25 December 1998

EASTON LODGE

Taking care of piglets…

BECAUSE one-third of the pre-weaning deaths in our pig unit are caused by overlaying on the first day, we are considering more widespread use of prostaglandins. These will encourage sows to farrow down during working hours and help us to achieve closer attention at parturition and immediately afterwards, writes Jasper Renold.

To help us with our objectives, we have been using the HM Boot Pig Business Programme to obtain the latest picture of the occurrence of piglets born dead over the past six months from Jun 1 to Nov 30, 1998,

Overall analysis

The overall analysis of litter performance by parity in terms of born alive, born dead and mummified appears in table 1. The first batch of PIC gilts are now entering their third parity.

The born-dead figures are lowest for gilts at 0.6/litter but curiously, the worst parities, which might have been expected to be the older ones, were, in the event, those for parity 3 and 4 at 1.3 and 1.4/litter respectively.

It is interesting that the average gestation period is practically the same for all parities, averaging out at 114.9 days.

It would seem that for our herd, litters with larger numbers born dead (table 2) are not associated with larger numbers born alive, although they do seem to have greater numbers born mummified. Perhaps there is a biological explanation for this in terms of different sows ability to maintain pregnancy.

Picture emerges

An interesting picture emerges when litter performance is analysed according to actual gestation period (table 3). I have always felt that sows with larger litters tend to farrow earlier and those with smaller litters farrow later and this is confirmed in the figures. Harder to understand is why both born deads and pre-weaning mortality are worse for gestation periods shorter and longer than the average of 115 days. Perhaps there is an aspect of our husbandry we need to examine.

Our sows are weaned at 8.30am on Thursdays and 46% are served the following Monday, 39% on Tuesday and 7% on Wednesday, with expected farrowing dates therefore on Thursday, Friday and Saturday respectively.

For a trial period we aim to farrow all the sows down to day 114 after service. In that way the 50% of sows which actually farrow on day 115 and later will be brought to day 114 .

The 20% of sows which farrow on day 113 and earlier, will of course not be induced since we dont know which they are unless they have a consistent record of farrowing early.

Table 1:Litter performance by parity

Parity 1 2 3 4 5 6 7 8+ Oall av

Av no

born alive 11.9 11.4 11.4 11.9 11.2 11.6 10.4 10.4 11.4

Av no

born dead 0.6 1.0 1.3 1.4 1.1 1.1 1.0 1.1 1.1

Ave.no

born mumm 0.1 0.2 0.3 0.2 0.3 0.3 0.4 0.3 0.2

Av gest

(days) 114.7 115.3 115.4 114.7 114.5 114.9 115.2 115.0 114.9

Table 2:Litter size by number born dead

No born Av no born Av no born

dead % litters alive/litter mumm/litter

0 46 11.1 0.2

1 29 12.0 0.3

2 14 11.1 0.3

3 6 10.9 0.5

4 4 10.9 0.5

5 1 11.8 0.6

Table 3:Litter performance by gestation period

Gestation Av no born Av no born Av no born % Pre-wean

period (days) % litters alive/litter dead/litter mumm/litter mortality

112 5.1 12.5 0.6 0.3 13.5

113 15.4 11.9 1.2 0.2 16.2

114 27.0 11.7 1.1 0.2 14.3

115 25.4 11.3 0.9 0.2 11.6

116 11.0 10.3 1.0 0.3 13.8

117 8.9 10.4 1.2 0.3 9.6

118 4.9 9.9 1.7 0.4 13.5

(outside range) (2.3)