This study investigated the effect of three dietary regimes for replacement gilts on lameness and carcass traits.

In the paper in Livestock Science, first-named author, A.J. Quinn and co-authors report that they used the following dietary treatments:

1. a diet specifically formulated for replacement gilts (diet 1: 14.0MJ of digestible energy (DE) per kg and 0.75 per cent lysine),
2. a finisher diet (diet 2: 13.5MJ DE per kg and 1.02 per cent lysine) and
3. a gestation sow diet (diet 3: 13.0MJ DE per kg and 0.69 per cent lysine).

The latter two diets are traditionally fed to replacement gilts.

Thirty-six gilts were selected at day (d)0 (70.8 kg±0.78 SE, aged approximately 130 days), housed individually and allocated at random to:

• DEV (restricted access diet 1, n=12)
• FIN (ad-libitum access diet 2, n=12) or
• GES (initially ad-libitum access diet 2, then restricted access to diet 3 from day 30, n=12).

All gilts were fed ad-libitum from days 71 to 83.

Locomotory ability (0=normal to 5=severely impaired) and limb lesions (0=normal to 3=severe) were scored weekly until day 82. Hind-claw lesions and toe unevenness were scored (0=normal to 3=severe) on days 0, 40 and 82.

Gilts were weighed on days 0, 28, 70 and 82. Carcass traits were recorded at slaughter (day 83) and one front leg was removed for dual-energy X-ray absorptiometry (DXA) to establish areal bone mineral density (aBMD).

Joint surface lesions of the humeral condyle (HC; 1=normal to 4=severe, 5=osteochondrosis dissecans) and anconeal process (AP; 1=absent 2=present) were scored.

The percentage of lame animals (locomotion score ≥2) on one or more occasions were DEV=0 per cent (0/11), FIN=73 per cent (8/11) and GES=75 per cent (9/12; (P<0.01).

Fewer DEV gilts than FIN and GES gilts had humeral condyle lesions: DEV=64 per cent (7/11), FIN=100 per cent (11/11) and GES=100 per cent (12/12; P<0.01).

DEV gilts had lower scores for humeral condyle lesions (median; IQR: 2; 2) than GES (4; 1) and FIN gilts (4; 3) (P=0.05).

DEV gilts weighed less (132.5kg±2.8) than FIN (142.9±2.0) gilts on day 70 (P<0.05).

DEV gilts had a lower average daily gain than FIN (P<0.05) and GES (P<0.001) gilts from days 0 to 28, lower energy intake than FIN and GES gilts from days 0 to 28 (P<0.001) and higher energy intake than FIN gilts from days 71 to 82 (P<0.05).

The DEV diet formulated for replacement gilts and fed restrictively from 70kg to until around 130kg, then fed ad-libitum until around 140kg improved locomotory ability, toe evenness and humeral condyle joint lesions compared with traditional diets, according to Quinn and co-authors.

They added that it is likely these improvements were related to slower growth rates.

Reference

Quinn A.J., L.E. Green, P.G. Lawlor and L.A. Boyle. 2015. The effect of feeding a diet formulated for developing gilts between 70kg and ~140kg on lameness indicators and carcass traits. Livestock Science. 174:87-95.

April 2015