A NEW CONCEPT FOR ORGANIC PIG PRODUCTION, DESIGNED TO IMPROVE NUTRIENT CYCLING, AND ANIMAL WELFARE.

Jorgensen, T.V. (1), Eriksen, J. (2), Sorensen, K.H. (3),

Sorensen, C.Aa.G. (3), Nissen, H. (4), Serup, T.B. (1)

(1)Danish Agricultural Advisory Service, Udkaersvej 15, DK-8200 Aarhus

(2)Danish Institute of Agricultural Sciences, Blichers Allé, Postbox 50,DK-8830 Tjele

(3)Danish Institute of Agricultural Sciences, Schüttesvej 17, DK-8700 Horsens

(4)Danish Bacon & Meat Council, Axeltorv 3, DK-1609 Copenhagen V

Summary

A new concept for organic pig production is evaluatedat the organic experimental station Rugballegaard in Denmark. The concept is designed to improve farmerseconomic return on organic pig production, by reducing labour input, and improving animal welfare, reducing nutrient leaching, andimproving nutrient cycling.Resultsto date show a reduction of labour input by 10%, and69 % increased fodder productionvia silage production in the grazing pens. The evaluation will be completedin spring 2005. At the IFOAM 2005 conference results from the completed evaluation will be presented.

Introduction

The concept focuses on:

Better on-farm nutrient cycling, and reduction of nutrient losses

This is achieved through maximum grazing/roughage-productionin the summer grazing pens combined with a new type of winter area.During the grazing period the pens are enlarged according to the sows grazing needs. This makes room for silage production in spring. (Roughage for pregnant sows the following winter) With each enlargement troughs and huts are moved to new locations. This disperses nutrients more evenly and gives grass in the old part of the pens a pause to recover from rooting.

Picture 1 Pregnant sow pen 19’th of June 2004. Sows are in the oldest part of the pen with least grass.

The winter area is a smallpart of the summer-grazing pen, covered by a thick layerof straw. The straw mat collects all manure from the herd during autumn, winter and early spring. The mat is removed and the manure spread before sowing spring crops the following growing season. In a traditional free range system all manure from this period would land on the ground/grass, and a large part of nutrients lost through leaching.

The mat has a dual purpose. It allows for the collection of nutrients that can be used for crop production elsewhere on the farm. And by reducing the nutrient load in the pens, less area is required to meet the environmental standards of outdoors pig production. Thus more land is available for grain/feed production.

Picture 2 Pregnant sows on the winter straw mat October 2004

Replacing bought-in concentrate for pregnant sows with home grown grain, (barley and triticale) wholecrop barley/pea silage, grass silage and maximum grazing is another key element in improving on-farm nutrient cycling.

Improving animal welfare

It is common practice to nose ring free range organic sows in Denmark, to keep the grass mat intact, and thereby reduce leaching during winter. In the concept nose-ringing is no longer necessary as nutrients are absorbed in the straw mat. Walking on a straw mat also causes less leg problems for sows, than walking on frozen ground. Both are elements that improve animal welfare.

Reducing labour requirement

This is achieved through absence of nose rings and keeping the herd on less land, especially during winter. It makes transportation and observation less time consuming.

Methodology

The performance of the concept is evaluated in the period April 2004 to May 2005, at the organic experimental station Rugballegaard.The concept only involves sows and litters, no slaughter pigs. Litters are weaned to a stable production system at 8 weeks. Herd size during the evaluation is 37,9 sows on average.

Summer grazing april-october 2004

The pregnant sows weredivided into 3 groups with approx. 10 sows in each. During the grazing season each group washoused in commune-huts in a pen thatwas enlarged 4 times from 900 square metres at the beginning of the season to 3800 square metres at the end. The farrowing sows were kept in 15 single huts in pens that were enlarged 3 times from 198 square metres at the beginning of the season to 638 square metres at the end.

Winter straw mat October 2004-april 2005

The straw mat is 6066 square metres Each of the pregnant-sow groups has900 square metres of pen, and each af the 17 farrowing pens is 198 square metres.

The straw mat was established using big bales and a manure spreader. 34,5 tons of rapeseed straw was spread directly on the grass, and 20 tons of oat straw was spread on top of the rapeseed straw. The idea of this sandwich construction was to create an airfilled bottom (rapeseed straw) to facilitate composting, and a quick drying, water repellent top layer (oat straw). Within two days the sows had mixed it all up, so no effect could be seen.

Nutrient cycling

Nutrient cyclingfocuses on nitrogen. Input into the system is measured by calculating nitrogen input by feed and straw. Output is calculated from nitrogen in weaned litters and analysis of the nitrogen content in the straw mat, when it is removed in april 2005. Nitrogen leaching from under the mat is measured, using ceramic suction cups.Before establishing the straw mat cups were installed at 1 meter depth below the mat. In the pregnant sow section and in the farrowing section, five groups of suction cups were installed across the full with of the mat. Each group consisted of three suction cups positioned 2 m apart. The aim was to determine variations on a small scale (~1 m) as well as a larger scale (1020 m). In addition, two groups each consisting of three suction cups were installed outside the straw mat as a reference. From October 2004 to April 2005, a suction of about 80 kPa was applied about every 2 weeks, 3 days prior to sampling. Samples were analysed separately or bulked per group for nitrate content.

Time consumption / labour requirement

Time consumption with all types of work related to the herd is measured 3 times. Once in the traditional free range system, used prior to the concept. Once during summer grazing in the concept, and once when the herd is on the winter straw mat. Both daily routines and periodical task are measured.

Economic performance

Calculating economic performance of the concept means putting money on all the details measured in the concept. Such as daily feed and roughage input, total silage production from the pens and estimated grass uptake by the sows, numbers of litters born and weaned, and time consumption. When the evaluation is completed the economic performance of the concept will be compared to traditional organic production. During the evaluation key performance parameters such as total feed consumption per sow per year, live born litters per sow and weaned litters per sow is registered and presented on the concept homepage (in Danish).

By measuring silage production and time consumption the grazing management system is tested for its practicality, and ability to produce grass despite the rooting of sows with no nose-rings.

Midway results and conclusions

Year
Period / 2004
01jun-17aug / 2004
18aug-19oct / 2004/2005
20oct-31jan / Traditional free range organic
Reproduction
No. liveborn/farrowing / 12,3 / 12,4 / 11,0 / 11,0
No.Weaned/farrowing / 10,9 / 9,9 / 9,2 / 9,4
Feed consumption SFU (1 Scandinavian Feed Unit = energy content of 1 kg barley)
Total per sow/year / 2134 / 1763 / 2408 / 2500
Pregnancy / 926 / 738 / 854 / -
Farrowing-weaning / 1209 / 1025 / 1554 / -
% roughage (only pregnant sows) / 45 / 33 / 28 / 28

Table 1 Reproduction and feed consumption during concept evaluation, compared to traditional free range organic system (Udesen 2004),(Gravsholt 2002).

Year
Period / 2004
Before concept / 2004
Concept Summer / Traditional free range organic
Average hours/day / 1,78 / 1,43 / -
Hours/sow/year / 15,37 / 13,75 / 18

Table 2 Time consumption per sow/year before the concept evaluation and during summer grazing, compared to traditional free range organic production

Conclusions from the grazing season 2004 are:It is possible to keep sows without nose-rings.They will root, but the grass will recover during the grazing season, and when the sows are moved to the winter straw mat. It is also possible to establish a catch crop like mustard or rye in parts with no grass recovery, after sows are moved. Silage production in the grazing pens eliminates old grass that sows don’t eat. The feeding value of the harvested silage is 2573 SFU per hectare equal to an increase in roughage production from the grazing area by 69 %. Time consumption is reduced by 10% compared to the system used before the concept.

References

Website: Udesen, Finn K. (2004) Grundlag for den beregnede notering for økologiske smågrise

[ 28. march 2005.

Website: Gravsholt, Hans (2002) Økologikalkuler 2002

[ Accessed 28. march 2005.