Effects of Preweaning Factors on Sow Lifetime Productivity

Dr. Joe Cassady, PhD. PASDepartment of Animal ScienceNorth Carolina State University

Outline

● Introduction● Background● Justification● Research Objective● Project Description● Current Status● Future Direction

Introduction

● In 2009, more than 1 billion people worldwide were undernourished, according to “The State of Food Insecurity”, an annual report from the United Nations Food and Agriculture Organization (FAO).

Introduction

● American pork producers have remained competitive in the global market despite higher labor and input costs through adoption of technology leading to greater productivity and efficiency.

Introduction

● New methods must be devised for producing pork that reduce inputs, minimize environmental impacts, provide for improved pig welfare, and ensure a safe, nutritious pork supply.

● Sow lifetime productivity is directly linked to economic efficiency, biological efficiency, feed costs, and pig welfare.

Introduction

● Many factors impact sow lifetime productivity.— Gilt development— Boar exposure— Estrus detection— Gestation housing— Lactation feed intake— Herd health— Etc.

Introduction

● The impact of gilt preweaning management on sow lifetime productivity is not well understood.

Background

● Donald HP, 1939, The relative importance of sow and litter during the growth of suckling pigs: a comparison of fostered and normally reared pigs. Emp. J. Exp. Agric.

● He concluded that the dam and nurse dam influenced growth rate equally.

Nelson and Robison 1976, J. Anim. Sci., 43: 71--77

● Used cross-fostering to create litters of 6 and litters of 14.

● Pigs were weaned at 8 weeks of age.

● Gilts from small litters were 4.5 kg heavier then those from large litters at weaning.

Nelson and Robison 1976, J. Anim. Sci., 43: 71--77

Robison, OW, 1981, Livestock Production Science, 8:121--137

● Robison OW, 1981, The influence of maternal effects on the efficiency of selection; a review, Livestock Production Science.

● Concluded that gilts nursed in large litters grow slower, reach puberty later, and produce smaller litters

Robison, OW, 1981, Livestock Production Science, 8:121--137

● These results suggest that maternal performance should be measured at three to four weeks of age and prior to the initiation of creep feeding. Further, they suggest that early weaning may alleviate the negative association between direct genetic and maternal effects. This would allow more effective selection.

Holl and Robison, 2003, J. Anim. Sci.

● Published the results of 9 generations of selection for increased litter size.

● Gilts in the select line were raised in litters no larger that 10 pigs.

Holl and Robison, 2003 J. Anim. Sci.

Times have changed● Average number born alive increased by 10%

from 1998 to 2008 (10.2 to 11.4) (PIGCHAMP 1998, 2008).

● Pigs are weaned earlier

● Diets have improved

● New health challenges exist.

Justification

● The impact of the preweaning environment and management on sow lifetime productivity in modern swine production is not well understood.

Recent Work

● We have completed 2 projects related to preweaning factors impacting pig performance.

Fix et al. 2010

Birth wt. vs. Probability of being a full value market hog.

Pigs that were classified as full value, survived tillharvest, >100 kg BW, and free of injuries, belly ruptures, major health issues, etc.

Fix et al., 2010, Livestock Science

Fix et al., 2010, Livestock Science

Bishop, 2011 http://repository.lib.ncsu.edu/ir/bitstream/1840.16/7079/1/etd.pdf

Trait CF a NFb P - valueNumber of pigs per litter

At birth 11.1 ± 0.26 11.7 ± 0.28 0.14At weaning 8.5 ± 0.22 8.7 ± 0.23 0.59

At nursery exit 7.3 ± 0.21 7.4± 0.22 0.74Average weight, kg

At birth 1.50 ± 0.018 1.45 ± 0.019 0.07At weaning 5.9 ± 0.06 5.9 ± 0.07 0.34

Weight variance within litterAt birth 0.08 ± 0.005 0.08 ± 0.005 0.46

At weaning 1.2 ± 0.06 1.1 ± 0.06 0.42Average daily gain, kg/ d

Pre-weaning 0.21 ± 0.003 0.20 ± 0.003 0.21

a CF = Cross foster treatmentb NF = Non-cross foster treatment

Table 3. Least squares means and standard errors for growth traits

The 10K Gilt Project

Objective

● To estimate the impact of preweaning environment and management of gilts on subsequent sow lifetime productivity.

Production System

● Two 1200 sow multiplication units within the Murphy-Brown, LLC system.

● After leaving the nursery gilts will go to 1 of 4 gilt development units.

● Finally gilts will be sent to one of 10 commercial sow farms.

Methods

● Born between June 1st and Dec. 1st, 2012

● 13,000 gilts will be tagged at birth.

● Both individual and litter birth weights will be recorded

Methods

● Cross-foster status will be documented

● Sex ratio of the litter at birth, after cross-fostering, and at weaning will be recorded.

● Weaning weights will be taken one or two days prior to weaning.

Methods

● Mortality will be documented through 4th parity

● Weaning weights will be taken one or two days prior to weaning.

Methods

● Female performance will be documented on each sow farm.

● Data will be submitted to a centralized data base.

● Sow lifetime productivity is defined as pigs per female per day of herd-life

Current Status NumberTotal tagged gilts 8,213

Gilts that were tagged for weaning 6,975

Tagged gilts that have been weaned 5,677

Deaths up to last weaning 1,298

Litters weaned 1,088

Nursery Deaths 90

Gilts moved to finishers 2,623

Projections NumberLitters 2,000Total tagged gilts 13,000Gilts Weaned 10,500

Gilts Placed in the Finisher 9,500Gilts Available for Selection 9,000Gilts Entering Sow Farms 7,250Gilts Farrowing 6,000P4 litters produced 2,000

Future Direction

We will continue to tag gilts and record data until we have successful tagged 13,000 gilts.

We will continue to record mortalities from birth until entry into the sow farm and beyond.

We will record performance on the sow farm including

Future Direction

Gilts were from single-sire matings.

Tail tissue was retained on each gilt at birth as a source of DNA.

Pending the outcome of the initial experiment and the availability of funding, we intend to genotype a sample of the gilts to identify genomic regions associated with variation in sow lifetime productivity.

Funding

● National Pork Board● Murphy-Brown, LLC● Smithfield Premium Genetics● North Carolina Agriculture Research Service

Acknowledgements● Dr. Ashley DeDecker – Murphy-Brown, LLC.● Dr. Kent Gray - SPG● Dr. Perry Harms - SPG● Dr. Justin Holl● Dr. Mark Knauer – NCSU● Dr. Mark Estienne – Virginia Tech● Mr. Tom Hagood – Murphy-Brown, LLC.● Ms. Amanda Cross - NCSU● Ms. Emily Cook - NCSU● Ms. Cassie Farring - NCSU● Mr. Stewart Callahan– Virginia Tech