concrete floor. Piglet anemia is characterized by labored spasmodic breathing(popularlyknownasthumps); hemoglobinlevelfalls to 3-4mg/100ml of blood, poor growth rate, wrinkled skin, rough coat, lack of healthy pink color of visible mucous membrane.

3.    Why pig industry in India has not yet been developed?

Ans: It is mainly due to the fact that pig is not used as meat by majority of meat eaters.

4.    Why it is advisable to offer cereal based ration to the piglets only after two weeks?

A. Answer the following questions

1.    Why ducks are highly susceptible to aflatoxicosis?

Ans: Ducks are about 200 times more sensitive than broilers and layers. Ducks contain a very high level of enzyme in the livertoconvert aflatoxinB to “aflatoxacol”. Besides, aflatoxin metabolism is 90 times faster in the duck liver than in rat liver.

2.    Why duck should have never access to feed without water?

Ans: Most mashes form a sticky paste when mixed with saliva and adhere to the papillae and other structures bordering the outer margin of the tongue and upper and lower bill. This caking interferes with the movement of the food mass to the tongue resulting in reduction of food intake and increase in feed wastage which occurs when the duck attempts to shake or wash off the mash adhering to its mouthparts.

A. Answer the following questions

1.    What are metabolic diseases?

Ans: It is defined as disturbances of the internal homeostasis of the body brought about by an abnormal change in the rate of one or more critical metabolic processes.

2.    How do you prevent milk fever by nutritional management?

Ans: By providing a ration that contains 0.5-0.7% Ca and 0.3-0.4% P and by feeding 20 Million Units of vitamin D/cow/ day starting about 5 days before calving and continue for maximum7 days postpartum.

3.    What is the nutritional management strategy to prevent grass tetany?

Ans: A salt lick of 10 parts each of MgSO₄ and Ca(PO₄)₂ with 80 parts of salt is effective. Besides a mixture of 2 parts of MgO and 1 part salt is also effective measure.

4.    Write down the preventive measures of ketosis?

A. Answer the following questions:

1.    What is NPN substances?

Ans: Feedstuffs which contain nitrogen in the form other than protein or peptides aretermed as non-protein nitrogen (NPN).

2.    What is liquid diet?

Ans: Liquid molasses containing 2-3% of uniformly mixed urea fortified with minerals andvitaminsis named as ‘liquiddiet’.

3.    Name few amides.

Ans. Urea (46.6% N) and Biuret (35%N)

4.    Name few amines:

Ans. Histamine from Histidine, Tryptamine from Tryptophan, Tyramine from Tyrosine, Betaine from Sugar beet pulp.

5.    Name few alkaloids.

A. Write True or False of the following statements

1.    Goats have higher threshold level for bitter taste than other ruminants.

2.    Cattle is acknowledged as mobile pruning machine.

3.    Creep feed should have at least 10% DCP and 58% TDN. 4. Goat under brows condition performs better.

5.    Colostrumshould be fed to the kids @ 10ml/kgbodyweight.

6.    Creepfeed maybe introduced to kidsfrom101 days onwards.

7.    Due to difference in MBS, DMI is higher in larger breeds than smaller breeds.

8.    30-40% of feed intake by goat consists of leaves of shrubs and bushes.

A. Answer the following questions

1.    What is balanced ration?

Ans: According to Morrison (1956), a balanced ration is one that furnishes nutrients in such proportions and amounts that it will properlynourisha givenanimalfor 24hours.The required nutrients must be contained in the DM provided during the 24 hrs period otherwise the ration can not be considered as balanced.

2.    What is ration?

Ans: A ration is the feed allowed for a givenanimal duringthe day of 24 hours.

3.    What is effective rumen degradable protein? (ERDP)

Ans: It has been defined as a measure of the total nitrogen supply that is actually captured and utilized by the rumen microbes for growth and synthetic purpose.

4.    How heat treatment causes protein protection?

Ans Heating causes denaturation of protein and this may be beneficial because of reduced ruminal degradation partly by blocking reactive sites for ruminal proteolytic enzymes and partly byreducingprotein solubility.

A. Answer the following questions

1.    Define feeding standards?

Ans: Feeding standards are the statements or quantitative descriptions of amounts of one or more nutrients needed by the animals or human.

2.    Limitation of feeding standard?

Ans: Palatability and physical nature of the ration are not included and does not included the environmental factors because environment may change the nutrient requirements.

3.    Write down the merits of ME system?

Ans: ME gives more correct result than DE or TDN. It is because energy losses in urine and GDP are corrected in ME system and ME is cheaper and easier to obtain than NE values.

4.    What is the purpose of following feeding standard?