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AVS 3750 (3)
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Lecture 1

AVS 3750 Lecture 1: Test 2

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Clemson University
Animal and Vet Sciences
AVS 3750

Protein Processing Meal: extract oils from ingredient to concentrate protein • Will have anti-nutritional factors o Anti trypsin  also effects chymotrypsin o Enzymes ▪ Urease o Plant’s protection against consumption • Best way to decrease anti nutritional factors is heat treatment Protein supplements have 20% protein DMB • Increase availability and digestibility by removing oil and anti nutritional factors • Plant and animal origins o Which one is better? ▪ Want a balance of amino acids • Oil seed byproducts: o Soybean meal is the most used containing between 43-48% protein on a dry matter basis o Cottonseed, canola, linseed meal are also important plant protein sources ▪ Gossypol anti-nutritional factor ▪ Erucic acid removed when heat treat canola (rape seed) o Dehydrated alfalfa meal is also an important source of plant protein ▪ Early stages have ~25% CP [methionine is limiting in livestock] Blood meal has higher level of M (or purified AA to add to diet) Lysine is deficient in corn Lysine to Methionine ratio • Dividing amount of L to M • Usually 3L : 1M • Look for this profile in nutrient analysis of CP Swine has good basic AA formulation • Ruminants formulate for metabolizable protein because the diet is modified by microbes so more advanced AA profile define for nonruminants due to little modification of AA profile • Tissue and milk has ideal AA profile • Bacteria cannot synthesize enough of M so feed RUP Biological Value • It is common for producers to feed animals plant proteins, rather than animal proteins. o Animal proteins are must better because AA are extracted from same source as tissues so resemble what the animal has in terms of AA o Animals products have higher biological value • These plant proteins are of lower biological value for our animals tat are animal proteins. • BV a measure of: protein (N) retained to protein (N) absorbed (digested) • As a general rule, animal proteins have greater BV than plant proteins • Amount retained relative to amount digested Digestion Coefficients • Determined for CP, NDF, ADF, CF and EE • Use to determine TDN • Expressed on a percentage basis • Digestibility of dry matter (organic matter and ash as well) • Can be calculated for any nutrient by eq: o %dig = (tot nutrient consumed – tot nutrient excreted) X 100 tot nutrient consumed • builds up to biological value • this only calculates digestibility of ingredients [Example of N content in feed] • ONLY APARENT NITROGEN DIGESTABILITY True Digestibility • Includes N in the feces of endogenous origin o Endogenous N =.5% N (in the 50 g of feces) ▪ Endogenous N = .25g o True N digestibility = Nfeed – (Nfeces – Nendogenous) X100 Nfeed Nitrogen Retention/balance • Balance is the better term • Balance expressed in g • Retention expressed as percentage • N balance = total N intake – Total N excreted (f + u) o Retention is balance / total intake o %digested is N balance / (total diegested – fecal loss) Protein in feed: Measuring BV • True is higher than apparent when remove endogenous N from feces and urine Processing methods • Hydraulic o Mechanical method leaving high levels of oil in the meal ▪ Rarely used today ▪ Called Extrusion ▪ Leave about 10-20% fat in the grain ▪ Used more in organic producers • Expeller o Method developed for soybeans, mechanical, uses a screw press o Used world wide o Creates pressure to expel oil from the seed o Cannot get rid of antinutritional factors o Does not increase RUP ▪ Another method for SBM or CM uses hydraulic and expeller • Solvent o A chemical process o Removes almost all of the fat  99% o Most SBM is still being produced this solvent (hexane) method Soy Protein concentrate: • See it added to a lot of different foods that we consume o Infant formulas for babies ▪ soy protein milk protein • quality isn’t good for AA profile • digestibility is more difficult Why processing SMB? • Remove urease and trypsin inhibitors o Release ammonia from urea o Reduce activity of enzyme trypsin Heat Treatment: • Denature the proteins • Maillard RXN: o Forms base or ketone ▪ Base is reversible, ketone will not be able to be digested • Reduce availability of this protein • Reduce fraction A, increase fraction B and C o A fraction: NPN o B fraction: True Protein, Soluble Protien o C fraction: denatured, heat damaged, lignin bound • Heating causes significant losses of lysine, cysteine and arginine o Lysine is the most sensitive and undergoes destruction and decreased availability • Overheat at 120 degrees C Calf Nutrition (Chapter 9) Need to know the lifecycle of an animal for their nutrition • Developmental stages • Production Life cycle of a dairy cow **All stages characterized by different management and lactation** • Birth  weaning o Increase available nutrients and maximize utilization ▪ Liquid or solid feeding ▪ High amount of nutrients that are going to go into this stage of the animal o Should be ready to wean at 4-8 weeks o Minimize morbidity and mortality rates ▪ Ideal >5% mortality rate • First transition period of the animal @ weaning and transition to group feeding o TMR or grazing • Pre-pubertal between 9-10 months o Considered until animals are bred • Breeding @ 13-15 months o AFC = age at first calving ▪ 22-24 months ▪ that is when we maximize milk production in subsequent lactations nd • 2 transition period: just before calving in heifers and immediately after calving o Fresh early lactation (from calving to 100 days after parturition) o 21 days o Transition diet- high forage diet • Breed again at 60 days after calving o VWP = voluntary waiting period o Lasts for about 60 days (including 21 days from early lactation) ▪ Not exact because different farm to farm • Dry off period = 60 days before calving o Antibiotics to fend off any infection in the mammary gland ▪ Involution of mammary and reproductive tract  Regression of cells to a state of rest o Needs time to recover and prepare alveoli for lactation o Can be divided into far off and close up period o High amount of forages because not lactating o Need to watch body condition score ▪ Don’t want problems with dystocia  Obstructed parturition ▪ Don’t want obesity or ketosis during early lactation • Close up period: 21 days before calving o Another transition period to ensure pregnancy is still viable o Change diet because of high demand for nutrients for lactation ▪ Modify forage to concentrate ratio to match lactation diet o part of the 60 day dry period • Calving @ 280-290 after breeding o Calving interval @ 365 days o Want each cow to calve 1 type per year o We want a whole year for this process to occur so that we have a good interval US Culling rate • 30% every year • determines how many lactations are expected per cow o 3.3 lactation periods Stages of rumen development: After the animal has been pregnant and growing • Animal is a fully functioning ruminant Rumen development: • When the animal is born the rumen is 25% of stomach- it is not developed and or functioning – prerumen • At 6 months rumen is 60% of stomach • Mature ruminant rumen is 80% of stomach Omasum: • Not much change • 10 to 10 to 8 Abomasum: • 60 to 25 to 7 Rumen papillae development in 6 week old calves on different diet • Milk  no papillae • Milk and grain  papillae o 12 weeks much better than milk and hay o muscularization for contractions o increased absorption • Milk and hay  little papillae development o Milk and hay development took longer ~12 weeks ▪ 3 months of heavy management conditions 3 main factors of rumen development: • Papillary growth (chemical) for absorption • Muscularization (from feed structure) for contractions • Rumen vascularization (interaction of chemical and feed structure) for transport o Comes from chemicals and butyrate (from feed digestion) Rumen site and Papillae Density: • Different points of papillae development • Success with long, dense finger like projections with high vascularization • Increases the surface area for absorption VFA Absorption (Chemical) • Molar proportion of VFA o Acetate 70%- will be the main end product when you have a mainly forage diet ▪ 30% metabolized ▪ 50 @ portal blood o Propionate 20% ▪ 50% metabolized ▪ 10 @ portal blood  higher development of rumen o Butyrate 10% ▪ 50% metabolized ▪ 1 and 4 (beta OH but) metabolized Starter with Grass Hay (physical) • Level of fiber important for scratch/abrasion factor • Increase grain increases papillae growth and development but too much grain can have highly acidic environment o papillae make carotene to protect papillae but block absorption • Inclusion of finely chopped hay increased absorption of papillae by removing the carotene wax from papillae (scratch factor) Different selection of corn: • Most of the time starters have corn, wheat, or SBM • Measured rumen development with different types of processed corn o Saw better effect in intake, pH and VFA production and growth with roasted and whole corn (no difference between the two) ▪ Economically whole corn is better because no processing Rumen Development: • Accoplished by o Grain feeding  butyric and propionic acid production o Increased bacterial growth o Muscularization by rumen contractions o Absorption by increasing papillaries ▪ Remove carotene with scratch factor [Butyric acid most potent in influencing the rumen development] • propionate and butyrate are highly metabolized • but forms ketone bodies that have high correlation with development of papillae • leads to higher epithelial cells and metabolization rates Liquid feeding: Step 1 • During fresh period cow is producing colostrum o Not going to go into the rumen because there isn’t an established microbial environment ▪ Warm milk that can spoil causes for an uncomfortable situation ▪ So they have developed the Esophageal Groove- it bypasses the rumen digestion o Fed to baby calves and increase their immunity and influence development ▪ Lactose, fat, protein and ANTIBODIES/IMMUNOGLOBULINS • During first 12 weeks there is the esophageal groove o Influenced by suckling response and proteins in milk ▪ Closure of rumen still occurs about 30 min after feeding milk  Want to avoid giving water immediately after milk because you don’t want to dilute colostrum or milk and increase the rate of passage o Avoid rumen so it doesn’t spoil and so that the milk is properly digested by the abomasum (true stomach) ▪ Short period of time where large proteins can be absorbed through the small intestine (antibody absorption) Step 2 Clotting of milk: • Rennin: chymosin and pepsin o Protein degradation enzymes • Occurs within 3-6 minutes o Divides into ▪ Whey  Lactose, protein, minerals • Contains Immunoglobulins • Passes really fast to small intestine • Sugar for immediate energy and protein (IG that need to be absorbed as quick as possible) and minerals to assist absorption o Limited amount of time where absorption of full IG is possible ▪ within first 24 hours of life ▪ SI has bigger gaps between the tight junctions of lumen epithelial cells so large proteins can be absorbed ▪ Curd  Protein (casein), lipids • Delayed for optimization of absorption • Longer digestion for increased absorption Blood IgG levels depends on: • Timing of colostrum feeding o Efficiency of absorption decreases with time o Usually near zero by 24-30 hours o Other large proteins ingested interfere with IgG absorption • Quality of colostrum fed o High contamination (not stored properly) ▪ Can absorb bacteria • Quantity of colostrum fed o If not enough taken by calf feed straight to abomasum with tube to ensure the calf receives what it needs Immunglobulins in Colostrum: • All are important but the predominant quantity of igG makes the measurement of the concentration in blood serum an adequate indicative of the transfer of passive immunity o Need 10 g/L ▪ No placental transfer of antibodies ▪ Active immunity does not kick into until about 21 days after birth  Before then, very prone to disease so need to have good quality IgG in colostrum for passive immunity Sugar in colostrum correlates with IgG in colostrum • Brix Refractometer Feed milk from 8-10% of bw/2 feedings per day • Decrease consumption of starter Common fat and protein levels in milk replacer • Most of them will have 20% fat – 20% CP Additives for milk replacers: • Antibiotics o Prevent disease, increase intake • Ionophores/coccidiostats o Prevent disease • Herbs, garlic, oregano o Could cause some resistance we are not sure of the full effects that these have on the development • Probiotics o Beneficial microbes • Yeasts o probiotic • Mannan-oligosaccharides o Prebiotics o Increase bifido bacteria Calf starters: • Start at 3 days of age • High energy high protein (16-20%CP) o Molasses to increase intake • Low fiber o Scratch factor o muscularization • Grain mixes o Corn, SBM, oats ▪ No allergens or ANF ▪ Good for newborn o Added Ca, P and minerals • Many have low doses of antibiotics o No active immunity so want to ensure no disease When can we wean? • Wean as early as 3 weeks o Most progressive farms do this • 4-6 weeks adequate Starter consumption • calves must be strong and consuming at least 1% of body weight as grain starter before they are weaned • You can not forget about the transition Weaning action plan • Liquid feeding: 8-10% bw • Start feeding grain after 3 days • Heifer Nutrition Age at first calving and percent of time spent as heifers by herd milk production level for dairy cows • Not producing any revenue • Can be ignored • Every day the animal is a heifer and not producing milk, costs money to operation • Increase level of milk production, increase culling rate • Depends on less time spent as a heifer • Epigenetic factors: environment over genotype • Pay more attention to how feeding animal • Half the time in low producing herds are culled out anyway o So they will spend more time as a heifer than as a producing cow  but you should be able to get more this is where good nutrition Heifer Feeding Program • 3 phases o preweaning feeding program o prepubertal feeding program o postpubertal feeding program Keep mortality low ( 3-9 months is prepubertal phase • feeding milk, starter, some forage and grains before this stage • 1.9 is highest limit for animal growth • impact milk production the most • 1.7-1.9 lbs per day for ADG o if they grow faster than 1.9 ADG have big impact on mammary gland development • get animals ready to be breed from 13-15 months so that they are calving by 2 years of age Postpubertal phase: after breeding • Monitor body condition score (1-5) • Want about 3 or 3.5 • Have animal calving at 22-24 months o BCS @ 3.25-3.75 • BCS can affect parturition and have dystocia o Too high have trouble with fat mobilization Pre-weaning period • Animal grows at good level • Double size by weaning time (8 weeks) • Higher ADG before weaning has large effect on milk production throughout life • Depends on age at weaning • By 8 weeks of age calves should double their body weight- regardless of age at weaning Isometric vs. allometric • Organs/parts grow at same or different rates • Important to monitor ADG to have direct effect on mammary gland development o Allometric growth = relative growth rates of different body parts within a specie during development. Ideal ADG to give best milk production • Metanalysis • If animal grows too fast, will produce less milk Critical Phases • 1: before puberty o really high ADG during this period affect mammary gland development because it affects the adipose tissue around the paranchyma of the alveoli which decreases overall milk production o excess pre-pubertal growth has a long term negative impact on milk production • 2: Pre parturition o Heifers with insufficient growth rate in late pregnancy may have increased dystocia What is the optimal ADG before puberty? • 1.7 lbs/d or 800 g/d What is allometric growth and when does this occur in the mammary gland of the heifer? • Faster growth before puberty Important to also measure height in correlation with body weight • Nutrition and puberty development go hand and hand together How fast should heifers grow? • .35Kg/d growth is too slow • .75-0.8 g/d growth is about normal • we will breed them at 55% of their body weight and they will calve at 85% of their body weight Holstein • Mature Weight 650-725 kg or 1500 to 1600 lbs • Weight at breeding 750-800 lbs. ADG 0.75-0.80 kg/d • Height at withers at breeding 48-50 in. • Hip height at breeding 50-52 in. • Weight at calving 1250-1350 lbs. • Height at withers at calving 55-57 in. Jersey • Mature Weight 425-500 kg or 940 to 1100 lbs • Weight at breeding 525-575 lbs. ADG 0.50-0.55 kg/d • Height at withers at breeding 43-45 in. • Hip height at breeding 45-47 in. • Weight at calving 775-850 lbs. • Height at withers at calving 48-50 in. Body composition is altered • If overfeeding, higher accumulation of fat o Affect mammary gland development After puberty: • In general there is not much influence in mammary gland development • Make sure that the animal reaches optimal growth and AFC Heifer has reach puberty at 9 mos and weighs 650 lbs • Target AFC is 23 mos, 1350 lbs = 1250 lbs post partum • 12 mos to calving (360 d) 600 lbs to gain • post puberty ADG = 600/360 = 1.7 How can we determine a post pubertal ADG and why is it important? • Divide amount need to grow by the days it has to grow o Important due to economical factor and don’t want any problems with over/underweight animals Tools to monitor growth • Plot your heifers against goals • Summary of group averages • Groups or individual animals Rate of gain limitations and body weight at calving limitations • ADG pre puberty o 1.7 lbs/day • ADG post puberty o Use equation Compensatory growth • Animals that are underfed have to catch up • Use as a strategy to increase efficiency • If undergrowth and then start on higher plane of nutrition difficult to control accumulation of fat at mammary gland Ration balancing for Dairy Heifers • In general if you are balancing a ration using computer models, the estimated DMI exceeds the actual DMI by 20-30%. • Suggested strategy: o Balance the diet, then ADJUST DMI to achieve the desired ADG o Need to measure ADG Changes in nutrient requirements with age in Holstein heifers • Not getting requirement, structural growth is decreased Energy Requirements • Provide to meet maintenance and growth o NEm = 0.0834 X BW^.75 o Neg = 5.4185 X (current BW/Mature BW)^.75 X ADG^1.097 • NRC overestimate energy intake • Be sure to monitor performance after adjustments are made • Ionophores and some other feed additives improve energy utilization What is the correct approach to balance a diet to be fed to growing dairy heifer? • Ration Balancing for Dairy Heifers Pre-Calving • Bred heifers can be managed similarly to other yearling heifers until 3 months before calving • Greater energy and protein is needed for the growth of the fetus and to attain a proper BCS • Heifers need a proper transition to the milking cow ration and environment Control Intake • Metabolic nutrient costs are increased when higher amounts of DM are consumed • Increased tissue energy is retained, decreased heat energy produced (reduce metabolic heat) • Feed efficiency is improved • NEm and Neg are similar o Increase NEm required for similar ADG as level increase or quantity decrease of feed ingredient [diet slides and equations] Explain what happens to nutrients when they are being fed at a higher level of intake/lower quality? • Increase requirements for maintenance • Decrease efficiency of the animal Digestibility fermentation and growth • Put all components together to increase animal performance Lactating Cow Nutrition 2/24/2017 4:43:00 PM Chapter 9 reading Don’t forget that most importantly we need to control the diet during the prepubertial age so that we can control the AVD Nutrients are going to be different depending on stage of lactation Take stress factors into consideration as lactation is affected by stress Phases 1. 1 60-21 days before calving = Far off 2. last 21 days dry = close period 3. 0-21 days = fresh • most metabolic diseases occur in phase 3 • This sets the tone for the rest of the time when will she peak and how well will she peak etc. 4. 21 - ~ 80 days = peak milk 5. ~80 – 200 days = mid/ peak D.M. • incidence of negative energy balance o this is the reason we have a lot of cows get ketosis • peak milk occurs before the increase of DMI 6. 200 – 330 days = late • go back to phase 1/dry period Dry period Lactating phases Lactation changes = diet changes Most emphasis on taking care of animal during fresh period • We can not forget about that 365 day interval we want the cow to have a baby and then within one year turn right back around and have another one. • because of imbalance in energy body, weight decreases because reserves are mobilized and being utilized for milk production • make sure that body weight doesn’t decrease too much because body score will go down and animal could have ketosis [acidosis = at rumen level, result of high amount of carbohydrates] [ketosis = reduction of blood pH, increase of accumulation of ketone body as a result of mobilization of triglycerides in animal reserves] Phase 1: Far off Dry Cow • The 60 days before calving are really what we are focused on • Amount of time required for mammary involution • Research over the years to decrease the dry period for no dry period • Goals of a traditional dry cow program: o Udder involution ▪ 15 days to regress ▪ hypocalcaemia o Fetal needs ▪ Most of the needs of the fetus come in the last 1/3 of gestation we need to watch for this o Body condition ▪ Can overfeed and cause ketosis at parturition ▪ Don’t want her to loose too much or gain too much o Immune system o Cow comfort ▪ Overcrowding is a problem ▪ Most involution occurs when lying down (same with milk production) ▪ Problems like using the proper bedding etc. o Maintain papillae ▪ Don’t want to decrease absorption of VFA so to not have a negative energy balance increase during next lactation • Far off dry cow groups o Drying off cows (involute) o Thin dry cows (add BCS) o Heavy dry cows (maintain) ▪ Adipose tissue development so you may need to separate these to keep up with your BSC o Springing heifers ▪ Gain 1.5 lb plus pregnancy • Dry Cow economics o Low quality feed = $1/ day o Balanced ration = $1.75/day o With close up = $2.25/day • Far off dry cow Nutrient Guidelines o DMI = ~28 lbs o %CP = 13 o %RDP = 70 o %RUP = 30 o %SP = 35 • Far off Dry cows o %TDN = 60 (below 60 = low quality) o NEl (net energy of lactation) = 0.63 mcal/lb o %fat = 2 (no supplemental fat) o %ADF = 30 ▪ don’t want regression of papillae ▪ need to absorb fermentation end products o %NDF = 40 o %NFC = 30 • Body Condition Scores o Target is 3.5 +/- .25 ▪ By the time you are at the far o Excellent managers = 3.5 -4 o Poor managers = 3 – 3.5 ▪ Don’t want overweight going into lactation  ketosis Phase 2: close up dry period • Goals: o Control metabolic disorders ▪ Blood calcium  Maintain low calcium before parturition to not have hypocalcaemia really really really bad ▪ NEFA’s ▪ Ketosis ▪ Most occur after parturition o Shift rumen environment ▪ It should take/last along 21 days just the amount of time that it takes to shift that rumen microbial population ▪ How long it takes to adapt rumen to a new diet ▪ Low quality w/ high fiber for non lactation ▪ Need to adjust microbial population to be able to break down starch, protein, sugars to avoid negative energy balance that occurs during lactation o Build immune system ▪ Colostrogenesis takes about 15 days ▪ Need to have good colostrum for calves ▪ Injection procedures o Build dry matter intake ▪ Minimize negative energy balance ▪ Cannot be consuming same amount that she was in far off period ▪ Don’t want to have overweight animals so have them consuming less DM in this period • Close up dry cow guidelines o DMI = >22lbs o %CP = 15 o %RDP = 60 ▪ higher for colostrum and immune system o %RUP = 40 o %SP = 30 • Close up Dry Cows o %TDN = 67 o NEl = 0.69 mcal/lb o %Fat = 3 o %ADF = 24 o %NDF = 35 o %NFC = 34 • Minerals are also super important during the Dry up Stage as well o • if feeding anionic salts want to increase Ca so to reduce risk of hypocalcaemia after parturition o Chlorine, sulfur and magnesium • • DCAD = dietary cation anion difference o Feeding negatively charged items in the diet • • Dry matter intake decreases for close up cows o May decline by 30% by time of calving o DMI, %BW: Far off = 1.8-2.1 Close up = 1.5 – 1.8 o DMI lb/day: Far off = 28 Close up = 23 o Necessitates increased nutrient density to compensate for lower DMI • Close up diet o 40 – 50% grain ▪ if you do increase the grain you want to add more long stem ingredients this will increase the saliva activity which will help to increase the microbial environment (it will help to buffer the pH) o 15 – 16% protein o 20 – 25% of long forage ▪ increase chewing, increase salivation, increase buffering factors to increase rumen pH to avoid acidosis w. increased NFC o 1/3 – 1/2 DM high group TMR 1 group TMR o anionic salts (DCAD)  last 3 weeks ▪ not as palatable ▪ decrease DMI o yeast culture = aid buffer capacity o niacin (6 gram) o propylene glycol / Ca prop • Length of Dry period: Hystorical view o DHI data suggested 45 – 70 day dry periods ▪ Not based on control studies o 15 days for mammary gland to involute o 15 days for cow to regenerate the mammary gland (lactogenesis) and colostrum synthesis (colostrogenesis) o 30 day total “rest period” o more effective in first lactation animals ▪ subsequent lactations take less time for lacto and colostrogenesis Phase 3: Fresh cow period • Really close monitoring for 2 – 3 weeks after dry period/calving • Transition occurs after phase 3 • Goals for Fresh cows: o Increase nutrient intake o Stabilize rumen ▪ Active microbial population for increasing the diet ▪ Make sure close up period was successful ▪ Displaced abomasum from lack of DMI (goes to the left) o Optimize DMI ▪ Increase quality and amount of NFC for lactogenesis o Close monitoring ▪ Make sure clean and doing well ▪ Sets how the lactation will progress ▪ Energy balance is negative during time of production  Time when losing weight o Set the lactation profile • Fresh Cow protocols o Body temperature o Rumen movement o Ketosis testing o Eating behavior • How long to stay? o 14 days for animal to be ready ▪ uterus/repro tract involution can occur in this time w/ good managing practices o usually 21 days so ensure that cow is ready to move on w/o constant monitoring o increases costs o vets come to check 1 a week • if don’t adapt the microbes to a high energy ration will not be able to make the VFAs necessary and have a high build up of lactic acid o VFA’s are the highest form of energy for cattle we need to make sure that VFA absorption comes back to 100% • Periparturient cow factors o TMR: management of adaption from dry cow to lactation rations ▪ Even distribution of particle size ▪ Limit energy density changes to about 10% per ration o Feed enough effective fiber ▪ The amount of fiber that is going to trigger rumination- all of the particles that will stay in the rumen o Consider RUP levels o Increase nutrient ration nutrient concentration to allow for the lower feed intake ▪ Mycotoxin, nitrite testing important o Limit added fat ▪ We are decreasing the amount of fat because fat builds up in the liver and gives away to ketosis (over whelms the liver) o Yeast culture o Niacin o Propylene glycol Phase 4: Peak Milk Production • Depending on how high they peak determines how much milk the animal produces in the whole lactation • ~21 to 70 days post partum • second month on DHI test • Peak amount X 200 = lactation total potential o Ex: 90 lb @ peak X 200 = 18,000 lb for that lactation st • Heifers (1 lactation) have a lower production than older cows o 75% of older cows ▪ ex: 66lb/85lb = 77.6% • if heifer is higher than older cows, means older cows are not being managed well • significant decrease in BW because reserves are mobilized • on curve, lowest BW but highest milk production o high demand for nutrients o negative energy balance o mobilizing adipose reserves for nutrients to meet milk production • monitor feed efficiency o milk produced/lb feed o high efficiency during this phase because cannot account for mobilized reserves • Lactation strategies o Increase peak milk: ▪ Feed high quality forages  Early harvested forages with high content of starch, sugar and protein ▪ Provide sources of RUP  Not enough microbial P synthesis so need to supplement  Not as high concentration as fresh cow because high DMI ▪ Increase grain gradually  Forage = 60% and concentrate = 40%  This is the stage we want to see the highest increase of grain ▪ Allow for adequate feed bunk space to increase DMI  Enough space to eat  Head locks at feeding locations for easy monitoring and access • Use at 90% capacity • Cows can choose where they want to go o Important for cow comfort ▪ Fresh cow programs  Any metabolic diseases in this period will decrease peak milk production  Result shown of good management in this stage because of amount produced • Persistency: o Drop is unavoidable o 1 lactation cows drop 6% per month after peak o older cows drop 9% per month after peak o rbST can start being used after 60 after parturition or 60 days in milk (DIM) ▪ bovine somatotropin (recombinant) ▪ growth hormone that keeps persistency for a longer period of time ▪ cant start earlier because it will decrease demand for nutrients and it will cause stress because of negative energy and reserve mobilization and lose too much weight ▪ not used in most places even though it doesn’t have any effect on human health, just being eliminated by human perception • cheapest unit of milk is that extra pound of milk produced • Good management for efficient milk production o profile at the current production o when peak milk occurs o evaluating the lactation curve o trends in young cows vs. old cows o looking for weak phases ▪ adjust diet to improve o impact of BsT or other factors o impact of group changes Phase 5: Mid lactation • DMI and Milk yield o DMI, maintenance and milk production ▪ 13lb Holstein maintenance tax  13lb of DM used only for maintenance ▪ (DMI – 13lb) X 2  ex. (53lb – 13lb) X2 = 80lb milk produced o Dairy efficiency: Lb milk/ Lb DMI ▪ Excellent = >1.5 ▪ Concern = <1.3  Animals not producing enough  Could be something wrong ▪ Ex. 75lb milk/50lb DMI = 1.5 ▪ Best during peak because nutrients coming from reserves as well  Fake feed efficiency  Can be around 2.1 ▪ Selected for high yields of milk  Large animals, but not as efficient  Sometimes 1:1 • Can peak at 150lb of milk but not be very efficient in terms of feed to milk ratio o Additional DMI factors: ▪ Total as-fed intake per cow may be 110 to 120lb/d  If have a very wet diet, cannot consume more than that so decrease DMI ▪ Lame cows can reduce DMI by 5-8 pounds  Laminitis @ about 60%  Inflammation of the hoof • Scores for levels of inflammation  Cannot walk well  Increase nutrient requirement and will not eat as much so reduce DMI and milk production ▪ Largest meals occur after milking  15-20% per meal in 2x  fresh TMR ready to be consumed  don’t want them to immediately lay down after milking because can increase mastitis • spynctor not closed all the way and can allow for more bacteria entering the mammary gland ▪ 10-12 meals per day with TMR and good bunk management ▪ weigh backs of 2-4% of total and no sorting  feed shaker box • can use refusals to find what kind of particles the animal is sorting for • analyze to improve diet so cow receives total formulated nutrition  don’t want cows to refuse whole ration or parts of the ration  want to do this every day  don’t want to leave refusals in with new ration because will begin to degrade and cause build up of fermentation products and mycotoxins o maximize DMI ▪ transition diets/metabolic disorders ▪ quality of forage (NEl >.6 Mcal) ▪ optimum fiber (19-20% ADF) ▪ adequate NFC (34-38%)  70% from starch ▪ Starch (25-27%) ▪ TMR (2-3 times/day)  Increase cows going to feed bunk  Will assist in increasing DMI ▪ Avoid wet rations (over 55% moisture)  ½ DM and ½ moisture Phase 6: late Lactation • Provide correct nutrients so animal is not overweight • Focus on body weight loss o Low producers have less decrease in BW ▪ Negative energy balance not as dramatic
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