CNCPS biology and NDS An update - AFMA Forum 2020

CNCPS biology and NDS

An update

1

Websile: www.rumen.it

e-mail : [email protected]

RUM&N SasVia Sant’Ambrogio, 4/A - 42123 Reggio Emilia - ITALY

Tel. +39 0522 560093

Ermanno Melli & Emiliano Raffrenato

✓ CNCPS Model definition and basic concepts

✓ Dynamic vs. static formulation approach

✓ Rumen dynamics

✓ Model flow and evaluation

✓ CNCPS updates over the years

✓ CNCPS implementation in NDS Professional

✓ Summary and conclusions

Outline of the presentation2

The CNCPS (Cornell Net Carbohydrate and Protein System) is a

nutritional model designed to accurately evaluate diets and

performance for cattle, using principles of rumen functions,

microbial growth, feed digestion and particle passage, and animal

physiology.

Basic concepts of the CNCPS3

The model was developed to predict nutrient requirements and

supply and evaluate the nutrient status of a variety of cattle under

unique, farm-specific environmental and nutritional management

conditions.

CNCPS evaluates the environmental and nutritional resources

available in an animal production system and enables the formulation

of diets that closely match the predicted animal requirements.

Basic concepts of the CNCPS4

Model purposes

• Improve the efficiency of converting feed nutrients to human food

• Improving cattle nutrition:

➢ improves productivity➢ improves health➢ reduces feeds resources use➢ reduces environmental impact

• Help livestock industry sustainability which depends on minimizingfeed costs per unit of milk or meat produced (improves IOFC)

• Take for nutritional and management factors affecting performanceon each individual farm into consideration

5Basic concepts of the CNCPS

By accounting for the farm-specific animal, feed, and environmentalcharacteristics, the model deals with the following tasks for eachproduction groups and for the whole herd:

1. predicts animal requirements and supply of nutrients in each

production unit (pen) from inputs available on the farm

2. optimizes diet accurately and quickly even using Optimizer tools

(Linear and Nonlinear)

3. predicts nutrient excretions of the herd for a defined period of time

4. predicts feeds needed in the herd for a defined period of time


Criteria on which the CNCPS is based includes:

1. Inputs needed by the model are routinely available on the farm orthrough analyses for nutrient fractions in feed testing laboratories

2. The model is based on wide documented researches

3. It is updated as new information became available

4. The output from the model helps producers improve their feedingprograms

5. It designed to apply the notion of Precision Feeding Management (PFM)

6. It is used routinely by nutritionists helping them with nutritionmanagement and “on-site” decision making.


The CNCPS is a combination of empirical and mechanisticapproaches (algorithms) describing:

1. feed intake and rumen fill

2. ruminal fermentation of protein and carbohydrates

3. nutrient supply and requirements under most management conditions

4. intestinal digestion and absorption

5. utilization of absorbed nutrients for maintenance, growth, lactation,and pregnancy

6. body reserves dynamics (Energy balance and BCS change)

7. efficiency of nutrient use (N, P, K), nutrient excretion and GHGemissions

8. milk yield and milk components (yield and content) with their relativeimpact on cheese production



The CNCPS model differs from other conventional nutritional

systems (defined as static or conventional) because it

includes dynamic aspects of digestion and it is so considered

as a quasi-dynamic model, where nutrient utilization,

primarily in the rumen, is described by a series of research-

derived non-linear equations.

➢ Breaks down carbohydrates and protein into “fractions” and modelstheir fermentation/digestion (rumen and gut functions)

➢ Dynamic vs. static

❑ Amounts of nutrient fractions fermented/degraded in the rumendepend upon competition between rates of degradation andrates of passage

❑ Values for CHO and protein degradability are not constant

Characteristics of a dynamic model compared

to conventional formulation programs


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Dynamic vs. static

Basic concepts of the CNCPS

A system for cattle diet evaluation is defined as static when energy and

protein values are intrinsic characteristics of each feed, which therefore

has unique energy and protein values, regardless of the characteristics

of animals and diets to which it belongs.

Accordingly, characteristics of the diet are the result of the weighted

average of fixed nutritional parameters (static) set down to each

ingredient included in it.

12

Dynamic vs. static


Conventional Ration Formulation System

Feeds Kg DM NEl MJ/kg Energy supply MJ/day

Forage 12,0 4,81 57.7

Concentrate 12,0 9,20 110.4

Total 24,0 7,00 168,1

Diet outcomes are simply the result of the weighted average of

fixed nutritional values set down to each ingredient included in it.

13

Dynamic vs. static


J.Bryant and B.R,

Moss, Montana State

University –

retrived from

https://www.scribd.co

m/presentation/24790

1836/proteins20-

20ruminants1-1-ppt

A nutritional model has dynamic characteristics when it simulates the

effects of nutrients intake, ruminal fermentation, intestinal digestion,

absorption, and metabolism, depending on animal performance.

In the CNCPS model, instead of having feeds with one predefined

energy value as well as degradable and undegradable protein values,

they are described by their chemical fractions and fermentation

characteristics.


Underlying Assumptions

From a dynamic standpoint, the competition betweenrumen degradation and passage is the basic conceptsfor the CNCPS dynamics

15

▪ Kd %/h: degradation rate for each fraction

▪ Kp %/h: passage rate from the rumen

➢ Kpf %/h : passage rate of forages

➢ Kpc %/h: passage rate of concentrates

➢ Kpl %/h : passage rate of liquids

Pool Associated Rates of Degradation and Passage



The Key to Understanding the Rumen

CNCPS adopts the kinetic approach proposed

by Waldo et al. to describe the fermentative

digestion of a homogeneous nutrient pool

(fraction) for protein and carbohydrates.

• Degradation rates are pool and feed specific

• Currently assumed to follow first-order kinetics (constantproportion of the pool is degraded per unit of time)

• Can be altered by degree of processing

• Can be altered by ruminal pH

• Degradation rate of protein and carbohydrate C fractions, etherextract and minerals assumed to be zero

• Triglycerides can be lipolyzed by the bacteria and fatty acidsbio-hydrogenated

• Minerals can be taken up by bacteria and flow with them

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Degradation Rates


• Passage rates are intrinsic to the animal

• Assumed to follow first-order kinetics (constant proportion ofthe pool pass out of the rumen per unit of time)

• Kp is calculated for concentrates, forages, and liquid phase

• Adjustment factor calculated for each feed

• Kp = f (DMI, Forage content, Body Weight)

• Adjustment Factor = f (NDFI %BW)

• Each component pool of a feedstuff is assumed to pass at thesame rate

18 Basic concepts of the CNCPS

Passage Rates

19

Feed Dynamics in the Rumen


80%

57%

40%

68%


Carbohydrate fractions

CHO A1 Acetic, propionic, butyric acids

CHO A2 Lactic acid

CHO A3 Organic acids

CHO A4 Total sugar

CHO B1 Total starch

CHO B2 Soluble fiber (by difference)

CHO B3 Potentially digestible NDF (pdNDF = aNDFom - CHO C)

CHO C uNDF (unavailable NDF)

Protein fractions

PRO A1 Ammonia N (CP equivalent) available very quickly

PRO A2 True soluble protein more rapidly degradable

PRO B1 True Insoluble protein more slowly degradable

PRO B2 True protein bound to NDF and slowly degradable

PRO C Unavailable true protein (bound to ADF)

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Rumen Flow of Nutrients: Passage vs. Degradation


RD = Kd / (Kd + Kp)

RE = 1 - RD

Calculation of Ruminal Degradation

• Calculated for each feed fractions separately

• Where:– Rd = Amount degraded in the rumen, g/d– I = Intake of the fraction, g/d– kd = Degradation rate for the fraction, %/h– kp = Feed passage rate, %/h

KpKd

Kd*IRd

+=


Calculation of ruminal degraded NDF (pdNDF or CHOB3 fraction) from a corn silage

• Where:– Rd = Amount of pdNDF really degraded in the rumen, g/d– I = Intake of pdNDF from corn silage, g/d– kd = Degradation rate for pdNDF, %/h– kp = Forage passage rate, %/h

forageCHOB3

CHOB3

CHOB3CHOB3

KpKd

Kd*IRd

+=

grgr 18168,13,7

3,7*Rd 2700CHOB3) Silage(Corn =

+=


NDF %DM pdNDF % DM Intake kg DM

44,0 32,9 8,2

Microbial Yield


Degraded CHOs represent the substrate for microbial growth.

Microbial yield predicted from substrate available and considering NH3

availability and rumen environment. g Bact./g CHO


CNCPS Model Flow

Ration consumed

CHO Pools PRO Pools Ash Fat and Fatty Acids

CHO Degraded PRO Degraded

NFC Bacteria

FC Bacteria

Escape NFC

Escape FC

Microbes Escape

Escape PRO

Escape Ash Escape Fatty Acids

Intestinal Digestibility

Metabolizable Energy

Metabolizable Protein

Metabolizable Amino Acids

Mineral Absorbed

Maintenance

Pregnancy

Growth

Milk

Reserves

Fecal

Urine

RequirementsSub-model

Rumen Sub-model

CNCPS Model Flow

Lipid Sub-model

Lipolysis

Biohydrogenation

De novo production

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Liver

NH3

Urea

Rumen Modifiers

Sub-models

CNCPS Most limiting ME or MP Allowable Milk


CNCPS Model evaluation

For lactating cows is has been assessed based on first limiting ME or MP allowable milk.

❖ ME from digested nutrient and MP from microbial protein & RUP,are estimated for the whole diet. This nutrient supply is thenpartitioned to the animal requirements (maintenance, pregnancy,milk, growth, and reserves).

❖ Through the accurate characterization of the diets, it allowsremoving ‘safety factors’ that lead to nutrient overfeeding andgreater costs as well as environmental losses.

28 CNCPS Model calibration

❖ Also, thanks to the accurateprediction of current performance(model calibration), we canidentify opportunities forimproving the diets, makingdecisions that will improveefficiency and/or profitability.

29 CNCPS Updates over the years

• v1 - 1991

• v2 - 1993• v3 - 1994 • v4 - 2000

• v5 - 2003

• v6.0 - 2006 • v6.1 - 2009

• v6.5 - 2013

• v6.55 - 2015

❑ Fox, D. G., C. J. Sniffen, J. D. O'Connor, J. B. Russell, and P. J. Van Soest. 1992. A net carbohydrate and protein system for evaluating cattle diets. J. Anim. Sci. 70

❑ Model was reprogrammed to incorporate more dynamic approachesand data analyses and to adapt it to new IT technologies

❑ CPM Dairy was released as commercial application only for dairy cattle

❑ CPM v3 was released with modificationand addition compared to V5

❑ 2009: CPM officially disbanded

❑ Expanded CHO pools and changes in CHO rates❑ Updated protein pools❑ New passage rate equations and changes in passage assignments❑ From NDR to aNDF and new NFC calculation❑ Changes in nitrogen recycling and protein fraction rates❑ Modified fat model (fat digestibility)❑ Updated animal surface area and how heat production is calculated❑ Corrected error in microbial ash calculations❑ Update NFC bacteria rumen NH3 requirements❑ Updated MP Lactation efficiency (from 65% to 67%)

❑ Adoption of aNDFom (NDF on organic matter basis)❑ uNDF for undigestible NDF in place of Lig. x 2.4❑ Use of a multi-time point NDFD to calculate the CHO B3 kd based upon a new rate

calculator from E. Raffrenato et al.✓ these include 30, 120 and 240 hrs for forages✓ 12, 72 and 120 hrs for non-forage feeds✓ using 240h for forages and 120h for non-forages uNDF as CHO C instead of

Lig.x2.4❑ Adoption of uN Ross assay to characterize protein intestinal digestibility❑ CNCPS Feed Library re-edited and updated amino acid values expressed as %CP❑ Updated amino acid efficiencies for lactating cows combining maintenance and lactation

❑Adoption of the equation for forage and fiber passage rates from the NorFor (2011)❑Corrected the issue with amino acid supply and requirements when body tissue is

mobilized or accreted via BCS changes

NDS is the acronym of Nutritional Dynamic System, and it

identifies a computer platform designed to support field nutritionists,

helping them with nutrition management and “on-site” decision making.

The program is built around the latest version of the CNCPS

biological model, using licensed technology and in collaboration with

Cornell Department of Animal Science.

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NDS Professional is an “official” CNCPS platform.

It includes the current CNCPS biology (Version 6.55) and,through close collaboration with the Dept. of Animal Science atCornell, will continue to be updated as new researchesare conducted and become available

31

The platform includes for the following main facilities:

✓ Two masters feed dictionaries (CNCPS and RUM&N Feed Library)✓ Feed management system and feed import from labs (XML files)✓ Farm structure management✓ Animal input and production unit specification✓ Activity and animal group management specification✓ Ration evaluator✓ Auto-balancing system through a linear and nonlinear optimizer✓ Custom report generator✓ Data management and file structure (external .nds files)✓ Ration file and Farm file management (external .farm files)✓ Sharing file system through online clouds services

NDS Features32

NDS Farm Structure

From a whole-farm management perspective, the

Farm Structure facilitates the formulation for

groups receiving a specific recipe.

➢ Recipes can be saved according to the farm set up and the feeding groups available

➢ It is designed to allow the delivery of the same

recipe to different animal groups.

Several reports and summaries can be generated

on-farm basis to aggregate data form the animal

groups within the herd.

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NDS Sub-models and additional tools

NDS includes multiple-

species nutritional models

In addition to the CNCPS model, NDS was extended with several uniqueanalyses and evaluation tools.Designed by the RUM&N Team, to facilitate and enhance the decision-makingprocess in the nutritional, management and economics areas.

▪ Rumen pH sub-model

▪ Predictive milk fat sub-model

▪ Calf Model

▪ Beef Growth Model

▪ P-Size assessment tool

▪ Milk Step-Feeding tool

▪ Moving average resampling

▪ Multitasking Recipes

▪ What-If Analysis Tool

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NDS Auto-balancing system

The platform includes an advanced auto-balancing tool called NDS Optimizer.

It is able to work with two procedures for the optimization of recipes:❑ Linear optimization (Least cost formulation) – returns the least-cost ration

that is within the Min and Max by feeds and by nutrient analysis constraints❑ Nonlinear optimization (Goal-oriented dynamic formulation) – it is a dynamic

formulation system (or non-linear biological optimizer) returning solutionsaccording to the objective selected, choosing the best in the context of awider range of possible alternatives.

Being a biological model, CNCPS is intrinsically nonlinear

and it requires several nonlinear programming techniques

that converge quickly and efficiently towards optimal

solutions for field application.

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The human mind can formulate concepts and hypothesis, butcannot track quantitative relationship across time

Mathematical modeling is a technique that allows us tosystematically build representations of the real system usingsystems thinking

It allows us to analyze a huge amount of data and informationabout nutrition and metabolism that are available

Computer platforms like NDS help build our intuition andimprove our mental simulation capability

NDS can be used on farms to integrate and apply accumulatedscientific knowledge of animal requirements and rumen function

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Summary

NDS can be successfully used as a decision support tool to bothreduce the loss of nutrients to the environment from dairy foodproduction and improve the overall efficiency of nutrient use

NDS can serve as a readily available tool to help nutritionists,planners for concentrated animal feeding operations, andpolicymakers evaluate scenarios in real-time

The use of such a tool in precision feeding management and inassessing enteric CO2 and CH4 emissions of ruminant dietsprovided examples of the ability of the CNCPS to demonstrate thatthe livestock industry has the capacity for self-evaluation and theability to modify its behavior towards more efficient directions.

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Summary (cont.)

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Thank You!

CNCPS biology and NDS An update - AFMA Forum 2020

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