ANSC 318 1st Edition Lecture 9 Outline of Last Lecture I. Protein Digestion and Ways of Assessing Protein Requirements Outline of Current Lecture II. Ration FormulationIII. Feeding Standardsa. Nutrient Requirementsb. Metabolic Body Sizec. Standards for Growthd. Standards for Lactatione. Standards for PregnancyIV. Nutrient Availability of Feedsa. Factorsb. Factors Affecting Feed Intake in Pigsc. Different Effects on CattleCurrent Lecture (*** = know this)Ration Formulation•a balanced ration provides nutrients in the correct proportions and amounts to support physiological functions of an animal-required nutrients must be in a diet that the animal can consume within 24 hours-this is total feed formulation•Things that must be considered when formulating a ration:-nutrient availability of feeds-type of ration-nutrient requirement of animals-feed intake of animals•Feed Standards -The optimal concentration of a ration maximizes an animal’s output while minimizingcost-To the left of optimal is concentration to prevent deficiency and then the deficiencyconcentration where costs increase and output decreases-To the right of optimal is the area where production stays the same, but costs and netreturn lower-to a certain extent, the more lysine in a diet the better performanceThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Feeding Standards•amount of nutrients required by an animal•made to meet requirements of a specific animal for a specific function•expressed as nutrients required on a daily basis (g/day) OR concentration (%)•used in different ways (DE, NE, Digestible Protein)•Energy = #1 because it has the greatest amount in feed and the largest requirement by animalNutrient Requirements:•Major livestock species now have information on nutrient requirements (cattle, pigs, etc.)•Research trials on feeding standards are constantly being conductedFactors Affecting Nutrient Requirements:I. Body WeightII. Stage of MaturityIII. Physiological Function (i.e. growth, lactation)IV. Level of ProductivityV. Use of feed additives or growth promotantsVI. Genetics of the animalVII. EnvironmentMaintenance Energy Requirements (% of total feed)Class of Livestock% of Total EnergyDairy Cow @ 500 kg; 20 kg milk 35-45%Growing Steer @ 300 kg; 1.2 kg ADG 45-55%Growing Pig @ 50 kg; .75 kg ADG 45-55%Growing Chickens @ 1 kg; 35 g ADG 45-55%Beef Cow @ 500 kg; 200 kg weaned calf 65-75%Heat Production and Body Weight:-heat production/animal increases with body weight-HP/unit of BW decreases as BW increases-they are not linearly related (function of BW)Metabolized Body Size:•mathematical relation between BW and HP•used to compare proportionality of HP to MER•used to predict animal’s maintenance energy requirementsSpecies BW HP HP/BW HP/BW0.75Cow 500 8140 16.3 77Pig 70 7190 25.6 74Sheep 50 1020 20.3 56Fowl 2 134 67.3 80Rat .3 30 100.0 4Standards for Growth:I. Function of the energy retained in tissueII. Energy retained in tissue is a function of tissue growthIII. Adipose tissue has more energy than lean tissueIV. NEg = retained energyEffects of frame size, sex, and BW on NEg Requirements in Cattle:•Heifer>Steer>Bull•As body frame get smaller NEg increases•As muscle mass decreases and fat increases, NEg gets higher•As BW increases NEg increasesStandards for Lactation:I. Function of the amount of milk produced and the proportion of fat in the milk***II. NE (kcal/day) = kg of milk * (0.35 + [0.1 * % of fat in milk]) ***III. NE requirements are based on quantity of milk and % fat of milk produced•As milk and/or milk fat % increases NEl increasesStandards for Pregnancy:I. Function of the stage of gestation, number of fetuses, and birth weight of the newbornII. NEp = 4.43 * BW(0.0586 – 0.0000996* t)e(0.0323t-0.0000275t)t a. Where BW = birth weight and t = day of gestationNutrient Availability of Feeds•some factors that affect nutrient digestibility are:-animal species, nutrient composition of diet, level of intake, feed processing methods,associative effects between feeds, use of feed additives, and stage of plant maturity•some diets that can be formulated are: -total mixed ration, trace mineral mix, energy or protein supplements, and vitaminand/or mineral premixes for inclusion in total mixed rationImpacts of Feed Intake on Nutrient Density of Diet:I. Nutrient density dependent on animal’s nutrition requirement and daily feed intakeII. Formulated based on an estimate of what the animals will consumeIII. If animals consumes more than expected, nutrient density can be reducedIV. If animals consumes less than expected, nutrient density can be increasedFeed Intake Impact on Dietary CP Level:Ex. 440 lb large-frame steer gaining 2.2 lb/day. Requires  1.5 lb protein/day-if steer consumes 12.1 lb DM feed/day (2.75% BW)  diet should contain 12.4% CP DM-if steer consumes 9.9 lb DM feed/day (2.25% BW)  diet should contain 15.2% CP DMFactors Affecting Feed Intake in Pigs: *****I. Body weighta. DE intake (kcal/day) = 13.162 (1-e-0.0176*BW) II. Temperaturea. Cold increases intakeb. Heat decreases intakeIII. Pelleting of rationsa. Starter phase  -9%b. Growing/finishing phase  -3%IV. Feeding Antibiotics a. Starter phase  +8%b. Growing phase  +6%c. Finishing phase  +2%V. Space  allocation per animal (crowing)VI. Gender of pig  Barrows>Gilts>BoarsVII. Proteina. If % CP of ration > 25% or <10% feed intake will be depressedb. Breed  Durocs >> Hamps, Yorks, and LandracesFactors Impacting Feed Intake in PigsLower Feed Intake Higher Feed IntakeBody Weight Lower BW Higher BWEnvironment Heat (> TNZ) Cold (< TNZ)Ration Texture Pelleted Ration Non-pelleted rationSub-therapeutic use of antibioticsNo antibiotics Antibiotics addedConfinement Feeding Overcrowding No crowdingGender Boars<Gilts< BarrowsBeed Type Hamp=York=Landrace DurocDietary CP Level >25% CP or < 10% CP 10 to 25% CP Different Effects on Cattle Feed Intake:•around a 50/50 grain/forage diet maximizes feed intake•as body fat increases, feed intake decreases•breed type can effect intake (i.e. Holstein > Holstein-british cross > British)•Implanted cattle have higher feed intake