Progress 10/01/19 to 09/30/20
Outputs
Target Audience:Commodity groups, Soybean and Rice. Stakeholders including cattle producers, crop producers and wildlife enthusiasts. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?Results were presented to stakeholders attending forestry forums, crop meetings, consultants meetings, wildlife exposition and field days. What do you plan to do during the next reporting period to accomplish the goals?At present, our bait delivery system will deliver baits to the landscape on demand, however, the delivery of baits must occur over a wider area to allow bait consumption by a larger number of pigs. To achieve this goal, the delivery mechanism will be modified so that bait spheres will be dispersed over an area of approximately 4m2 area. Another method proposed by LDWF which includes the placement of baits within the ground using a bulb auger will be tested. We have successfully used this method and pigs rooted up the baits but did not consume. We believe this was due to the formation of nitrous acid while the bait was exposed to soil and the environment for 48 hours. If successful, this method would allow placement of baits within a rather large area frequented by feral swine without the use of cellular technology and delivery equipment.
Impacts
What was accomplished under these goals?
This past year, un-encapsulated sodium nitrite baits were produced and offered to feral swine via our delivery system using whole sounders. The delivery system was set up within the confines of our feral swine pen and loaded with a pre-determined number of baits to provide a 2X-lethal dose to all pigs having access to the delivery system. The delivery system was placed on one side of a wildlife feeder to mimic the user process that would happen on the landscape. As pigs began to use the wildlife feeder as their food source, baits were delivered when pigs were present. Using this approach, we determined two issues that needed to be resolved. First as baits moved through the delivery system pieces of bait left behind due to the mechanical movement of the baits caused the system to become clogged following two or three activations for bait delivery. This in turn negatively impacted the number of baits delivered and the number of pigs that succumb to sodium nitrite poisoning was lower than expected. This issue has been rectified. When baits were delivered in groupsof 8 to 10, one or two animals that were high in the social dominance order consumed most are all of the bait, reducing the number of pigs that had access to baits and resulting in a decreased death rate. Timing of bait delivery to the sounder is now being tested to determine if the delivery of baits over time might increase the number of pigs with access to consume the delivered baits. A second method of bait delivery was attempted. Six to 8-inch holes were drilled in ground using a bulb auger with a diameter of two inches in areas were pigs were known to frequent. Baits were placed in holes and covered. Pigs approached two days later and rooted up baits, these baits were picked up and carried approximately 6 to 10 feet and dropped. This year, plots containing two corn hybrids were planted this year that included 4 treatments and 3 replications. The two hybrids utilized were conventional and round-up ready. Treatments included Aizawai and Kurstaki varieties of Bacillus thuringiensis applied the conventional hybrid, a round-up variety and a non-treated conventional hybrid served as a control. Results showed that 107 days post-planting and 25 days following introduction of feral swine there were no differences in the percent damage across all treatments. However, by 114 days post-planting there was no difference between either the Aizawai or Kurstaki Bacillus thuringiensis treatments, but both were higher than the non-treated conventional hybrid. Likewise, damage to the round-up ready hybrid was higher and any other treatment. By day 121 post-planting all hybrids were almost 100% damaged and there were no differences across treatments. These findings show that pigs may prefer round-up ready corn compared with conventional hybrids, and that treatment of a conventional hybrid with Aizawai and Kurstaki varieties of Bacillus thuringiensis appears to increase preference over that of a non-treated conventional corn hybrid.
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Progress 10/01/18 to 09/30/19
Outputs
Target Audience:Commodity groups, Soybean and Rice. Stakeholders including cattle producers, crop producers and wildlife enthusiasts. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?Results were presented to stakeholders attending forestry forums, crop meetings, consultants meetings, wildlife exposition and field days. What do you plan to do during the next reporting period to accomplish the goals?We will continue to test the non-encapsulated baits using our cellular delivery system on whole sounders. Anti-emetics will also be employed, such as taste-free ginger extracts containing gingerols. The incorporationmethemoglobin inhibitors (MR) into the baitwill facilitate control of feral hogs while releasing less nitrite into the environment. Luteolin is a highly-potent, commercially-available, naturally-occurring, tasteless MR inhibitor. Adding small quantities of luteolin to the nitrite-containing bait will reduce a hog's ability to detoxify methemoglobin. Thus the baits can become more potent without adding more toxicant, increasing overall effectiveness.
Impacts
What was accomplished under these goals?
Corn varieties were planted with differing Bt protection along with a non-modified refuge corn. Pigs appeared to prefer the genetically modified corn compared with the refuge corn. This was an interesting result, in that in previous trials, round-up ready corn was preferred when compared with round-up ready and Bt protection. It appears as though the genetic modification may affect the palatability of field corn for pigs. We foundthat sodium nitrite does not undergo chemical changes in an alkaline environment. This finding allows us to produce and store baits without the need for encapsulation.Individual feeding trails showed that these baits are toxic to pigs and that the pigs prefer the non-encapsulated baits compared with encapsulated baits. The development of the delivery system has progressed. An approach was tested to keep the Louisiana Black bear from consuming sodium nitrite laced baits from a feeder was tested. Results from these tests show that bears cannot gain access to a bucket containing pogie fish. This enhances in our ability to place the delivery system in areas containing bears without fear of intrusion and subsequent death. A more shielded case for the delivery system was developed and toxic baits were dispensed within a enclosure containing a sounder. We recorded the deaths of 30% of pigs.
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Progress 11/01/17 to 09/30/18
Outputs
Target Audience:Commodity groups, Soybean and Rice. Stakeholders including cattle producers, crop producers and wildlife enthusiasts. Changes/Problems:The use of zinc phosphide was discontinued due to the production of phosgene gas within the digestive tract. This accumulation poses a risk to hunters that dress a wild pig and cut into its digestive tract. What opportunities for training and professional development has the project provided?Training included participation of one graduate student How have the results been disseminated to communities of interest?Results were presented to stakeholders attending forestry forums, crop meetings, consultants meetings, wildlife exposition and field days. Approximately 1,525 stakeholders attended these functions. What do you plan to do during the next reporting period to accomplish the goals?We will continue to develop an ecapsulation protocol which will include our shellac, ethocel and chitosan protocols as well as alkaline water. We will also continue to refine our delivey system.
Impacts
What was accomplished under these goals?
Concentrations of encapsulated sodium nitrite (SN) resulted in different percent of lethal outcomes compared with non-encapsulated SN. Baits were offered to pigs containing 200 or 400 mg/kg of either encapsulated or non-encapsulated SN, pigs receiving the non-encapsulated SN died regardless of concentration of SN, however, those pigs that received 200 mg/kg of encapsulated SN did not perish, while some of the pigs receiving the encapsulated form at 400 mg/kg survived and others did not. We completed the assessment of zinc phosphide as a toxicant for feral swine. The zinc phosphide was delivered to feral swine via gelatin capsules at 150, 200, 250 and 300 mg/kg and results indicated that we reached a 65% death rate at the 300 mg/kg level. However, time to death was highly variable with an average of 11 hours at the highest concentration, however, some pigs did not succumb until greater than 24 hours following administration. Because of this finding resulting in the elevated risk to hunters that may kill a live pig poisoned with zinc phosphide these experiments were discontinued and zinc phosphide in our opinion is not a good option for feral swine control. Changes in encapsulation of SN laced bait matrices resulted in a 66% of pigs consuming the baits expiring within three hours. However, when SN was encapsulated with Ethocel and offered to pigs in limited trials, no pigs died. In corn hybrid preference trials, we used twelve, 2,700 square foot plots, were planted with either round-up ready or round-up ready, liberty link and Bt corn hybrids. Over the course of the growing season pigs were allowed access to these hybrids and damage was accessed. Based on location within the experimental area pig damage was higher in the round-up ready corn compared with the round-up ready, liberty link and Bt corn. Theratio of pigs damaging the round-up ready only corn ranged from 1.88 to 5.10 times higher compared with the hybrid containing liberty link and Bt. At 82 days post-planting, corn ear worm damage was not different across hybrids, but tended to be different, indicating that secondary metabolites may play a role in pig preference.
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