Effects of peat feeding on the performance and health status of fattening pigs and environmentally derived mycobacteria

Abstract

The purpose of the present study was to investigate the effects of feeding peat as a supplement in the period after weaning on the performance and health status of pigs. Also to assess the risk of the development of tuberculous lesions in the lymph nodes and parenchymatous organs, caused by conditionally pathogenic mycobacteria present in peat. Twenty Large White × Landrace pigs in equal numbers of barrows and gilts (mean live weight 18.0 ± 1.7 kg) were used in the experiment. The experimental group was fed a diet containing commercial underground peat in the dose of 80 g peat/kg dry matter for 30 days. Subsequently, they were fed an identical diet with the control group without peat for 60 days. A short-time feeding peat did not significantly affect the growth and performance of pigs. From day 21, a statistically highly significant (P < 0.01) increase in the consumption of the experimental diet was recorded, however, without a positive effect on the growth of experimental animals. The conversion of the peat containing diet was comparable to the conversion of the control diet. It follows from the results of biochemical analysis of blood that peat feeding for 30 days did not adversely affect the metabolic profile and health status of experimental animals. No tuberculous or tuberculoid lesions in lymph nodes or parenchymatous organs were detected in any of 20 slaughtered animals. Despite that, mycobacteria were isolated from 10 (25.0%) tissues of 5 (50.0%) pigs from the experimental group. One isolate was identified as Mycobacterium avium subsp. hominissuis (IS901– and IS1245+). Seven of nine isolates were determined as conditionally pathogenic atypical mycobacteria: M. fortuitum (n = 2) and M. xenopi (n = 5). It follows from the present results that feeding of a peat supplemented diet to pigs may be considered as economically non-effective and due to the findings of mycobacteria as risky.

Effect of feeding treated peat as a supplement to newborn piglets on the growth, health status and occurrence of conditionally pathogenic mycobacteria

“…This contrasts with control Group C, average body weight of piglets from Group PP was higher by 6.9% at the end of peat feeding (day 23) and by 7.2% at the end of the monitored period (day 67). The body weight in piglets from Group PI was higher by 1.8% (day 23) and 2.7% (day 67) in comparison with control Group C. Non-significant growth stimulation was recorded in our previous study focused on feeding peat to pigs with the body weight of 25 kg for 30 days (Trckova et al, 2006).…”

“…Most studies used peat in a form of various preparations, extracts or isolated humic substances. In our previous experiment with the short-term feeding of peat to pigs during the fattening period did not show a significant beneficial effect on growth and performance of animals (Trckova et al, 2006).…”

“…These were caused by mycobacteria contamination of fully mineralised "black" peat stored under unfavourable conditions (Kazda, 2000;. Secondary contamination of peat with conditionally pathogenic mycobacteria (CPM) mainly represented the highest potential risk during peat feeding Trckova et al, 2006). Counts of contaminating CPM have been markedly reduced on farms by disinfection of natural peat with per acetic acid or by purchase of ionised commercial peat packaged in sealed polyethylene bags (non-published data).…”

The use of humic acids in livestock

“…Humic acid is highly concentrated organic material derived from leonardite, an oxygenated product of lignite, rich in humic acids and various types of elements, such as natural amino ac-ids, minerals and vitamins just to mention a few [4,[6][7][8].…”

Mycobacteria in peat used as a supplement for pigs: failure of different decontamination methods to eliminate the risk

“…The numbers of detectable living mycobacteria are inversely proportional to the depth from which the sample is taken, and viable mycobacterial cells were not found in the profile of peat from 70 cm and deeper (Kazda 2000;Trckova et al 2005Trckova et al , 2006a.…”