Transcript Energy balance changes in cows and matching calving

Energy balance changes in cows and matching
calving seasons with forage availability
TIES Seminar
Kotaro Baba
1. Tedeschi, L. O., D. G. Fox, M. J. Baker.2004 Unveiling the
production efficiency of the beef cow: A systematic approach
using nutrition models modification of paper presented at the
NY beef cattle winter management meeting. Jan.2004
2.Reynoso-Campos, O., D. G. Fox, R. W. Blake,M. C.
Barry,
L. O. Tedeschi. C. F. Nicholson, H. M. Kaiser,
P. A. Oltenacu.2004. Predicting nutritional
requirements and lactation performance of dual-purpose
cows using a dynamic model. Agricultural Systems.
80:67-83
PAPER # 1
Tedeschi., L. O., D. G. Fox, M. J. Baker.2004
Unveiling the production efficiency of the
beef cow: A systematic approach using
nutrition models modification of paper
• Increase beef production
-Enhance reproduction indexes
-Enhance nutrition concepts
-Enhance genetic selection
- Enhance ranch management
This paper introduces a model (CVDS) which
Tedeschi is developing.
The objectives of the model
• Computing the energy requirements of individual
beef cows each day of the year and simulating the
growth of the nursing calf given the information
available
• Computing energy balances for the herd each day of
the year to evaluate the balance between herd
numbers and requirements with the forage available
• Identifying differences in efficiency among individual
beef cows in a herd
The brief description of the model
• This model is based on those developed at
Cornell as described by
Reynoso-Campos et al.(2004)
Fox et al. (1988)
An evaluation of the model, as the peak milk
yield increases, the weaning weight increases.
• Paste figure 3
An evaluation of the model, energy efficiency of
the cows
• Paste figure 3 B
Tedeschi implies
Forage availability, milk yield, calf growth,
and calving interval
-The milk level should be based on forage
available.
A practical application of the model
A practical application of the model
Hints from the Tedeschi’s paper for our
Yucatan case
1. The milk level should be based on forage
available.
2. Matching breeding and calving seasons
with availability of forage.
Reynoso-Campos et al
Reynoso-Campos, O., D. G. Fox, R. W. Blake,M. C.
Barry,L. O. Tedeschi. C. F. Nicholson, H. M. Kaiser,
P. A. Oltenacu.2004. Predicting nutritional
requirements and lactation performance of dualpurpose cows using a dynamic model. Agricultural
Systems. 80:67-83
• Animal nutrition
• Cornell Net Carbohydrate and Protein
System(CNCPS)
-Milk production
-ME balance
-MP balance
-BW change
-Changes in Body reserve
through the reproductive cycle.
Look at table 1. Page 70-71.
• Table 1 is nicely summarized nutritional
constraints and strategies for intensifying
dual-purpose cattle systems in the tropics.
• This table is related to our Yucatan beef
project very much.
Objectives of this study 1
1.
Describe a dynamic application of the
CNCPS model that was developed to
account for the cyclical changes in energy
and protein balances that occur during the
reproductive cycle of dual-purpose cows in
the tropics.
Objectives of this study 2
2.
Demonstrate the use of this dynamic
application of the CNCPS model in
evaluating dual-purpose cow performance
over the reproductive cycle in specific
production situations.
Inputs for the simulation
• Crossbred of Holstein x
Brahman
• 2nd lactation
• Age --- 65 mo
• CI --- 420days
• Dry periods—150 days
• Weight --- 470 kg
• Calf BW--- 31.5 kg
• Temperature
-Previous 26C°
-Current 26C°
• Milk
-Production 11.5
kg/day
-Fat
4.1 %
-Protein 3.9 %
• Rolling herd average
--- 2500 kg/270 day
lactation with the CI of
420 days
Feed information
• Lactating cows
-Graze forage Star grass (Cynodon
plectostachyus)
- 2 kg of commercial supplement
(Both energy and protein concentrates)
• Non-lactating
-Only grazed forage
Chemical components of Star grass
Juarez et al., 1999
• Lactating (fertilized)
NDF --- 71.6
CP --- 10
Lignin – 7.3
NDF digestion rate
--- 7.0 %/h
• Dry (unfertilized)
NDF --- 78.3
CP --- 6.6
Lignin – 7.6
NDF digestion rate
--- 5.0 %/h
Source , Reynoso-Campos et al.,2004
Source, Reynoso-Campos et al.,2004
Source, Reynoso-Campos et al.,2003
Comparison of ME allowable milk with and without
ME contribution from mobilized body tissue
Conclusion by Reynoso et al
• The CNCPS analyzes and integrates the
nutritional and productive performance of
cows on a dynamic basis throughout a
calving interval.
• Changes in the predicted nutritional status
of animals reflect dynamic, cyclic
processes of tissue mobilization and
repletion associated with variation in
production requirements and nutrient
availability during the CI
Hints from the Reynoso’s paper for our Yucatan
case
• The CNCPS is a useful tool to monitor
energy balance through the calving
interval.
• The CNCPS can show the tissue
mobilization and repletion in the prediction
of nutrient requirement
My conclusion
• Energy balance, protein balance, and body
condition score are different from physiological
stages (early or late lactation, and early or late
pregnancy), and feed quality and quantity. Not
accounting for the fluxes of body tissue leads to
unrealistic predictions of dietary requirements.
• It is important to think about forage availability,
and energy requirements for each physiological
stage