FEEDING MANUAL Feed manual TOPIGS Finishers TOPIGS Support & Development Updated: 13 August 2012 Copyright TOPIGS Feeding advice Talent progeny Target Group: Nutritionists and Farm managers Explanation: Feed advice and feed guidelines for feeding the progeny of the Talent Terminal boar
Index 1. Introduction... 2 2. The aim of the manual... 2 3. Typology, characteristics of Talent... 3 4. Nutritional requirements... 4 4.1 Basic assumptions... 4 4.2 Nutritional requirements Talent... 5 4.3 Example of diet calculations for Corn Soybean Markets... 6 4.4 Example of diet calculations for Wheat-Barley Market... 7 5. Specific situations... 8 5.1 Ad libitum vs. restricted feeding... 8 5.2 Health conditions... 8 5.3 Paylean (Ractopamine)... 8 5.4 Pellet vs. Mash feed... 9 5.5 Immune castration... 9 5.6 Hot climates... 9 5.7 Liquid feeding... 10 5.8 Split sex feeding... 10 5.9 TOPIGS Feed Monitor... 10 5.10 TOPIGS Nutrition Website... 10 Appendix... 11 1. Amino acid/ Lysine ratio used to estimate amino acid requirements... 11 2. Standardized ileal digestible (SID) vs. apparent ileal digestible (AID) lysine... 12 3. Phosphorus... 13 Disclaimer: The TOPIGS Feeding MANUAL is a product of TOPIGS. No part of its contents may be reproduced or published without the prior written consent of TOPIGS. TOPIGS declares that this product has been compiled carefully, conscientiously and impartially. However, the publisher is not liable for any loss or injury that may result if this advice is followed. The reader is advised not to use this information in isolation but to review it on the basis of his or her education and experience. The information entered in this online tool will be stored and can be used for internal evaluation by TOPIGS. The information will not be published or distributed. TOPIGS, Copyright 2012 Page 1
1. Introduction With the continued progress in swine genetics, TOPIGS is improving the efficiency of pork production together with other desirable characteristics. Therefore the periodic re-evaluation of the nutritional requirements of our genetic lines are necessary. Pigs have daily requirements for absolute quantities of specific nutrients. TOPIGS estimate the daily nutritional requirement for energy and protein. Various factors affect voluntary feed intake and/or performance of swine, and thus will affect the concentration of nutrients that should be provided in the diet. Thus knowing the daily feed intake of the animals and understanding the factors involved, diet formulations can be adjusted accordingly to ensure optimal production at an economical cost. 2. The aim of the manual The aim of this manual is to provide a feeding guide based on the nutritional requirements of the Talant genotype to achieve an optimum genetic performance, calculated in terms of daily gain. Daily gain is described in this manual as the sum of protein and fat deposition. Achieving the optimum genetic performance will result in optimal growth and minimal feed conversion ratio. However depending on the production system and market demands will not necessarily lead to the best economical results. Maximum lean growth can be achieved only when the nutrients, specifically amino acids and energy, are supplied in the diet at the appropriate amount. The recommendations in this manual are based on protein and fat deposition. Protein and fat deposition is influenced by factors like sex, age, feed intake, health status and genetic line. Body protein and lipid mass and their deposition in the body are most often used to describe compositional pig growth models and can be estimated separately. The results in the tables are derived from our own Pig Growth Model (IPG Pig Growth Model, 2011) and from the analysis of field data under various environments. This manual can only be used for TOPIGS genetics. Page 2
3. Typology, characteristics of Talent Talent boar is known as the TOPIGS D-line. The Talent boar combines high carcass and meat quality with high feed efficiency. The qualities of the progeny of the Talent boar are: Efficient; combines high daily gain with low feed conversion High meat percentage and excellent hams Good meat quality, intramuscular fat, low drip loss Robust and vital Uniform and strong finishers To benefit from its genetic potential, it is important to feed closely to its capacity. Page 3
4. Nutritional requirements 4.1 Basic assumptions Multi-phase feeding Animals fed Ad libitum Dry mash diet, with dry matter of 88 % (using pelleted feed improves the digestibility of the diet) Conventional health Sexes separately housed and fed Ideal ambient temperatures Page 4
4.2 Nutritional requirements Talent Table 1. Daily nutritional requirements, weight development and feed intake curves of Talent finishers Days in phase BW, kg Feed intake, kg/day Castrates Gilts Boars Immune-castrates 2,3 NE, MJ/day 1 Lys. SID, g/day 1 BW, kg Feed intake, kg/day NE, MJ/day 1 Lys. SID, g/day 1 BW, kg Feed intake, kg/day NE, MJ/day 1 Lys. SID, g/day 1 BW, kg Feed intake, kg/day NE, MJ/day 1 1 25,0 1,32 14,74 16,54 25,0 1,23 13,96 15,33 25,0 1,26 13,22 16,27 25,0 1,26 13,22 16,27 8 31,6 1,56 15,51 17,48 31,4 1,39 14,50 16,25 31,6 1,38 14,05 17,08 31,6 1,38 14,05 17,08 15 38,1 1,74 16,62 17,85 37,9 1,55 15,08 17,04 38,2 1,50 14,65 17,82 38,2 1,50 14,65 17,82 22 45,2 1,90 17,75 18,48 44,6 1,69 16,00 17,80 44,9 1,61 15,81 18,09 44,9 1,61 15,81 18,09 29 52,4 2,05 18,96 18,50 51,4 1,81 17,08 18,28 51,7 1,72 16,75 18,38 51,7 1,72 16,75 18,38 36 59,8 2,17 20,35 18,54 58,3 1,93 18,40 18,65 58,6 1,82 17,84 18,76 58,6 1,82 17,84 18,76 43 67,2 2,27 21,52 18,69 65,3 2,02 19,40 18,95 65,5 1,94 18,74 19,24 65,5 1,94 18,74 19,24 50 74,7 2,38 22,23 18,79 72,4 2,10 20,11 19,36 72,5 2,05 19,63 19,65 72,5 2,05 19,63 19,65 57 82,3 2,47 22,81 18,57 79,4 2,19 20,98 19,85 79,5 2,14 20,75 20,02 79,5 2,14 20,75 20,02 64 89,6 2,54 23,41 17,75 86,4 2,27 21,67 19,75 86,5 2,23 21,63 20,19 86,5 2,23 21,63 20,19 71 96,6 2,62 23,71 17,15 93,1 2,34 22,53 19,23 93,3 2,32 22,42 20,29 93,3 2,32 22,42 20,29 78 103,2 2,68 23,96 16,11 99,6 2,40 23,40 18,66 100,0 2,41 23,32 19,64 100,0 2,41 23,32 19,64 85 109,4 2,74 24,30 15,12 105,9 2,46 23,86 18,27 106,5 2,48 23,65 18,83 106,5 2,48 23,65 18,83 92 115,4 2,80 24,74 14,18 112,0 2,51 24,21 17,89 112,8 2,55 24,02 18,47 115,4 2,80 24,74 16,51 99 121,0 2,84 25,01 13,31 117,8 2,56 24,56 17,33 119,0 2,61 24,46 17,95 121,0 2,84 25,01 15,31 106 126,4 2,88 25,37 13,18 123,4 2,60 24,95 16,78 124,9 2,66 24,89 17,46 126,4 2,88 25,37 14,13 113 131,6 2,92 25,64 12,85 128,8 2,64 25,24 16,24 130,7 2,71 25,09 16,97 131,6 2,92 25,64 13,04 Lys. SID, g/day 1 1 2 3 Net energy (NE) and standardized ileal digestible (SID) lysine requirements are expressed as the amount required per day to achieve optimal performance. Based on the IPG Pig Growth Model (2011). For the immune-castrates the change to the final diet should be realized at the end of the first week after second vaccination (Vivax or Improvac ). TOPIGS assumes that immune-castrated pigs behave like boars up to the second vaccination, considered here as 92 days in phase, and thereafter, behave as super-castrates. Page 5
4.3 Example of diet calculations for Corn Soybean Markets Table 3. Nutritional requirement (g/kg) for Talent finishers, based on a 5 phase feeding program 1 2 3 4 5 Sex Castrates Gilts Boars Immune-castrates Body Weight (kg) Starter Grower 1 Grower 2 Finisher Final 25-35 35-55 55-75 75-100 100-130 Ave Daily feed intake, kg/day 1 1,50 1,89 2,27 2,56 2,83 NE, MJ/kg 2, 3 10,3 10,2 10,1 9,9 9,9 ME, Mcal/kg 2, 3 3,35 3,30 3,25 3,20 3,20 Lys. SID, g/kg 2 11,6 10,3 8,60 7,40 6,40 SID Lys/NE, g/mj 1,13 1,01 0,86 0,75 0,65 Ca, g/kg 8,47 7,27 6,53 5,70 5,00 Available P, g/kg 4, 5 4,03 3,46 3,11 2,71 2,38 Digestible P, g/kg 4, 5 2,92 2,51 2,25 1,97 1,72 Ave Daily feed intake, kg/day 1 1,38 1,74 2,07 2,34 2,58 NE, MJ/kg 2, 3 10,4 10,3 10,2 10,1 9,9 ME, Mcal/kg 2, 3 3,35 3,32 3,30 3,25 3,20 Lys. SID, g/kg 2 12,0 10,6 9,00 8,00 7,20 SID Lys/NE, g/mj 1,15 1,03 0,88 0,79 0,73 Ca, g/kg 8,40 7,50 6,50 6,00 5,10 Available P, g/kg 4, 5 4,00 3,57 3,10 2,86 2,43 Digestible P, g/kg 4, 5 2,90 2,59 2,24 2,06 1,76 Ave Daily feed intake, kg/day 1 1,36 1,65 1,98 2,30 2,60 NE, MJ/kg 2, 3 10,5 10,4 10,2 10,1 9,9 ME, Mcal/kg 2, 3 3,40 3,35 3,30 3,25 3,20 Lys. SID, g/kg 2 12,6 11,1 9,90 8,80 7,30 SID Lys/NE, g/mj 1,20 1,07 0,97 0,87 0,74 Ca, g/kg 8,60 7,80 6,80 6,30 5,40 Available P, g/kg 4, 5 4,10 3,71 3,24 3,01 2,57 Digestible P, g/kg 4, 5 2,97 2,69 2,34 2,17 1,86 Ave Daily feed intake, kg/day 1 1,36 1,65 1,98 2,30 2,83 NE, MJ/kg 2, 3 10,5 10,4 10,2 10,1 9,9 ME, Mcal/kg 2, 3 3,40 3,35 3,30 3,25 3,20 Lys. SID, g/kg 2 12,6 11,1 9,90 8,80 6,40 SID Lys/NE, g/mj 1,20 1,07 0,97 0,87 0,65 Ca, g/kg 8,60 7,80 6,80 6,30 5,00 Available P, g/kg 4, 5 4,10 3,71 3,24 3,01 2,38 Digestible P, g/kg 4, 5 2,97 2,69 2,34 2,17 1,72 Average daily feed intake based on the advised feeding curve. Net energy (MJ/kg), Metabolizable energy (Mcal/kg) and SID-lysine (g/kg) are calculated on an ADFI (kg/d). NE = ME X 0.74 (The conversion factor could be different for each country); MJ = Mcal X 4.184 Advised available phosphorus levels are based on diets formulated without the use of Phytase. The use of Phytase implicates in the necessity of readjusting these phosphorus levels. Definitions of Available and Digestible phosphorus are indicated in Appendix 3. Page 6
4.4 Example of diet calculations for Wheat-Barley Market Table 4. Nutritional requirement (g/kg) for Talent finishers, based on a 3 phase feeding program Sex Boars Gilts Castrates BW, kg Starter Grower Finisher 25-45 45-75 75-130 Ave Daily feed intake, kg/day 1 1,64 2,18 2,71 NE, MJ/kg 2 9,7 9,3 9,0 EW 3 1,10 1,06 1,02 Lys. SID, g/kg 2 10,8 8,30 6,30 SID Lys/NE, g/mj 1,11 0,89 0,70 Ca, g/kg 8,01 6,70 5,36 Available P, g/kg 4, 5 3,81 3,20 2,55 Digestible P, g/kg 4, 5 2,76 2,31 1.85 Ave Daily feed intake, kg/day 1 1,51 1,99 2,47 NE, MJ/kg 2 9,8 9,4 9,2 EW 3 1,11 1,07 1,05 Lys. SID, g/kg 2 11,1 9,00 7,00 SID Lys/NE, g/mj 1,13 0,95 0,76 Ca, g/kg 8,00 6,80 5,55 Available P, g/kg 4, 5 3,80 3,23 2,64 Digestible P, g/kg 4, 5 2,75 2,34 1,91 Ave Daily feed intake, kg/day 1 1,46 1,90 2,47 NE, MJ/kg 2 9,9 9,8 9,5 EW 3 1,12 1,11 1,08 Lys. SID, g/kg 2 11,8 10,1 7,70 SID Lys/NE, g/mj 1,19 1,02 0,81 Ca, g/kg 8,20 7,20 5,70 Available P, g/kg 4, 5 3,91 3,42 2,71 Digestible P, g/kg 4, 5 2,83 2,48 1,97 1 2 3 4 5 Average daily feed intake based on the advised feeding curve. Net energy (MJ/kg) and SID-lysine (g/kg) are calculated on an ADFI (kg/d). EW = 8,8 x NE (MJ/kg). Advised available phosphorus levels are based on diets formulated without the use of Phytase. The use of Phytase implicates in the necessity of readjusting these phosphorus levels. Definitions of Available and Digestible phosphorus are indicated in Appendix 3. Corn-soybean and wheat-barley are the two main feed markets in the world. Pigs fed wellbalanced wheat-barley based diets can perform as well as those fed corn-soybean diets. The minimal energy levels reachable when using these two different feed sources is what differentiates these two markets. Therefore, the feed schedules and calculations will be different for these two markets. Nevertheless, the daily nutrient requirements of Talent finishers are the same. Page 7
5. Specific situations 5.1 Ad libitum vs. restricted feeding The daily feed intake of a finisher will be the key determinant for the feed industry to design a proper feed program, which will give the farmer the highest economic return. Due to the variation in feed intake, TOPIGS will support their clients by calculating the energy and digestible lysine per day, as given in this manual. When the nutritional requirements per day are known, the actual feed consumed by pigs at various body weights (or over time) is necessary to estimate the dietary levels in the diets. In the event of pigs being given food ad libitum the estimation of actual intake may also be indicative of the appetite prevailing under the particular circumstances of food type, pig type, management quality, herd health and housing environment. To achieve optimal growth in Talent offspring, essential nutrients (AA and energy) must not be limiting. Therefore, to achieve the best performance, Talent must be fed an ideal lysine to energy ratio. In the manual the tables with the ideal ratios are shown. When animals are fed ad libitum or restrictively, it is essential to keep the ratios between energy and lysine based on the given recommendations. The Talent offspring s can be fed ad libitum. 5.2 Health conditions The efficiency of nutrient utilization in pigs is optimized under high health environments. A high health status not only increases productivity and efficiency, but also leads to an increased nutrient demand. When pigs are immunologically challenged, nutrients are diverted away from productive functions (i.e., lean tissue growth) towards the activated immune system. Therefore under conventional health situations (most farms in the world), the immune system of the animal has to cope with all kinds of pathogens. Under SPF conditions the animals can increase their feed intake with ±10-15%, reduce maintenance with some 10% and increase protein deposition capacity with around 25g/d. The following points need to be taken under consideration for SPF animals : SPF animals grow faster, therefore have the capacity to reach higher protein deposition rates. The higher feed intake capacity in SPF animals does not reflect in an increased protein deposition level, if the protein: energy ratio s in the diet is limited. 5.3 Paylean (Ractopamine) Ractopamine-HCl, is a β-adrenergic agonist, and is labelled for use in swine diets during the final growth stages. Dietary inclusion has shown consistent improvement in pig growth performance and has led to its widespread use in the swine industry. When fed, it promotes lean growth rather than fat deposition by directing nutrients away from the fat depots towards muscle development. Fat tissue deposition requires more energy than lean growth, thus increasing lean deposition leads to improved feed efficiency prior to market and a leaner carcass. Because of the increased protein accretion, pigs that are fed Ractopamine have an increased dietary amino acid requirement. TOPIGS advices to follow the nutritional guidelines of the specific manufacturer, when using these additives. Page 8
5.4 Pellet vs. Mash feed The feeding behaviour and performance of pigs can also be influenced by the feed type (pellet vs. mash). Feeding pelleted diets to pigs has been shown to increase nutrient digestibility and improve FCR from 5% to 8% in finishing pigs. Improvements in animal performance have also been attributed to decreased feed wastage, reduced selective feeding, decreased ingredient segregation, less time and energy expended for pre-hension, destruction of pathogens, thermal modification of starch and protein, and improved palatability. The improvements in FCR are highly depended on pellet quality, percentage fines and pellet size. Another advantage to pelleted diets are the ability to grind grains to smaller micron sizes and to use a higher percentage of alternative ingredients in the diets and still maintain good feed flowability. All the feed curves given in this manual are based on mash diets, therefore the total nutrient intake when using pelleted feed can be higher. 5.5 Immune castration A vaccine against gonadotropin-releasing hormone (GnRH) for controlling boar taint has been introduced to the global market as an animal-welfare-friendly alternative to surgical castration. The vaccine is already licensed in a number of countries. The first dose of the injection primes the pig s immune system, but does not alter testes size or function. The second dose stimulates the protective immune response that inhibits testes function. Until the second injection the animal behaves like a boar, after that it behaves like a super castrate. After the second vaccination the animals tend to eat much more, even more than regular castrates of the same weight and therefore deposit more fat. Based on this, the advice is that after the second vaccination the finishers should (preferably) be restricted and should be fed the lysine/energy ratio of castrates. TOPIGS calculated the nutritional requirements of Immune castrates, based on the above statement. 5.6 Hot climates The environment can serve as a significant factor affecting both the voluntary feed intake level and the overall nutrient requirements of pigs. Temperature, probably more than any other environmental factor, can be used to explain a majority of the variations associated with differences in feed intake and performance among groups of pigs. Given the fact that animals tend to eat less when temperature rises, feed intake capacity can be a limiting factor for optimal performance. Swine diet formulations should be adjusted to account for the variations in feed intake associated with environmental temperature changes. Some alternatives can be used to optimize the performance in hot climates. Under heat stress, pigs reduce their feed intake in order to reduce their heat production due to the thermal effect of feed (TEF). The reduction of feed consumption results in a decrease of growth of pigs which affects the profitability of the swine producers. Nutritional solutions can mainly be described according to their ability to reduce dietary heat increment or to increase dietary nutrient density. The increase of crude protein supply is associated with a higher protein turn over which enhances heat production. What might be beneficial is: (1) Low crude protein diets. Practically, crude protein is partially replaced by starch and/or fat and industrial amino acids in order to meet the protein requirement for optimal performance. (2) Offer the feed during cooler phases of the day/night Page 9
(3) Feed more times per day. Feed will be less per meal and have a lower influence on the energy needed to digest / internal heat etc. (4) Ensure the availability of fresh clean water. Water should be available ad libitum. Ensure a minimum flow rate of 1.5 litre water per minute. 5.7 Liquid feeding Working with liquid feeding systems requires certain precautions. For each type of diet there is an ideal dilution, which depends on the ingredients used and on how each one was included. There can be decomposition into sub products which do not have proper time to be incorporated to the liquid diet, losses of vitamins and essential nutrients can also occur. When considering the type of grain used to elaborate the feed, it is important to consider the chemical composition and the effects that the raw materials can have on the pigs feed digestibility. Therefore, we advise regular laboratory analyses of the feed to guarantee that the pigs are not fed diets that can limit their performance and/ or affect the carcass quality negatively. 5.8 Split sex feeding In general, gilts will consume 10 to 12% less feed and be about 4% more efficient in converting feed to body weight gain during the finishing period as compared to castrates. To offset the reduction in feed intake, diets for gilts need to contain higher nutrient levels (namely protein or amino acids) to achieve adequate daily intakes of these nutrients. Boars will even be more efficient than gilts. The differences in feed intake, together with the differences in performance and carcass parameters, provide the basis for split-sex feeding. 5.9 TOPIGS Feed Monitor The TOPIGS Feed Monitor is an online tool that offers the possibility to compare your current feeding program, growth rates and feed conversion ratio s of a finisher unit to TOPIGS feeding advice and performance indicators. The aim of the Feed Monitor is to give insight, in a more practical manner, in the way the finishers are fed in relation to the feed advice of TOPIGS. It is a simple tool that compares basal requirements for energy and lysine intake. The tool is available online at http://feed.topigs.com, please contact your local TOPIGS office for the login information. 5.10 TOPIGS Nutrition Website For more information on feeding the TOPIGS genetic lines, nutritional products & support provided by TOPIGS and contact information of the TOPIGS Nutritionist please go to http://nutrition.topigs.com. Page 10
Appendix 1. Amino acid/ Lysine ratio used to estimate amino acid requirements Lysine is the first limiting amino acid in most practical swine diets. It is common practice to first define the adequate lysine level in the diet and then derive the required level of other essential amino acids from lysine on the basis of an ideal protein ratio, thus giving a balanced protein diet. A balanced protein diet contains sufficient levels of each essential amino acid to meet the biological needs of the animal while minimizing the amounts of excess amino acids. The InraPorc (2011) has defined the ideal balance of amino acids for each phase of production based on the concept of Ideal Protein. This serves as basis for TOPIGS recommendations. Feed ingredients have different amino acid digestibility coefficients. Therefore, when formulating diets that are more complex, it is recommended that standardized ileal digestible values are used in the formulation process. Table 1. Amino acid ratio s for finishers in a 5 phase feed program Amino Acids 1 Starter Grower 1 Grower 2 Finisher Final Lysine 100 100 100 100 100 Methionine 28 30 30 31 31 Met + Cys 60 62 62 64 64 Tryptophan 20 20 19 19 19 Threonine 65 67 67 70 70 Arginine 42 42 42 42 42 Valine 68 68 68 68 68 Isoleucine 55 55 53 53 53 Leucine 100 100 100 100 100 Histidine 32 32 32 32 32 Phenylalanine 50 50 50 50 50 Table 2. Amino acid ratio s for finishers in a 3 phase feed program Amino Acids 1 Starter Grower Finisher Lysine 100 100 100 Methionine 28 30 31 Met + Cys 60 62 64 Tryptophan 20 19 19 Threonine 65 67 70 Arginine 42 42 42 Valine 68 68 68 Isoleucine 55 53 53 Leucine 100 100 100 Histidine 32 32 32 Phenylalanine 50 50 50 1 All Amino Acids are expressed as standardized ileal digestible (SID) Page 11
2. Standardized ileal digestible (SID) vs. apparent ileal digestible (AID) lysine The terminology used to describe the bioavailability and ileal digestibility of amino acids in pig feed ingredients are explained in this appendix. Ileal digestibility values may be expressed as apparent ileal digestibility (AID), standardized ileal digestibility (SID), or true ileal digestibility (TID). These terms are used to specify how ileal endogenous AA losses are reflected in digestibility values. Ileal endogenous AA losses may be separated into basal losses, which are not influenced by feed ingredient composition, and specific losses, which are induced by feed ingredient characteristics such as levels and types of fiber and anti-nutritional factors. Values for AID are established when total ileal outflow of AA (i.e., the sum of endogenous losses and no digested dietary AA) is related to dietary AA intake. A concern with the use of AID values is that these are not additive in mixtures of feed ingredients. This concern may be overcome by correcting AID values for defined basal endogenous losses of AA, which yields SID values. Furthermore, if the AID values are corrected for basal and specific endogenous losses, then values for TID are calculated. However, reliable procedures to routinely measure specific endogenous losses are not yet available. It is suggested that SID values should be used for feed formulation, at least until more information on TID values becomes available. Table 3. Example of the differences between SID and AID Lys for Talent Castrates SID Lysine and AID Lysine 25-50 kg Basal (g/kg DM) SID Lysine AID Lysine Lysine 0.040 1.000 0.964 Methionine 0.011 0.280 0.270 Methionine + Cysteine 0.021 0.600 0.581 Threonine 0.061 0.650 0.596 Tryptophan 0.014 0.180 0.167 Page 12
3. Phosphorus Phosphorus is one of the most significant minerals in swine nutrition. It is essential for bone development, plays a key role in metabolic processes such as the formation of cellular membranes and is vital for enzymatic systems involved in protein and carbohydrate metabolism. The ratio between Calcium and Phosphorus is of importance because these minerals are antagonists of each other which mean that an oversupply of calcium can work negatively for the digestibility of Phosphorus. There are two expressions used for the phosphorus calculation by nutritionists: Available Phosphorus and digestible Phosphorus. The definition is as follows: Available Phosphorus = Total Phosphorus Innositol Phosphorus Digestible Phosphorus = P intake Faecal P / P Intake In raw materials, a large amount of Phosphorus is in the form of Phytic acid (myo-inositol hexaphosphate). The Phosphorus in Phytic acid is largely unavailable to the pig. Thus, a phytase enzyme is added to diets to enhance the pig s ability to use Phosphorus from Phytic acid. Because manufacturers have their own individual analytical techniques, it is often confusing to compare phytase sources by a single analytical method. To avoid this confusion, TOPIGS indicate the Phosphorus requirements without any influences of the Phytase enzymes. The available Phosphorus levels for maintenance and gain were estimated using the following equations based on Jongbloed et al. (1993) and Rostagno et al. (2011) : Castrates 25 50 kg - Available Phosphorus (g/day) = 0,046 x BW 0,75 + 5,81 x ADG (kg) 51 130 kg - Available Phosphorus (g/day) = 0,046 x BW 0,75 + 5,33 x ADG (kg) Gilts and boars 25 130 kg - Available Phosphorus (g/day) = 0,046 x BW 0,75 + 5,96 x ADG (kg) Page 13