Feeding replacement gilts as finishers or less?

• Feeding replacement gilts as finishers or less? M Neil, SLU, Box 7024, S-75007 Uppsala, Sweden; L Eliasson-Selling, Svenska Djurhälsovården, Kungsängens gård, S-75323 Uppsala, Sweden; K Sigfridson, Lantmännen Lantbruk, S-20503 Malmö, Sweden.About 50% of the breeding sows have to be replaced each year, so obviously sow longevity needs to improve. The feeding regime during rearing might be one tool to affect longevity. Current goals are to produce gilts for mating at 2nd-3rd oestrus, 230 days of age, 140 kg live weight (LW) and 12-13 mm ultrasonic backfat (BF). The present study was undertaken to investigate effects of energy allowance and feed lysine level on growth, BF accretion, and early reproduction. The study comprised 4 batches of 20 female L*Y pigs, born in June (batch 1-2) and December-January (batch 3-4). Litter sisters were allocated to 4 feeding treatments in a 2*2 factorial design. The factors were high (HL) or low (LL) lysine level (0.83 or 0.57 g sid lys per MJ NE) and high (he) or low (le) daily energy allowance (increasing from 14.5 MJ NE at 30 kg LW to 25.9 MJ NE at 60 kg which equals the standard for finishers, or a slower increase to 23.3 MJ NE at 60 kg which is about 10% less). At the age of 9 weeks and LW approximately 30 kg, gilts were placed in groups of 10 in pens with feeding stalls and were fed individually after training. Gilts were weighed and BF was measured repeatedly. Oestrus detection started at 150 days of age. At 151 days of age mean LW was 102, 104, 108 and 111 kg, and BF 8.3, 8.6, 7.7 and 7.8 mm, in LLle, LLhe, HLle and HLhe gilts respectively. HL gilts were heavier (p<0.001) and tended to have lower BF (p=0.08) than LL gilts. No difference in LW or BF at 151 days was detected between le and he gilts. Lysine level and feed allowance had no effect on age at first oestrus, whereas batch had a strong effect (p<0.001) with mean age of 186 days in batch 1-2, and 165 days only in batch 3-4. Thus, the applied difference in feed lysine level affected LW and BF in gilts whereas the applied difference in energy allowance did not. To affect LW and BF in gilts the energy allowance may need to differ more.

Ämnesord

LANTBRUKSVETENSKAPER  -- Husdjursvetenskap -- Husdjursvetenskap (hsv//swe)

AGRICULTURAL SCIENCES  -- Animal and Dairy Sience -- Animal and Dairy Science. (hsv//eng)

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