ROLE OF INTERNAL NUTRIENT STORAGE IN DUCKWEED GROWTH FOR SWINE WASTEWATER TREATMENT
Posted in: Environment by admin on January 1, 2005 | No Comments
UTILIZING WEB-BASED GIS AND SDSS FOR HYDROLOGICAL LAND USE CHANGE IMPACT ASSESSMENT
Posted in: Environment by admin on | No Comments
Effects of composted swine manure on weed seedbank
Posted in: Environment by admin on | No Comments
The effects of housing grow-finish pigs in two different group sizes on health status and the presence of injuries.
Posted in: Prairie Swine Centre by admin on | No Comments
Traditionally pigs have been housed in group sizes of approximately 25 pigs per pen. However, the swine industry is beginning to shift towards housing grow-finish pigs in groups as large as 100 to 1000. With increasing group size has come concerns that pigs in these groups will suffer a higher degree of injuries, such as lameness, and reduced health status.
We conducted a series of studies on pigs in groups of 18 and 108 examining a number of factors in relation to the pigs’ health and welfare. Injury scores were carried out on a biweekly basis, at the same time as weighing. The pigs were scored for the presence of flank bites, tail bites, lesions on the legs and lameness. Scores increased as severity increased. Twice daily walk-through health assessments were also conducted, and any illnesses were recorded in detail and treated as necessary.
Overall flank bite and tail bite scores were not affected by group size (Table 1). Group size did, however, have an effect on lameness scores (Table 1, Figure 1a). Overall, pigs housed in the large groups experienced more lameness. This was particularly evident during the second and final scoring periods, when the pigs weighed approximately 50 kg and 95 kg, respectively. One possible explanation may be that pigs in the large groups spent more time inactive than pigs in small groups, which may have increased the occurrence of limb stiffness resulting in lameness. Another possibility is that large group housing allows more space for running. If the pigs’ feet were to get caught in the slats while running, injury to the limb would be more likely. Casual observations of pigs running through a large group indicate that they also run into walls and other pigs more often, likely because they are traveling too fast to stop in time.
Overall leg lesion scores were higher among large group pigs (Table 1, Figure 1b). The difference in lesion scores was most evident during the second scoring period. Large group pigs may have experienced a higher score for these injuries because they spent more time lying down than small group pigs, which would have allowed their legs to rub on the concrete more frequently than the legs of pigs in the small groups.
Although there were significant differences in leg lesion and lameness scores among small and large groups, the severity did not justify antibiotic treatment or a pig’s removal from the trial (Tables 2 and 3). It is possible that the higher overall scores were an artefact of a large number of low lameness or lesion scores that would not justify antibiotic treatment or animal removal, rather than a minimal number of high lameness or lesion scores that would justify treatment or removal. Mortality rates ranged from 0.7 to 0.9 % and did not differ between the group sizes.
Large group housing for grow-finish pigs is not as detrimental to pig vitality as once presumed. When provided with adequate space, large group pigs experience a marginal increase in lameness and leg lesion prevalence. However, the occurrence does not appear severe enough to justify treatment. Overall, large group housed pigs do not seem to suffer reduced welfare as long as regular and thorough health checks are performed.
Effect of Pig Slurry Solids on Aeration Efficiency and Odour Generation
Posted in: Prairie Swine Centre by admin on | No Comments
Two laboratory-scale experiments were carried out in this study to determine the effect of slurry solids content on aeration efficiency and the odour generation potential for the treated slurry during post-aeration storage. Pig slurry with four total solids levels (05, 10, 20, and 40%) were used for both experiments. In the first experiment, the slurry was aerated and the oxygen transfer coefficient (OTC) for each solids level was determined. When the solids content increased from 05 to 40%, a reduction in OTC from about 059 to 015 min1 was observed. However, no statistically significant differences in OTC were found between slurry with a 05% and 10% total solids content and between slurry with a 20% and 40% total solids content, while the difference was significant between these two solids groups. In addition to OTC, the oxygen-holding capacity of the aerated manure decreased significantly with increasing slurry solids content. In the second experiment, slurry with the same four solids categories was contained in Plexiglas columns and aerated at a
dissolved oxygen level of 1mg l1 for 15 days. After aeration, the slurry was left in the columns to simulate long-term storage (180 days). The removal rates of volatile fatty acids (VFA), an odour indicator, by aeration were 98, 96, 67, and 31% for total solids content of 05, 10, 20, and 40%, respectively. During the entire storage period, the VFA concentrations for slurry with solids contents of 05% and 10% were consistently lower than 230 mg l1, indicating that the chance for offensive odour to return was moderate. In contrast, the slurry in the two upper solids categories showed VFA levels consistently higher than 230mg l1 throughout the 180 day storage period. At the end of the storage, the odour detection threshold values were 531, 708, 812, and 1627 for slurry with solids content from 05 to 40%.
Composter les porcs morts
Posted in: French Articles by admin on | No Comments
La disposition des pertes par mortalité est devenue une plus grande préoccupation pour les producteurs de porc dans les dernières années. L’enterrement a perdu de la popularité à cause des risques de contamination des eaux souterraines perçus comme étant élevés et des considérations esthétiques. Le service de cueillette à la ferme des carcasses de porcs morts, un service gratuit autrefois, doit maintenant être payé (e.g $0.09/kg en Alberta et en Saskatchewan). Maintenant que les producteurs de porcs adoptent des protocoles de biosécurité plus stricts, certains trouvent le ramassage des carcasses à la ferme trop risqué. Par conséquent, plusieurs font la transition vers des méthodes alternatives de disposition de carcasses. L’une de ces alternatives est le compostage.








