Bermuda Hay Research Articles

56 Establishing grain-based modified protocols for the nutritional and physical reconditioning of malnourished horses

Abstract From April to June 2023, we conducted a study to evaluate the effects of Total Equine containing Ascophyllum nodosum seaweed and chelated minerals on the continued recovery and reconditioning of 10 horses. Horses were used on a preceding 8-wk study and given a 21-d, 24-h turnout, with ad libitum access to Bermuda hay washout period between trials. Once the washout was complete horses were randomly assigned to one of three diets: Control (Ctrl) - a commercial grain product and Bermuda hay (n = 3); Treatment (Trt) - Total Equine and Bermuda hay (n = 4); and Grain only (Grn) - Total Equine without Bermuda hay (n = 3); for 8 wk with ad libitum access to water. For Ctrl and Trt diets we offered hay twice a day in port-a-gazer tubs to control waste, adjusted daily for a 3% refusal rate, and orts were collected twice a day. Individuals were weighed weekly, and their body condition score (BCS) was evaluated during the standardization period, wk 4 and wk 8. Grain was offered at a rate of 0.005% BW + 227 kg and divided into 2 equal feedings for Ctrl and Trt diets, while for the Grn diet horses were offered up to 9.07 kg of grain divided into 3 daily feedings, with grain amounts adjusted weekly based on BW. For physical reconditioning, horses were exercised 5 d/wk with a Priefert hot walker, increased in duration and intensity from wk 1 to 8. We collected samples of grain, hay, and orts for DM, NDF, ADF, EE, CP, and ash analysis. Blood samples were collected at wk 0, 4, and 8 for analysis. Baseline health parameters as rectal temperature, heart, and respiratory rate were measured weekly throughout the study to evaluate possible detrimental effects of the trial. Data were analyzed using Proc Mixed procedures in SAS. Investigation into Dry matter intake (DMI) between the Ctrl and Trt cohorts revealed no significant difference. However, significant differences (P ≤ 0.05) were observed in Overall DMI (grain + hay) among Grn and other diet pairs. Significant average daily gain (ADG) and Efficiency (EFF) observations in wk 1, 4, and 6 (P ≤ 0.05) suggest that Total Equine grain had better overall performance in both groups during the first 6 wk of the trial compared with the Ctrl grain. Our results demonstrate the successful outcome of a modified, grain-based protocol in nutritional and physical reconditioning of a cohort of malnourished horses. Further evaluation of larger populations is still needed.

55 Establishing grain-based modified protocols for re-feeding malnourished horses

Abstract Increased feed costs, forage availability, and the increasing number of malnourished horses present major challenges to the equine industry. The goal of this project was to test an adapted refeeding protocol using Bermuda hay and two commercial grain products in severely malnourished horses. So, an 8-wk study from January to March 2023 was conducted to evaluate the effects of Total Equine in the refeeding of 10 emaciated horses. Horses were previously destined for slaughter and purchased from an auction with an average body condition score (BCS) of 2.01 (S.D. ± 0.69), then quarantined for 30 d before starting the study following recommended biosecurity protocols. During quarantine, horses were evaluated by a veterinarian and received treatment as needed, vaccinations, deworming, and mares were pregnancy checked. All horses were provided with ad libitum Bermuda hay and water. Upon completion of the quarantine period, horses were blocked into two groups based on age, BCS, pregnancy status, and gender and randomly assigned to a diet. The Control (Ctrl) diet consisted of a commercial grain diet recommended and used by five local West Texas horse rescue groups and the Treatment (Trt) diet consisted of Total Equine. Both diets included ad libitum access to water and Bermuda hay (TDN 56.5) offered twice daily in port-a-grazer tubs to control waste and the amount was adjusted daily to maintain a 3% refusal rate. Grain was offered at a rate of 0.005% BW + 227 kg per the manufacturer’s suggestion, divided into 2 equal feedings with amounts adjusted weekly. Individual horses were weighed weekly using an electronic scale and BCS was evaluated at wk 0, 4, and 8. All horses were allowed a 1-h turnout in a dry-pen per day for 6 d each week. Blood samples were collected at wk 0, 4, and 8 for analysis. Health parameters were measured weekly throughout the study. Samples (grain, hay, hay orts) were collected twice weekly for DM, NDF, ADF, EE, CP, and Ash analysis. Data was analyzed using Proc Mixed in SAS. Overall, there was no significant difference between DMI by diet (Ctrl 8.74 kg/d and Trt 9.44 kg/d). However, a tendency for increased ADG (P = 0.06) for the Trt diet (Ctrl 0.20 kg/d & Trt 1.34 kg/d) was noted. Efficiency calculated as (ADG/DMI) was significantly improved (P = 0.04) indicating an improvement in the efficiency of BW gain for the Trt diet compared with the Ctrl. Improved BW gain and efficiency of gain are of interest when rehabilitating malnourished horses. The establishment of accessible modified feeding protocols may improve efficiency and reduce the cost involved in the rehabilitation of malnourished horses and would be a step forward for the equine industry.

79 Dietary buffer comparison and tannins supplementation modulating subacute ruminal acidosis and fermentation in beef cattle

Abstract As the demand of nutrients by the population will continue to grow over the years, efficient practices are required in the food chain to satisfy the demand. This practice involves the intensification of production systems. Moreover, intensification can potentially harm the animal or environment if the resources are used to the limit. The latter, product of pushing to the limit the ruminal environment. Dietary buffers and tannins offer a key role addressing issues related to intensification. This study aimed to evaluate the effects of two dietary buffers and tannins. Ruminal fermentation parameters, in vitro methane production, ruminal pH, in vitro organic matter digestibility were measured. Eight ruminally cannulated steers were used in a duplicated 4 x 4 Latin square design. Steers were fed with a basal diet comprised of 35.5% corn silage, 18.7% protein supplement, 21.5% corn grain, 22% bermuda hay, 1% mineral supplement (DM basis). Four treatments were used: BICARB (Basal diet + 1.2% DM Sodium Bicarbonate), BRIC-050 (Basal diet + 1.2% DM BRIC), BRIC-150 (Basal diet + 1.2% DM BRIC + 0.15 % DM Tannins), TAN (Basal diet + 0.15% DM Tannins). Steers were housed in individual pens and received every morning a TMR and water ad libitum. The experiment consisted of 4 periods with 16 days total, composed by 3 d of covariates, 7 d of treatment adaptation, 1 d of 50% feed restriction, 1 d SARA challenge, 4 d of recovery, and 20 d of washout between periods. Two in vitro batch culture were performed in every period at the last day of covariates and last day of recovery, collecting ruminal fluid from each animal. Treatments with BICARB promoted a higher pH than TAN during the adaptation at 4 h after feeding (P = 0.01). Moreover, BRIC-150 showed similar results with a tendency to increase (P = 0.07) when compared with TAN. During the feed restriction BRIC-150 showed a greater pH (P = 0.01) when compared with TAN. While, for BICARB and BRIC-050 pH tended to be greater (P = 0.06) than TAN. During the SARA challenge and the recovery, treatments with buffer tended to have greater pH (P < 0.1). A significant reduction ammonia nitrogen was observed for BICARB and TAN compared with BRIC-050 and BRIC-150 (P < 0.01). Overall, the three buffers tested showed similar results in terms of maintaining a greater pH than treatment without buffer.

Preconditioning beef cattle for long-duration transportation stress with rumen-protected methionine supplementation: A nutrigenetics study.

In general, beef cattle long-distance transportation from cow-calf operations to feedlots or from feedlots to abattoirs is a common situation in the beef industry. The aim of this study was to determine the effect of rumen-protected methionine (RPM) supplementation on a proposed gene network for muscle fatigue, creatine synthesis (CKM), and reactive oxygen species (ROS) metabolism after a transportation simulation in a test track. Angus × Simmental heifers (n = 18) were stratified by body weight (408 ± 64 kg; BW) and randomly assigned to dietary treatments: 1) control diet (CTRL) or 2) control diet + 8 gr/hd/day of top-dressed rumen-protected methionine (RPM). After an adaptation period to Calan gates, animals received the mentioned dietary treatment consisting of Bermuda hay ad libitum and a soy hulls and corn gluten feed based supplement. After 45 days of supplementation, animals were loaded onto a trailer and transported for 22 hours (long-term transportation). Longissimus muscle biopsies, BW and blood samples were obtained on day 0 (Baseline), 43 (Pre-transport; PRET), and 46 (Post-transport; POST). Heifers’ average daily gain did not differ between baseline and PRET. Control heifer’s shrink was 10% of BW while RPM heifers shrink was 8%. Serum cortisol decreased, and glucose and creatine kinase levels increased after transportation, but no differences were observed between treatments. Messenger RNA was extracted from skeletal muscle tissue and gene expression analysis was performed by RT-qPCR. Results showed that AHCY and DNMT3A (DNA methylation), SSPN (Sarcoglycan complex), and SOD2 (Oxidative Stress-ROS) were upregulated in CTRL between baseline and PRET and, decreased between pre and POST while they remained constant for RPM. Furthermore, CKM was not affected by treatments. In conclusion, RPM supplementation may affect ROS production and enhance DNA hypermethylation, after a long-term transportation.

197 Gene-regulation control of muscle fatigue during transportation with rumen-protected methionine supplementation

Abstract Different participants generally located distant among them compose the U.S. beef production chain, therefore shipping is required for cattle at least once in their lifespan. The aim of this study was to determine the effect of Rumen-Protected Methionine (RPM) supplementation on muscle fatigue gene network, creatine synthesis (CKM), and Reactive Oxygen Species (ROS) metabolism after a transportation simulation in a 1.7-miles oval test track. Angus heifers (n = 18) were stratified by body weight (408 ± 64 kg; BW) and randomly assigned to dietary treatments: 1) control diet (CTRL), and 2) control diet + rumen-protected methionine (RPM). After a successful adaptation period to Calan gates, animals received a common diet of Bermuda hay ad libitum and a soy hulls and corn gluten feed based supplement. After 45 days under supplementation, animals were loaded onto a 32 × 7 ft. trailer and transported for 22 hours. Skeletal muscle biopsies, BW and blood samples were obtained on day 0 (Baseline), 43 (Pre-transport, “PRET”), and 45 (Post-transport, “POST”). Heifer’s average daily gain did not differ between Baseline and PRET (P = 0.41). Control heifer’s shrink was 8% of BW while RPM heifers shrink was 10% (P = 0.29). Cortisol level decreased after transportation, but no differences were observed between treatments (P = 0.94). Messenger RNA was extracted from skeletal muscle tissue and gene expression analysis was performed by RT-qPCR. Results showed that AHCY (Creatine synthesis pathway), SSPN (Sarcoglycan complex), DNMT3A (DNA Methylation), and SOD2 (Oxidative Stress-ROS) were upregulated (P < 0.05) in CTRL between baseline and PRET and, decreased between PRET and POST (P < 0.05) while they remained constant for RPM. Furthermore, CKM was not affected by treatments (P = 0.11). In conclusion, muscle fatigue related genes were not affected by RPM. Although, RPM could affect ROS production, after a long-term transportation.

PSXIV-4 Fetal programming effect of rumen-protected methionine on Angus-Simental heifer offspring’s performance and adipogenesis, oxidative stress and DNA methylation gene expression regulation

Abstract An extensive body of literature reported positive effects of Rumen-Protected Methionine (RPM) on dairy cattle; however, its effects are unknown on beef cattle. The objective of this study was to assess the effect of RPM supplementation on Angus-Simmental heifer’s offspring during late gestation, lactation, and after weaning (~65d). Ninety days prior to calving, 22 Angus-Simmental heifers were stratified by body weight (454 ± 85 kg; BW) and randomly assigned to dietary treatments: 1) Control diet (CTRL), and 2) Control diet + RPM (RPM). Dams had access to Bermuda hay ad libitum, and a soy hull:corn gluten based supplement. After weaning, calves were allocated by dietary treatments based on their dam’s treatment. Calves received Bermuda hay ad libitum and early-wean feed supplement after weaning. Offspring’s BW and Longissimus dorsi (LM) muscle samples were obtained on days 0, 25, 50, 100 after weaning. Messenger RNA was extracted from LM for RT-qPCR analysis. There was a tendency for RPM calves to be heavier at birth compared to control calves (P = 0.07). Although, no differences in BW were detected at weaning and after weaning (P = 0.20). Calves average daily gain between birth and weaning was greater for RPM calves as compared to CON (P = 0.02) suggesting a greater milk production, with no differences after weaning (P = 0.53). RT-qPCR results showed a treatment × time interaction for PPARG, LPL, CEBPG, DNMT1, SOD2 and NOS3 (P < 0.05). Furthermore, PPARG had a treatment and a time effect, which was upregulated in RPM calves (P < 0.01) from 50 to 100 days after weaning. In conclusion, dam’s RPM supplementation during late gestation increased offspring’s BW when inside the womb and probably their milk production. Offspring’s RPM supplementation after weaning potentially stimulates an early differentiation of adipocytes in LM samples, detected by PPARG upregulation.

145 Digestibility of forages in ruminally cannulated Jersey steers supplemented with liquid glycerol on a wheat straw forage diet

Abstract The purpose of this study was to determine the impact of supplementation of glycerol at a rate of 15% of DMI on forage digestibility on a diet of mature wheat hay. Forages tested included bermuda hay, wheat hay, alfalfa hay, and sorghum sudan hay. Samples were ground through a 2mm screen and placed in Ankom forage in-situ bags. Samples were run in triplicate to reduce error and increase statistical significance. Two ruminally cannulated steers were used in a 2x2 Latin square design for the study with ad libitum access to wheat hay and water. Animals were housed in a dry lot pen for the study. Diets offered were Control = wheat hay and Treatment= control + glycerol at 15% of daily DMI. The study consisted of 2 three-week periods. Each period had a 2-week standardization followed by a 1-week test period. During the test period, forage bags were placed in each steer for 0 h, 48 h, 72 h, 96 h, and 144 h for fermentation. At the end of the incubation period, bags were collected and cold shocked to stop microbial digestion. The samples were then dried at 55°C and stored for later analysis for NDF. A significant impact on NDFdig by treatment (P < 0.0001) was observed. NDFdig was 59.2% w/ glycerol versus control at 49.13% overall. In addition, there was a significant difference between steers (P = 0.0001) on glycerol treatment (51.95% versus 66.45% NDFdig between steer A and B), indicating difference in ruminal population efficiency between individual animals. No significant difference (P = 0.98) between steers on the control treatment was observed. Implications of this study are the inclusion of dietary glycerol in the diet of ruminants on a low-quality forage diet may increase energy level and improve ruminal digestibility and animal response may be dependent on the unique ruminal environment of individual animals.

54 Digestibility of forages in ruminally cannulated Jersey steers supplemented with liquid glycerol on a wheat straw forage diet

Abstract The purpose of this study was to determine the impact of supplementation of glycerol at a rate of 15% of DMI on forage digestibility on a diet of mature wheat hay. Forages tested included bermuda hay, wheat hay, alfalfa hay, and sorghum sudan hay. Samples were ground through a 2mm screen and placed in Ankom forage in-situ bags. Samples were run in triplicate to reduce error and increase statistical significance. Two ruminally cannulated steers were used in a 2x2 Latin square design for the study with ad libitum access to wheat hay and water. Animals were housed in a dry lot pen for the study. Diets offered were Control = wheat hay and Treatment= control + glycerol at 15% of daily DMI. The study consisted of 2 three-week periods. Each period had a 2-week standardization followed by a 1-week test period. During the test period, forage bags were placed in each steer for 0 h, 48 h, 72 h, 96 h, and 144 h for fermentation. At the end of the incubation period, bags were collected and cold shocked to stop microbial digestion. The samples were then dried at 55°C and stored for later analysis for NDF. A significant impact on NDFdig by treatment (P < 0.0001) was observed. NDFdig was 59.2% w/ glycerol versus control at 49.13% overall. In addition, there was a significant difference between steers (P = 0.0001) on glycerol treatment (51.95% versus 66.45% NDFdig between steer A and B), indicating difference in ruminal population efficiency between individual animals. No significant difference (P = 0.98) between steers on the control treatment was observed. Implications of this study are the inclusion of dietary glycerol in the diet of ruminants on a low-quality forage diet may increase energy level and improve ruminal digestibility and animal response may be dependent on the unique ruminal environment of individual animals.

Behavioral responses of gravid Culex quinquefasciatus, Aedes aegypti, and Anopheles quadrimaculatus mosquitoes to aquatic macrophyte volatiles.

Mosquitoes use many cues to assess whether a habitat is conducive for reproduction, possibly including the presence of stimuli from aquatic macrophytes. The effect of water infusions of water hyacinth (Eichhornia crassipes), water lettuce (Pista stratioles), parrotfeather (Myriophyllum aquaticum), and water pennywort (Hydrocotyle umbellata) on mosquito oviposition and attraction was investigated. Gravid Culex quinquefasciatus deposited significantly more egg rafts in water hyacinth, water lettuce, or Bermuda hay (positive control) infusions compared to water, while water pennywort and parrotfeather infusions did not differ from water. In-flight attraction responses of Cx. quinquefasciatus, Aedes aegypti, and Anopheles quadrimaculatus were evaluated. The strongest attraction of gravid Cx. quinquefasciatus and Ae. aegypti occurred in the presence of volatiles from infusions of water hyacinth and water lettuce, which were equal in attractiveness to hay infusion. Water pennywort and parrotfeather infusions were not attractive. Gravid An. quadrimaculatus were not attracted to aquatic plant volatiles. The results suggest that water hyacinth and water lettuce emit volatile chemicals that attract two of three mosquito species tested and stimulate oviposition by Cx. quinquefasciatus, demonstrating that the level of attraction of aquatic plant volatiles varies among species in ways that may have relevance to bait-based detection and control methods.

Effects of substitution of Bermuda grass hay with Trichoderma fermented rice straw on growth, blood, and rumen fluid parameters in Barbados sheep

ABSTRACTThe study was to ascertain the feasibility of using rice straw fermented by Trichoderma as ruminant roughage. Three species or three strains of Trichoderma (NTLg-Te S5-1, NTLg-Te S9-1, and Tien Chung Ca6-1) were used to inoculate hot water-sterilized rice straw. Result showed that rice straw fermented with Trichoderma NTLg-Te S5-1 had the highest cellulase and xylanase activity. Antioxidant ferulic acid content of water extract was improved after fermentation. Eighteen Barbados sheep were randomly distributed into one of three dietary groups. Ration of Bermuda hay group (BER) is 90% Bermuda hay with 10% concentrate. Unfermented rice straw (RS) group and fermented rice straw (FRS) group substituted 25% of Bermuda hay with rice straw or fermented rice straw. Dry matter intake, daily weight gain, blood analysis, and feed conversion ratio were not significantly different among groups after 4 weeks of trial. Dry matter digestibility of BER was the highest, and of FRS was significantly higher than RS. Malondialdehyde (MDA) content in serum of FRS and BER was lower than RS. These results indicated that 25% substitution of Bermuda hay with Trichoderma-fermented rice straw in the diet of Barbados sheep could increase digestibility and inhibit lipid oxidation when compared to unfermented rice straw.

Enteric methane emissions and protozoa populations in Holstein steers fed spent mushroom (Flammulina velutipes) substrate silage-based diets

Direct modification of rumen microbial fermentation could provide universal and cost-effective solutions to reduce methane emissions from ruminant livestock. In this study, the effect of feeding spent mushroom (golden needle mushroom, Flammulina velutipes) substrate (SMS)-based silage supplemented with or without urea on the enteric methane emission and total rumen protozoa populations in Holstein steers was investigated. Spent mushroom substrate and whole crop corn were ensiled for 60days with or without urea as follows: Silage 1 (SMS 900g/kg and whole crop corn 100g/kg); Silage 2 (SMS 900g/kg, urea 10g/kg and whole crop corn 90g/kg); Silage 3 (SMS 800g/kg and whole crop corn 200g/kg); Silage 4 (SMS 800g/kg, urea 10g/kg and whole crop corn 190g/kg) on dry matter (DM) basis. Five dietary treatments were prepared as follows: 1) a control diet made-up of 500g/kg of concentrate and 500g/kg of bermuda hay (Cynodon dectylon), and 2) four diets formulated by replacing 400g/kg of the bermuda hay in the control diet with the four SMS-based silages described above. Five Holstein steers (mean BW 542±72kg) were assigned to a 5×5 Latin square design in which the five dietary treatments were offered across 5 periods, with 14days of adaptation plus 7days of samples collection in each period. Holstein steers fed diets containing SMS-based silages had lower total protozoa population (3.37×105/mL vs. 6.09×105/mL), rumen acetate (55.43mM/L vs. 57.08mM/L) and methane emission (211g/day vs. 252g/day) (P<0.05) than Holstein steers fed control diet. When comparing the inclusion levels of SMS-based silages in the diets, cattle fed diets of lower levels of SMS-based silages (800g/kg of SMS) had higher acetate contents (56.61mM/L vs. 54.25), protozoa population (3.92×105/mL vs. 2.84×105/mL) and methane emission (226g/day vs. 196g/day) than heifers fed diets of higher levels of SMS-based silage (900g/kg of SMS). The study demonstrates that feeding Holstein steers with SMS-based silage significantly decreases protozoa populations in the rumen and enteric methane emission. Although the mechanisms are not fully understood, the phytochemicals in SMS could be responsible for the reduction in rumen protozoa populations and the inhibition of rumen methanogenesis.

Time Matters: Effectiveness of Steaming Times on Forage for Animal Consumption

The goal of this research is to determine the effectiveness of portable hay steamer equipment for horse owners averaging 1-15 head. Hay is a large portion of horses’ diets, but it has a short shelf life. Dust from hay also becomes a problem due to respiratory diseases. There is a need for a healthier alternative for storing and feeding hay in order to promote optimum animal health. This study tests the effectiveness of four steaming times on the cleanliness of high-quality, Bermuda hay in the portable steamer. Swabs were taken from pre and post steaming hay samples and incubated on nutrient agar plates at 37 degrees Celsius for 24 hours. After incubation, bacterial colonies were counted to compare the change in bacteria present from before and after the steaming process. Using two-sample mean differences tests, we found steaming time had a significant impact on the cleanliness of hay.

Performance of dairy cows fed high levels of acetic acid or ethanol

Ethanol and acetic acid are common end products from silages. The main objective of this study was to determine whether high concentrations of ethanol or acetic acid in total mixed ration would affect performance in dairy cows. Thirty mid-lactation Holstein cows were grouped in 10 blocks and fed one of the following diets for 7wk: (1) control (33% Bermuda hay + 67% concentrates), (2) ethanol [control diet + 5% ethanol, dry matter (DM) basis], or (3) acetic acid (control diet + 5% acetic acid, DM basis). Ethanol and acetic acid were diluted in water (1:2) and sprayed onto total mixed rations twice daily before feeding. An equal amount of water was mixed with the control ration. To adapt animals to these treatments, cows were fed only half of the treatment dose during the first week of study. Cows fed ethanol yielded more milk (37.9kg/d) than those fed the control (35.8kg/d) or acetic acid (35.3kg/d) diets, mainly due to the higher DM intake (DMI; 23.7, 22.2, and 21.6kg/d, respectively). The significant diet × week interaction for DMI, mainly during wk 2 and 3 (when acetic acid reached the full dose), was related to the decrease in DMI observed for the acetic acid treatment. There was a diet × week interaction in excretion of milk energy per DMI during wk 2 and 3, due to cows fed acetic acid sustained milk yield despite lower DMI. Energy efficiency was similar across diets. Blood metabolites (glucose, insulin, nonesterified fatty acids, ethanol, and γ-glutamyl transferase activity) and sensory characteristics of milk were not affected by these treatments. Animal performance suggested similar energy value for the diet containing ethanol compared with other diets. Rumen conversion of ethanol to acetate and a concomitant increase in methane production might be a plausible explanation for the deviation of the predicted energy value based on the heat of combustion. Therefore, the loss of volatile compounds during the drying process in the laboratory should be considered when calculating energy content of fermented feedstuffs.

Husbandry Methods for Pocket Gophers

Abstract Described husbandry practices for pocket gophers are rare. Antiquated practices do not satisfy current husbandry standards, requiring investigators to modify methods to meet the needs of their research. We report techniques for housing Baird's pocket gopher (Geomys breviceps) that sustain health of captives, encourages natural behaviors, and meet necessary husbandry requirements. Twenty-six G. breviceps were housed at the University of Arkansas at Little Rock over an 18-month period. A diet consisting of fresh vegetation promoted apparently normal development, and parasitic treatments were effective. Individuals were housed within simulated tunnel systems constructed of multiple cages and plastic tubing and allowed to structure their environment with a combination of topsoil, Bermuda hay, and pine wood chips. Animals readily adapted to this caging system, which can be easily disassembled and sanitized for routine maintenance. Given the effectiveness of these techniques at sustaining G. breviceps,...

Effect of a feed/fast protocol on pH in the proximal equine stomach

Risk factors for the development of gastric squamous ulcers include various management procedures, such as intermittent feed deprivation that can occur during weight management regimens or stall and dry lot confinement. To investigate the effect of intermittent feed deprivation relative to continuous feed intake on proximal intragastric pH, specifically in the region of the squamous mucosa of the lesser curvature. In 6 horses, pH electrodes were placed just inside of the oesophageal sphincter in the stomach for each of two 72 h protocols (A and B) in a randomised, cross-over design. Protocol A consisted of 12 h fed, 12 h fasted, 24 h fed and 24 h fasted, in sequence. Protocol B consisted of 72 h fed. During the fed periods of each protocol, horses had ad libitum access to coastal Bermuda hay and were fed sweet feed (1 kg, b.i.d.). Horses had ad libitum access to water at all times. Proximal intragastric pH was significantly lower during protocol A, than during protocol B. However, hourly mean pH was significantly different only during the day and evening hours between protocols. During protocol B, mean proximal pH decreased significantly from 03.00 to 09.00 compared to 19.00 to 23.00 h. A moderate positive correlation of hay intake vs. proximal gastric pH could be established. Intermittent feed deprivation decreased proximal gastric pH in horses relative to those horses for which feed was not restricted. However, the effect was only significant when fasting occurred during the day and evening hours, as a nocturnal decrease in pH occurred simultaneously in the fed horses. Episodes of daytime feed deprivation should be avoided if possible, as proximal gastric acid exposure rapidly increases during such events.

FIELD COMPARISON OF BERMUDA-HAY INFUSION TO INFUSIONS OF EMERGENT AQUATIC VEGETATION FOR COLLECTING FEMALE MOSQUITOES

Field experiments were conducted in east-central Alabama in 2003 and 2004 to compare the attractiveness of selected gravid-trap infusions to ovipositing female mosquitoes. Comparisons were made among infusions of the following plants: Bermuda hay, Cynodon dactylon, and 3 species of emergent aquatic plants typical of Culex larval habitats, i.e., soft rush, Juncus effusus; a common sedge, Rhynchospora corniculata; and broad-leaf cattail, Typha latifolia. Experiments were conducted at a site in Lee County, AL, with an abundance of common nuisance mosquitoes, including Culex quinquefasciatus and Aedes albopictus. Carbon dioxide-baited miniature light traps were operated concurrently with gravid traps to provide an activity index of mosquito species at the site. Gravid traps with hay infusion collected the greatest numbers of Cx. quinquefasciatus and Culex restuans females (2003). The results indicate that hay infusion is highly attractive to Cx. quinquefasciatus and is the infusion of choice for collecting females of this species in gravid traps. In the case of Ae. albopictus, infusions were not determined to be significantly different from one another in their attractiveness to gravid females. In general, females of Cx. quinquefasciatus and Cx. restuans demonstrated selectivity when choosing an oviposition site, whereas Ae. albopictus females did not. Factors associated with the oviposition biology of the latter species most likely account for their lack of preference for any single infusion type.

PRELIMINARY FINDINGS ON PRODUCING ORGANIC VIDALIA ONIONS

There has been interest in producing Vidalia onions organically among both conventional and organic growers. In the 2000–01 season we began to look at producing onions organically. Starting with conventionally produced transplants that were transplanted at standard commercial spacings on beds prepared with 10.2–15.2 cm of incorporated compost and 2,802 kg·ha–1 rate of fresh poultry litter. This was sidedressed with an additional 2,500 less/acre (2,802 kg·ha–1) poultry litter. Yields were about half of conventional onion production. In 2002–03, production of organic transplants with 10.2 cm of incorporated compost with 2.24 t·ha–1 rate of poultry litter, which was followed by an additional sidedressing of 2.24 t·ha–1 rate of poultry litter resulted in similar findings. The weight of harvested transplants was about half that of conventionally produced transplants. In the 2002–03 and 2003–04 seasons various natural mulches were evaluated for weed control. They included wheat straw, oat straw, Bermuda hay, pine straw, and compost. None of these performed better than hand weeding and the wheat straw, oat straw, and Bermuda hay actually reduced yields apparently due to allelopathic effects. Finally in the 2003–04 season rates of poultry litter from 0–22.4 t·ha–1 were evaluated for transplant production with rates of 13.4, 17.9, and 22.4 t·ha–1 yielding plants comparable to conventional transplants. Work continues in the area of organic Vidalia onion production. One of the greatest challenge for future work will be finding a cost-effective and practical method of controlling weeds in transplant production.

EVALUATION OF OVIPOSITION SUBSTRATES AND ORGANIC INFUSIONS ON COLLECTION OF CULEX IN FLORIDA

Gravid mosquito traps are commonly used for both arbovirus surveillance and population surveillance of mosquitoes of the genus Culex. Oviposition substrates, used as baits in these traps, were tested against Culex under laboratory and field conditions. In the laboratory all substrates tested as 1% and 10% dilutions in 2-choice bioassays against female Cx. quinquefasciatus were significantly more effective than well water controls in eliciting oviposition. Strongest responses were to dilutions of dairy effluent, followed by larval water and infusions of alfalfa hay, alfalfa pellets, Bermuda hay, oak leaves, and Typha leaves, with lowest responses to cow manure infusion. In the field, few significant differences in collections were obtained between traps baited with different infusions. Significantly more Cx. quinquefasciatus and Cx. nigripalpus were collected in traps baited with cow manure infusion (highest) compared to alfalfa hay infusion (lowest). Responses of Cx. quinquefasciatus to dairy effluent and infusions of Bermuda hay, oak leaves, and Typha leaves were not significantly different from either cow manure infusion or alfalfa hay infusion. Responses of Cx. nigripalpus were highest to cow manure infusion and equally low to infusions of alfalfa hay and Typha leaves; moderate responses were observed to dairy effluent and infusions of Bermuda hay and oak leaves. Gravid females comprised 66.7-81.9% of the collections for each infusion type, with no significant difference among infusions in the proportion of gravid females collected.

The Economic Impacts of Restricting Agricultural Uses of Manure on Hog Farms in Southern Seaboard

ABSTRACT EPA in December, 2000 proposed rules that would bring more livestock operations under regulation and restrict manure application more closely to crop nutrient needs. This paper, using individual whole-farm modeling applied to survey data, assessed the impacts of the proposed regulation on hog farms in the Southern Seaboard region. Results showed impacts would be particularly severe on large-size farms (over 2,500 pigs) applying manure to Bermuda hay. Feeding hogs a phytase diet that reduces phosphorous in manure reduced the income loss for farms with limited acres for applying manure.

Factors associated with development of ileal impaction in horses with surgical colic: 78 cases (1986–2000)

Deal impaction is prevalent in the south-eastern USA, where feeding of Coastal Bermuda hay has been implicated as a risk factor. Alternatively, infection with the tapeworm Anoplocephala perfoliata has been identified as a risk factor for ileal impaction in the UK. We hypothesised that feeding Coastal Bermuda hay and failure to administer routinely an anthelmintic with efficacy against tapeworms would place horses at risk of developing ileal impaction in the USA. Seventy-eight horses, with surgically confirmed ileal impaction and 100 horses admitted for colic that did not have an ileal impaction, were selected retrospectively for logistic regression analysis. Using odds ratios (OR) as an index of risk, feeding Coastal Bermuda hay (OR = 2.9) and failure to administer a pyrantel salt within 3 months of admission (OR = 3.1) placed horses at risk of development of ileal impaction. This study confirms the belief that feeding Coastal Bermuda hay places horses at risk of ileal impaction, although the quality of the hay may also play a role. Periodic administration of anthelmintics with efficacy against tapeworms should be considered to reduce risk of ileal impaction.