5 Digestive System stomach in ruminants comprises 25 % of body rumen comprises 75 % of stomachfermentation: digest cellulose, plant tissue, urea, NPN, B & K vitaminsconsist of bacteria and protozoa (200 billion/teaspoon)
6 Characteristics of Ruminants Mouthno upper incisor or wolf teethuse lips and tongue to grab foodfour compartments to the ruminantConsist of microorganismsProduce Volatile Fatty Acids/ acetic, propionic, butyric
7 Volatile fatty acids (VFA) Produced in large amounts through ruminal fermentation and are of paramount importance in that they provide greater than 70% of the ruminant's energy supply. Virtually all of the acetic, proprionic and butyric acids formed in the rumen are absorbed across the ruminal
8 VFA’s cont.epithelium, from which they are carried by ruminal veins to the portal vein and hence through the liver. Continuous removal of VFA from the rumen is important not only for distribution, but to prevent excessive and damaging drops in pH of rumen fluid.
9 Ruminants Prehension- the process of gathering food to the mouth Mastication - the process of chewingEructation (belching of gas)Carbon DiOxide and MethaneEnzymes- organic catalyst which speed up a biochemical reaction without being used up
10 Rumination Rumination-fermentation rechewing usually > 8 hours/day dependent on diet (increase fiber, increase rumination time)CO2 and Methane are the primary gases given off during rumen fermentation
11 Digestion and Utilization of Prot, CHO and Fats
15 FUNCTION OF FEEDSMaintenance- a ration which is adequate to prevent any loss or gain of tissue in the body when there is no productionthe difference in energy needs are related to the amount of activityGrowth- increase in size of muscles, bones, internal and external parts of the body (the foundation of animal production)Finishing- the laying on or deposition of fatProduction – lactation, conception, etc.
16 FEEDSDefinition- any ingredients or material fed to animals for purposes of sustaining themClasses of Feedsroughagesconcentratesby-productsprotein supplementsminerals, vitamins, and additives
17 Classes of Feeds-Roughages Definition: >18% fiber and lower in energy & low digestibility compared to concentratesGenerally; TDN=40-60% and is high in Ca & KForage/Pasture, hay, crop-residue (corn, milo), silage (fermented, high-moisture forage), haylage (low-moisture type silage), green chop
18 Classes of Feeds cont.Concentrates- high in energy, low in fiber and < 20% protein – Corn, milo, oats, etc.By-product feeds (from plant and animal processing) carrots, turnip tops, fodder beetsProtein supplements- high in nitrogenOilseed Plant by-products (SBM, CSM)
19 Classes of Feeds cont. NPN= non-protein nitrogen urea, ammoniated molasses or chloride, biruet, etcUrea=45% Nitrogen X 6.25 = 281% protein equivalentMinerals - NaCl, limestone, dical, etc.major -Ca, P, Mg, Strace - Cu, Fe, I, Mn, Zn, Se, etc.
20 Classes of Feeds Vitamins Special Feeds Natural versus synthetics water vs fat soluble classificationA,D,& E are most common in ruminantsSpecial FeedsFats and oils (increase calories without bulk)molasses (increase energy and palatability)
21 Classes of Feeds Feed additives and implants increase efficiency of gain, prevent diseases, preserve the feedantibiotics, hormones, growth promotants, repartitioning agents, etc.
22 Evaluation of Feedstuffs Measuring EnergyTDN= sum total of the digestible protein, fiber, and nitrogen free extract, and fat X 2.2540% is low for forages while 60% is highMost concentrates are 80-90%
23 Calorie or California Net Energy System Net Energy= gross energy-fecal energy-gaseous energy-urinary energy-heat incrementgross energy = combustion heatdigestible energy = portion of gross energy that is not excreted in fecesMetabolic energy = portion of gross energy that is not lost in feces, urine and gasheat increment = difference between ME & NEheat unavoidably produced by an animal in digestion and metabolism
24 Evaluation of Feedstuffs Analyzing FeedstuffsProximate analysis1) H2O (DM vs As Fed),2)CP 3) Ash 4) FatFiber (ADF, NDF)Energy (Net or TDN) – bomb calorimeterMinerals & Vitamins
25 Ration Formulation Consideration points availability and cost of feedstuffsmoisture contentcomposition of feedstuffssoil analysisnutrient allowances and requirementscomposition of ration and ingredients
26 Beef Cow Nutrition Objective feed little as possible as long as we don’t damage reproduction, milk, or longevityoverfeeding causes decreased longevity, dystocia, reprod. rate, and milk prod.underfeeding causes delayed estrus, puberty, lowers conception rate and milk prod.
27 Phase Feeding for the Beef Female feeding accounts for approx. 2/3 of total costs after real estate acquisitionfeeding has the greatest influence on growth and performanceYet, reproduction is the most important economic important traitfeeding influences growth, reproduction (most critical), lactation, etc.
28 Phases of Feeding Birth to weaning Weaning to first breeding First breeding to first calvingFirst two productive years (1st two calves)Third and subsequent years of production
29 Phase FeedingPlane of nutrition is dependent upon energy and protein requirements along with forage quality and availabilityCan be somewhat breed dependentEuropean cattle are later maturing and will utilize more forage
30 Phase Feeding First phase- Birth to Weaning objective is to develop replacement females to weaning with maximum subsequent productivity at minimum costs
31 Phase FeedingGrowthier females at weaning will usually reach puberty earlier, calve on time and return to rebreeding earlier than slower growing heifersWeaning is usually around 205 days or 7 months of age
32 Phase Feeding Second phase - Weaning to First Breeding objective is to promote adequate growth to insure sexual maturityfirst breeding should be done at % of the estimated mature weightADG of lbs. per day is recommended
33 Phase Feeding Third phase - First Breeding to First Calving objective is to promote sufficient growth and body development to allow heifers to deliver a calf, and to prepare the heifers physiologically to be able to withstand the rigors of first lactation and rebreeding.
34 Phase FeedingFemales should gain 70-75% of their weaning weight or be 70-75% of their mature weight at their first calving time.
35 Phase Feeding Fourth phase - First two productive years Objective is to provide a sufficient plane of nutrition to allow the young cows to lactate, rebreed and continue to growcows should not lose more than 15% of their weight during the winter
36 Phase Feeding Fifth phase - Third and subsequent productive years Objective is to maintain efficient productivitynutrient requirements actually decreaseShould not lose more than 20% during the winter
37 Feeding in General Obesity can be a major problem Body Condition Scores should be utilizedScores of 1-9, where 1 is very thin and 9 is obese : HandoutThis can be breed, feed or frame size dependent
38 Feeding in General Heifers - breed more than needed breed 30 days before the mature cowspalpate 60 days after breeding seasonCows > 10 years of age; the physical condition will diminishBulls - during intense breeding season; requirements may increase by 2-3 XIf forage is limiting, feed bulls separate
39 Feeding Systems Creep feeding- the supplemental feeding of young nursing animals in an enclosure which is accessible to them but not to their parentgains for young animals are cheap gains due to less fat content in young animals and less consumption/body wt.adv.- increases weaning wt., facilitates fall calving, uniformity, achieve genetic potential, assists first calf heifers, etc.
40 Creep feeding- is it feasible? whenever it is most likely profitableusually when forage or milk is limitedconditions we see in drought that results in overgrazing by mother, thus forage is limitedyoung cows or very old cowsTo be feasible, value difference of the calf should be over the cost of the creep feedOver creep feeding can cause reduced subsequent milk production because of excessive fat in udders
41 Feeding and Management of Brood Cows critical time of nutrition30 days before calving70 days after calvinggrowth of calfreproduction efficiency of cowLactationRebreeding
42 Feeding and Management of Brood Cows feed the herd according to cow reproductive patterndependant upon:dry pregnancylactatingreplacement heifers
43 Feeding and Management of Brood Cows heifers – the last 3-4 months before parturition is importantweight makes a differenceprovide for maintenance and growthBCS
44 Feeding and Management of Brood Cows Reproduction and Nutritionenergy is more important than proteinP supplementation increases % calf cropincrease Vit Alevel of feed before and after calvingpregnant cows should not gain over 100 lbs during gestation
45 Feeding and Management of Brood Cows Winter Feedinggrass decreases in proteinmust either drylot or supplementenergy is important and should be increased by 10% for every 10 degrees below 20 degrees FRange Feeding Deficienciesenergy- lack of feedprotein - mature grassesminerals - lowered salt and P/ vit. - A & ? D, E
46 Feeds for supplementation Oilseed mealsGrainBreeder/range cubesProtein blocksLiquid feeds (protein or protein/energy)Syrup blocks or tubsHays
47 Supplementation when supplementing; need to know 4 things: nutrient compositionavailabilityIntakerequirements
48 Supplementation questions how much to feed and still make max usewhat kindwhat formhow oftenadditivesAlternatives
50 Feeding of Bulls age and condition / exercise increase bulk, decrease grain ( do not want them too fat)feed young bulls more for growth and development- overfeeding results reduced sperm counts, unsoundness, etc.mature bulls- increase lbs of grain plus roughage as needed to fit BCS
51 Bulls cont. Young bulls Feed a 12-14% CP ration at 1.5-2% of CWT Make sure they have plenty of free choice forageThumb rule is to feed a 14% CP ration until 14 months of age
52 Pastures two kinds- native and improved range covers > 40% of the world land areagrasses, browse (woody stem perennial), forbs (hollow stem annual)-weedscattle prefer grasses, deer prefer browsethumb rule- graze 1/2 in summer and save 1/2 for the winter
53 Forages Forage intake vs digestibility Factors that influence intake body sizeforage availability- biggest problem we faceforage palatabilitygut fillrate of passage
54 Forage intake higher the Quality forage, higher intake early maturity lower proportion of cell wallshigher proteinincreased rate of passagedigestibility increaseslowers gut fill
55 Forages Rate of passage or digestion depends on: plant species plant maturity- more mature, less digestiblecell walls=cellulose vscell contents=sugars
56 Forages maturity increases, cell content decreases protein content> 6% for optimum digestionpreparation method - pelleting, grinding, etc
57 Characteristics of grasses on native range slower growth rate- reduces qualitylonger period to reach maturityslower re-growth
58 Proper utilization of range maintain grazing distribution through:fencing watershade burningmowing or sprayingfertilizersupplemental feeding
59 Improved pastures Don’t graze in early fall or late summer bermuda grass- adaptablehybrids- *coastal, Tifton 85, commongood response to N and waterproblems- requires cross fencing & N
60 Proper Managementgraze when 6-8”, fertilize NPK early spring and N in summer and late summercan overseed with fescue, wheat, rye in the fall for winter pasturean increase in N does not necessarily increase performanceyet, it increases quantity, thus stocking rate
61 Thumb Ruleswhen a cow consumes enough energy, she usually consumes enough proteinWinter- cow should consume 1.5% of body wt with poor forage2.0% with good quality hay2.5% with excellent forage such as alfalfa or wheat
62 NPN- non-protein nitrogen Urea is most popular; other ammonium chloride, biuret, etc.most effective with high CHO source diet and low protein requirement, twice daily feeding, bacteria in the rumen require energynot as well utilized at > 12 % protein or in young growing calves or creep