NRC 2012 Models for Estimating Nutrient Requirements of Pigs
Case studies
Contents
1 INTRODUCTION AND GENERAL OVERVIEW (6)
2 GESTATING SOWS (6)
Effects of Stage of Gestation and Feeding Regimen on Nutrient Requirements (6)
Effects of parity and anticipated litter size on nutrient requirements (9)
Effects of housing and environmental conditions on nutrient requirements (10)
Matching observed with predicted performance (12)
3 LACTATING SOWS (14)小朵朵和大魔法师
Effects of parity and litter growth rate on nutrient requirements (14)
Effects of sow body weight and litter growth rate on nutrient requirements (16)
Effect of environmental temperature on feed intake and sow performance (18)
Effect of feed intake on sow performance and nutrient requirements (19)
4 GROWING-FINISHING PIGS (21)
Effect of body weight on nutrient requirements (21)
Effects of gender, immunization against GnRH and feeding Ractopamine on nutrient
requirements of finishing pigs (23)总和
生育率 博尔赫斯Interactive effect of pig genotype and feeding level on nutrient requirements during the
early finisher phase (24)
Matching observed with predicted performance – based on mean intakes, days to slaughter, and probe back fat thickness (26)
Matching observed with predicted performance – based on observed feed intake and
growth curves (FOR ADVANCED USERS ONLY) (28)
5 DIET FORMULATION AND FEEDING PROGRAMS (31)
江苏警官学院学报Use of the Feeding Program & Diet Formulation module (31)禤沛钧
Evaluate the environmental impact of alternative feeding programs (35)
Evaluate the effect of using high-fiber coproducts on threonine requirements and energy
utilization in finishing pigs (37)
1
Introduction and General Overview
These case studies have been prepared to help users understand the use and application of the NRC (2012) models to estimate nutrient requirements of swine.
A detailed description of the models is provided in Chapter 8 of the 11th revised edition of Nutrient Requirements of Swine published by the U.S. National Research Council (NRC, 2012). Appendix 1 o
f that publication also contains a User Guide. A slightly updated version of the User Guide can be downloaded with the models.
The four models (one for starting pigs, one for growing-finishing pigs, one for gestating sows, and one for lactating sows) are combined into a Microsoft Excel workbook and stored in the file NRC swine 2012 v1. The program also includes a database with nutrient profiles of ingredients and a means to formulate diets and generate feeding programs. The nutrient database and formulation module allow the amounts of nutrients supplied in specified feeding programs to be compared with estimated requirements. The program also enables nitrogen, phosphorus, and carbon losses into the environment to be estimated.
Before operating the model, it is recommended that the original program is saved and a copy is used. Doing this will protect the settings in the original version of the program. To operate the models, start Excel and open the file NRC swine 2012 v1.
The program contains macros. Depending on the security settings on your computer you may have to enable macros as outlined in the User Guide.
When the program opens, the user is asked to agree with the warning about the program’s use. The
user is then directed automatically to the Main Menu, which allows access to the models and the module Review Feeding Program s. The ingredient database and the feed formulation system are accessed via the Review Feeding Programs button.
The program allows alternative systems for energy (DE, ME, and DE), amino acids (standardized ileal digestible [SID], apparent ileal digestible [AID], and total content [applicable to corn and soybean meal-based diets only]), and phosphorus (standardized total tract digestible [STTD], apparent total tract digestible [ATTD], and total content [applicable to corn and soybean meal-based diets only]. Energy and nutrient systems are specified on the Main Menu.
In the models, determinants of nutrient requirements can be entered, and current levels of performance can be specified. After changing the model inputs and before exploring nutrient requirements, calculations must be executed by clicking the Calculate button at the top of the screen. During these calculations nutrient utilization parameters and estimates of nutrient requirements are generated and stored for individual days.
Once model calculations are executed, estimates of animal performance, key aspects of nutrient utilization, and nutrient requirements can be explored simply by entering the body weight range (starting and growing-finishing pigs) or time period (for gestating and lactating sows) .
Results are presented in graphs and summarized in printable reports.
Notes:
Changes that are made to model inputs, diet compositions, and feeding programs are used for the current session only. To store changes to inputs for use in future sessions, simply save the entire file, using a new name.
When using the models to estimate nutrient requirements, there is no need to evaluate feeding programs. When first using the program it is recommended that No is selected following Do you wish to evaluate a feeding program? on the Main Menu.
2
Gestating Sows
EFFECTS OF STAGE OF GESTATION AND FEEDING REGIMEN ON NUTRIENT REQUIREMENTS
First, ensure that the appropriate nutrient systems are chosen. To do this, navigate to the Main Menu
and under Step I use the three pull-down menus to select ME for energy, SID f or amino acids, and STTD for phosphorus. Under Step II, select No following Do you wish to evaluate a feeding program?
Under Step III select Gestating Sows. A new window will appear with navigation and action buttons at the top of the screen. To ensure that the default values are entered for model inputs, click Enter Default Inputs. The following information should be displayed under INPUTS:
Diet characteristics that affect nutrient requirements
Metabolizable energy (ME) content, kcal/kg 3300
Fermentable fiber content, % 9.0
Sow performance:
Sow body weight at breeding, kg 165
Parity 2
Gestation length, day 114
Anticipated litter size 13.5
Anticipated birth weight, kg/pig 1.4
Feed intake
巨星影业Feed intake / (feed intake + feed wastage) 0.95
Start day 1 30 60 90
豫公网安备41160202000603
站长QQ:729038198
关于我们
投诉建议