Sow Mortality A Lifecycle Perspective

The Death of a Sow in Optimum Production

There is much focus on sow mortality throughout the global pig industry, but how do we define ‘sow mortality’ as an industry?

I believe the primary recorded cause of ‘sow mortality’ is as the death of a sow in optimum production. I define ‘optimum production’ as the period in the lifetime production cycle of a sow that begins with the final selection, and the stimulation of the oestrus cycle of the gilt in which she will be served to begin her first pregnancy, and her weaning at the end of her fifth production cycle. However, there is significant strategic value to operational husbandry in a percentage of sixth parity sows being retained in production.

In this piece I am considering both sow death mortality, and sow culling mortality.

Therefore, the economics of sow mortality includes all animals selected for culling, and the consequences of this are that the recorded cause/reason for sow mortality should include the culling decisions. This means that the economics of sow mortality relate to a 100% of breeding females.

Within this 100% there are the known knowns, known unknowns, and the unknown unknowns of radical uncertainty that pose the greatest risk in the daily operation of pig production. Sow herd longevity is a largely unchartered opportunity to significantly reduce risk.

The reference we look at for the cost of 100% sow mortality is the sow retention rate, which we get at through the results of lifecycle analysis. Regular readers will be familiar with the data sample I am analysing here, it is 24773 UK sows in 50 exclusive lifecycle herd cohorts, the population split is 60% indoor, and 40% outdoor production.

The average herd life cycle sow mortality is 11.84% from an average lifecycle cohort of 495 sows recording an average of 58.64 deaths, 40.34 deaths in parities 1 to 5 and 18.30 deaths in parities 6 to 10.

The percentage share of sow death mortality in each of the 10 production cycles in the retained populations (Parity =P) is:

P1 1.62%, P2 2.08%, P3 1.52%, P4 1.35%, P5 1.19%,

P6 0.86%, P7 0.68%, P8 0.51%, P9 0.49%, & P10 0.42%.

The percentage share of sow culling mortality in each of the first 6 production cycle populations (in order of non-productive culls / productive culls) is:?

·????????Non-productive culls are the animals served and culled

·????????Productive culls are the animals served, farrowed, weaned, and culled

P1 6.86% / 7.13%,?P2 7.71% / 5.59%,?P3 5.77% / 6.24%

P4 5.63% / 8.20%,?P5?4.15% / 12.26%,?P6 4.08% / 13.74%

As an aside at this point it is interesting to see the impact of conception failure which will comprise most of the animals served and culled 34.2% of the culls in the first 6 parities.

The total (combined culls) including all the animals that were recorded as deaths, and those culled/died in parity 7+ is:

P1 14.00%,?P2 13.29%,?P3 12.02%,?P4 13.84%,? P5 17.10%,?P6 17.82%,?P7+ 11.93%

On balance it is reasonable to assume that a replacement breeding female reaches economic breakeven during her third gestation, some time after the beginning of the third production cycle. (I accept that this breakeven limit may vary across global market conditions however the metric principle is a useful guide) When the first three non-productive cull, and the first two productive cull percentages are combined the result is 33.06%. This means that 33 out of every 100 replacement females are not reaching economic breakeven. With sow feed at 30% of the total cost of production, and feed cost @ per tonne of ￡250, $315, or €295, the minimum cost before margin (to the first two parities, not including served-culled third parity sows) per 100 sows is ￡30,544, $38,485, and €36,042. At a sow feed cost of ￡300, $378, or?€354 per tonne, the minimum cost before margin per 100 sows is ￡36,653, ￡46,183, and €43,250.

As a matter of interest, the average lifecycle cohort size of 495 sows, the minimum cost before margin of the herds in the data analysed above at the two feed cost levels is, at the lowest per tonne cost level, ￡151,192, $190,500, or €178,405, and at the highest per tonne cost level ￡181,431, $228,603, or €214,088.

In the global industry there are some very large single businesses breeding populations, and for multiples of 10,000 sows respectively, the minimum cost before margin looks like this: ￡3,054,390, $3,848,531, or €3,604,180. And with an extra ￡50, $63, or €59 per tonne ?￡3,665,258, ￡4,618,225, or €4,325,004.

Notwithstanding that I have not considered the cost of parity 3 sows served, not farrowed/weaned, and culled.

The importance of breeding female genetic development, and flourishing physiological survival to parity 5 carries a significant economic ‘sow herd’ premium. To maintain investment in the reach of genetic development producers must continue to value the genetic premium if genetic turnover is to be recalibrated to address longevity. If sow herd longevity is a heritable trait, an example of the economic value is clearly stated above. The science of genomics will answer this. However, until it does I believe we must respond from the 3E perspective of 3Economics, 3Ethics, and the 3Environment.

The genetics of sow herd longevity (if they exist, and I believe that they do) have a significant part to play in the future of the industry through increased productivity of operational husbandry. Improved sow herd longevity equates either to more pigs from the same population size or the same number of pigs from less sows. What we are looking at is the possible genetic mitigation of the various points of breakdown that contribute to sow cull mortality, and sow death mortality . These include skeletal, connective tissue, and reproductive failures, I am sure that veterinary science will have a more comprehensive list. Resistance to disease challenges is another point of breakdown. If strengths can be produced to prevent these breakdowns, then genetic longevity will become a sure foundation of practical pig production upon which to build strategic, operational husbandry. This will include the Gilt Watch Together? principles around management planning. The economic values are already presented here. The ethical gains characterized by sow herd longevity that incorporate strategic husbandry practice to minimize social stress, includes animal welfare and the narrowing of the gateway to health challenges, these will benefit the narrative of the industry, as will the environmental gains of reduced-source-productivity.

Sow mortality as a conventional key performance indicator, is an example of the unnecessary limitation of per sow per year metrics on current proprietary analytics. The same data made available to lifecycle analysis is an essential element of today’s strategic development of tomorrow’s world.

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