动物营养学猪的营养需要英

1、动物营养学动物需要什么？如何满足动物需要？需要什么？蛋白质、碳水化合物、脂肪、维生素、矿物质、能量营养代谢原理需要多少？动物营养需要的度量与研究方法饲 料？饲料的化学组成、动物对饲料的消化吸收、饲料营养价值评定管 理？营养需要维持的营养需要生长育肥的营养需要繁殖的营养需要泌乳的营养需要产蛋的营养需要 猪牛养猪王国我国年均猪存栏量年头东北民猪西北八眉猪两头乌大围子猪拥有地方猪品种64个新淮猪东北花猪哈尔滨白猪北京黑猪培育品种有20多个巴克夏猪大约克夏猪克米洛夫猪长 白 猪引进品种猪肉在肉食品中的地位 第十三章猪的营养需要(Nutritional needs of swine)Nutrition

2、of the Growing PigWhat?Feature?How?Amount?Chapter 13-1 Nutrition of the Growing Piglearning goals:Be master of the concept and the importance of growth; rhythm of growth and development,body composition; the feature of nutrient metabolism and utilization; efficiency of nutrient utilization of growin

3、g-finishing pigs.Swine体重 （kg）消化器官重量（g）猪消化器官重量随个体生长的变化微生物消化为主物理、化学消化化学消化仔猪出生后消化酶的变化动态 In swine diet formulation, the nutrients or nutrient categories of most concern are energy (DE or ME), essential amino acids, calcium, phosphorus, trace minerals, and vitamins.机体化学成分的积累（合成代谢速度大于分解代谢速度）Growth is gene

4、rally defined as an increase in the live weight gain1. GrowthFirst period Rhythm of growth and development细胞的增殖和增大，组织器官的发育和功能日趋完善；生长育肥是指断奶后不同于种用动物的强化饲养满足经济需求肉 质指肉用畜禽生长后期经强化饲养而使瘦肉和脂肪快速沉积。Fatten (肥育)Finishing pig (肥育猪)是养猪生产的重要环节，发展养猪生产的最终目标生长速度饲料利用率2. Growth rhythmThere are three kinds of curve to des

5、cribe the rhythm of weight gain.Cumulative growth curve (累积生长曲线)Absolute growth curve (绝对生长曲线)Relative growth curve (相对生长曲线)2.1 Weight gainCumulative growth curve0-A: embryonic period; A-B: rapid growth; B-C:slow growth; C-: maturity ACB0AgeBody weight (kg) Complete puberty Complete pubertyAbsolute

6、growth curveRelative growth curve (i)1224Rate of gainAge of the moonBirthLog(gain/body weight)30405060708090100Body weight(kg)78910111220181614Relative growth curve (ii)4590BoneFatMuscleRate of gain (%)low level of nutritionlate varietyHigh level of nutritionearly varietyBody weight (kg)2.2 Tissue g

7、rowth Forepart: bonesMetaphase: musculature, body lengthAnaphase: adipose tissue, body heightMain part of growth4590BoneFatMuscleRate of gain (%)low level of nutritionlate varietyHigh level of nutritionearly varietyBody weight (kg)Body are mainly composed of water and protein in the early growth sta

8、ge; Fat concentration of the body increases rapidly at the expense of water and, although the percentage of protein remains rather stable.3. Body composition rhythmChemical body composition of pigsfatproteinwaterash8.571173.53052153%Body weight15120WaterFatWeekChemical muscular composition of pigsPr

9、otein16.61.981.522.65.671.8%g/dF/GdProtein retentionFat retentionFeed/weight gainFatten time(25-100 kg liveweight)Nutritional levelGrowth rate Retention Fat ProteinThe minimal feed/weight gain is at 33.5 maintenanceMaintenance requirements根据生理特点和发育规律，按猪的体重将其生长过程划分为二个阶段即生长期和育肥期生长期：20-60kg机体各组织、器官的生长发

10、育功能不很完善，这个阶段主要是骨骼和肌肉的生长，而脂肪的增长比较缓慢育肥期：60kg- 出栏各器官、系统的功能都逐渐完善，尤其是消化系统有了很大发展，对各种饲料的消化吸收能力都有很大改善脂肪组织生长旺盛，肌肉和骨骼的生长较为缓慢Second period Nutritional needs of growing-finishing pigs1. Energy requirementsThe factorial approach (析因法)From performance back to intakeFrom the result back to the requirementInformati

11、on needed for factorial approach -anatomy of energy requirements-net values-efficiencies of utilization1.1 Anatomy of energy requirementsEnergy requirementsMaintenanceGrowthMuscular tissue (Protein)Adipose tissue (Fat)Information needed for factorial approach -anatomy of energy requirements:-net val

12、ues: -efficiencies of utilization: maintenance, protein and fatbasal metabolism, protein and fat retention1.2 Net valuesY = (0.47666 + 0.02147X 0.00023758X2 + 0.000000713X3) x 127.5Body weight (kg)Protein accretion (g/d)Protein retention in growing pigs (g/d)DWG(g/d)Body weight (kg)30405060708090100

13、 400 93 97 500104108109108 600115119120119116111104 700126130131130127122115107 800141142141138133126118 900153152149144137129 1000160155148GFE, 1987DWG(g/d)Body weight (kg)30405060708090100 400 55 81 500 84110137163 600113140166193219245372 700142169195222248275301328 800198225251277304330356 90025

14、4280307333360386 1000336362389Fat retention in growing pigs (g/d)GFE, 1987The growth rate of musculature decreases, while it increases in adipose tissue rapidly from forepart to anaphase, which results that the fat of body weight gain is increased, contrary to lean.Information needed for factorial a

15、pproach -anatomy of energy requirements:-net values: -efficiencies of utilization: maintenance, protein and fatbasal metabolism, protein and fat retentionenergy: km, kp, kfEnergy intake and energy retention (Gaus, 1984; W=69 kg)-0.60.811.21.4RE (MJ/kg W0.75)IME (MJ/kg W0.

16、75)RERPE1.3 Efficiencies of utilization The energy cost of protein deposition is greater than that for fat depositionThe efficiency is 35 % for protein and 70+% for fat deposition (DENE)It has been estimated that in a pig of 25 kg, protein synthesis amounts to 250-450 g/d, but the net protein deposi

17、ted is only 100 g/d.The reason for the lower efficiency of protein may be because of its dynamic state and more rapid turnover in the body than for lipid tissues Energy consumed by the growth of lean and fat GE(kcal/kg)DE requirement for growth (kcal/kg)Lean1195 3346 (k = 36 %)Fat8604 11711 (k = 73

18、%)Energy utilization efficiency is higher for the growth of lean than fat, therefore, good economic returns could yield in lean productionChemical body composition of pigsfatproteinwaterash8.571173.53052153%Body weight (kg)15120Energy requirement for body weight gain is increased, and the feed/weigh

19、t gain is increased. The time for slaughter is better at 90 kg body weight (5-6 month age)2. Estimate of energy requirements Energy requirements= Maintenance requirements + Production requirements (Protein + Fat)ME=NEmkmNEpkpNEfkfExample1) DE requirements for maintenance = 110500.75 = 2068 kcal/d2)

20、DE requirements for protein retention = 196.254.00.32= 1484 kcal/d3) DE requirements for fat retention = 2009.00.725 = 2483 kcal/d4) Total requirement for DE = 206814842483 = 6035 kcal/d Pig: body weight 50 kg, daily gain 600 g (N retention 19 g/d, fat retention 200 g/d) protein, 4.0 kcal/g; fat, 9.

21、0 kcal/gGrowth trials (生长试验)From the relationship between intake and performance back to the requirementIncrements of the nutrient in question then are added to the basal diet, and body weight gain and feed consumption over the experimental period are recorded.Level of metabolizable energy addedkcal

22、/dDaily weight gain (g/d)6052.5For the nutritionist, feeding standards provide a useful base from which to formulate diets or estimate feed requirements of animals.Energy requirements of growing pigs-China Liveweight(kg)Daily gain(g/d)DE requirements(kcal/d)20-35500471035-60600682060-906508770Energy

23、 requirements of growing pigs-NRCIntake and performance levelsSwine liveweight (kg)1-55-1010-2020-5050-110Expected weight gain, g/d 200 250 450 700 820Expected feed intake, g/d 250 460 9501900 3110Expected efficiency, gain/feed0.8000.5430.4740.3680.264Expected efficiency, feed/gain 1.25 1.84 2.11 2.

24、71 3.79Digestible energy intake, kcal/d 85015603230646010570Metabolizable energy intake, kcal/d 80514903090620010185Energy concentration, kcal ME/kg diet 3220324032503260 3275These figures are the minimum requirements for maximum production and do not include a margin of safety.Many nutritionists us

25、e their judgment to provide a margin of safety by increasing the figures by 5 or 10 percent or more.Food intakeMaintenanceProductionLossProductionExcess intakeOptimum intake for average populationDeficient intakeNutrient levelPerformanceA theoretical example of how nutritional requirements may be sh

26、ifted for individuals or groups of animals by any of a number of causative factorsEnvironmental conditions, stress, animal housing conditions, breed or strain of animal, disease incidence, and projected length and conditions of feed storage are factors that might influence selection of an appropriat

27、e margin of safety.Intake Utilization RetentionRetentionIntakeMaintenanceMaximumutilizationMaximumretentiondeficient optimum surplusApplication of the NRC philosophy in developing countries is inappropriate and that, instead, the objective should be to optimize the use of available resources.NRC req

28、uirements generally cannot be economically achieved and optimal production is less than maximal.Cereal gains: mainly corn sorghum, barley, and wheat may be usedThe commercial availability of enzymes (e.g., -glucanase) has increased the feasibility of using barley and oats in swine feeding.Cereal gai

29、nsThe main energy source in swine diets is usually starch from cereal grains.Except for the preweaning pig, starch is completely digested in the small intestine; pigs younger than three weeks have insufficient pancreatic amylase secretion for maximum starch digestionCassava meal and sweet potato mea

30、l are high energy feedstuffs available for swine feeding.FiberIn many developing countries, swine are fed grass and aquatic weeds, and fibrous agricultural by-products.Most swine diets in industrialized countries are high in energy and low in fiberWhen crude fiber content of the diet exceeds 10 to 1

31、5 %, caloric intake may be reduced because of excessive bulk or reduced palatability.Alfalfa meal fiber and other sources of fiber are fermented in the hindgut, producing VFA (Kass et al., 1980), which can provide up to 30 percent of the maintenance energy requirementLipidsTheoretically, if pigs eat

32、 to meet their energy requirements, substitution of fat for carbohydrate should not increase performance or energy intake.In general, so long as the diet is adequate in protein content, addition of fat trends to improve gains and reduce the ME required per unit of gain (NRC, 1988).2. Protein require

33、ments2.1 Estimate of protein requirementsProtein requirementsMaintenanceProduction(protein retention)Body weight = 50 kg，N retention = 19 g/d (measured by nitrogen balance trials) Digestible protein for maintenance (DCPm) = 2.23W0.75 = 2.23500.75 = 41.9 gBody protein retention = 196.25 = 118.8 gDCP

34、for production (DCPp) = 118.850% = 237.5 gTotal requirement of DCP = 41.9237.5 = 279.4 gTotal requirement of CP = 279.480% = 349.3 gExampleDCPm = 2.23W0.75 = 35.5 gBody protein retention = 50022 % = 110 gDCPp = 11050 % = 220 gTotal DCP requirement = 35.5220 = 255.5 gTotal CP requirement = 255.580% =

35、 319.4 gExampleBody weight = 40 kg，muscle weight gain = 500 g/d (comparative slaughter technique) CP of muscle = 22 %:DWG(g/d)Body weight range (kg)20406080100Protein (g) 400190 500225250 600261277300295 700296312332318 800347367354 9003834023891000437424Recommendations for growing pigs-CP1GFE, 1987

36、UKChina and JapanThe standard for lean pigsLiveweight(kg)CP(%)Liveweight(kg)CP(%)Liveweight(kg)CP(%)5514 (weigh gain)35-60145516 (lean)60-9013Recommendations for growing pigs-CP2Effect of protein intake on protein retention in pigs of 60 kg (Susenbeth et al, 1994)DWG(g/d)Body weight range (kg)204060

37、80100Lysine (g) 400 9.5 50011.212.5 60013.013.815.014.8 70014.815.616.515.8 80017.318.217.5 90019.120.019.3100021.721.0Recommendations for growing pigs-lysGFE, 1987Optimal AA pattern for growing pigs- the Ideal Protein - Lysine (6.5 g / 16 g N)100 Methionine + cystine50-55 Threonine65-70 Tryptophan

38、17-19* Valine 65-75 Isoleucine50-60 Leucine 95-110 Histidine30-40 Tyrosine + phenylalanine 95-110 * at high lysine intakeCereal grainsSoybean meal is the most common protein supplement used, though many other plant protein supplements (e.g., canola meal, cottonseed meal, peanut meal) have a place wh

39、en economics for their use are favorableSwine is fed corn-soy diets, with corn as the energy source and soybean meal as the protein supplement. In the same way that corn is the standard to which other feed grains are compared, soybean meal is the standard to which other protein supplements are compa

40、red.A corn-soy diet will meet the protein and energy requirements of virtually all classes of swine, except perhaps for the very young early-weaned pig.Examples of swine diets based on corn and soybean mealIngredientStarter diet, %(18 % CP)Grower diet, %(16 % CP)Finisher diet, %(14 % CP)Salt, minerals, vitamins555Corn697482Soybean meal262115Animal proteinThe composition of the protein supplement is best determined by least cost diet formu