What are New Born Litters Saying?
Every new born litter is another reference with which to build your pig production evidence base. For the amount of time it takes to record a few simple facts, and better still to observe what is being recorded, it is a management task with one of the highest return values. The evidence base in turn, informs your management strategy accurately. Pig production is required to be a low cost process. To succeed, process control is critical and the new born litter is a font of information, to this end.
There is no particular order of importance in the following observations however, sequence is by default.
The information that is available from a new born litter is drawn from specific factors that have some overlapping relativity. I will start with the environment at farrowing in terms of safety for the emerging piglet. If the environment is compromised, then the message from the new born litter will communicate little of value in terms of genetics and the birth-mother. This is just a reflection of the current low level of management strategy. When the environment favours a safe and warm arrival with easy access to colostoral nutriment from the sow’s udder then some clear messages can be read relative to the sow’s age and condition coming into parturition and the genetics of the dam and sire-line parents. The level of the success of the gestation management will also be apparent.
These messages are obvious to stock-people but they are worth reviewing occasionally, it keeps us sharp in our focus. Below are a couple of thoughts on the subject. I am sure there are better stock people out there who could add to these.
Length of Parturition
Intervention: this can be relative to age in terms of cause although intervention is practiced in order to prevent death in the birth canal due to delay caused by obstruction of fatigue. Intervention introduces unwanted foreign bodies however hygienic the practice, and can cause injury that later impacts on subsequent conception and farrowing of the sow. Intervention must be properly evaluated at the time for cause and effect to prevent sows being recycled into the service group at weaning that could reduce the efficiency of the service group. Piglets born with intervention, to a gilt, if they are obstructive due to size raise consideration of nutritional levels during gestation. If positioning is an issue they raise a possible consideration of the age and size of the gilt at farrowing, this will be down to the stock-person’s judgement. The extreme consideration in a gilt could be a genetic mismatch between the parent female and the sire-line. Fatigue is usually the cause of intervention in a sow and this will come either from her age or condition/nutrition at farrowing. A litter can be saying it’s time for Mum to go.
Large Litters: in gilts this tells us that fertility and uterine health/capacity is good, as long as the pigs are of an even and viable size themselves. If the litter is marked by a low litter weight and several small piglets the relative consideration is the condition and age of the gilt at point of farrowing and, if this appears to be satisfactory, the further consideration has to be the nutritional management of the pre-natal litter. If both considerations are favourable the message from the large gilt litter of small sub-optimal piglets is what are the management strategy options. One option would be to allow the litter 18 to 24 hours of birthmother colostrum and then foster piglets onto another sow. There are two considerations at this stage based on the size variation within the litter. If it is an even litter of robust piglets then selection is straightforward, if the litter is varied then a decision has to be made whether to select the strongest or the weakest piglets. For the gilt litter it should be the weakest as she needs good lactation stimulus to aid her development at this critical stage. If this is the preferred option, then teat size (relative to the size of transferred piglet) is critical and normally teats get bigger as the sow gets older. Another option would be to foster these pigs onto a gilt with a small litter, this gilt is likely to be culled (in some herds) if she has farrowed below the management target. The fostering option is taken on the basis that the gilt might be worth retaining and given a second parity (chance) to prove herself, therefore she will need to suckle a full and robust first litter for a full lactation. Always bear in mind that any fostering is a bio-security risk between litters that must be kept to a minimum.
In older (post parity 5) sows the message of the large litter is interpreted through the variation in size of the piglets, producing a growing percentage of sub-optimal pigs for the later stages of production. I would not retain, except in the case of a limited number of replacement gilts available to the current service group, sows beyond parity 5. Gilt availability is compromised by poor planning, pig health and/or reducing conception rates in service groups.
Small Litters: in gilts consideration needs to be given to the herd target for litter size in gilts. Some producers will cull a gilt (as mentioned above) that delivers below a target of 7. This is because a small litter is an indicator that the birth-mother will repeat this in a subsequent production cycle. There is some confusion around this statistic as, particularly in herds with younger parity distributions, this does not appear to be supported. The truth is that the level of culling of the early parities reduces the re-occurrence of small litters by default and further analysis often reports that low litter gilts are among the early culls due to breeding failure. This in itself may be the result of low litter gilts experiencing oestrus in lactation and therefore not fitting the service and observation pattern. Weaned low litter gilts and sows will often appear to stand for artificial insemination with the ‘crowd’ and then become irregular returns within the system.
The hungry litter is an early warning system that must be heeded immediately. The sow is not producing milk in sufficient quantity or at all. This is serious in terms of available colostrum. There are veterinary guidelines on what to use to stimulate the sow in milk production. If the occurrence of hungry litters is frequent the failure could be an indication that the pre-farrowing feed regime may be the cause. Post-natal pigs that are experiencing starvation should be transferred onto another newly farrowed sow and that sow’s piglets ‘boxed for a couple of hours. The piglets should then be returned to their original mothers It is also possible to put a stronger litter onto the gilt/sow, that is not yet producing milk, to stimulate her trough more robust demand. If a hungry litter begins to deteriorate after measures have been taken to mitigate a poor milk supply, then health has become an issue.