Performance response of growing-finishing pigs to an air-cooled environment during a simulated hot weather growth period

Transcription

1 Performance response of growing-finishing pigs to an air-cooled environment during a simulated hot weather growth period Presented at the 2016 Minnkota Meeting Jackpot Junction Hotel March 11, 2016 Larry Jacobson, Lee Johnston, Brian Hetchler, Adrienne Hilbrands, & Curt Reese University of Minnesota

2 Temperature response for finishing pigs Thermoneutral Zone For pigs > 150 lbs

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4 Chronic Heat Impacts 280 IA-SMN Pig Liveweight at Slaughter Lb Week of year Brumm, 2013, AACC Course Lecture Brumm 2012

5 Objectives of Study This project will determine the pig performance benefits of maintaining a thermal neutral condition (avoid heat stress) in a group of grow-finish pigs compared to allowing the room environment to exceed the pig's thermal neutral zone (heat stress).

6 Study conducted during the winter at U of MN s WCROC in Morris Easier to add heat to barn (room) to reach heat stress temperatures than to cool barn (room) in summer to keep pigs in thermoneutral range

7 Experimental Design of Study Two treatments were imposed with the Control treatment housing pigs as close to their thermoneutral conditions as possible. The Heat Stress treatment housing pigs under conditions that simulate estimated heat stress conditions during a Minnesota summer. The room temperature in the Control room were changed on Monday mornings automatically by the ventilation controller starting at 70 F day and 65 F at night when pigs are brought into the room (60 lbs) and gradually down to 57 F (day) and 52 (night) when marketed (290 lbs).

8 Experimental Design of Study Room temperature settings for the Heat Stress room were changed manually on Monday and Thursday mornings to one of the following five heat stress scenarios: 82 F (Day) and 63 F (Night) 85 F (Day) and 65 F (Night) 87 F (Day) and 68 F (Night) 90 F (Day) and 69 F (Night) 95 F (Day) and 75 F (Night) Temperature changes in both rooms occurred as close to 7:00 a.m. as possible. Daytime was from 7:00 AM to 7 PM while nighttime was from 7 PM to 7 AM. Ventilation rates were managed to maintain CO 2 levels in each room to 5,000 ppm or less.

9 Table 2. Activity Timeline Date Activities - Move pigs to finishing barn. Implement pre-experiment room temperature regimen. 1-5& Ear tag pigs Weigh pigs - Weigh feed in feeders - Select 8 focal pigs in each room - Begin experiment - Measure water flow rates on all pens - Measure water temperature on 4 pens per room Record respiration rates on focal pigs Weigh pigs, feed weighbacks Measure water flow rates on all pens - Measure water temperature on 4 pens per room Record respiration rates on focal pigs Weigh pigs, feed weighbacks Measure water flow rates on all pens - Measure water temperature on 4 pens per room Record respiration rates on focal pigs Measure water flow rates on all pens - Measure water temperature on 4 pens per room Record respiration rates on focal pigs Weigh pigs, feed weighbacks Exp. End - Weigh pigs, feed weighbacks when pigs average 270 pounds in a room

10 Stages Furnace 2 West Side Stages Control Room Wall fan 8 8 Wall fan 216 pigs Pit fan 1 2 Pit fan 24 9 pigs/pen Wall fan 5 6 Wall fan 97.9 lbs average on 1/6/15 Wall fan 3 4 Wall fan Pit fan 1 2 Pit fan Wall fan 7 7 Wall fan 1 Furnace

11 East Side Furnace 1 Heat Stress Room Wall fan 7 7 Wall fan Pit fan 1 2 Pit fan 216 pigs Wall fan 3 4 Wall fan 24 9 pigs/pen Wall fan 6 5 Wall fan 99.6 lbs average on 1/6/15 Pit fan 1 2 Pit fan Wall fan 8 8 Wall fan Water Sprinklers turned OFF 2 Furnace

12 Same Diets fed to both Rooms Table 3. Diet composition (% as fed) Ingredient GF1 ( lb) GF2 ( lb) GF3 ( lb) GF4 (191 mkt) Corn SBM 46.5% CP Corn DDGS DENCO ANS GF Basemix ANS GF Basemix 30% DDGS Tylan Total Calculated analysis: ME, kcal/lb Crude protein, % SID Lys, % Ca, total % P, dig %

13 Results

14 Average daily room temperatures

15 120 Average Daily Rm & Outside Temperatures Temperature (F) Dec-14 Jan-15 Feb-15 Mar-15 Apr-15 Date warm cool OUTSIDE TEMPERATURE ( F) SETPOINT ( F) warm

16 Heat Stress Temperature Strategy Temperature (F) Date warm warm set point cool cool set point

17 Effect of heat stress on resting respiration rate

18 Effect of heat stress on average body weight Trt: P = Time: P < Trt x Time: P = 0.003

19 Effect of heat stress on average daily gain Trt: P = Time: P < Trt x Time: P = 0.282

20 Effect of heat stress on average daily feed intake

21 Effect of heat stress on gain:feed ratio

22 Effect of heat stress on backfat depth Trt: P = 0.252

23 Effect of heat stress on loin eye area Trt: P = 0.672

24 7000 CO 2 Average Daily Concentrations 6000 Carbon Dioxide, ppm warm cool Dec-14 Jan-15 Feb-15 Mar-15 Date

25 35 NH 3 Average Daily Concentrations 30 Ammonia, ppm warm cool Dec-14 Jan-15 Feb-15 Mar-15 Date

26 1400 H 2 S Average Daily Concentrations 1200 Hydrogen Sulfide, ppb warm cool Dec-14 Jan-15 Feb-15 Mar-15 Date

27 Brief Summary Experimental Method of doing heat stress study in winter was successful Pigs were heat stressed (higher respiration rates) but not to the level? that most pig performance metrics were impacted Suggest providing more severe heat stress scenarios (higher nighttime minimums) for future studies that reflect more recent summer temperatures in the Midwest.

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