9 August 2002

EASTON LODGE PIGS

Researchingstill-births

WE have built up a good relationship with the veterinary colleges, particularly the Royal Veterinary College, London. Over the past few years a number of mainly second-year students have come to us in the summer to gain experience in pig husbandry, writes Jasper Renold. They are always keen to learn and pull their weight with stock tasks.

Recently, fifth-year student Faye Campey approached us to do a small research project, as part of her course work, to examine the occurrence and accuracy of recording of still-born piglets.

Because many litters may not be inspected for an hour or more, or even considerably more where night farrowing is concerned, it is inevitable that some piglets that were born alive and die later may be mis-classified as still-born.

The implication is that earlier intervention by the stockman could have prevented a proportion of them. It also raises the question of whether changes in feeding regime, house temperature or sow condition would reduce the general risk of still-borns occurring.

Fayes literature search indicated that relatively little work has been carried out and published on still-born pigs and what there is often gives conflicting results. It seems the level of still-birth incidents has not decreased in recent years, despite better understanding of the processes involved.

Her study of Easton Lodge piglets, which we had classified as born dead over a period of 13 days in May, were individually labelled and weighed and were taken away for individual autopsy. A total of 37 piglets were examined from 21 sows.

During that period, a further 14 sows farrowed without any born dead which gave an overall figure/litter for all farrowings of 11.51 born alive, 1.03 born dead and 0.2 born mummified.

At Easton Lodge, the classification of born dead depends on any instance of piglet movement, appearance and positioning of tongue, any hardening of the feet, general discoloration and wetness of skin.

The autopsy was based on the appearance of the lungs and airways, the presence or absence of meconium (piglet faeces) in these and on the skin, and the general coloration of the skin. The three-fold classification is given in Table 1.

The pie chart shows the proportion of piglets in each classification and indicates that 22% of our recorded stillbirths were actually alive soon after birth.

Piglets do not start breathing following birth until 5 to 10 seconds post-delivery, so any aeration of the lungs means the piglet lived at least this long. From an economic standpoint, it is difficult to assess how much extra stockpersons time is needed to prevent even half these deaths.

A more difficult area to research is how many of the parturient deaths could be prevented by better control of the speed of farrowing in order to reduce the risk of the rupture of umbilical cords and therefore oxygen starvation of the piglet.

As many units have found, the incidence of still-births seems to increase with parity. Easton Lodges figures for the three months to May 31 appear in Table 2.

Based on last years experience, as Table 3 reveals, larger litters give disproportionately more still-births.

This research project has proved to be a useful exercise and indicates there could be opportunities to reduce further our stillbirths.

Certainly, the high number of piglets showing meconium staining in the parturient and post-parturient groups would suggest that hypoxia is something which should be addressed. &#42

Table 1: Classification of the time of death based on autopsy findings

Classification of piglet Description of findings

Preparturient Advanced autolysis, discoloration of the skin, pale and friable parenchymatous organs.

Parturient Uninflated lungs, meconium staining to the skin, presence meconium in the airways.

Post-parturient Partially inflated or inflated lungs, meconium staining to the skin, presence of meconium in the airways.

Table 2: Still births by parity

Parity 1 2 3 4 5 6 7 8 Overall Av

No born dead/litter 0.7 0.8 0.8 1.1 1.4 1.0 2.1 1.8 1.1

No born alive/litter 10.5 10.0 12.1 11.8 12.1 12.1 10.4 11.5 11.3

Table 3:Still births

by litter size

Number born alive Number born and dead per litter dead per litter

6 0.5

7 0.8

8 0.4

9 0.7

10 0.6

11 0.7

12 0.9

13 1.1

14 1.2

15 1.6

16 2.2

17 2.0

18 1.9