dr. mark knauer - evaluating body condition & reproductive performance
DESCRIPTION
Evaluating Body Condition & Reproductive Performance - Dr. Mark Knauer, North Carolina State University, from the 2014 Allen D. Leman Swine Conference, September 15-16, 2014, St. Paul, Minnesota, USA. More presentations at http://www.swinecast.com/2014-leman-swine-conference-materialTRANSCRIPT
Evaluating body condition & reproductive performance
September 15, 2014
Knauer, M. T., and M. Bryan
NCSU Swine Extension Specialist
Focus
– Swine genetics and production management
Appointment
– 70% extension, 30% research
Start date – July 2011
Training graduate students Animal Science – Animal Breeding & Genetics
– M.S. (4)
John Langdon
Cassie Ferring
Austin Putz
Matt Morrison
– PhD (2)
Emily Cook
Miranda Bryan
Pellet quality
Sow body condition
Genetics of
piglet quality
Evaporative Cooling
Selection for improved reproduction under
heat stress
Outline
Making a case for objective body condition tools
Research
– Exp. 1 – Ideal body condition in relation to reproduction
– Exp. 2 – Ideal body condition change in relation to
reproduction
Economic impact of implementing the sow caliper
Summary
Sow feeding management concepts Repartition gestation intake to lactation
– Reducing gestation feed intake improves Feed cost
Subsequent lactation feed intake
– Increasing lactation feed intake improves Litter weight gain
Wean-to-estrous interval
Subsequent farrowing rate
Subsequent litter size
Cull weight
Example of repartitioning gestation feed to lactation
0
500
1000
1500
2000
Gestation Lactation Total
Feed intake per sow per year, lb.
Feed budget A Feed budget B
Superior reproductive throughput
Feeding based on visual body condition
Pros
Inexpensive
Cons
Requires continuous training
Farm to farm variation
Potential for reduce profitability
Problem – visual BCS
If you cannot objectively measure body condition
– How will you
manage it?
will you improve?
Optimal
0
5
10
15
20
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
%
Caliper
Farm 1
Farm 2
Validating problems with
BCSThin Fat
Sow caliper score
Differences in body condition
Trait P-13 (n=75) P-23 (n=150)
Parity 3.9 3.4
Weight, lb. 486 545
Backfat, in. 0.90 1.15
Farm BCS 2.9 3.2
Expert BCS 2.7 3.4
Caliper 12.1 16.5
*All means differ (P < 0.05)
Farm 1 Farm 2
Problem – visual BCS
Underfeeding Overfeeding
High feed costs
Farrowing problems
Increased preweaning mortality
Impaired reproduction
Well-being concerns
0
5
10
15
20
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
%
Caliper
Farm 1
Farm 2
Impaired reproduction
Well-being concern
Optimal
High feed costs
Farrowing problems
↑ preweaning mortality
Problem – visual BCS
Sow caliper score
Adoption of objective body condition tools
Standardize farms & people
Train new/existing employees to visually
score sow condition
Fast and accurate tools will reduce
weaned pig cost
Commercial sow farm in eastern NC
August 2012 - May 2013
1,500 whiteline sows
Multiparous
Exp. 1 – Define ideal body condition in relation to reproduction
Sow housing
Stalls
– Weaning to ~35 days
Pens
– ~35 days to
farrowing
– 8×10ft
– 4 to 5 sows per pen
Body condition traits
Caliper score (CS)
Weight (WT)
Backfat (BF)
Loin eye area (LEA)
Visual BCS
– 1-5 by experienced
technician
Knauer sow body condition caliperAn objective body condition tool – the sow caliper
The concept…
Adapted from Edmonson et al. (1989)
Data analyzed with SAS using PROC GLM
Fixed effects
– group
– barn
– group x barn interaction
– parity
Example model
– reproductive trait = group + barn + group*barn + parity + body
condition trait
Statistical analysis
Relationships between body condition measures at breeding with subsequent reproductive performance
CS CS2 WT BF LEA LEA2 BCS BCS2
NBA
BW
NW
WW
PS
WCI
= (P<0.05)2Denotes quadratic body condition term. NBA= number born alive, BW= litter birth weight, NW= number weaned, WW= litter weaning weight, PS= piglet survival, WCI=wean-to-conception interval.
Optimum sow caliper score for piglet survival
80
85
90
95
10 11 12 13 14 15 16 17 18 19
Piglet survival,
%
Sow caliper score
Lighter weight sows had greater piglet survival
80
85
90
95
Piglet survival,
%
Sow weight at breeding, lb.
Parity p>0.05
Optimum sow caliper score for reproductive throughput
25
26
27
28
29
30
10 11 12 13 14 15 16 17 18 19 20
Pigs weaned per sow per year
Sow caliper score
Exp. 2 – Define ideal body condition change in relation to reproduction
Commercial sow farm in eastern NC
– 885 sows
– 250 gilts
Smithfield Premium Genetics
February to August, 2013
Traits measured
26
Sow caliper
Heart girth (gilts)
Ultrasound backfat
2 3 4
Farm body condition score
Backfat, BCS, caliper and gilt weight traits
gestation
breeding day 35 day 105
Gain early gestation
Gain late gestation
Gestation gain
Statistical analysis 24 body condition traits related to reproduction
Data analyzed with SAS using PROC GLM
Fixed effects
– farrowing group
– parity
Example model
– reproductive trait = farrowing group + parity + body condition
trait
Results – in general
Reproduction associated with
– Gilts body condition change but not specific body
condition
– Sows specific body condition but not body condition
change
Results - giltsAt
breeding Day 35 of gestation
Day of gestation
105
Early gestation
gain
Late gestation
gain
Gestation gain
Backfat
NBA
STB
NW
BCS
NBA
STB
NW
Caliper score
NBA
STB
NW
Weight
NBA
STB
NW
= (P<0.05)NBA= number born alive, STB= stillborn, NW= number weaned.
Results - sowsAt
breeding Day 35 of gestation
Day of gestation
105
Early gestation
gain
Late gestation
gain
Gestation gain
Backfat
NBA
STB
NW
BCS
NBA
STB
NW
Caliper score
NBA
STB
NW
NBA= number born alive, STB= stillborn, NW= number weaned. = (P<0.05)
Distribution of gilt weight at breeding
Average weight at breeding = 360 pounds
0
10
20
263 285 306 328 349 371 392 414 435 457 478
%
Gilt weight, lb.
Gilts that gained condition during gestation farrowed fewer piglets
11.611.1
10.610.0
9.5
8.0
9.0
10.0
11.0
12.0
-2 -1 0 1 2 3
NBA
Caliper score gain/loss
Early gestation
Late gestation
Gilts that gained condition farrowed fewer piglets
8
9
10
11
12
0
10
20
30
-2 -1 0 1 2 3 4
NBA% of gilts
Gestation caliper gain/loss
11.611.0
10.4
44% of gilts gained condition
Identifying “ideal” sow body condition
10.5
11.0
11.5
12.0
11 12 13 14 15 16 17 18 19
NW
Caliper score
10.0
10.5
11.0
11 12 13 14 15 16 17 18 19
NW
Caliper score
Exp. 1
Exp. 2
Benchmarking gestation feed intake
0
10
20
30
≤ 4.0 4.0 4.5 5.0 5.5 6.0 ≥ 6.5
%
Gestation feed intake, lb.
Agri Stats 2005 to 2010
Gestation feed intake per day, lb.
18,000 sows - implementation of sow caliper in 2013
8 farms – 18,000 sows
4.24.44.64.85.05.25.4
2012 2013 2014
Gestation feed
intake per day,
lb.
Year
savings of $285,000, $15.82 per sow
Summary
Repartitioning gestation feed intake to lactation can
improve herd reproduction/profitability
The sow caliper is an objective tool that can be used to
manage body condition
– We recommend maintaining sows at a caliper score between a
12 and 15
– Sow calipers are available to the public – contact
Summary
Sows
– “Ideal” body condition in relation to sow reproductive
throughput was identified
– Heavy sows have greater preweaning mortality
Gilts
– A one caliper score increase in body condition during
gestation decreased NBA by 0.57 piglets
Body condition extension materials
Sow body condition poster – Free – Available @ pork.org – Pork Store
Thank you
Dave Baitinger
Dr. Dustin Kendall
Mark Daughtry
Tommie Dale
Bob Ivey
Stacey Jones
Dr. Cary Sexton
Miranda Bryan
Frank Hollowell