|RICHERT, BRIAN - Purdue University|
|RICHERT, JACOB - Purdue University|
|Lay Jr, Donald|
Submitted to: International Society of Applied Ethology
Publication Type: Abstract Only
Publication Acceptance Date: 7/31/2017
Publication Date: N/A
Technical Abstract: Piglet mortality remains a serious welfare and economic problem. Much of the early mortality is due to crushing by the sow. Tryptophan has been shown to reduce aggression and have a calming effect on behaviour, which may reduce the number and type of posture changes, thereby altering risk of crushing. The aims of this experiment were to determine if feeding dietary tryptophan around farrowing would affect quantitative measures of posture-changing behavior and piglet mortality. Twenty-four multiparous sows (parity 2, 3 and 4) were moved to the farrowing house on d 110 of pregnancy and randomly assigned to one of two treatments; 1) standard lactation diet (CTL), or 2) experimental lactation diet with same energy content but containing four times the amount of tryptophan contained in the standard diet (TRYP). Treatments were applied from entry to the farrowing house until 3 d post-farrowing, with all sows receiving standard lactation diet thereafter. Sow behaviour was video-recorded continuously from entry until 7 d post-farrowing and all occurrences sampling was used to determine number and type of posture changes from 3 d before until 2 d after birth of first piglet. Posture changes recorded were all transitions between standing, sitting, kneeling, lying sternally and lying laterally. Production data recorded included sow weight on entry to farrowing crate, sow weight at weaning, sow feed intake, number of piglets born alive, dead and mummified, birth weight, 24 h weight, mortality and cause (physical inspection in conjunction with video data), number weaned, and weaning weight. Data were analyzed using the MIXED procedure accounting for repeated measures when appropriate. Dietary treatment had no effect on total litter size or number of piglets born alive (P=0.30), but TRYP sows tended to give birth to fewer dead piglets than CTL sows (1.0 ± 0.4 vs. 2.5 ± 0.7, P=0.07). Total feed intake over the immediate pre- and post-farrowing period and sow lactation weight loss was not different between treatments, but on the day of farrowing, TRYP sows tended to eat more than CTL sows (3.0 ± 0.4 vs. 1.8 ± 0.4 kg, P=0.09). Piglet birthweight, weaning weight and growth rates did not differ and total piglet mortality (born dead + liveborn mortality) was similar between treatments (TRYP 17.0 ± 2.8 vs. CTL 24.3 ± 5.4 %, P=0.29). The number and type of posture changes varied over time, but the only difference between treatments during the critical immediate 2 d post-farrowing period, was that CTL sows transitioned less between sitting and lying than TRYP sows (TRYP 34.9 ± 5.6 vs. CTL 21.2 ± 2.0, P=0.03). Overall, feeding a high tryptophan diet around the time of farrowing had little effect on sow posture-changing behavior and no effect on liveborn piglet mortality. There may be a beneficial effect on stillbirth incidence and farrowing day feed intake, which could affect early lactation milk production, but this requires further investigation.