If there’s a problem with small pigs in GB herds, Stephen Hall argues that the blame shouldn’t be put on large litter sizes, but management failure
The latest BPEX figures for 2014 show the average pigs born alive/sow/year was 29.08 (+0.59 on 2013) for indoor herds, with 25.71 (+0.78) weaned, while outdoor herds achieved 25.40 (+0.12) born alive and 21.82 (+0.13) weaned. If the average wean to finish mortality rate of 4.7% is applied to these figures, a total loss of 4.57 pigs indoors and 4.90 pigs outdoors is recorded per sow per year.
I believe there’s growing interest in the UK in the survival management of small piglets, which is understandable. However, we’re not actually achieving enough pigs born alive per litter. If we’re considering piglet survival management an issue at these levels, then, logically, a greater realisation of the UK genetic potential for productivity is going to make the current problem worse.
Before we spend time and money on pursuing this, it would be good to consider the reasoning. The small pig must be defined and then followed back to the foundational management that produced it. It must also be followed from birth to slaughter in sibling and peer group studies. Finally, carcase quality should be quantified. Full costings must be recorded against the performance of every pig, including siblings and peer groups. The “small” pig may surprise us.
In the absence of any supporting (full value pig) analysis of the performance of the small pig through to carcase, let’s consider the foundational management that produces the pig – small, medium or large – in the first place. The litter has a natural maximum weight potential of 22kg, and the weight range of viable piglets ranges from 700g to 1,900g. Ideally we want a litter size of 12 to 16 that’s even in terms of size and weight. In a perfect world, litters of 14 pigs born alive at 1,500g birthweight would suffice.
Parent generation gilts should be selected from grand-dams recording consistently even litters. It’s also worth remembering the importance of excellent gilt management through to second parturition, as well as maintaining a herd parity distribution of one to six. Parity six-plus sows begin to produce increasingly uneven litters and the return on investment declines.
Low birthweight piglets born at 500g or less have the following survivability statistics; 75% are lost to pre-weaning mortality, 20% to post-weaning mortality and those that remain don’t make any profit. A difference of 200g at birth equates to a difference of 10kg at slaughter (depending on end weight).
We have to work with variation because it exists, but we have to seek greater control of production outcomes to reduce this.
Put into context, the “small” piglet the industry is interested in keeping alive weighs less than 700g at birth. At birth, this piglet has cost the same as its siblings and its peer group against the herd average cost per production cycle. Any intervention to promote survival is increasing the cost per pig of the litter and reducing the potential margin.
In herds where there’s a management strategy of maintaining a parity distribution of one to five, small pigs will simply be at the lower end of the 700g to 1,900g spectrum, and survival is often just the initial practice of grading litters (remixing by size). In herds where there’s a percentage of sows in parity six or greater, small pigs are those lost before weaning, often having succumbed to infection, or dying in the nursery or grower stages of the feeding herd. The longer they’re kept alive, the more they reduce the potential margin of the herd.
It’s worth considering an early fate for such pigs before extra cost is incurred; they have already cost as much as the surviving/growing pigs, but have no value. There are elaborate systems being used to ensure the survival of marginal pigs, and producers are successfully saving pigs, however they’re not saving money.
In the foundational practices outlined above, large litters in the 700g-plus spectrum (indoor production) wean the excess piglets (creep eaters) at 10-plus days, retaining them in the farrowing area on the correctly presented nutrition until the weaning day of the original service group. The original cost/value of the production cycle that produced them is maximised.
It’s management that creates marginal pigs, and it’s this that needs addressing – not the survival of piglets.