JUAN KU, RUTILIO NAVA-MONTERO, ROBERTO BELMAR
Chapingo Autonomous University, Regional University Centre of Peninsula of Yucatan, Mexico
In Yucatán, the most easterly territory of México, both poultry and pig production are carried out resembling an industrial model. Their main problems are the import-dependency of feedstuffs from the USA and their polluting effect.
In order to assess an outdoor pig production system (OutPPS) as an option to conventional system (ConPPS), an in-farm comparative trial was carried out. In a medium-sized farm, 52 pigs (males and females, cross-bred, 95 day-old, 39.8 7.5kg) were assigned to both systems for a 60-day measuring period. ConPPS pigs (n=28) were managed as usual. OutPPS pigs (n=24) were raised on a yard (0.27ha) of grass (Cynodon nlemfuensis) and weeds. Both groups were fed ad libitum with the same feed. The objectives were to compare animal performance (feed intake, live"=weight gain, feed conversion rate, back"=fat accretion, and parasitic infestation) and the use of water and labour; as well as to assess the pig effect on pasture cover and soil fertility.
ConPPS yielded a greater live-weight gain (6.1 kg; p < 0.01), and a thicker back-fat layer (1.15 mm; p < 0.05) than OutPPS. Neither differences were found in intake nor in feed conversion rate (p > 0.05). Both groups were infested by parasites of Isospora and Trichuris genus. Oesophagostomum parasites were detected in ConPPS.
332.3 L water/pigsday in OutSSP were saved with respect to ConPPS, whereas 11.67 more minutes of labour/pigsday were required in the latter than in OutPPS (p < 0.001).
The plant dry-matter removal reached 62.9%, which represents 0.95kg DM/pigday. Pasture cover was reduced only by 2%. No changes in C and N in soil contents occurred (p > 0.05); however the potentially mineralisable N in soil organic matter increased by four fold at the end of the period.
Thus, saving water and labour; removing the polluting effect; and improving both carcass quality and soil capacity, have all a cost in terms of animal efficiency. Better management of the yard could possibly improve these results. However, in Yucatán where the soil is karstic and the underground water tables are too shallow, the industrialised livestock system do not seem to have good perspectives.
Keywords: On-farm research, outdoor system, pig, saving water, Yucatan