Pen Trials Research Articles

Rhipicephalus (Boophilus) microplus aquaporin as an effective vaccine antigen to protect against cattle tick infestations.

BackgroundVaccination as a control method against the cattle tick, Rhipicephalus (Boophilus) microplus has been practiced since the introduction of two products in the mid-1990s. There is a need for a vaccine that could provide effective control of R. microplus in a more consistent fashion than existing products. During our transcriptome studies of R. microplus, several gene coding regions were discovered to encode proteins with significant amino acid similarity to aquaporins.MethodsA cDNA encoding an aquaporin from the cattle tick, Rhipicephalus microplus, was isolated from transcriptomic studies conducted on gut tissues dissected from fully engorged adult female R. microplus.ResultsBioinformatic analysis indicates this aquaporin, designated RmAQP1, shows greatest amino acid similarity to the human aquaporin 7 family. Members of this family of water-conducting channels can also facilitate the transport of glycerol in addition to water. The efficacy of this aquaporin as an antigen against the cattle tick was explored in cattle vaccine trials conducted in Brazil. A cDNA encoding a significant portion of RmAQP1 was expressed as a recombinant protein in Pichia pastoris, purified under native conditions using a polyhistidine C-terminus tag and nickel affinity chromatography, emulsified with Montanide adjuvant, and cattle vaccinated intramuscularly. The recombinant protein provided 75% and 68% efficacy in two cattle pen trials conducted in Campo Grande, Brazil on groups of 6 one year old Holstein calves.ConclusionThe effectiveness of this vaccine in reducing the numbers of adult female ticks shows this aquaporin antigen holds promise as an active ingredient in cattle vaccines targeted against infestations of R. microplus.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-014-0475-9) contains supplementary material, which is available to authorized users.

Assessing risks to non-target species during poison baiting programs for feral cats.

Poison baiting is used frequently to reduce the impacts of pest species of mammals on agricultural and biodiversity interests. However, baiting may not be appropriate if non-target species are at risk of poisoning. Here we use a desktop decision tree approach to assess the risks to non-target vertebrate species in Australia that arise from using poison baits developed to control feral house cats (Felis catus). These baits are presented in the form of sausages with toxicant implanted in the bait medium within an acid-soluble polymer capsule (hard shell delivery vehicle, or HSDV) that disintegrates after ingestion. Using criteria based on body size, diet and feeding behaviour, we assessed 221 of Australia's 3,769 native vertebrate species as likely to consume cat-baits, with 47 of these likely to ingest implanted HSDVs too. Carnivorous marsupials were judged most likely to consume both the baits and HSDVs, with some large-bodied and ground-active birds and reptiles also consuming them. If criteria were relaxed, a further 269 species were assessed as possibly able to consume baits and 343 as possibly able to consume HSDVs; most of these consumers were birds. One threatened species, the Tasmanian devil (Sarcophilus harrisii) was judged as definitely able to consume baits with implanted HSDVs, whereas five threatened species of birds and 21 species of threatened mammals were rated as possible consumers. Amphibia were not considered to be at risk. We conclude that most species of native Australian vertebrates would not consume surface-laid baits during feral cat control programs, and that significantly fewer would be exposed to poisoning if HSDVs were employed. However, risks to susceptible species should be quantified in field or pen trials prior to the implementation of a control program, and minimized further by applying baits at times and in places where non-target species have little access.

Effect of hops β-acids (Humulus lupulus) on performance and intestinal health of broiler chickens

To evaluate a novel feed additive, hops β-acids, a pen trial using 1,440 one-day-old broiler chickens, in a randomized design with 6 treatments and 6 replicates of 40 birds/pen, was conducted. The experimental treatments were a negative control (NC) basal diet, a positive control (PC) basal diet supplemented with zinc 30 mg/kg of bacitracin, and 4 additional treatments consisting of the basal diet supplemented with 30, 60, 120, and 240 mg/kg of hops β-acids in a microencapsulated form. All birds were vaccinated against coccidiosis by eye drops. Productive performance, jejunum morphology, andClostridium spp. count in jejunum and cecum contents were evaluated. At 21 d of age, the birds fed the PC, 30, or 60 mg/kg of β-acids had the same weight gain of those fed the NC, whereas the highest level of β-acids decreased the gain. In addition, feed intake was decreased and FCR was improved in all treatments when compared with the NC. At 42 d, compared with the NC, the treatments containing 30 or 240 mg/kg of β-acids and the PC resulted in improved FCR. No differences were found for other performance variables. No difference was observed among the treatments on villus length, crypt depth, and villus-to-crypt ratio. Except for one sample, all others had negative results forClostridium spp. based on the methodology of sulphite reduction. In this study, we demonstrated positive effects of supplementation of hops β-acids on productive performance of broilers, and the best results were obtained with addition of 30 mg/kg.

Dying to be clean: pen trials of novel cat and fox control devices

Predation by feral cats (Felis catus) and red foxes (Vulpes vulpes) are key threatening processes for many endangered wildlife species. Toxin delivery through compulsive oral grooming is a potential mechanism to supplement existing control techniques for feral cats and red foxes, particularly when high prey densities reduce the uptake of toxic food baits by cats. We investigated the efficacy of different grooming traps by applying a gel containing toxic para-aminopropiophenone (PAPP) to the fur of feral cats and red foxes in experimental pens. Grooming behaviour and signs of poisoning in these animals were recorded by video. More cats interacted with “walk past” grooming traps triggered by sensor beams than with trap models that required the cat to enter a pipe or baited cage. After triggering a trap that had applied PAPP gel to their fur, 14 of 16 feral cats showed symptoms of anoxia, and 8 of these cats were dead by the following morning without exhibiting signs of distress. Seven of 12 foxes were observed to groom fur to which toxic gel had been applied and 3 of these ingested a lethal quantity of PAPP as a result. Our successful proof-of-concept trials support further development of grooming trap sensors and toxin delivery mechanisms to provide humane and targeted feral cat control, although this technique is unlikely to be as successful for fox control, given that foxes appear to not groom as fastidiously as cats.

Control of tick infestations and pathogen prevalence in cattle and sheep farms vaccinated with the recombinant Subolesin-Major Surface Protein 1a chimeric antigen

BackgroundDespite the use of chemical acaricides, tick infestations continue to affect animal health and production worldwide. Tick vaccines have been proposed as a cost-effective and environmentally friendly alternative for tick control. Vaccination with the candidate tick protective antigen, Subolesin (SUB), has been shown experimentally to be effective in controlling vector infestations and pathogen infection. Furthermore, Escherichia coli membranes containing the chimeric antigen composed of SUB fused to Anaplasma marginale Major Surface Protein 1a (MSP1a) (SUB-MSP1a) were produced using a simple low-cost process and proved to be effective for the control of cattle tick, Rhipicephalus (Boophilus) microplus and R. annulatus infestations in pen trials. In this research, field trials were conducted to characterize the effect of vaccination with SUB-MSP1a on tick infestations and the prevalence of tick-borne pathogens in a randomized controlled prospective study.MethodsTwo cattle and two sheep farms with similar geographical locations and production characteristics were randomly assigned to control and vaccinated groups. Ticks were collected, counted, weighed and classified and the prevalence of tick-borne pathogens at the DNA and serological levels were followed for one year prior to and 9 months after vaccination.ResultsBoth cattle and sheep developed antibodies against SUB in response to vaccination. The main effect of the vaccine in cattle was the 8-fold reduction in the percent of infested animals while vaccination in sheep reduced tick infestations by 63%. Female tick weight was 32-55% lower in ticks collected from both vaccinated cattle and sheep when compared to controls. The seroprevalence of Babesia bigemina was lower by 30% in vaccinated cattle, suggesting a possible role for the vaccine in decreasing the prevalence of this tick-borne pathogen. The effect of the vaccine in reducing the frequency of one A. marginale msp4 genotype probably reflected the reduction in the prevalence of a tick-transmitted strain as a result of the reduction in the percent of tick-infested cattle.ConclusionsThese data provide evidence of the dual effect of a SUB-based vaccine for controlling tick infestations and pathogen infection/transmission and provide additional support for the use of the SUB-MSP1a vaccine for tick control in cattle and sheep.

Para-aminopropiophenone and its Registration and Use as a Vertebrate Pesticide in New Zealand

Author(s): Eason, Charles; Murphy, Elaine; MacMorran, Duncan | Abstract: PAPP is short for para-aminopropiophenone and is a new vertebrate pesticide. It is a compound with the formula C9H11NO, it is comparative humane, has low secondary poisoning risk, and has an antidote. PAPP was originally trialed in the 1960s as an antidote for human radiation and cyanide poisoning. In the USA, it has been investigated as a tool for coyote control and was found to be specifically much more toxic to carnivores than to birds and humans. In Australia, it will be used for field control of foxes, wild dogs, and feral cats. In New Zealand, PAPP was registered in 2011 for the control of stoats and feral cats, following the completion of pen and field trials and submission of extensive dossiers covering its effectiveness as a pest control agent and on its ecotoxicology, toxicology, and metabolism.

Rhipicephalus ( Boophilus ) microplus aquaporin as an effective vaccine antigen to protect against cattle tick infestations

Vaccination as a control method against the cattle tick, Rhipicephalus (Boophilus) microplus has been practiced since the introduction of two products in the mid-1990s. There is a need for a vaccine that could provide effective control of R. microplus in a more consistent fashion than existing products. During our transcriptome studies of R. microplus, several gene coding regions were discovered to encode proteins with significant amino acid similarity to aquaporins. A cDNA encoding an aquaporin from the cattle tick, Rhipicephalus microplus, was isolated from transcriptomic studies conducted on gut tissues dissected from fully engorged adult female R. microplus. Bioinformatic analysis indicates this aquaporin, designated RmAQP1, shows greatest amino acid similarity to the human aquaporin 7 family. Members of this family of water-conducting channels can also facilitate the transport of glycerol in addition to water. The efficacy of this aquaporin as an antigen against the cattle tick was explored in cattle vaccine trials conducted in Brazil. A cDNA encoding a significant portion of RmAQP1 was expressed as a recombinant protein in Pichia pastoris, purified under native conditions using a polyhistidine C-terminus tag and nickel affinity chromatography, emulsified with Montanide adjuvant, and cattle vaccinated intramuscularly. The recombinant protein provided 75% and 68% efficacy in two cattle pen trials conducted in Campo Grande, Brazil on groups of 6 one year old Holstein calves. The effectiveness of this vaccine in reducing the numbers of adult female ticks shows this aquaporin antigen holds promise as an active ingredient in cattle vaccines targeted against infestations of R. microplus.

A note on the effect of adding sea urchin shell powder in diet on growth performance in chicken and litter quality

A small pen trial was conducted to evaluate the effects of diet supplementation with sea urchin shell powder on the broiler performance and ammonia emissions in poultry houses for 28 days. A total of 120 male broilers (n = 30 birds/treatment) were fed four diets supplemented with 0%, 0.1%, and 1.0% sea urchin shell powder or 1% feed additives. The use of sea urchin shell powder and feed additives improved growth performance compared to the controls. When compared with the control group at four weeks, ammonia fluxes were decreased by 29.2%, 37.6%, and 27.9% for 0.1% and 1.0% sea urchin shell powder and 1% feed additives, respectively, which could be due to the reduced litter pH. The addition of 1% sea urchin shell powder was effective in improving growth and reducing negative environmental impacts. It is suggested that the decrease in the ammonia level was mainly related to the lower litter pH.

Stratification of bacterial concentrations, from upper to lower, in broiler litter

There have been numerous research studies concerning the different types of bacteria in broiler litter. However, very little is known about the spatial distribution of bacteria from the top to the bottom of the litter bed. Two experiments were conducted, one of a single flock in a pen trial, and the second on a commercial broiler farm for 8 consecutive flocks. Core litter samples were taken and 3 fractions of litter were removed from each core for bacterial analysis: the upper 5.08 cm of litter, the exact middle of the litter, and the lower section of litter directly on top of the dirt pad, being sure to include some dirt pad. Core litter samples were taken specifically at 7 d before placement then again at 1, 7, 14, 21, 35, and 49 d of age in experiment 1, and 14 and 35 d of age in experiment 2. Core samples were removed from 6 pens in the first experiment. In experiment 2, core litter samples were taken near the evaporative cooling cells, the environmental control room or middle of the house, and near the exhaust fans. Litter fractions were analyzed for Staphylococcus spp., Clostridium perfringens, Escherichia coli, Salmonella spp., total aerobes, and total anaerobes. A decrease was observed from the top to middle and from middle to bottom fractions of litter for all bacteria. From upper to lower, all bacteria concentrations were reduced by at least 99%. Therefore, the concentration of bacterial populations within broiler litter could shift dramatically within only a few inches of litter and the lower fraction of litter holds relatively less bacteria than the upper or middle fractions.

A review of recent non-target toxicity testing of vertebrate pesticides: establishing generic guidelines

An analysis of the range, extent and importance of New Zealand-based ecotoxicology studies has been completed to better understand the hazards and non-target risks associated with new toxins and baits. This review focuses on compounds that have been recently developed for incorporation into bait for terrestrial vertebrate pest control, namely cholecalciferol, para-aminopropiophenone (PAPP) and zinc phosphide and the effects of these toxins on non-target species. Testing of these compounds has included cage and pen toxicity and bait acceptance studies. Locally conducted acute toxicity studies clarify overseas data and enhance risk assessments. Consistency in approach and selection of surrogate species, and careful selection of native non-target species for acute toxicity testing in cage and pen trials are recommended as important steps before field trials. We propose a systematic approach to cage and pen trials and offer guidelines on species selection.

Protective action of Tagetes minuta (Asteraceae) essential oil in the control of Rhipicephalus microplus (Canestrini, 1887) (Acari: Ixodidae) in a cattle pen trial

The Rhipicephalus microplus tick is globally regarded as the most economically important ectoparasite of livestock, and the evolution of resistance to commercial acaricides among cattle tick populations is of great concern. The essential oil derived from Tagetes minuta may be efficacious against cattle tick infestation, and the results of a cattle pen trial using this essential oil for the control of ticks are reported here. The chemical composition of the essential oil was determined by GC–MS and NMR spectroscopy analyses, which revealed the presence of four major components in the essential oil. These components represent more than 70% of the essential oil: limonene (6.96%), β-ocimene (5.11%), dihydrotagetone (54.10%) and tagetone (6.73%). The results of the cattle pen trial indicated significant differences among the average values of the analyzed biological parameters, including the number of ticks, the average weight of the ticks, the average egg weight per engorged female and larval viability. Treatment with the T. minuta essential oil prepared in this study promoted significant effects on all biological indicators analyzed. Based on the biological indicators, the essential oil showed 99.98% efficacy compared to the control group when used at a 20% concentration. The results obtained in this study suggest that the T. minuta essential oil is a potential R. microplus tick control agent and may be used to mitigate the economic losses caused by tick infestation.

Effect of a by-product of solid state fermentation (Synergen™) on broiler performance

SummaryThe trial was conducted to evaluate the effect of a by-product of solid state fermentation (Synergen™ (SGN), Alltech Inc, Nicholasville KY, USA) on broiler performance and health. One thousand two hundred and eighty male Ross 308 broilers were used in a 42 day pen trial. The trial was designed as a 2 × 2 factorial, with two diet specifications (standard and reformulated) plus or minus SGN (0 and 200 g/t, SGN replaced with commercial enzyme Ronozyme™ at 150 g/t) to give four dietary treatments in total in a corn-soy based diet formulated to commercial standards. Birds fed the reduced energy diets had significantly lower cumulative feed intakes at 42 d (P < 0.01) compared to those on the full specification standard diet. There were no significant differences in broiler body weight due to treatments at any age. Significant improvements (P < 0.05) in FCR, primarily due to SGN inclusion in the feed, were observed for all weekly reported data. There were no significant differences in either mortality or EPEF for any of the treatment diets. The present study indicates that SGN, a by-product of solid state fermentation (SSF) can improve feed conversion of broilers fed a corn-soy diet.

Housing system affects broiler characteristics of local Chinese breed reciprocal crosses

Artificial selection in closed populations can fix or differentiate alternative alleles of loci associated with selected traits. Two closed chicken populations, A and B, originating from Jiuwu, a Chinese native breed, were bred for more than 10 generations. We compared progeny from reciprocal crosses (AB and BA) under free range (trial 1) and cage and pen (trial 2) systems. Traits measured included feed conversion, live BW, subcutaneous fat thickness, percentages of carcass, semi-eviscerated carcass, eviscerated carcass, breast muscle (pectoralis major and minor), leg muscle (boneless drum and thigh), heart, gizzard, proventriculus, liver, comb, and abdominal fat, plus moisture and fat content in breast muscle at 91 d. In trial 1, there were no significant differences between crosses for any trait except percentage proventriculus (AB > BA). Males were significantly heavier with greater proportions of semi-eviscerated carcass, leg muscle, heart, and comb than females, whereas females had thicker subcutaneous fat and higher percentage abdominal fat, breast muscle, gizzard, and proventriculus than males. In trial 2, chickens raised in cages were significantly heavier, had superior feed efficiency, thicker subcutaneous fat, higher fat content and percentage abdominal fat, carcass, semi-eviscerated carcass, liver, and comb than those reared in pens. Those reared in pens exhibited significantly greater proportions of breast muscle, gizzard, and proventriculus than those raised in cages. The only significant 2-way interaction was cross × sex for percentage semi-eviscerated and eviscerated carcass, because BA males were greater than other combinations. Interactions of cross × sex × housing system for percentage liver and abdominal fat were significant; cage-reared AB females displayed higher percentages than pen-reared BA males. Results implied that subpopulations should be considered rather than a single larger population as a way to reduce loss of genetic variation in local and heritage stocks. Although performance of reciprocal crosses was similar across housing systems, caging during the finishing stage of a slow-growing breed enhanced feed efficiency, BW, and meat composition.

Dose-Responses of Broiler Chicks, Given Live Coccidia Vaccine on Day of Hatch, to Diets Supplemented with Various Levels of Farmatan® (Sweet Chestnut Wood Tannins) or BMD®/Stafac® in a 42-Day Pen Trial on Built-Up Litter

Dose-Responses of Broiler Chicks, Given Live Coccidia Vaccine on Day of Hatch, to Diets Supplemented with Various Levels of Farmatan® (Sweet Chestnut Wood Tannins) or BMD®/Stafac® in a 42-Day Pen Trial on Built-Up Litter

An Assessment of Richardson’s Ground Squirrel Activity and Potential Barriers to Limit Access to Sensitive Sites at Malmstrom Air Force Base, Montana

Small mammals pass through or under chain link security fences, triggering sensors and undermining facility infrastruc- ture at sensitive military sites. Traditional methods of rodent control are not practical because of the vastness of land to be maintained with limited manpower. Permanent barriers (above and below ground) and low-maintenance, long-term bait stations offer potential permanent and cost-effective solutions to mitigate rodent intrusions. We assessed Richardson's ground squirrel populations, activi- ties, and burrows at Malmstrom Air Force Base, MT. We also conducted preliminary barrier trials in the outdoor rodent buildings of the USDA National Wildlife Research Center in Fort Collins, CO. Ground squirrels were very numerous and active at most sites visited in Montana. Burrows were both simple and short as well some being elaborate and deep (to 5+ ft). Squirrels readily passed through and under the 2-inch mesh chain link fences as well as under site gates. Several effective barriers were identified in pen trials that prevented above-ground and below-ground intrusions. These will need to be field tested. Future studies will investigate designs for a low-maintenance, long-term rodenticide bait stations for deployment at remote sites.

Effects of Dietary Antibiotics, Actigen<sup>®</sup> Yeast Cell Wall Derivative, or Both on Broiler Chicken Live Performance in a Fifty-Two Day Pen Trial on Built-up Litter

Effects of Dietary Antibiotics, Actigen<sup>®</sup> Yeast Cell Wall Derivative, or Both on Broiler Chicken Live Performance in a Fifty-Two Day Pen Trial on Built-up Litter

A Trilingual Scribe from Abbasid Egypt? A Note on CPR XXII 17

A part of CPR XXII 17, 1b was identified in the edition as pen trial. It is, however,written in Arabic. This note argues that the Arabic part was written by the same scribe as theGreek and the Coptic passages in the papyrus. This revelation throws light on how Greek, Copticand Arabic were simultaneously used in early Islamic Egypt and suggests that there might havebeen scribes who were capable of handling all three languages very efficiently.

Meta-Analysis Summary of Broiler Chicken Trials with Dietary Actigen® (2009-2011)

2 Abstract: Statistical meta-analyses of results from broiler pen trials and a few field trials published during 2009-2012 using dietary Actigen were conducted. Actigen (Alltech, Inc., Nicholasville, Kentucky, USA) is a second-generation, yeast cell wall product considered to be a permitter through its roles in immune modulation and improved intestinal health. Parameters evaluated were dietary inclusion rates for Actigen, age of birds, body weight, Feed Conversion Ratio (FCR) or feed/gain ratio (F/G ratio) and mortality %. Eighteen reports were collected allowing 29 comparisons of negative control (nCON) diets and Actigen supplemented diets (200 to 800 g/tonne) fed during the entire trials. Similarly, 15 reports were collected allowing 20 comparisons of positive control (antibiotic supplemented) diets and Actigen supplemented diets (200 to 882 g/tonne). When added to basal diets continuously to an average broiler age of 41.72 days (n = 29), Actigen significantly and beneficially changed body weight by +0.0.80 kg (+3.34%), FCR or F/G ratio by -0.033 (-1.84%) and mortality % by -0.80 (-12.5% relative to nCON). Compared with positive control (antibiotic) results, dietary Actigen fed continuously to an average broiler age of 42.73 days (n = 20) gave results statistically equivalent with those of dietary antibiotics. Comparisons between this present meta- analysis and those done previously on another yeast cell wall compound (Bio-Mos) suggest that the second generation product Actigen may be more effective in terms of growth promotion.

Effect of High Peroxide Value Fats on Performance of Broilers in an Immune Challenged State

A floor pen trial was conducted to determine the effect of high peroxide value fats on th e performance of broilers in an immune challenged state. Ross 708 broilers were randomly assigned to 48 floor pens with each pen containing 30 birds. Dietary treatments were developed as a 3 x 2 factorial using three levels of fat rancidity, with Peroxide Values (PV) of 0, 75 and 150. One half of each peroxide value diet also received an antioxidant at 125 ppm. Six dietary treatments with eight replicates were fed to broilers from hatch to day 49. Diets were formulated based on standard industry diets with the exception of fat being forced into the diet at 3% for the starter ration (0-3 wks), 6% in the grower ration (3-5 wks) and 6% in the finisher ration (5-7 wks). At 4 weeks of age the broilers underwent a coccidial challenge. The trial measured the performance of the immune challenged broilers based on the parameters of Feed Intake (FI), Body Weight Gain (BWG) and feed conversion (F:G). An initial pen weight was taken on day 0 for each of the 48 pens. Birds were weighed at 3, 5 and 7 weeks of age to calculate F:G. At week 7, four birds per pen (32 birds/treatment) were sacrificed and processed in order to obtain a fat pad weight, carcass weight, percent meat yield and cecal scoring. The results indicated that birds consuming diets with a peroxide value of 75 or greater exhibited poorer feed conversion than the treatment with an acceptable peroxide value. Furthermore, diets with the added antioxidant demonstrated no statistical difference in feed conversion due to peroxide value. There were also no significant effects of the immune challenge in combination with peroxide levels on bird performance.

Reducing ammonia emissions and volatile fatty acids in poultry litter with liquid aluminum chloride

This study was a pen trial in which the effects of adding different rates of liquid aluminum chloride (AlCl3) on litter pH, total volatile fatty acids (VFAs), and ammonia (NH3) fluxes was evaluated. Liquid AlCl3 treatments used in this study were sprayed on the rice hull surface at rates of 100 g, 200 g, and 300 g liquid AlCl3/kg rice hulls; untreated rice hulls served as controls. Litter pH, total VFAs, and NH3 fluxes were all lowered (P< 0.05) by all of the liquid AlCl3 treatments compared with controls during certain times of the 5 week study. However, there were no significant differences among treatments on litter pH at the end of the study (from 3 to 5 weeks) or NH3 fluxes at beginning of the study (0 to 3 weeks). Total VFAs were reduced 16 %, 29 %, and 53 % by 100 g liquid AlCl3/kg rice hulls, 200 g liquid AlCl3/kg rice hulls, and 300 g liquid AlCl3/kg rice hulls, respectively. Liquid AlCl3additions reduced NH3 fluxes by 35 %, 57 % and 67 %, respectively, at the low, medium and high rates. In summary, these results indicate that adding liquid aluminum chloride to rice hulls would be a useful tool in reducing the negative environmental impact of poultry litter. It should be noted that the decreased VFA production and NH3 volatilization was chiefly associated with reduction in litter pH.