Evaluation of the Cornell Net Carbohydrates and Protein System for sheep in growing lambs in Yucatan

1
Evaluation of the Cornell Net Carbohydrates and
Protein System for sheep in growing lambs in
Yucatan

• Luis Alberto Nabté Solis

2
Background

• Increase in world human population ? Increase in
  animal production
• Yucatan Production Mostly beef cattle, however
  increase in sheep production.
• Productivity potential and efficiency
• slaughter weight (35-40 kg), due to malnutrition,
  usually takes over a year. These lambs do no
  command high prices because the market wants
  lambs of that weight but with aged under eight
  months and in regular amounts.

3

• Sheep world population compared with cattle

4
Country Observations Peso (kg) DS Peso (kg) DS Reference
Country Observations Singles Doubles Reference
México 69 y 32 2,6 0,5 2,1 0,5 Castillo et al., 1972
México 185 y 52 2,8 2,3 Valencia et al., 1973
México 32 2,4 0,59 2,4 0,59 Castillo et al., 1977b
México 169 y 476 2,6 0,4 2,1 0,4 Avalos et al., 1977
México 147 2,63 2,63 González et al., 1978
México 46 y 16a 2,8 0,5 2,1 0,3 González et al., 1983
México 42 y 17b 2,6 0,4 2,1 0,3
Cuba 227 y 318 3,36 0,7 2,74 1,4 Limas et al., 1983
Cuba 75 y 91a 3,43 0,7 2,83 0,7 Fuentes et al., 1983a
México 717 y 176a 2,74 0,5 2,22 0,5 Valencia et al., 1983
México 715 y 168b 2,58 0,5 2,07 0,5
Cuba 69 y 93b 8,30 0,6 2,83 0,6 Fuentes et al., 1987
Title needed, other table
a Machos.b Hembras.
5
FAO, 2002
6
AntecedentsYucatan
7
(No Transcript)
8
Rain and Temperature distribution
9

• Forage production, effect of seasonality

10
Precipitation effect on forage production
11
(No Transcript)
12
not only forage production is affected

• Animal performance affected by climatic
  conditions
• Heat stress
• Reduction in feed consumption
• Water intake
• Change in body mass, body composition, and energy
  requirements of ruminants
• Influence of hot environments on protein and fat
  deposition and ultimately energy deposition has
  not been widely studied

13
Growth curve and difference in deposition of
components
14
Energy and Body Frame effect on growth
15
Adaptation phenomena

• Maintenance requirements reduction (up to 50)
• Visceral organs reduction
• Feed selectivity enhanced
• Body reserves use
• How to manage under these conditions

16
Sheep breeds in Yucatan

• Pelibuey
• Blackbelly
• Dorper

• Probably closely related to the West African, Red
  African, African or Africana breed of Colombia
  and Venezuela
• Mature rams and ewes weigh 54 and 34 kg,
  respectively
• Litter size relatively low at 1.24. First
  lambing 16 to 19 months of age. Lambing
  interval less than 210 days. Lambs average 12 kg
  at 120 days of age

17
Sheep breeds in Yucatan

• Pelibuey
• Blackbelly
• Dorper

Barbados Blackbelly evolved from crosses of
African hair sheep and European wooled breeds
Mature Barbados Blackbelly ewes have a high
prolificacy. Studies have shown the average
lambing rate to range between 1.50 to 2.30 lambs
per ewe lambing, and an average lambing interval
of eight to nine months. mature ewes 100 pounds,
and rams 105 to 125 pounds Good meat flavor
18
Sheep breeds in Yucatan

• Pelibuey
• Blackbelly
• Dorper

South Africa 1930 A live weight of about 36 kg
can be reached by the Dorper lamb at the age of
3- 4 months. 2.25 lambs in average per year.
19

• Growth, multiple variables. So, how to analyze?

20
Models

• Several Models, INRA, CSIRO, ARC, NRC, CNCPS
• CNCPS-Cattle ? diverse animal, feed, and
  environmental production situations for all
  classes of beef, dairy, and dual-purpose cattle
• CNCPS-Sheep ? Developed based on CNCPS-C

21

• CNCPS ? calculates NE requirements for
  maintenance, growth, pregnancy, lactation, and
  body reserves, which then are converted to ME
  using ME efficiency coefficients for each of
  these physiological functions
• But, is appropriate to use it in Yucatan
  conditions?
• Yes, with necessary calibration or validation!!!
• Temperature, seasonality, forage availability ?
  forage composition and kinetics, animal behavior
  responses e.g. DMI, breeds

22
Model evaluations

• CNCPS-S Cannas et al. (2004) evaluation
• Sheep of diverse body sizes and physiological
  stages, fed diverse diets at various levels of
  nutrition
• Accurately predict nutrient requirements, body
  weight gains and losses
• So, concluded that is a useful tool to evaluate
  diets and animal performance in different
  production settings ranging from extensive
  grazing situations to highly productive sheep

23

• First step to be able to use the model
• Validation, evaluation
• CNCPS-C around the world in dairy cows, beef, and
  tropical dual purpose cattle.
• Different uses for models
• CNCPS-S, absence of evaluation under tropical
  conditions

24

• Objectives
• Evaluate CNCPS-Sheep predictions under Yucatan
  conditions in growing animals, using experimental
  data that had enough information to describe
  animal, feeds and the environment as required by
  the model.
• Identify limiting factors in CNCPS-Sheep model
  requiring further research and analysis.

25
Material and Methods.

• Model evaluation
• Data needed
• Model inputs
• Forage composition, animal weight, BCS, Body
  Composition, DMI
• Data collection
• Simulations
• Statistical validation

26
Data needed
Input Description
Animal type Category of animals for which the diet is evaluated
Age Mean age of the group of animals
Body Weight Current shrunk body weight or full body weight
Standard Reference Weight at BCS 2.5 FBW by a specific animal of certain breed, age, sex and rate of gain, skeletal development complete and BCS 2.5
Wool Depth Depth of the wool measured perpendicularly to skin surface.
Clean Wool Production Production of clean wool per year
Current Temperature current mean daily (24 h) air temperature (C)
Previous Temperature previous month average daily air temperature (C)
Wind Speed measured at ground level
Rainfall only for sheep kept outdoors
Horizontal distance daily distance walked by sheep every day on flat surfaces
Vertical distance the vertical component of the movement
Feed consumed Diet description and composition
BCS current body condition score scale 0-5
27
(No Transcript)
28
(No Transcript)
29
Data collection

• Experiment carried out by UADY-FMVZ
• Three groups of animals (Pelibuey and F1 crosses
  of Pelibuey x Dorper and x Katahdin)
• Two different diets will be supplied to each
  group of animals from weaning (15 kg) until
  slaughter (40 kg).
• One animal will be slaughtered by each group and
  diet at 15, 30 and 40 kg.
• Carcass characteristics, ultrasonography, and
  dissection of half carcass to quantify muscle,
  fat and bone.

30

• Feed analysis, chemical composition and kinetics
  of feeds
• Environmental data from meteorological stations
• Simulation with all data collected will be
  carried out choosing groups and animals
• Comparison between actual and simulation results
• Daily gain, body composition, body condition
  score, energy for maintenance and growth

31

• Statistical analysis
• mean bias, the mean square prediction error
  (MSPE), and the statistical measures of model
  performance
• Regression between the observed and the
  model-predicted

32
Expected results

• Model accuracy and precision
• Model limiting factors
• Identification of critical points in the model
  and in the management methods
• Proposal of a tool to analyze hypothetical
  situations in sheep production

33
Thank you for your attention!!!