Impact of Wean Age and Feeding Program on Nursery Performance

Christina Phillips, Ph.D.Director of Production Research

Smithfield Hog Production Division

September 19, 2016

Outline Background Brief Literature Review Wean age and nursery feeding program: Exp 1 Wean age and nursery feeding program: Exp 2 Overall Implications Acknowledgements Questions

Background

The swine industry adopted the practice of earlier weaning to: Improve farrowing crate utilization Increase numbers of pigs born per sow per year Improve piglet health

Many producers and scientists are re-evaluating weaning age decisions, by comparing growth performance of pigs of different wean ages.

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Literature Review Increasing wean age (15.5, 18.5, and 21.5 d) linearly

improved nursery (0-42 d) ADG and decreased nursery mortality (Main et al., 2004). Magnitude of growth rate improvement is predictable within a

system, but magnitude of mortality improvement is dependent upon baseline mortality, pig flow, and specific health challenges.

Nursery diet complexity (defined as more or less complex) determined by amount of lactose and spray-dried animal plasma in the diet, did not influence performance.

4

Literature Review

Increasing wean age (from 20 d to 15 d) increased nursery (0-42 d) ADG, decreased the coefficient of variation for weaning weight, and decreased morbidity (Smith et al., 2006).

Increasing wean age (from 21.8 to 18.9 d) improved nursery (0-42 d) ADG (Bass et al., 2007).

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Experiment 1

Experiment Title: Impact of wean age and feed program on nursery performance

Experiment Objective: To determine the impact of wean age and nursery feeding program on nursery performance

Experimental Design

2420 mixed sex pigs (Sow farm, NC) were allocated to 1 of 12 treatments (Research Nursery Farm, NC) in a 3 x 4 design. 3 wean age groups and 4 dietary feeding programs

Pigs were weaned weekly and allotted to the appropriate wean age group. All wean age groups were represented in each week. Six weeks of weaned pigs were used in the trial. A PRRS break was confirmed 7 d after the 1st group was

placed.

Experimental Design

Groups were created to avoid confounding wean age with week of weaning.

Litters Room 1 Room 2 Room 3 Room 4 Room 5 Room 6 Room 7 Room 8

Week 42 1 24 13 9

Week 43 15 3 28 2

Week 44 15 6 14 12

Week 45 10 3 15 14

Week 46 17 4 17 13

Week 47 7 9 9 21 5

Experimental Design Sow farm

All pigs were ear tagged at processing and location recorded No piglets were cross fostered after processing Day before weaning litters were painted with respective color to

correspond to wean age group Research Nursery farm

Pig sorted by color (wean age group) Pigs assigned to pens within each color grouping Pigs were placed at 2.5 sq.ft./pig Pens were then assigned to dietary treatments within each wean age

group

Experimental Design

Standard nursery management Comfort boards placed in all pens for 21 days Gruel fed pens with avg wt less than 12 lbs for 3 days Treatments administered daily, pigs pulled if non responsive in 3 days

PRRS Outbreak Protocol (Implemented in week 2) Water meds: Electrolytes, Oral aspirin; Denagard/Neomycin/Tetracyline

if needed Individual treatments : Draxxin (d 0 – 14), Baytril (d 15-28), Excede (d

29 – sale), Predef 2X (anytime)

Experimental Design 3 wean ages:

≤ 25 d (18-25 d) 26-29 d ≥30 d (30-38 d)

4 dietary treatments, combined total = 23 lbs of early wean (EW) and pre-starter (PS), remainder fed for 49 d nursery period was starter: 0 lbs EW, 23 lbs PS 2.5 lbs EW, 20.5 lbs PS 5 lbs EW, 18 lbs PS 7.5 lbs EW, 15.5 lbs PS

Data Collection and Analysis Data Collection

Pens were weighed at days 0, 7, 14, 28, and 49 post placement Amount of feed delivered to each pen Fall behinds and mortality were recorded Feed samples for every diet phase and treatment were collected

Data Analysis General Linear Model Main Effect Age Diet Age X Diet

ResultsTreatments SE Age Diet

Age X Diet

18 - 25d 26 - 29d 30 - 38d

Item0 EW 23

PS2.5 EW 20.5 PS

5 EW 18 PS

7.5 EW 15.5 PS

0 EW 23 PS

2.5 EW 20.5 PS

5 EW 18 PS

7.5 EW 15.5 PS

0 EW 23 PS

2.5 EW 20.5 PS

5 EW 18 PS

7.5 EW 15.5 PS (P<) (P<) (P<)

Number of pens 11 11 11 11 6 7 6 7 10 10 10 10

Start Weight, 0d, lb 10.00 9.91 9.68 9.99 13.88 13.21 13.92 13.04 15.05 15.10 15.57 14.87 0.58 <0.01 0.68 0.84

Trial Duration (0-49d)

ADG, lb 0.66 0.63 0.65 0.68 0.93 0.89 0.93 0.89 0.99 0.99 1.02 0.94 0.05 <0.01 0.64 0.71

Mortality, % 22.7% 26.1% 23.5% 18.2% 4.5% 3.9% 3.0% 4.5% 5.0% 3.6% 7.3% 7.3% 4.5% <0.01 0.97 0.77

Fall behinds, % 2.8% 2.5% 2.6% 4.1% 2.9% 2.3% 0.7% 5.5% 3.8% 3.3% 3.2% 5.0% 1.3% 0.35 0.02 0.86

F:G 1.47 1.54 1.53 1.49 1.47 1.43 1.38 1.36 1.48 1.46 1.47 1.44 0.04 <0.01 0.44 0.52

Sale weight, lb 46.9 46.97 47.04 48.46 60.8 58.19 59.74 58.67 64.9 65.02 68.02 63.94 2.15 <0.01 0.74 0.71

Period Results

ADG, lb (0-7 d) -0.03 -0.03 -0.03 -0.03 0.18 0.19 0.21 0.15 0.33 0.32 0.36 0.30 0.05 <0.01 0.75 0.99

ADG, lb (7-14 d) 0.32 0.25 0.26 0.26 0.60 0.48 0.52 0.51 0.73 0.70 0.72 0.55 0.06 <0.01 0.04 0.30

ADG, lb (14-28 d) 0.67 0.62 0.65 0.68 0.90 0.88 0.89 0.85 0.97 0.99 1.00 0.94 0.04 <0.01 0.80 0.78

ADG, lb (28-49 d) 1.13 1.16 1.17 1.21 1.34 1.30 1.34 1.33 1.32 1.34 1.40 1.33 0.05 <0.01 0.58 0.76

Main Effect of Agea

AGEItem 18 - 25d 26 - 29d 30 - 38d SE (P<)Number of pens 44 26 40

Start Weight, 0d, lb 9.90 13.51 15.15 0.28 <0.01Trial Duration (0-49d)

ADG, lb 0.66a 0.91b 0.98c 0.02 <0.01Mortality, % 22.6%a 4.0%b 5.8%b 2.2% <0.01Fall behinds, % 3.0% 2.8% 3.8% 0.6% 0.35F:G 1.51a 1.41b 1.46c 0.02 <0.01Sale weight, lb 47.4a 59.35b 65.48c 1.04 <0.01

Period ResultsADG, lb (0-7 d) -0.03a 0.18b 0.33c 0.03 <0.01ADG, lb (7-14 d) 0.27a 0.53b 0.68c 0.03 <0.01ADG, lb (14-28 d) 0.66a 0.88b 0.97c 0.02 <0.01ADG, lb (28-49 d) 1.17a 1.33b 1.35b 0.02 <0.01

aMeans that do not share superscripts differ by p <0.05.

Main Effect of Dieta

DIET

Item0 EW 23 PS

2.5 EW 20.5 PS

5 EW 18 PS

7.5 EW 15.5 PS SE (P<)

Number of pens 27 28 27 28Start Weight, 0d, lb 12.98 12.74 13.06 12.64 0.28 0.68

Trial Duration (0-49d)ADG, lb 0.86 0.83 0.87 0.84 0.02 0.64Mortality, % 10.8% 11.2% 11.3% 10.0% 2.1% 0.97Fall behinds, % 3.2%a 2.7%a 2.2%a 4.9%b 0.6% 0.02F:G 1.47 1.48 1.46 1.43 0.02 0.44Sale weight, lb 57.6 56.73 58.26 57.02 1.05 0.74

Period ResultsADG, lb (0-7 d) 0.16 0.16 0.18 0.14 0.03 0.75ADG, lb (7-14 d) 0.55a 0.48b 0.50ab 0.44b 0.03 0.04ADG, lb (14-28 d) 0.85 0.83 0.85 0.82 0.02 0.80ADG, lb (28-49 d) 1.26 1.27 1.30 1.29 0.02 0.58

aMeans that do not share superscripts differ by p <0.05.

Conclusions There were no Age x Diet interactions. Regardless of wean

age, pigs responded similarly to the different feeding programs.

As wean age increased there was significant improvement in livability and growth rate.

No differences in performance due to feeding program.

Experiment 2

Experiment Title: Impact of wean age and feed program on nursery performance

Experiment Objective: To determine the impact of wean age and nursery feeding program on nursery performance

Experimental Design

3454 mixed sex wean pigs were allocated to 1 of 12 treatments in a 3 x 4 design. Pigs were weaned weekly and allotted to the appropriate

wean age group. Eight weeks of weaned pigs were used in the trial. All wean age groups were not represented in each week. Pigs were considered PRRS stable.

Experimental DesignGroups were unable to be created to avoid confounding wean age with week of weaning.

Nursery Room 1 Room 2 Room 3 Room 4 Room 5 Room 6 Room 7 Room 1

Week 14 15 16 17 18 19 20 22

No. Pens

18-25 d 14 19 14 10 4 7 3

26-29 d 2 4 10 12 7 15

30-38 d 2 2 4 7 3 18

Experimental Design Sow farm

All pigs were ear tagged at processing and location recorded No piglets were cross fostered after processing Day before weaning litters were painted with respective color to

correspond to wean age group Research Nursery farm

Pig sorted by color (wean age group) Pigs assigned to pens within each color grouping Pigs were placed at 2.5 sq.ft./pig Pens were then assigned to dietary treatments within each wean age

group

Experimental Design 3 wean ages:

≤ 25 d (18-25 d) 26-29 d ≥30 d (30-38 d)

4 dietary treatments, combined total = 23 lbs of early wean (EW) and pre-starter (PS), remainder fed for 49 d nursery period was starter: 0 lbs EW, 23 lbs PS 2.5 lbs EW, 20.5 lbs PS 5 lbs EW, 18 lbs PS 7.5 lbs EW, 15.5 lbs PS

Data Collection and Analysis Data Collection

Pens were weighed at days 0, 7, 14, 28, and 49 post placement Amount of feed delivered to each pen Fall behinds and mortality were recorded Feed samples for every diet phase and treatment were collected

Data Analysis General Linear Model Main Effect Age Diet Age X Diet

ResultsSE Age Diet

Age X Diet

Growth Performance0 EW 23 PS

2.5 EW 21.5 PS

5 EW 18 PS

7.5 EW 14.5 PS

0 EW 23 PS

2.5 EW 21.5 PS

5 EW 18 PS

7.5 EW 14.5 PS

0 EW 23 PS

2.5 EW 21.5 PS

5 EW 18 PS

7.5 EW 14.5 PS (P<) (P<) (P<)

Number of pens 18 18 17 18 13 13 12 12 9 9 9 9Start Weight, 0d, lb 12.64 12.85 12.75 12.72 15.40 15.44 15.28 15.32 18.32 18.34 18.03 18.14 0.24 <0.01 0.70 0.98

Trial Duration (0-49d)ADG, lb 0.89 0.92 0.91 0.91 0.94 1.00 0.97 0.96 1.01 1.06 1.00 0.99 0.02 <0.01 0.01 0.65Mortality, % 3.0% 3.0% 3.2% 5.3% 5.2% 3.5% 6.8% 7.2% 5.1% 6.1% 10.6% 6.6% 1.5% <0.01 0.02 0.26Fall behinds, % 4.5% 4.5% 5.3% 6.6% 5.9% 4.2% 3.8% 3.8% 3.5% 4.0% 5.1% 4.0% 1.5% 0.41 0.96 0.62F:G 1.38 1.38 1.31 1.30 1.45 1.39 1.42 1.33 1.53 1.52 1.51 1.44 0.10 0.03 0.53 1.00Sale weight, lb 57.5 59.34 58.91 58.77 63.4 65.95 64.73 64.26 69.7 71.71 70.32 68.96 0.99 <0.01 0.02 0.89

Interim ResultsADG, lb (0-7 d) 0.10 0.13 0.10 0.12 0.11 0.15 0.17 0.15 0.20 0.22 0.10 0.20 0.03 <0.01 0.21 0.28ADG, lb (7-14 d) 0.53 0.51 0.49 0.50 0.60 0.61 0.55 0.55 0.79 0.83 0.78 0.72 0.03 <0.01 0.03 0.73ADG, lb (14-28 d) 0.88 0.92 0.91 0.88 0.93 1.01 0.97 0.93 0.93 1.04 0.98 0.99 0.03 <0.01 <0.01 0.77ADG, lb (28-49 d) 1.30 1.35 1.36 1.38 1.37 1.43 1.41 1.43 1.45 1.46 1.43 1.39 0.04 <0.01 0.57 0.73

18 - 25d 26 - 29d 30 - 38dTreatments

Main Effect of Agea

aMeans that do not share superscripts differ by p <0.05.

Item 18 - 25d 26 - 29d 30 - 38d SE (P<)Number of pens 71 50 36

Start Weight, 0d, lb 12.74a 15.36b 18.21c 0.12 <0.01Trial Duration (0-49d)

ADG, lb 0.91a 0.96b 1.02c 0.01 <0.01Mortality, % 3.6%a 5.7%b 7.1%b 0.8% <0.01Fall behinds, % 5.2% 4.2% 4.5% 0.7% 0.41F:G 1.34a 1.40ab 1.50b 0.05 0.03Sale weight, lb 58.6a 64.6b 70.2c 0.50 <0.01

Interim ResultsADG, lb (0-7 d) 0.11a 0.15ab 0.18b 0.02 <0.01ADG, lb (7-14 d) 0.51a 0.58b 0.78c 0.02 <0.01ADG, lb (14-28 d) 0.90a 0.96b 0.99b 0.01 <0.01ADG, lb (28-49 d) 1.35a 1.41b 1.43b 0.02 <0.01

AGE

Main Effect of Dieta

aMeans that do not share superscripts differ by p <0.05.

Item0 EW 23 PS

2.5 EW 21.5 PS

5 EW 18 PS

7.5 EW 14.5 PS SE (P<)

Number of pens 40 40 38 39Start Weight, 0d, lb 15.45 15.54 15.35 15.39 0.12 0.70

Trial Duration (0-49d)ADG, lb 0.95a 0.99b 0.96ab 0.95ab 0.01 0.01Mortality, % 4.4% 4.2% 6.9% 6.4% 0.8% 0.02Fall behinds, % 4.7% 4.3% 4.7% 4.8% 0.7% 0.96F:G 1.45 1.43 1.41 1.36 0.05 0.53Sale weight, lb 63.5a 65.7b 64.7ab 64.0ab 0.50 0.02

Interim ResultsADG, lb (0-7 d) 0.14 0.17 0.12 0.16 0.02 0.21ADG, lb (7-14 d) 0.64a 0.65ab 0.61a 0.59ac 0.02 0.03ADG, lb (14-28 d) 0.92a 0.99b 0.95ab 0.93a 0.01 <0.01ADG, lb (28-49 d) 1.37 1.41 1.40 1.40 0.02 0.57

DIET

Conclusions There were no Age x Diet interactions. Regardless of wean

age pigs responded similarly to the different feeding programs.

As wean age increased there was significant improvement growth rate.

Mortality rates appeared higher in older wean pigs, but the higher rate is believed to be due to more litters of older wean age occurring during a period of elevated nursery mortality.

No differences in performance due to feeding program.

Overall Implications

Increasing wean age increases growth rate. Increasing wean age improves nursery mortality in

an acute PRRS break. Feeding a 2 phase nursery diet program provides

similar growth for older wean pigs, in comparison to a 3 phase nursery diet program.

Acknowledgements

Alma Terpening, Intern Tim Autry, Sow Farm Manager Piotr Zubrowicz, Production Specialist Daniel Sykes, Research Specialist

Contact Information

Christina Phillips, Ph.D.Director of Production Research

Smithfield Hog Production DivisionEmail: cephillips@smithfield.com

Phone: 910-282-4025