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1.
J Econ Entomol ; 110(2): 487-490, 2017 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-28334171

RESUMO

The invasive brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is an important pest of soybean (Glycine max L. Merr.) in the Mid-Atlantic United States. In order to assess the influence of nonmanaged wooded borders on H. halys infestation patterns in soybean, 12 soybean fields in Orange and Madison Counties, VA, were sampled each week from July to October in 2013 or 2014 for H. halys. At each location, five 2-min visual counts of H. halys life stages were made on tree of heaven (Ailanthus altissima Mill.) and other favorable host trees along a wooded border, on the adjacent soybean edge, 15 m into the soybean field, and 30 m into the field. Seasonal data showed a clear trend at all locations of H. halys densities building up on A. altissima-dominated wooded borders in July, then, gradually moving into adjacent soybean field edges later in the summer. Halyomorpha halys did not move far from the invading field edge, with approximately half as many bugs being present at 15 m into the field and very few being detected 30 m into the field. These results have implications for continued monitoring and management using field border sprays, particularly on edges adjacent to woods.


Assuntos
Glycine max , Heterópteros/fisiologia , Árvores , Ailanthus , Animais , Proteção de Cultivos/métodos , Espécies Introduzidas , Dinâmica Populacional , Estações do Ano , Virginia
2.
J Econ Entomol ; 109(6): 2586-2589, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27744285

RESUMO

Sampling soybean fields for the brown marmorated stink bug, Halyomorpha halys Stål (Hemiptera: Pentatomidae), can be challenging. Both adults and nymphs have a "startle response" and drop to the ground with even the slightest disturbance. This behavior could reduce the effectiveness of the traditional sweep net and ground cloth sampling methods. In 2013 and 2014, in Virginia, Delaware, and Maryland, we evaluated a visual plant inspection method that consisted of counting the number of brown marmorated stink bug nymphs and adults seen on soybean plants in a 2-min inspection period while walking carefully between two rows. After a 30-min interval, which allowed the stink bugs to reposition in the canopy, the area was resampled using 15 sweeps with a 38-cm-diameter sweep net. In total, 76 soybean fields and 2,042 paired comparisons were used to determine a strong linear relationship between sampling methods (y = 0.984x + 0.4359, R2 = 0.6934, where y = brown marmorated stink bugs/2-min visual count and x = brown marmorated stink bugs/15 sweeps). An average visual count of 5.4 brown marmorated stink bugs in 2 min was estimated as being equivalent to the current economic threshold of 5 stink bugs per 15 sweeps. Visual inspection appears to be an effective method for assessing brown marmorated stink bug populations in soybeans.


Assuntos
Glycine max , Heterópteros/fisiologia , Controle de Insetos/métodos , Animais , Delaware , Heterópteros/crescimento & desenvolvimento , Maryland , Ninfa/fisiologia , Dinâmica Populacional , Glycine max/crescimento & desenvolvimento , Virginia
3.
Curr Oncol ; 23(4): e332-9, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27536182

RESUMO

BACKGROUND: Screening clinical breast examination (cbe) is controversial; the use of cbe is declining not only as a screening tool, but also as a diagnostic tool. In the present study, we aimed to assess the value of cbe in breast cancer detection in a tertiary care centre for breast diseases. METHODS: This retrospective study of all breast cancers diagnosed between July 1999 and December 2010 at our centre categorized cases according to the mean of detection (cbe, mammography, or both). A cbe was considered "abnormal" in the presence of a mass, nipple discharge, skin or nipple retraction, edema, erythema, peau d'orange, or ulcers. RESULTS: During the study period, a complete dataset was available for 6333 treated primary breast cancers. Cancer types were ductal carcinoma in situ (15.3%), invasive ductal carcinoma (75.7%), invasive lobular carcinoma (9.0%), or others (2.2%). Of the 6333 cancers, 36.5% (n = 2312) were detected by mammography alone, 54.8% (n = 3470) by mammography and cbe, and 8.7% (n = 551) by physician-performed cbe alone (or 5.3% if considering ultrasonography). Invasive tumours diagnosed by cbe alone were more often triple-negative, her2-positive, node-positive, and larger than those diagnosed by mammography alone (p < 0.05). CONCLUSIONS: A significant number of cancers would have been missed if cbe had not been performed. Compared with cancers detected by mammography alone, those detected by cbe had more aggressive features. Clinical breast examination is a very low-cost test that could improve the detection of breast cancer and could prompt breast ultrasonography in the case of a negative mammogram.

4.
J Clin Endocrinol Metab ; 100(10): E1362-9, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26259131

RESUMO

CONTEXT: GLIS3 (GLI-similar 3) is a member of the GLI-similar zinc finger protein family encoding for a nuclear protein with 5 C2H2-type zinc finger domains. The protein is expressed early in embryogenesis and plays a critical role as both a repressor and activator of transcription. Human GLIS3 mutations are extremely rare. OBJECTIVE: The purpose of this article was determine the phenotypic presentation of 12 patients with a variety of GLIS3 mutations. METHODS: GLIS3 gene mutations were sought by PCR amplification and sequence analysis of exons 1 to 11. Clinical information was provided by the referring clinicians and subsequently using a questionnaire circulated to gain further information. RESULTS: We report the first case of a patient with a compound heterozygous mutation in GLIS3 who did not present with congenital hypothyroidism. All patients presented with neonatal diabetes with a range of insulin sensitivities. Thyroid disease varied among patients. Hepatic and renal disease was common with liver dysfunction ranging from hepatitis to cirrhosis; cystic dysplasia was the most common renal manifestation. We describe new presenting features in patients with GLIS3 mutations, including craniosynostosis, hiatus hernia, atrial septal defect, splenic cyst, and choanal atresia and confirm further cases with sensorineural deafness and exocrine pancreatic insufficiency. CONCLUSION: We report new findings within the GLIS3 phenotype, further extending the spectrum of abnormalities associated with GLIS3 mutations and providing novel insights into the role of GLIS3 in human physiological development. All but 2 of the patients within our cohort are still alive, and we describe the first patient to live to adulthood with a GLIS3 mutation, suggesting that even patients with a severe GLIS3 phenotype may have a longer life expectancy than originally described.


Assuntos
Doenças Ósseas/genética , Hipotireoidismo Congênito/genética , Deficiências do Desenvolvimento/genética , Diabetes Mellitus/genética , Resistência à Insulina/genética , Hepatopatias/genética , Fenótipo , Fatores de Transcrição/genética , Doenças Ósseas/congênito , Proteínas de Ligação a DNA , Diabetes Mellitus/congênito , Feminino , Humanos , Lactente , Recém-Nascido , Hepatopatias/congênito , Masculino , Proteínas Repressoras , Transativadores
5.
J Hum Evol ; 65(3): 266-81, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23891007

RESUMO

Recent genetic studies based on the distribution of mtDNA of haplogroup U6 have led to subtly different theories regarding the arrival of modern human populations in North Africa. One proposes that groups of the proto-U6 lineage spread from the Near East to North Africa around 40-45 ka (thousands of years ago), followed by some degree of regional continuity. Another envisages a westward human migration from the Near East, followed by further demographic expansion at ∼22 ka centred on the Maghreb and associated with a microlithic bladelet culture known as the Iberomaurusian. In evaluating these theories, we report on the results of new work on the Middle (MSA) and Later Stone (LSA) Age deposits at Taforalt Cave in Morocco. We present 54 AMS radiocarbon dates on bone and charcoals from a sequence of late MSA and LSA occupation levels of the cave. Using Bayesian modelling we show that an MSA non-Levallois flake industry was present until ∼24.5 ka Cal BP (calibrated years before present), followed by a gap in occupation and the subsequent appearance of an LSA Iberomaurusian industry from at least 21,160 Cal BP. The new dating offers fresh light on theories of continuity versus replacement of populations as presented by the genetic evidence. We examine the implications of these data for interpreting the first appearance of the LSA in the Maghreb and providing comparisons with other dated early blade and bladelet industries in North Africa.


Assuntos
Cavernas , Fósseis , Sedimentos Geológicos/química , Antropologia Cultural , Teorema de Bayes , Evolução Biológica , Osso e Ossos/química , Sedimentos Geológicos/análise , Humanos , Marrocos , Datação Radiométrica , Tecnologia
7.
J Med Genet ; 46(7): 480-9, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19447831

RESUMO

BACKGROUND: The recognition of the 17q21.31 microdeletion syndrome has been facilitated by high resolution microarray technology. Recent clinical delineation of this condition emphasises a typical facial appearance, cardiac and renal defects, and speech delay in addition to intellectual disability, hypotonia and seizures. METHODS AND RESULTS: We describe 11 previously unreported patients expanding the phenotypic spectrum to include aortic root dilatation, recurrent joint subluxation, conductive hearing loss due to chronic otitis media, dental anomalies, and persistence of fetal fingertip pads. Molecular analysis of the deletions demonstrates a critical region spanning 440 kb involving either partially or wholly five genes, CRHR1, IMP5, MAPT, STH, and KIAA1267. CONCLUSION: These data have significant implications for the clinical diagnosis and management of other individuals with 17q21.31 deletions.


Assuntos
Anormalidades Múltiplas/genética , Cromossomos Humanos Par 17 , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/patologia , Criança , Pré-Escolar , Hibridização Genômica Comparativa , Feminino , Deleção de Genes , Humanos , Lactente , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Fenótipo , Síndrome
8.
Am J Clin Nutr ; 64(4): 659-62, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8839518

RESUMO

The Internet provides many opportunities to learn, to educate, and to communicate new ideas. This article introduces concepts and terms that will facilitate the use of electronic information media by nutritional scientists. A vast array of sites on the Internet are relevant to the nutritional scientist, including those developed by government, industry, and educational sources, professional societies, and individuals. Using the wide variety of electronic sources that make up the Internet in an efficient and effective manner is an important skill not only for locating specific information, but also for keeping abreast of novel developments and new concepts as they are introduced and discussed. Uncritical acceptance of information appearing in the electronic media, however, is problematic; electronic publishing may occur without the rigorous peer-review process common for publishing in scientific journals. Those intending to publish material electronically must accept responsibility for the veracity of the information, realizing that anyone, from the lay consumer to the professional, may have access to that information. The Internet and its electronic relatives (eg, the World Wide Web and newsgroups) can become invaluable tools for nutritional scientists, extending beyond traditional sources of information (eg, the library) to support research and educational efforts, but use of this new technology must be tempered with knowledge of its limitations as well as potentials.


Assuntos
Redes de Comunicação de Computadores , Bases de Dados Factuais , Fenômenos Fisiológicos da Nutrição , Humanos , Serviços de Informação
9.
Home Healthc Nurse ; 14(5): 372-7, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8847222

RESUMO

For continuity in delivering healthcare across the continuum, an institutionally based home healthcare department was established at Georgia Baptist Medical Center, Atlanta, Georgia. The overall mission of home healthcare services is to maintain high levels of care while maintaining the lowest reasonable costs. Much of the department's patient care focuses on patients challenged with diabetes. This article describes the creation of a progressive, self-directed diabetes education model within this hospital-based home care program.


Assuntos
Diabetes Mellitus Tipo 1/enfermagem , Serviços Hospitalares de Assistência Domiciliar/organização & administração , Modelos Educacionais , Modelos de Enfermagem , Educação de Pacientes como Assunto/organização & administração , Procedimentos Clínicos , Humanos
10.
J Dairy Sci ; 77(10): 3111-7, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7836599

RESUMO

Forty-eight multiparous Holstein cows were blocked according to month of parturition, age, and previous milk yield and arranged in a randomized complete block design to evaluate the effect of a naturally occurring sodium sesquicarbonate on DMI, milk yield, milk composition, milk value, and systemic acid-base status. Cows were assigned at parturition to diets containing sorghum silage, alfalfa hay, concentrate, and 0 or 1% naturally occurring sodium sesquicarbonate (DM basis); cows were fed these diets for 308 d postpartum. Blood was collected every 4 wk via jugular venipuncture for analysis of pH, HCO3, partial pressure of O2, and partial pressure of CO2. Sesquicarbonate exhibited alkalogenic properties by increasing blood HCO3, partial pressure of CO2, and total CO2 for the 308-d lactation. Buffer tended to increase DMI and increased milk protein throughout lactation. During 0 to 56 d postpartum, sodium sesquicarbonate did not affect milk yield or composition. In midlactation (56 to 252 d postpartum), buffer increased milk protein content only. During 252 to 308 d postpartum, milk fat and protein contents increased with buffer supplementation. Hence, the value of milk yielded daily was similar for all cows. Effects of dietary buffer on all variables were more pronounced during late lactation.


Assuntos
Equilíbrio Ácido-Base/efeitos dos fármacos , Bicarbonatos/farmacologia , Carbonatos/farmacologia , Bovinos/fisiologia , Lactação/efeitos dos fármacos , Análise de Variância , Animais , Bicarbonatos/administração & dosagem , Carbonatos/administração & dosagem , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Leite/química , Fatores de Tempo
12.
J Dairy Sci ; 76(11): 3571-9, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8270700

RESUMO

The objective of this study was to evaluate the influence of dietary buffer value index on ruminal fluid pH, buffering capacity, and buffer value index in lactating cows. Three Holstein cows averaging 18 +/- 10 DIM were used in a 3 x 3 Latin square with 3-wk experimental periods. Diets contained grain:sorghum silage DM ratios of 50:50, 60:40, and 70:30. By analysis, these diets had buffer value indexes of -74, -41, and -7. The analyzed dietary buffer value index of the total diets was higher than the index that was calculated from the buffer value index of individual ingredients. Although milk fat content tended to be highest for milk from cows fed the 50:50 concentrate to forage diet and although milk protein production was highest for cows fed the 70:30 concentrate to forage diet, milk yield, 4% FCM, milk fat yield, protein content, and milk fat content were not significantly affected by dietary buffer value index. Dietary buffer equivalents were calculated to be 11% of total buffering equivalents available to the cow, and dietary acid equivalents were 15% of total acid production in the rumen. Compared with ruminal acid production and salivary buffering in the rumen, dietary acid and dietary buffer contributions to the acid-base balance of the cow are minor quantitatively. Ruminal fluid pH, hydrogen ion concentration, buffer value index, buffering capacity, and total VFA were not affected significantly by dietary buffer value index. Hence, dietary acid-base status alone is inadequate as a predictor of the need for buffers in the diet of lactating cows.


Assuntos
Ração Animal , Bovinos/fisiologia , Grão Comestível , Lactação , Silagem , Animais , Soluções Tampão , Ácidos Graxos Voláteis/metabolismo , Feminino , Concentração de Íons de Hidrogênio , Metabolismo dos Lipídeos , Leite/metabolismo , Proteínas do Leite/metabolismo , Rúmen/metabolismo
13.
J Dairy Sci ; 76(9): 2664-73, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8227668

RESUMO

The objective was to determine the effects of dietary inert fat on estimated energy balance, hormones in plasma, and reproduction during early lactation. From wk 0 to 12 postpartum, 14 pluriparous Holstein cows were fed individually a TMR, and blood samples were taken twice weekly for quantification of IGF-I, progesterone, and cholesterol. During wk 5 to 12, one-half of the cows remained on the TMR, and the other half were fed the TMR containing inert fat at 1.8% of dietary DM. Estrous behavior was monitored twice daily, and body condition scores were recorded every 4 wk. Cows fed inert fat between wk 5 and 12 postpartum had similar concentrations of IGF-I in plasma but greater luteal phase progesterone secretions than cows fed the control diet. Total cholesterol in plasma also was greater in cows fed inert fat than in cows fed the control diet. Intervals to first, second, and third ovulation or estrus did not differ among cows fed control or inert fat diets. Body condition scores, daily DMI, and milk production were not affected by dietary inert fat. Inert fat fed to cows between wk 5 and 12 postpartum did not affect ovulatory activity but may enhance luteal activity.


Assuntos
Bovinos/fisiologia , Gorduras na Dieta/farmacologia , Metabolismo Energético , Hormônios/sangue , Lactação/fisiologia , Reprodução/fisiologia , Animais , Peso Corporal , Colesterol/sangue , Estro/fisiologia , Feminino , Fator de Crescimento Insulin-Like I/metabolismo , Ovulação/fisiologia , Progesterona/sangue
14.
J Dairy Sci ; 76(8): 2222-34, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8408868

RESUMO

Four ruminally cannulated, lactating Holstein cows were assigned to a 4 x 4 Latin square to monitor effects of intraruminal NaHCO3 infusion on temporal changes in ruminal and systemic acid-base status and mineral metabolism. Twice daily from 2 to 4 h postfeeding, cows were infused with 0, 110, 220, or 330 g of NaHCO3 dissolved in 3.8 L of water. All cows had access to their TMR of sorghum silage and concentrate (35: 65, DM basis) for 2 h twice daily. Ruminal fluid, blood, and urine were collected at feeding and every 30 min postfeeding for 12 h on the last day of each 14-d period. Total urine volume also was measured during this interval. Infusion of buffer increased ruminal fluid buffering capacity transiently at 4.5 h postfeeding but otherwise did not markedly affect ruminal fluid acid-base status. Systemic acid-base status was unaffected by the buffer primarily because renal excretion of base successfully reduced systemic base load. Urine volume increased in response to NaHCO3 infusion. Buffer infusion increased urinary excretion of Na, Mg, and K but decreased Ca excretion for 12 h postfeeding; Cl excretion was not affected. Buffer infusion tended to increase total VFA in ruminal fluid. Our data indicate that homeostatic mechanisms can eliminate exogenous base via the kidneys; hence, acid-base status was not perturbed by infusion of NaHCO3. The increased excretion of Mg and K with buffer infusion indicates that the dietary requirements for these minerals may be increased by NaHCO3. Although loss of Ca through the urine was reduced by buffer infusion, this reduction may indicate reduced availability of Ca to the cow. The diuresis accompanying large doses of NaHCO3 may increase dietary requirements for some minerals.


Assuntos
Equilíbrio Ácido-Base/efeitos dos fármacos , Bovinos/fisiologia , Minerais/metabolismo , Rúmen/efeitos dos fármacos , Bicarbonato de Sódio/administração & dosagem , Animais , Cálcio/urina , Diurese/efeitos dos fármacos , Magnésio/urina , Potássio/urina , Rúmen/fisiologia , Sódio/urina , Bicarbonato de Sódio/farmacologia
15.
J Dairy Sci ; 75(9): 2394-408, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1333496

RESUMO

The influence of dietary buffer value index and dietary ADF content on ruminal fluid pH, buffering capacity, and buffer value index was measured. Four lactating Holstein cows (two primiparous) averaging 72 +/- 60 DIM were used in a 4 x 4 Latin square with 3-wk experimental periods. Treatments were a 2 x 2 factorial arrangement of TMR containing two ADF concentrations (16 and 21% of DM) and two buffer value indexes (calculated from analysis of individual dietary ingredients to be -200 and 0). Milk fat content and milk fat yield tended to be increased by high ADF, and protein yield tended to increase with low buffer value index and low ADF. Although the high ADF diets increased ruminal fluid pH, they reduced buffering capacity; because the magnitude of the pH increase was greater than the reduction in buffering capacity, ruminal fluid buffer value index was increased by added ADF. The high buffer value index diets reduced ruminal fluid pH and increased ruminal fluid buffering capacity; effects on pH outweighed those on buffering capacity so that the ruminal fluid index paradoxically decreased as the dietary index increased. Ruminal fluid acetate increased and propionate decreased as ADF increased. We conclude that ruminal fluid buffer value index increases with dietary ADF, likely because of reduced ruminal concentrations of fermentation acids. Because diets with the highest index produced the lowest ruminal indexes, dietary buffer value index must be studied further before it can be included in any model purporting to predict the need for supplemental dietary buffers.


Assuntos
Equilíbrio Ácido-Base/fisiologia , Bovinos/fisiologia , Fibras na Dieta/farmacologia , Lactação/fisiologia , Rúmen/fisiologia , Acetatos/metabolismo , Animais , Líquidos Corporais/fisiologia , Soluções Tampão , Butiratos/metabolismo , Ácido Butírico , Detergentes , Feminino , Alimentos , Concentração de Íons de Hidrogênio , Cinética , Propionatos/metabolismo
16.
J Dairy Sci ; 75(9): 2409-20, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1333497

RESUMO

Our objective was to compare the influence of dietary NaHCO3 and a multielement buffer on ruminal acid-base status and lactation performance of dairy cows. Five ruminally fistulated, primiparous and multiparous lactating Holstein cows averaging 123 +/- 21 d postpartum were assigned randomly to treatments in a 5 x 5 Latin square with 3-wk experimental periods. Treatments were a basal diet without supplemental buffers, with 1.5% NaHCO3 or 1.5% multielement buffer, or with NaHCO3 or multielement buffer solutions poured into the rumen via cannula at 2 h postfeeding. Addition of either buffer to the diet reduced ruminal fluid hydrogen ion concentration from 0 to 6 h postfeeding; only NaHCO3 reduced ruminal fluid acidity when dosed via the cannula. Addition of buffers via ruminal cannula appeared to retard the reduction in ruminal fluid acidity that normally occurs from 6 to 12 h postfeeding; this may have been related to a feedback mechanism inhibiting salivary buffer secretion. Buffering capacity of ruminal fluid tended to increase with buffer addition; the increase was greatest during infusion of NaHCO3. The ruminal fluid buffer value index increased by 4 units for control cows from early (0 to 6 h) to late (6 to 12) postfeeding; smaller increases were noted for addition of multielement buffer. This index was not different for NaHCO3 during these two intervals. Milk yield and DMI were not affected by buffer addition. Although milk fat content tended to be higher with the multielement buffer than with NaHCO3, it was not accompanied by the expected alterations in ruminal acid-base status. Therefore, this increase may be related to systemic effects of specific minerals in the multielement buffer rather than to a more stable ruminal environment. Based on the ruminal fluid buffer value index, NaHCO3 tended to maintain the most stable ruminal acid-base status.


Assuntos
Equilíbrio Ácido-Base/fisiologia , Bicarbonatos/farmacologia , Bovinos/fisiologia , Lactação/fisiologia , Rúmen/efeitos dos fármacos , Sódio/farmacologia , Acetatos/metabolismo , Equilíbrio Ácido-Base/efeitos dos fármacos , Animais , Bicarbonatos/administração & dosagem , Líquidos Corporais/fisiologia , Soluções Tampão , Butiratos/metabolismo , Ácido Butírico , Dieta , Feminino , Cinética , Propionatos/metabolismo , Rúmen/fisiologia , Sódio/administração & dosagem , Bicarbonato de Sódio
17.
J Anim Sci ; 70(4): 1238-50, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1582954

RESUMO

Our objective was to evaluate the effectiveness of a low dietary cation-anion balance (DCAB) in preventing milk fever and udder edema in dry cows consuming a high-Ca diet and to evaluate the effect of this diet on calves delivered by these cows. Seventy primiparous or multiparous cows and 50 pregnant heifers were offered alfalfa hay-based diets beginning 4 wk before their projected calving date. Diets contained 1.6% Ca and a DCAB of -3 or +9 mEq/100 g of diet DM. Blood and urine samples were collected weekly from 3 wk prepartum until 3 wk postpartum. Blood samples were collected from calves at parturition and weekly thereafter for 3 wk. Feeding a low vs high DCAB in a high-Ca diet for 3 wk prepartum did not reduce the incidence of milk fever; this lack of response may have been attributable to the relatively low DCAB of each diet and the small difference in DCAB between the two diets. Udder edema seemed to regress more rapidly postpartum for cows that had consumed the low DCAB during the dry period. Test diets fed to prepartum cows did not affect systemic acid-base status or plasma mineral content of their calves, although plasma Ca was somewhat lower for calves from cows consuming a low DCAB and was higher for calves from primigravid cows. Correlations of plasma mineral concentration of the cows with those of their calves were highest for plasma Ca (r = .75; P less than .001). We conclude that the prophylactic effects on the occurrence of milk fever of feeding a low DCAB during the dry period may be absent when diets contain greater than 1.6% Ca and DCAB is greater than or equal to -3. The cation-anion balance of the diet consumed by dry cows did not affect the acid-based status or plasma mineral content of their calves.


Assuntos
Cálcio da Dieta/administração & dosagem , Doenças dos Bovinos/prevenção & controle , Dieta , Paresia Puerperal/prevenção & controle , Equilíbrio Ácido-Base , Animais , Animais Recém-Nascidos , Ânions/administração & dosagem , Cátions/administração & dosagem , Bovinos , Edema/prevenção & controle , Edema/veterinária , Feminino , Lactação , Análise dos Mínimos Quadrados , Glândulas Mamárias Animais/patologia , Minerais/administração & dosagem , Minerais/metabolismo , Gravidez
18.
J Dairy Sci ; 75(3): 811-9, 1992 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1314858

RESUMO

Our objective was to develop a buffer value index that would incorporate alterations in both ruminal fluid pH and buffering capacity as indicators of the influence of dietary buffering and alkalinizing agents on ruminal acid-base status. This index was evaluated using ruminal fluid from four lactating Holstein cows fed either sorghum silage or alfalfa hay in high or low concentrate diets. Ruminal fluid was incubated in vitro for 1, 2, 3, 4, or 5 h with no buffer or with 7.1 g of either NaHCO3, sodium sesquicarbonate, or a multielement buffer added per liter of ruminal fluid. Ruminal fluid pH was lower for diets based on high concentrate or alfalfa; buffering capacity between pH 5 and 7 was greater for high concentrate diets but was not affected by forage type. Ruminal fluid pH was higher for sesquicarbonate than for NaHCO3, the multielement buffer, or the control; however, ruminal fluid H+ concentration was similar between sesquicarbonate and NaHCO3, and both were lower than for the multielement buffer. Hydrogen ion concentration for the multielement buffer was lower than for the control. Buffering capacity was highest for NaHCO3, followed by sesquicarbonate, the multielement buffer, and the control. The buffer value index, which accounted for alterations in both H+ concentration and buffering capacity, was highest for NaCHO3, followed by sesquicarbonate, the multielement buffer, and the control. The poor response to the multielement buffer may be attributable to our relatively short incubation interval (less than 5 h). Dietary buffers increase both ruminal fluid pH and buffering capacity; both of these responses are beneficial.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Equilíbrio Ácido-Base , Ração Animal , Bovinos/metabolismo , Rúmen/metabolismo , Animais , Bicarbonatos/metabolismo , Soluções Tampão , Carbonatos/metabolismo , Bovinos/fisiologia , Ingestão de Alimentos , Ácidos Graxos Voláteis/análise , Feminino , Concentração de Íons de Hidrogênio , Lactação , Leite/análise , Leite/metabolismo , Poaceae , Rúmen/química , Silagem , Sódio/metabolismo , Bicarbonato de Sódio
19.
J Dairy Sci ; 74(10): 3496-504, 1991 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1660496

RESUMO

Four ruminally cannulated, lactating Holstein cows were assigned to a 4 X 4 Latin square to monitor the effects of NaHCO3 infusion on ruminal environment of cows receiving dietary sodium bicarbonate. Sodium bicarbonate (110 g) was mixed with 3.8 L of water and infused at a constant rate into the rumen from 0 to 2, 2 to 4, or 4 to 6 h postfeeding twice daily. All cows were fed sorghum silage and concentrate in a 35:65 DM ratio for 45 min twice daily. Ruminal fluid was collected at feeding and every 30 min postfeeding for 8 h on the last day of each 1-wk experimental period. Dry matter intake was not affected by NaHCO3 infusion. Yields of milk and its components were reduced with 4- to 6-h NaHCO3 infusion. At certain isolated times, especially during infusion, NaHCO3 infusion increased ruminal fluid buffer. Concentrations of ruminal fluid total VFA were not affected by NaHCO3 infusions, whereas acetate to propionate ratio tended to be reduced. Ruminal liquid volume tended to be increased by 0- to 2-h NaHCO3 infusion, and ruminal outflow rate tended to be reduced by the 2- to 4-h infusion. Intraruminal infusion of NaHCO3 into cows receiving supplemental dietary NaHCO3 altered ruminal acid-base status as typically reported for those receiving dietary NaHCO3; however, these alterations were not accompanied by shifts in ruminal VFA patterns or in milk composition that normally result from such feeding regimens. The effects of NaHCO3 infused directly into the rumen may be different from those of dietary NaHCO3 and are possibly related to the different time of entry into the rumen relative to feeding.


Assuntos
Bicarbonatos/farmacologia , Bovinos/fisiologia , Rúmen/fisiologia , Sódio/farmacologia , Equilíbrio Ácido-Base , Animais , Bicarbonatos/administração & dosagem , Soluções Tampão , Ingestão de Alimentos/efeitos dos fármacos , Ácidos Graxos Voláteis/análise , Feminino , Conteúdo Gastrointestinal/química , Concentração de Íons de Hidrogênio , Cinética , Lactação/efeitos dos fármacos , Leite/análise , Leite/metabolismo , Rúmen/química , Sódio/administração & dosagem , Bicarbonato de Sódio
20.
J Dairy Sci ; 74(7): 2296-302, 1991 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1654349

RESUMO

We evaluated the influence of supplemental dietary NaHCO3 on K metabolism of young dairy calves. Thirty-two Holstein and Jersey male and female calves were blocked at 56 to 70 d after birth according to breed, sex, and age and assigned randomly to a 2 x 2 factorial arrangement of dietary treatments for 8 wk: .4% K with 0% NaHCO3, .4% K with 2% NaHCO3, .6% K with 0% NaHCO3, and .6% K with 2% NaHCO3. Feed intake was not affected by dietary KCl or NaHCO3 supplementation, but average daily gain increased with increased K and tended to be reduced by dietary NaHCO3. Plasma K was elevated by increased dietary K but generally was unaffected by NaHCO3. Urinary Ca excretion appeared to be reduced by NaHCO3; urine pH increased with supplemental NaHCO3. Results indicate 1) the K requirement of the growing calf is between .40 and .55% of diet DM, 2) because urinary K excretion was elevated by dietary NaHCO3, the K requirement may be increased when the diet is supplemented with NaHCO3, and 3) average daily gain and plasma K are sensitive indicators of dietary K in the growing calf.


Assuntos
Bicarbonatos/farmacologia , Bovinos/metabolismo , Potássio/metabolismo , Sódio/farmacologia , Animais , Bicarbonatos/administração & dosagem , Cálcio/sangue , Cálcio/urina , Cloretos/sangue , Cloretos/urina , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Concentração de Íons de Hidrogênio , Masculino , Potássio/sangue , Potássio/urina , Distribuição Aleatória , Sódio/administração & dosagem , Sódio/sangue , Sódio/urina , Bicarbonato de Sódio , Aumento de Peso/efeitos dos fármacos
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