Management Strategies for Utilizing Hardwood Sawdust as Poultry Bedding Final Report
Many concentrated poultry-producing areas of the USA including the Delmarva Peninsula have shortages of quality pine-base bedding materials. Yet, there are often ample supplies of cost-effective hardwood sawdust (HW) that could supplement this deficit. However, the poultry industry has been reluctant to use HW due to periodic mold-induced respiratory health concerns. A demonstration was implemented to evaluate management strategies for utilizing HW as poultry bedding. On a commercial farm growing roaster chickens; loblolly pine (LP), yellow poplar (YP) and white oak sawdust (WO) were each placed in 2 houses. For each bedding type, 1 house received fresh-cut sawdust (SD) directly from sawmills or SD held in storage for 3 months. One half of each house also received a peracetic acid-base mold inhibitor prior to chick placement. The average moisture content of SD for all species at placement in Flock 1 was 31%. Moisture content of SD obtained directly from sawmills was higher (39%) compared to that which had been in storage for 3 months (23%). While in storage the temperature of the SD averaged 137 F. Storage and the use of the mold inhibitor had little influence on bedding mold populations. However, there was a two-log reduction in mold populations in Flock 2 compared to Flock 1, and a one-log reduction in LP compared to the HW species. Two-week mortalities were less in Flock 2 for all bedding types. Based on the weight and content of the gizzards there were indications chick prefer consuming the WO. In Flock 1 the incidence of foot pad dermatitis was less with fresh compared to stored bedding and less with YP compared to the other bedding types for both flocks. Based on the physical, chemical and biological observations in this field demonstration, the data suggests that YP may be viable alternative to LP in regions facing a bedding shortage. Under conditions of this demonstration, using a mold inhibitor or placing bedding materials in storage had no influence on mold populations and chick health. Another underutilized, low cost source of wood by-products in the many regions is grindings from land clearings. Although not suitable as bedding in its present form, when composted with other local by-products it may offer a treatment strategy to convert it into a potentially useful and cost-effective bedding material. A screened composted material derived from this source was evaluated in a small, floor pen study inside a commercial chicken house. Results …
Composted Municipal Garbage for Broiler Litter
Abstract Composted municipal garbage (CMG) from two sources was evaluated as broiler litter in three experiments involving a total of 33,920 broilers. An aerobically digested CMG and a windrow processed CMG were each compared to a wood shavings control. Broilers reared on the CMG had statistically or numerically improved body weights compared to the wood shavings control in all trials (31, 12, and 44 g heavier in Experiment 1, 2 and 3, respectively). Feed efficiency was also improved with CMG, whereas litter treatments did not differ in other production or carcass characteristics. Based on limited published reports with wood base litter materials, select trace elements and pesticide levels in CMG litter and tissue were generally within previously reported levels. Exceptions were high mercury, lead, chromium, and nickel in CMG litter, which will require additional research to quantitate significance.
Inhibition of Root Growth and Polyamine Metabolism in Sunflower (Helianthus annuus) Seedlings Under Cadmium and Copper Stress
Although sunflower is usually regarded as a highly tolerant crop, impairment of root growth at initial stages of plant development may result in poor crop establishment and higher susceptibility to pathogen attack. In order to evaluate if Cd2+ and Cu2+ may impact on sunflower germination and initial root development, a pot experiment under controlled conditions was carried out. Possible involvement of polyamine metabolism in sunflower response to these stressors was also investigated. Although Cd2+ and Cu2+ treatments affect neither seed germination nor radicle emergence, sunflower seedlings grown in the presence of these heavy metals showed significant inhibition of root growth, being this inhibition greater for Cd2+. Both metals caused significant increases in proline contents at the highest concentrations tested (0.5 and 1 mM), and these increments were more pronounced for Cd2+ treatments, especially between days 3 and 10. Metals also increased putrescine (Put) contents at all concentrations assayed from the seventh day onward, causing no variations on this polyamine time-course pattern. Spermine and spermidine contents, however, were increased only by 1 mM Cd2+. Arginine decarboxylase seems to have been the enzyme responsible for Put increases under both metal treatments. This work demonstrates that initial root growth of sunflower seedlings may be significantly impaired in Cd2+ or Cu2+ contaminated soils. It also shows that polyamines are key biological compounds, which are probably involved in signaling pathways triggered under stress environmental conditions.