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1.
J Environ Qual ; 42(4): 1213-25, 2013 Jul.
Article in English | MEDLINE | ID: mdl-24216373

ABSTRACT

On-site wastewater treatment systems (OWTSs) are commonly used by households in areas of low population density to treat household wastewater and recycle it back to the environment. However, new absorption field products of differing architecture types have recently become available. A 3-yr field study was conducted in Bethel Heights, northwest Arkansas to assess several newer architecture types (i.e., chambers, polystyrene-aggregate, and gravel-less pipe) relative to the traditional pipe-and-gravel design under wet- and dry-soil conditions. Thirteen products of four different architecture types were installed in 46-cm-deep trenches in a Captina silt loam (fine-silty, siliceous, active, mesic Typic Fragiudult). Products were evaluated based on in-trench solution storage measured with an electronic water-level sensor approximately weekly from January 2009 through January 2012. Between May 2010 and January 2012, the thickness of any biomat formation was measured approximately weekly by insertion of a wooden dowel through in-trench monitoring ports. Architecture type alone did not affect ( > 0.05) in-trench solution storage. However, solution storage among individual products differed under wet- and dry-soil conditions ( < 0.05). When present, biomat thickness differed significantly ( < 0.05) among all four architecture types, ranging from 1.4 to 6.2 cm thick on average in the pipe-and-aggregate and polystyrene-aggregate types, respectively. Regression analyses showed that biomat thickness increased in three products, did not change in nine products, and decreased in one product over time. Results showed that several currently approved alternative products had similar in-trench solution storage but that several alternative products also had greater solution storage than that of the traditional pipe-and-gravel system. With no observed effluent surfacing, the soil morphology approach appears to be adequate and appropriately environmentally conservative for assigning typical single-family loading rates to alternative OWTS products and to the traditional pipe-and-gravel system.


Subject(s)
Soil , Water Purification , Arkansas , Waste Disposal, Fluid , Wastewater , Water
2.
Plant Dis ; 96(12): 1805-1817, 2012 Dec.
Article in English | MEDLINE | ID: mdl-30727261

ABSTRACT

The importance of fungicide seed treatments on cotton was examined using a series of standardized fungicide trials from 1993 to 2004. Fungicide seed treatments increased stands over those from seed not treated with fungicides in 119 of 211 trials. Metalaxyl increased stands compared to nontreated seed in 40 of 119 trials having significant fungicide responses, demonstrating the importance of Pythium spp. on stand establishment. Similarly, PCNB seed treatment increased stands compared to nontreated seed for 44 of 119 trials with a significant response, indicating the importance of Rhizoctonia solani in stand losses. Benefits from the use of newer seed treatment chemistries, azoxystrobin and triazoles, were demonstrated by comparison with a historic standard seed treatment, carboxin + PCNB + metalaxyl. Little to no stand improvement was found when minimal soil temperatures averaged 25°C the first 3 days after planting. Stand losses due to seedling pathogens increased dramatically as minimal soil temperatures decreased to 12°C and rainfall increased. The importance of Pythium increased dramatically as minimal soil temperature decreased and rainfall increased, while the importance of R. solani was not affected greatly by planting environment. These multi-year data support the widespread use of seed treatment fungicides for the control of the seedling disease complex on cotton.

3.
J Environ Qual ; 38(3): 1005-17, 2009.
Article in English | MEDLINE | ID: mdl-19329689

ABSTRACT

The Arkansas poultry industry produced more than 1.2 billion broiler chickens (Gallus gallus domesticus) and generated approximately 1.3 million Mg of broiler litter in 2002. High transportation costs of relocating broiler litter have led to annual land applications near poultry houses, increasing concern for potential surface water contamination from runoff. The objective of this study was to evaluate the effect of broiler litter application rate on runoff water quality in response to natural precipitation. Six plots (1.5 by 6.0 m), located on a Captina silt loam (finesilty, siliceous, active, mesic Typic Fragiudult), were amended with fresh broiler litter at 0, 5.6, and 11.2 Mg ha(-1) (control, low, and high litter treatments, respectively) once annually for 4 yr (May 2003 through April 2007). Runoff collected after each runoff-producing event was analyzed for soluble nutrients and metals. Cumulative runoff did not differ among litter treatments over the 4-yr study. At times, flow-weighted mean (FWM) concentrations of As from all litter treatments exceeded the maximum contaminant level for drinking water (0.01 mg As L(-1)). Four-year FWM Fe concentrations and runoff losses were greater (P < 0.05) from the high than from the low litter treatment and unamended control, and the 4-yr FWM P concentration from the low litter treatment (3.0 mg L(-1)) was greater than that from the unamended control (1.8 mg L(-1)). Since precipitation is temporally variable, evaluating runoff water quality in response to natural precipitation over several years is key to ascertaining the long-term impacts of surface-applied soil amendments like broiler litter.


Subject(s)
Lolium/growth & development , Manure , Water Pollutants, Chemical/analysis , Water/analysis , Animals , Arkansas , Chickens , Electric Conductivity , Hydrogen-Ion Concentration , Metals/analysis , Nitrates/analysis , Organic Chemicals/analysis , Oxidation-Reduction , Phosphorus/analysis , Quaternary Ammonium Compounds/analysis , Rain
4.
Poult Sci ; 86(11): 2441-9, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17954596

ABSTRACT

Consumer interest in free-range and organic poultry is growing. An experiment was conducted to assess the impact of alternative genotype and production systems on the sensory attributes of chicken meat. Specifically, a slow-growing genotype and a fast-growing genotype were raised for 91 and 63 d. The slow-growing birds were placed before the fast-growing birds to achieve a similar final BW at processing. Each genotype was assigned to 4 pens of 20 birds each and raised in indoor floor pens in a conventional research facility; each genotype was also assigned to 4 floor pens in a small facility with outdoor access. The diet was formulated to be low in energy and protein for slow growth. Birds were commercially processed and deboned at 4 h postmortem. A descriptive analysis of breast and thigh meat was conducted on all treatments by a trained descriptive panel. A consumer analysis was also conducted on the breast and thigh meat from only 2 treatments: slow-growing birds raised with outdoor access and fast-growing birds raised indoors. A descriptive analysis indicated that the breast meat from birds with outdoor access was more cohesive than the meat from indoor birds (P < 0.05). There were no significant differences for most basic tastes; however, both the breast meat and thigh meat of the fast-growing birds tasted saltier than that of the slow-growing birds (P < 0.05). Meat of the slow-growing birds had more dark meat fat flavor than that of the fast-growing birds (P < 0.05). Results from the consumer panel showed no significant differences in overall liking, appearance, texture, or flavor of the breast meat or thigh meat. Just-About-Right distributions of consumer responses did not vary between slow-growing birds with outdoor access and fast-growing birds raised indoors for most attributes; however, more panelists found the breast meat of slow-growing birds with outdoor access too dry (P < 0.05). Although a descriptive panel detected some differences in texture and flavor among treatments, the consumer panel did not indicate differences in liking between conventional and specialty products.


Subject(s)
Chickens/growth & development , Chickens/genetics , Housing, Animal , Animal Husbandry , Animals , Color , Female , Genotype , Meat/standards
6.
Plant Dis ; 90(5): 597-602, 2006 May.
Article in English | MEDLINE | ID: mdl-30781135

ABSTRACT

The effect of flooding and Pythium ultimum on soybean, Glycine max, was determined in a series of greenhouse experiments using the cultivars Hutcheson and Archer. Seeds were planted into pasteurized soil either not infested or infested with sand-cornmeal inoculum of P. ultimum and either flooded at emergence for 2 days or at the four leaf node stage (V4) for 5 days. A nonflooded control was included in each experiment. Seeds placed directly into infested soil resulted in little or no stand for Hutcheson regardless of flood treatment, whereas stand was reduced for Archer only in the flooded infested soil treatment. Additional experiments were conducted by placing seed onto a 2- to 5-mm layer of pathogen-free soil on top of the infested soil. Flooding at emergence reduced plant height, growth stage, and top dry weight for Hutcheson and root fresh weight for both cultivars. Greater reductions for Hutcheson in root weight, and top dry weight in P. ultimum-infested soil in the soil layer experiments, also indicated that Hutcheson was more susceptible than Archer. Flooding alone decreased root weights, and infestation with P. ultimum reduced weights further resulting in an additive effect. This also was the case for plant height, growth stage, and top dry weight for Hutcheson for flooding at emergence. Root discoloration was greatly increased for both cultivars in infested soil flooded at emergence. Similar results were found when plants were flooded at V4; however, the effect was not as great as with flooding at emergence. These studies indicate that Pythium damping-off and root rot may account for a portion of the negative response of soybean to flooding. The results also indicate that Archer has some resistance to P. ultimum.

7.
J Med Entomol ; 42(1): 42-7, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15691007

ABSTRACT

The lesser mealworm, Alphitobius diaperinus (Panzer), is a carrier of Campylobacter spp. in poultry facilities; however, the beetle's importance in the epidemiology of campylobacteriosis is not known. A series of laboratory experiments were designed to test the vector and reservoir competence of the lesser mealworm for Campylobacter jejuni. In the first experiment, C. jejuni was swabbed onto the outer surface of adult and larval beetles to determine how long bacteria can survive on the beetles' exterior. Next, adult and larval mealworms were allowed to drink from a solution containing C. jejuni and the duration of internal carriage was monitored. For the third experiment, beetles drank from a Campylobacter suspension and the duration of fecal shedding of bacteria was determined. In the last experiment, 3-d-old chickens were fed either one or 10 infected beetles, and cloacal swabs were tested periodically for Campylobacter. C. jejuni was detected on the exterior of larval beetles for 12 h, from the interior of larvae for 72 h, and from the feces of larvae for 12 h after exposure. Ninety percent of the birds that consumed a single adult or larval beetles became Campylobacter-positive, whereas 100% of the birds that consumed 10 adults or larvae became positive. These experiments demonstrated that the lesser mealworm could acquire and harbor Campylobacter from an environmental source. We found that the lesser mealworm was capable of passing viable bacteria to chickens that consumed the beetle. The beetle should be included in attempts to maintain Campylobacter-free poultry facilities.


Subject(s)
Campylobacter jejuni/physiology , Coleoptera/microbiology , Disease Reservoirs , Animals , Campylobacter Infections/transmission , Campylobacter Infections/veterinary , Chickens/microbiology , Insect Vectors , Larva/microbiology , Poultry Diseases/microbiology
9.
J Nematol ; 34(4): 378-83, 2002 Dec.
Article in English | MEDLINE | ID: mdl-19265960

ABSTRACT

Reproduction of reniform nematode Rotylenchulus reniformis on 139 soybean lines was evaluated in a greenhouse in the summer of 2001. Cultivars and lines (119 total) were new in the Arkansas and Mississippi Soybean Testing Programs, and an additional 20 were submitted by C. Overstreet, Louisiana State Extension Nematologist. A second test of 32 breeding lines and 2 cultivars from the Clemson University soybean breeding program was performed at the same time under the same conditions. Controls were the resistant cultivars Forrest and Hartwig, susceptible Braxton, and fallow infested soil. Five treatment replications were planted in sandy loam soil infested with 1,744 eggs and vermiform reniform nematodes, grown for 10 weeks in 10 cm-diam.- pots. Total reniform nematodes extracted from soil and roots was determined, and a reproductive factor (final population (Pf)/ initial inoculum level (Pi)) was calculated for each genotype. Reproduction on each genotype was compared to the reproduction on the resistant cultivar Forrest (RF), and the log ratio [log(RF + 1) is reported. Cultivars with reproduction not significantly different from Forrest (log ratio) were not suitable hosts, whereas those with greater reproductive indices were considered suitable hosts. These data will be useful in the selection of soybean cultivars to use in rotation with cotton or other susceptible crops to help control the reniform nematode and to select useful breeding lines as parent material for future development of reniform nematode resistant cultivars and lines.

10.
Plant Dis ; 85(3): 256-260, 2001 Mar.
Article in English | MEDLINE | ID: mdl-30832038

ABSTRACT

Modified Nash and Snyder's medium (MNSM) has been used to study soil populations of the fungus Fusarium solani f. sp. glycines, the causal agent of sudden death syndrome (SDS) of soybean. However, no studies have been conducted to confirm the accuracy of this technique in enumerating the SDS pathogen. To determine what portion of the colonies enumerated on MNSM are the SDS pathogen, 282 isolates resembling F. solani f. sp. glycines were collected from soil of two fields with a history of SDS in Arkansas using a soil dilution method with MNSM. The colony morphology of these isolates was compared on MNSM and on potato dextrose agar (PDA). Of these isolates, 112 were tested for pathogenicity on soybean in the greenhouse. In addition to fungi that produced colonies typical of F. solani f. sp. glycines on MNSM, 5 isolates each of four common colony types on MNSM were collected from each field for a total of 40 isolates. These isolates were compared to F. solani f. sp. glycines for colony morphology on PDA and for pathogenicity. Isolates that had colonies on MNSM that resembled F. solani f. sp. glycines had colony morphologies on PDA similar to this pathogen and produced SDS-like foliar symptoms in greenhouse inoculations of soybean. There was a significant quadratic relationship between foliar symptom severity and plant fresh weight. None of the other isolates tested resembled F. solani f. sp. glycines on either MNSM or PDA or produced SDS-foliar symptoms in greenhouse inoculations. These non-SDS isolates were F. solani, F. merismoides, a Pythium sp., and a Paecilomyces sp. All of these isolates produced some root rot, but significantly less than the F. solani f. sp. glycines reference isolate. The results of this study established that soil populations of F. solani f. sp. glycines can be accurately enumerated using MNSM. It should be noted that, on both MNSM and PDA, F. solani f. sp. glycines can resemble some isolates of F. solani f. sp. phaseoli, so pathogenicity tests of random isolates may be required to confirm the forma specialis especially in fields that have a history of both Glycines max and Phaseolus vulgaris.

11.
J Nematol ; 33(4S): 314-7, 2001 Dec.
Article in English | MEDLINE | ID: mdl-19265895

ABSTRACT

In greenhouse pot experiments during summer 2000, 118 soybean cultivars were tested to determine their suitability as hosts for the reniform nematode, Rotylenchulus reniformis. The cultivars included 115 new entries into the Arkansas and Mississippi soybean variety testing programs and three entries submitted by an extension nematologist from Texas. Also included in the tests were the R. reniformis-resistant cultivars Forrest and Hartwig, the susceptible cultivar Braxton, and fallow R. reniformis-infested soil that served as controls. Total number of eggs and nematodes extracted from both the soil and roots from each pot and reproductive indices (Pf/Pi) were calculated for each cultivar. The ratio of the Pf/Pi of each cultivar to the Pf/Pi of Forrest (RF), and the log ratio[log(10) (RF + 1)], are reported. Cultivars with reproductive indices that were greater than the reproductive index on Forrest were considered to be suitable hosts for R. reniformis. These data will be useful in the selection of soybean cultivars to use in rotation with cotton or other susceptible crops to help control the reniform nematode.

12.
Plant Dis ; 83(6): 582-586, 1999 Jun.
Article in English | MEDLINE | ID: mdl-30849837

ABSTRACT

Infections at early stages of plant development followed by a long incubation period before symptoms appear during reproductive stages is characteristic of the disease cycle of stem canker of soybean, caused by Diaporthe phaseolorum var. meridionales. To determine the effect of plant growth stage at the time of infection on symptom development and yield components, soybean plants (cv. Walters) were grown in microplots and inoculated with a suspension of ascospores (106/ml) at the V1, V4, V6, V10, or R2 growth stage. Noninoculated plants served as controls. Development of foliar symptoms was quantified weekly after flowering (R2), and yields and seed weights were determined. The experiment was conducted twice, in 1992 and 1994. Foliar symptoms of stem canker developed for all treatments except the noninoculated control. Foliar symptoms appeared at the R2 to R5 growth stage and reached 90 to 100% incidence for most treatments. Disease development was delayed for the R2 inoculation, suggesting that a minimum incubation period of 34 to 41 days is necessary before foliar symptoms develop. Disease (area under the disease progress curve) was greater and yield, seed number, and seed weight were less in 1994 than in 1992. Quadratic equations significantly related these variables to time of inoculation and reached maximum or minimum values between 40.9 and 43.3 days after planting. This corresponded to the V6 growth stage. Yield and seed number were affected by disease development during pod formation (R2 to R5) in both years, while yield and seed weight were affected by disease development during seed formation (R5 to R6) in 1992.

13.
Plant Cell Rep ; 17(4): 298-301, 1998 Feb.
Article in English | MEDLINE | ID: mdl-30736610

ABSTRACT

Low initiation frequency is one of the main barriers in applying somatic embryogenesis to the clonal production of Pinus species. Factors affecting initiation, including basal medium, plant growth regulators, and Phytagel concentration, have been investigated in loblolly pine (Pinus taeda L.). BM1 basal medium proved superior to DCR1 and LP (LP basal salts plus BM1 organic nutrients). No extrusion from megagametophytes was exhibited on LP medium. The combination of 3 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg/l 6-benzylaminopurine (BA) resulted in a higher extrusion frequency than that of 11 mg/l 2,4-D, 4.5 mg/l BA and 4.3 mg/l kinetin. Phytagel at 1 g/l resulted in the highest explant browning, but the lowest extrusion frequency, while 4 g/l Phytagel induced some dry embryogenic extrusions. Phytagel at 2 g/l was regarded as the best level for initiation of embryogenic cultures.

14.
Med Vet Entomol ; 11(3): 257-64, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9330257

ABSTRACT

We show the relationships that exist between the amount of hair and quantity of sebum on cattle skin and the population density of the horn fly, Haematobia irritans. Brahman and Chianina steers had means of 2390 and 1587 hairs per cm2, respectively, significantly more than the mean number of hairs on Angus, Brahman x Angus Crossbred, Charolais, and Red Poll steers. The Chianina steers had > 30% more sebum present on their skin and hair (0.58g/929 cm2) than the Angus, Charolais, and Red Poll steers at the Beef Cattle Research Station Savoy, Arkansas. The Brahman steers had a significantly greater amount of sebum present on the skin (1.51 g/929 cm2) than the Crossbred and purebred Angus steers (0.55 and 0.25 g/929 cm2, respectively) at the South Central Family Farms Research Centre Booneville, Arkansas. The Brahman and Chianina steers had means of 61.9 and 17.0 horn flies per steer, respectively, during the fly season, whereas the Angus, Crossbred, Charolais and Red Poll steers had fly season means that ranged from 76.9 to 265.8 flies per steer. Regression analysis showed that an increase of 100 hairs per cm2, was associated with a reduction of 11 horn flies in the Angus II, 5 in Angus I, 20 in Charolais, 37 in Red Poll, and 0.4 in Chianina steers at the Savoy Station and a reduction of 6.6 horn flies for the Angus, Brahman, and Crossbred steers at the Booneville Centre. Regardless of cattle breed, an increase of 1.0 g of sebum per 929 cm2 output by the steer was associated with 478.5 additional hairs per cm2 on the animal. Each increase of 0.25 g of sebum per 929 cm2 resulted in a decrease of 9.2 horn flies per steer. We conclude that some of the factors responsible for fly-resistance in cattle are hair density and the corresponding amount of sebum present on cattle skin and hair.


Subject(s)
Cattle Diseases , Cattle/parasitology , Ectoparasitic Infestations/veterinary , Hair/physiology , Hair/parasitology , Muscidae , Animals , Crosses, Genetic , Ectoparasitic Infestations/parasitology , Hair/ultrastructure , Male , Microscopy, Electron, Scanning , Orchiectomy , Population Density , Regression Analysis , Sebum/physiology , Species Specificity
15.
J Med Entomol ; 33(6): 983-7, 1996 Nov.
Article in English | MEDLINE | ID: mdl-8961651

ABSTRACT

Larval and adult lesser mealworms, Alphitobius diaperinus (Panzer), were found to harbor a Congo red-binding strain of Escherichia coli (Migula) Castellani & Chalmers both on the external surface of their body and internally for 12 d. Thereafter, E. coli was not detected, even though the beetles were exposed continuously to a food source inoculated with the bacteria. Lesser mealworm larvae and adults discharge E. coli bacteria in their feces for up to 6 and 10 d, respectively. However, bacteria were no longer detected in their feces after larvae underwent a single molt to the next larval stage. This indicated there was no transstadial transmission of this strain of E. coli. Consumed infected larvae were found to cause more 1-d-old chicks to have positive cloacal swabs for Congo red-binding E. coli than consumed infected adults. The data indicated that the lesser mealworm may play a role in the direct transmission of E. coli and contribute to the spread of this bacteria in broiler production systems. This may be achieved by beetles being directly consumed by chickens or indirectly by spread of the bacteria throughout the broiler house by lesser mealworm feces.


Subject(s)
Coleoptera/microbiology , Escherichia coli/isolation & purification , Animals
16.
Med Vet Entomol ; 10(2): 129-36, 1996 Apr.
Article in English | MEDLINE | ID: mdl-8744704

ABSTRACT

Statistically significant differences were observed in the population density of the horn fly, Haematobia irritans irritans L., on Angus cows having significantly different frame sizes. Angus cows, averaging < 112.5 cm in height at the hip, had significantly lower numbers of horn flies than Angus cows that measured 112.5-117.5 cm, 117.5-120 cm, 120-126 cm and > 126 cm in height at the hip. The Angus I cows ( < 112.5 cm in height at the hip) were significantly shorter in length (mean distance from the withers to the hip bone) and were smaller in girth than the Angus II (112.5-126 cm) and Booneville Angus cows ( > 126 cm). The estimated heritability (h2) of horn fly resistance was 0.43 +/- 0.07 and 0.95 +/- 0.31 for 1989 and 1990, respectively. Horn fly counts on the Angus I herd ( < 112.5 cm in height) was 118.1 (probable breeding value, PBV = -20.69) to 165 horn flies per cow (PBV = 26.9 flies per cow in 1989) and from 75.9 (PBV = -29.1) to 134.5 (PBV = 29.5) flies per cow in 1990. Angus I bulls had PBV = -23.7 to 13.4 and from -26.5 to 14.75 in 1989 and 1990, respectively. The Angus II cows had horn fly counts that ranged from 159.6 (PBV of -23.5) to 208.1 (PBV of 25) per cow in 1989 and from 232.3 (PBV of -56.2) to 378.7 (PBV of 90) per cow in 1990. Angus II bulls had PBVs that ranged from -17.1 to 18.9 in 1989 and from -28.1 to 48.8 in 1990. The Angus I cows had significantly (P < 0.0001) lower numbers of horn flies (mean of 63.8 horn flies per m2) than the small, medium or large Angus II cows (mean of 129.4, 149.6 and 145.5 horn flies per m2, respectively). The data indicated that some specific factor(s) associated with cow size contribute(s) to innate resistance of cattle to the horn fly.


Subject(s)
Body Constitution , Cattle Diseases/parasitology , Ectoparasitic Infestations/veterinary , Muscidae , Animals , Cattle , Ectoparasitic Infestations/parasitology , Host-Parasite Interactions , Population Density , Selection, Genetic
17.
J Med Entomol ; 30(2): 414-20, 1993 Mar.
Article in English | MEDLINE | ID: mdl-8459419

ABSTRACT

Weekly estimates of populations of horn fly, Haematobia irritans (L.), were made on individual purebred Charolais, Chianina, Hereford, Polled Hereford, and Red Poll cows in 1988, 1989, and 1990 with Angus included in 1989 and 1990. During the study period, 94 of approximately 200 individual cows were classified as either fly resistant or fly susceptible. In general, individuals retained the same classification over the 3-yr study period. The mean number of flies on individual susceptible cows in all breeds was at least twice the number of flies on resistant cows. Susceptible Chianina cows averaged > 4.5 times as many flies as resistant cows of the same breed. Individual cows within all breeds classified as fly resistant ranged in age from 2 to 12 yr, whereas fly-susceptible cows ranged in age from 2 to 14 yr; therefore, cow age did not influence the abundance of horn flies on individual cows within breeds. Two-year-old fly-resistant cows were identified accurately according to their horn fly-population density, showing the potential of host resistance in horn fly-population management.


Subject(s)
Cattle Diseases/parasitology , Cattle/parasitology , Ectoparasitic Infestations/veterinary , Muscidae , Animals , Cattle/genetics , Cattle Diseases/genetics , Ectoparasitic Infestations/genetics , Ectoparasitic Infestations/parasitology , Genetic Predisposition to Disease , Immunity, Innate/genetics , Seasons
18.
J Econ Entomol ; 84(4): 1275-82, 1991 Aug.
Article in English | MEDLINE | ID: mdl-1842801

ABSTRACT

Statistically significant differences were observed in the population density of the horn fly, Haematobia irritans irritans (L.), on different breeds of beef cattle. The European breed Chianina had a population density of horn flies generally less than or equal to 50% than that of the British cattle breeds (Angus, Hereford, Polled Hereford, and Red Poll) and another European breed (Charolais). Generally, no significant difference existed among numbers of horn flies on Hereford, Polled Hereford, and Red Poll cows in 1988 or among Angus, Hereford, Polled Hereford, and Red Poll cows in 1989. Factors other than color appeared to be involved in the selective process between the horn fly and its host. Population densities on two white European breeds (Charolais and Chianina) were significantly different on all weekly intervals except for 4 wk in both 1988 and 1989. No significant difference existed among Charolais and British breeds except during 4 wk in 1988 and 3 wk in 1989. When weaning weights of all calves were adjusted for the effects of age to 205 d, sex of calf, and age of dam, the indirect effect of the horn fly on weaning weight showed a significant linear regression. Each 100 flies per cow caused a reduction of 8.1 kg in calf weaning weight. Cows within each breed with low numbers of horn flies weaned significantly heavier calves than cows with higher numbers of horn flies.


Subject(s)
Breeding , Cattle Diseases/genetics , Ectoparasitic Infestations/veterinary , Muscidae , Animals , Cattle , Ectoparasitic Infestations/genetics , Female
19.
Adolescence ; 26(102): 457-72, 1991.
Article in English | MEDLINE | ID: mdl-1927676

ABSTRACT

The relationship of familial, demographic, and individual characteristics to the probability of pregnancy was examined among 124 sexually active adolescent females. Logistic regression analyses revealed that adolescent pregnancy status was a function of a combination of demographic and familial variables. Adolescents who were pregnant at the time of the study perceived their families as having low levels of family strength, perceived communication with parents as closed, came from homes characterized by family fragmentation (i.e., only one parent or no parent living in the home), came from low-income households, were unlikely to use any method of birth control, and were more likely to be married than their nonpregnant counterparts.


PIP: The differences in demographic characteristics, sexual practices, perceptions of family functioning, and individual factors among pregnant and nonpregnant adolescents were studied. 124 sexually active adolescent Caucasian females aged 12-19 years from an Arkansas clinic of which 57% were pregnant, participated in a nonrandom sample in 1988-89. 62.1% were from disrupted families (39.5% divorced, 12.9% remarried, and 9.7% widowed). Family disruption was higher among the pregnant sample (72% vs. 50.8%). 16.9% of the total sample were high school dropouts, but the majority were in the pregnant sample (28% vs. 5%). 91% of the pregnant sample had a family income of $20,000 vs. 66% of the nonpregnant sample. The procedures and instruments used are described. The following questionnaires were involved: 1) a demographic questionnaire for age, race, educational and marital status, parents' marital status, and socioeconomic status; 2) a sexual history questionnaire for pregnancy status, use of birth control, prior pregnancies and outcomes, and frequency of sexual activity; and 3) the Family Adaptability and Cohesion Evaluation Scale, the Family Strengths Questionnaire, the Parent Communication Scale, and the Adolescent Self-Esteem Scale. Stepwise logistic regression and chi square tests were used to predict pregnancy status. 6 variables out of 11 were significantly related to pregnancy status: lower perception of family strengths, problems with parent communication, married, low family income, birth control, and single parent or no parent family composition. 80% of pregnant and nonpregnant teens were predicted. The mean for perception of family strengths for pregnant vs. nonpregnant adolescents was 33.29 vs. 39.87, which means for pregnant teens a perception of a lack of pride and harmony in their families. Lower scores were also evident on the Parent Communication Scale (-1.22 vs. 2.62). Although not significant, pregnant adolescents saw their families as flexible but not very cohesive and had lower self-esteem scores. Nonpregnant adolescents were more likely to use birth control than pregnant adolescents. The results support prior findings with some variation in the effect of parent and child communication, and insignificant effects of perception of family adaptability, and self-esteem. The limitations are the lack of generalizability to other regions, and the model itself which did not assess familial factors such as parental control or other developmental factors such as self-worth. Causality is not determined.


Subject(s)
Family/psychology , Pregnancy in Adolescence/psychology , Adolescent , Adult , Contraception Behavior , Female , Humans , Logistic Models , Marriage , Parent-Child Relations , Pregnancy , Self Concept , Sexual Behavior , Surveys and Questionnaires
20.
J Dairy Sci ; 70(8): 1595-600, 1987 Aug.
Article in English | MEDLINE | ID: mdl-3668031

ABSTRACT

Holstein bull calves were assigned to be reared in either a stall until 47 d of age, then moved to a hutch; a hutch until 47 d, then moved to a stall; or an elevated pen. Jugular blood samples were obtained at 42, 49, and 56 d of age. Two trials were run during the fall of successive years with 5 to 7 calves per treatment per trial. Stalls were .56 X 1.2 m with elevated wooden slotted floors. Pens were 1.2 X 1.5 m with elevated wooden slotted floors and were located in the same open front building as the stalls. Hutches were 1.2 X 1.2 X 2.4 m long, and calves were restrained with a collar and 2.4-m chain. Calves were placed on treatment between 12 to 24 h after parturition. A treatment by day interaction for triiodothyronine, thyroxine, and adrenocorticotrophic hormone-induced cortisol release indicated that conditions responsible for treatment effects were largely reversed 9 d after moving from stalls to hutches or hutches to stalls.


Subject(s)
Cattle/physiology , Housing, Animal , Stress, Physiological/veterinary , Animals , Hydrocortisone/blood , Leukocyte Count/veterinary , Lymphocytes/physiology , Male , Neutrophils/physiology , Stress, Physiological/blood , Stress, Physiological/physiopathology , Thyroxine/blood , Triiodothyronine/blood
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