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1.
J Vet Med Educ ; 50(2): 128-133, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35452361

RESUMO

Insuffient time for learning activities makes learning very difficult. Weaker students need more time to appropriately manage their learning objectives. To ensure enough study time, curriculum designers must monitor potential mismatches between needed versus provided study time. This study was conducted to measure students' time loads and compare them to the workload determined by the curriculum and measured in European Credit Transfer and Accumulation System (ECTS) credits. Time load entry using the Studo mobile application consisted of entering the time required for all learning activities, categorized into attendance, self-study, and writing student papers, per course. In addition to time load measures, socio-demographic information on travel time, care obligations, and employment status was recorded. Over six semesters (2018/2019-2021), the average response rate per semester was low (8%-17%). Of the 75 piloted courses (4-16 per semester), 2 exceeded the number of hours specified in the curriculum. Regarding socio-demographic data, 3%-34% of the evaluated students worked part time (≥ 10 hours per week). In summary, students were disinclined to measure their learning time. With consideration of potential nonresponse bias, no significant evidence of curriculum workload exceedance was found for the evaluated courses at the University of Veterinary Medicine, Vienna. However, some students are under increased individual time pressure due to part-time employment. The ratio of measured to estimated time should be monitored as a key component to improve performance and enhance student learning.


Abstrakt Lernprozesse können nicht optimal gesteuert werden, wenn dafür zu wenig Zeit zur Verfügung steht. Insbesondere schwächere Studierende benötigen mehr Zeit. Um sicherzustellen, dass Studierenden ausreichend Lernzeit zur Verfügung steht, müssen Curriculumgestalter∗innen mögliche Diskrepanzen zwischen benötigter und bereitgestellter Lernzeit überwachen. Diese Studie wurde durchgeführt, um die tatsächliche Zeitbelastung von Studierenden (Timeload) zu dokumentieren und sie mit der durch das Curriculum festgelegten Arbeitsbelastung (Workload), gemessen in Anrechnungspunkten des European Credit Transfer and Accumulation Systems (ECTS), zu vergleichen. Die unterschiedlichen Lernzeiten wurden mit Hilfe der mobilen Anwendung Studo eingegeben und setzen sich aus den Zeitaufwänden für Anwesenheit, Selbststudium und Verfassen von wissenschaftlichen Arbeiten pro Lehrveranstaltung zusammen. Neben den Lernzeiten wurden in der Applikation zusätzlich soziodemographische Angaben zu Betreuungspflichten, Beschäftigungsausmaß und Anfahrtszeiten erfasst. Die durchschnittliche Rücklaufquote pro Semester betrug zwischen 2017/18 und 2021 (6 Semester) 8% bis 17%. Von 75 erfassten Lehrveranstaltungen (4 bis 16 pro Semester) wurde die im Curriculum festgelegte Arbeitsbelastung in zwei überschritten. Bezogen auf die soziodemographischen Daten arbeiteten 3% bis 34% der Studierenden laut Auswertung in Teilzeit (≥ 10 Stunden pro Woche). Zusammenfassend waren die Studierenden zurückhaltend, ihre Lernzeit zu erfassen. Unter Berücksichtigung einer möglichen Schweigeverzerrung durch Antwortausfälle wurden für die evaluierten Lehrveranstaltungen an der Veterinärmedizinischen Universität Wien keine Hinweise auf eine Überschreitung der im Curriculum festgelegten Arbeitsbelastung gefunden. Einige Studierende stehen jedoch aufgrund von Teilzeitbeschäftigung unter erhöhtem individuellen Zeitdruck. Das Verhältnis von gemessener (Timeload) zu geschätzter Zeit (Workload) sollte als qualitativer Indikator für Studierbarkeit überwacht werden, um die Leistung und die Lernsituation der Studierenden zu verbessern.


Assuntos
Educação em Veterinária , Aplicativos Móveis , Animais , Carga de Trabalho , Currículo , Aprendizagem
2.
BMC Vet Res ; 18(1): 51, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-35057802

RESUMO

BACKGROUND: Specialized neurons in the diencephalon detect blood hypernatremia in dehydrated animals. These neurons are connected with the pituitary gland, subsequently producing antidiuretic hormone to reabsorb water from urine in the kidneys, and to the forebrain to generate thirst and trigger drinking behavior. CASE PRESENTATION: This is the first case report describing clinical findings, magnetic resonance imaging (MRI) and necropsy results of a Belted Galloway heifer with severe clinical signs of dehydration and hypernatremia, but concurrent adipsia and isosthenuria. Due to insufficient recovery with symptomatic treatment, owners elected euthanasia. Postmortem MRI and necropsy revealed a complex forebrain malformation: mild abnormal gyrification of the forebrain cortex, lobar holoprosencephaly, and corpus callosum hypoplasia. The affected brain structures are well known to be involved in osmoregulation and generation of thirst in dogs, humans and rodents. CONCLUSIONS: Complex forebrain malformation can be involved in the pathogenesis of hypernatremia and adipsia in bovines.


Assuntos
Doenças dos Bovinos , Corpo Caloso/patologia , Hipernatremia , Animais , Encéfalo , Bovinos , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/patologia , Feminino , Hipernatremia/diagnóstico , Hipernatremia/veterinária , Sede
3.
Vet Pathol ; 57(6): 812-820, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32841102

RESUMO

Bovine babesiosis, caused by Babesia divergens, is in general a rare disease in Europe. Nonetheless, local outbreaks can cause severe economic damage, and postmortem identification represents a diagnostic challenge. During a recent outbreak in May 2018 in northern Germany, 21 animals of a herd of 150 cattle died within 40 days having had clinical signs of fever and hemoglobinuria. Gross examination of 4 of the 21 deceased animals revealed a tick infestation, jaundice, and dark brown staining of urine and kidneys. Histologically, there were iron-positive deposits, hyperplasia of the red pulp of the spleen, and centrilobular necrosis of hepatocytes. In several locations, small basophilic granules suggestive of intraerythrocytic parasites were visible in hematoxylin-eosin- and Giemsa-stained sections. Peripheral blood smears from a living cow from the herd and polymerase chain reaction (PCR) of feeding ticks revealed B. divergens infection. In situ hybridization (ISH) was applied on formalin-fixed, paraffin-embedded (FFPE) tissue of the necropsied cattle to confirm babesiosis in these animals postmortem. Digoxigenin-labeled DNA probes were generated based on a specific nucleotide sequence for B. divergens, obtained by PCR and sequencing of DNA isolates from infected Ixodes ricinus ticks from deceased cattle. ISH using these probes allowed postmortem diagnosis of B. divergens infection in routinely fixed FFPE tissues.


Assuntos
Babesiose , Doenças dos Bovinos , Animais , Babesiose/diagnóstico , Bovinos , Doenças dos Bovinos/diagnóstico , Europa (Continente) , Feminino , Formaldeído , Alemanha , Hibridização In Situ/veterinária , Inclusão em Parafina/veterinária
4.
J Dairy Res ; 86(3): 296-302, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31409432

RESUMO

This research paper addresses the hypothesis that in times of negative energy balance around parturition in dairy cattle, lipids stored in adipocytes are mobilised in a more intensive manner out of the abdominal depots than out of the subcutaneous adipose tissues. Furthermore, the impact of niacin supplementation and energy density of the ration on adipose tissue mass gain and loss was assessed. Absolute masses of subcutaneous (SCAT), retroperitoneal (RPAT), omental (OMAT), mesenterial (MAT) and abdominal adipose tissue as a whole (AAT) were estimated by ultrasonography at -42, 3, 21 and 100 DIM. Absolute and relative daily gain during dry period (-42 to 3 DIM) and loss in fresh cow period (3 to 21 DIM) and early lactation period (22 to 100 DIM) were calculated. Feeding regime neither by niacin nor by energy density exerted any effect on adipose tissue masses. The AAT was always bigger than SCAT, but RPAT, OMAT and MAT did not differ amongst each other. All depot masses showed similar patterns with an increase during dry period and a decrease after calving. In fresh cow period AAT absolutely and relatively lost more mass than SCAT. This confirms that AAT is more intensively mobilised than SCAT during that time span. Further absolute daily gain during dry period was strongly negatively correlated with absolute daily loss during fresh cow period. This underlines the impact of individual body condition on adipose mobilisation in periparturient dairy cows. According to these results, it has to be taken into account that the largest amount of fat mobilised in the fresh cow period origins from AAT. This might impact the pattern of adipose derived metabolites and metabolic effectors interacting in physiological and deregulated adaptation to negative energy balance.


Assuntos
Gordura Abdominal/fisiologia , Bovinos/fisiologia , Metabolismo Energético/fisiologia , Gordura Subcutânea/fisiologia , Gordura Abdominal/diagnóstico por imagem , Gordura Abdominal/efeitos dos fármacos , Animais , Composição Corporal , Dieta/veterinária , Suplementos Nutricionais , Feminino , Alemanha , Lactação , Niacina/administração & dosagem , Parto , Período Pós-Parto , Gravidez , Reprodução , Gordura Subcutânea/diagnóstico por imagem , Gordura Subcutânea/efeitos dos fármacos , Ultrassonografia/veterinária
5.
Arch Anim Nutr ; 72(6): 458-477, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30296167

RESUMO

The aim of this study was to assess differences of ruminal pH and rumination activity between the prepartal and postpartal period of cows and to investigate changes of feeding behaviour and ruminal fermentation depending on postpartal rations with slight differences in roughage energy and fibre concentration. Therefore, 11 rumen-cannulated German Holstein cows were used from 3 weeks antepartum until 16 weeks postpartum. During the dry period, all cows received the same diet. After calving cows were assigned to two groups receiving partial mixed rations with different energy concentrations (6.1 MJ NEL/kg DM [moderate], with 18% straw on dry matter [DM] basis, group MR) or 6.5 MJ NEL/kg DM [high], with 6% straw on DM basis, group HR). In both groups, concentrates were supplied on average at 45% of total DM intake. Circadian measurements of ruminal pH, ruminal temperature and rumination activity were conducted weekly during the transition period and bi-weekly after week 4 postpartum. Throughout the postpartal period, feed intake behaviour was measured, and twice during the experiment, rumen fluid composition and net-acid-base excretion in urine were determined. Mean ruminal pH, feeding behaviour, rumination activity and rumen fluid composition did not differ between the groups, whereas group HR exhibited higher diurnal variations of pH and had a lower rumen temperature than group MR postpartum. However, these differences also occurred during the prepartal period when groups received equal rations. It was observed that ruminal pH values and the risk for subacute ruminal acidosis (SARA) were increased during postpartal period, whereby the circadian pH values showed high cow-individual variations. Overall, differences of energy and fibre concentrations in roughage did not affect the observed variables, whereby it should be noted that the number of cows was quite low in this study. Our results suggest that the ruminal pH characteristics are rather cow individual, indicating that cows presumably differ in their susceptibility to develop SARA.


Assuntos
Ração Animal/análise , Fibras na Dieta/administração & dosagem , Ingestão de Energia/fisiologia , Comportamento Alimentar/fisiologia , Lactação/fisiologia , Rúmen/efeitos dos fármacos , Animais , Bovinos , Fibras na Dieta/análise , Feminino , Concentração de Íons de Hidrogênio , Ruminação Digestiva/fisiologia
6.
Arch Anim Nutr ; 72(2): 100-120, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29392981

RESUMO

The aim of this study was to investigate the effects of different energy supplies from roughage and concentrates on performance, health and energy efficiency during early lactation. For this purpose an experiment was conducted containing 64 pluriparous German Holstein cows from 3 weeks prepartum until 16 weeks postpartum. During dry period all cows received an equal dry cow ration. After calving, cows were assigned in a 2 × 2 factorial arrangement to one of four groups, receiving either a moderate (MR, 6.0 MJ NEL) or a high (HR, 6.4 MJ NEL) energy concentration in roughage and furthermore moderate (MC, 150 g/kg energy-corrected milk (ECM)) or high amounts of concentrates (HC, 250 g/kg ECM) on dry matter (DM) basis, which were allocated from an automatic feeding system. Higher allocation of concentrates resulted in an increase of DM intake at expense of roughage intake. HC cows had a higher milk yield than MC cows, whereas ECM was higher in HR cows due to a decrease of milk fat yield in MR groups. Energy balance and body condition score were elevated in HC cows, but no differences occurred in development of subclinical ketosis. Furthermore, energy efficiency variables were lower in HC groups because the greater energy intake was not associated with a considerable elevation of milk yield. Consistency of faeces did not indicate digestive disorders in any of the treatment groups although the faecal manure score was significantly lower in HR groups. Our results underline the importance of a high energy uptake from roughage, which can contribute to an adequate performance and beneficial efficiency, especially at lower amounts of concentrates in ration. Feeding concentrates on an average amount of 9.4 kg/d compared to 6.4 kg/d on DM basis improved the energy balance in our trial, but without consequences for metabolic blood variables and general health of the cows.


Assuntos
Ração Animal/análise , Bovinos/fisiologia , Fibras na Dieta/análise , Ingestão de Energia , Metabolismo Energético , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta/veterinária , Feminino , Lactação
8.
Arch Anim Nutr ; 70(1): 1-16, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26654380

RESUMO

Diet change and fatness are supposed to challenge the immune system of the cow. Therefore, immunological and haematological consequences of adaptation to and continued feeding of a high-energy diet were studied in eight non-pregnant, non-lactating Holstein cows over 16 weeks. Blood haptoglobin concentration remained unaltered, suggesting that an acute phase reaction was not induced. Stimulation ability of peripheral blood mononuclear cells and stimulated oxidative burst capacity of granulocytes increased significantly in the course of the experiment after an initial drop. While total leucocyte counts increased, the proportion of granulocytes increased and that of lymphocytes decreased at the same time as the ratio of CD4(+)/CD8(+) lymphocytes did. Capability of rumen microbes to detoxify the immune-modulating mycotoxin deoxynivalenol (DON) was not compromised as indicated by the exclusive presence of de-DON as the detoxified DON metabolite in blood. In conclusion, both diet change and prolonged positive energy balance influenced the bovine immune system.


Assuntos
Bovinos/sangue , Bovinos/imunologia , Dieta/veterinária , Metabolismo Energético , Micotoxinas/metabolismo , Tricotecenos/metabolismo , Zearalenona/metabolismo , Tecido Adiposo/metabolismo , Ração Animal/análise , Animais , Bovinos/metabolismo , Indústria de Laticínios , Feminino , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Micotoxinas/toxicidade , Explosão Respiratória/efeitos dos fármacos
9.
Arch Anim Nutr ; 69(5): 319-39, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26305382

RESUMO

It is well observed that feeding energy-dense diets in dairy cows during the dry period can cause metabolic imbalances after parturition. Especially dairy cows with high body condition score (BCS) and fed an energy-dense diet were prone to develop production diseases due to metabolic disturbances postpartum. An experiment was conducted to determine the effects of an energy-dense diet and nicotinic acid (NA) on production and metabolic variables of primiparous and multiparous cows in late pregnancy and early lactation which were not pre-selected for high BCS. Thirty-six multiparous and 20 primiparous German Holstein cows with equal body conditions were fed with energy-dense (60% concentrate/40% roughage mixture; HC group) or adequate (30% concentrate/70% roughage mixture; LC group) diets prepartum. After parturition, concentrate proportion was dropped to 30% for all HC and LC groups and was increased to 50% within 16 days for LC and within 24 days for HC cows. In addition, half of the cows per group received 24 g NA supplement per day and cow aimed to attenuate the lipid mobilisation postpartum. Feeding energy-dense diets to late-pregnant dairy cows elevated the dry matter (p < 0.001) and energy intake (p < 0.001) as well as the energy balance (p < 0.001) without affecting the BCS (p = 0.265) during this period. However, this did not result in any metabolic deviation postpartum as the effects of prepartum concentrate feeding were not carried over into postpartum period. Multiparous cows responded more profoundly to energy-dense feeding prepartum compared with primiparous cows, and parity-related differences in the transition from late pregnancy to lactation were obvious pre- and postpartum. The supplementation with 24 g NA did not reveal any effect on energy metabolism. This study clearly showed that energy-dense feeding prepartum did not result in metabolic imbalances postpartum in multiparous and primiparous cows not selected for high BCS. A genetic predisposition for an anabolic metabolic status as indicated by high BCS may be crucial for developing production diseases at the onset of lactation.


Assuntos
Ração Animal/análise , Bovinos/fisiologia , Ingestão de Energia , Niacina/metabolismo , Animais , Dieta/veterinária , Suplementos Nutricionais/análise , Feminino , Lactação , Niacina/administração & dosagem , Período Periparto , Gravidez
10.
Gen Comp Endocrinol ; 198: 13-21, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24384531

RESUMO

Decreasing insulin sensitivity (IS) in peripheral tissues allows for partitioning nutrients towards the mammary gland. In dairy cows, extensive lipid mobilization and continued insulin resistance (IR) are typical for early lactation. Adiponectin, an adipokine, promotes IS. Supplementation with conjugated linoleic acids (CLA) in rodents and humans reduces fat mass whereby IR and hyperinsulinemia may occur. In dairy cows, CLA reduce milk fat, whereas body fat, serum free fatty acids and leptin are not affected. We aimed to investigate the effects of CLA supplementation on serum and adipose tissue (AT) adiponectin concentrations in dairy cows during the lactation driven and parity modulated changes of metabolism. High yielding cows (n=33) were allocated on day 1 post partum to either 100 g/day of a CLA mixture or a control fat supplement (CON) until day 182 post partum. Blood and subcutaneous (sc) AT (AT) biopsy samples were collected until day 252 post partum to measure adiponectin. Serum adiponectin decreased from day 21 pre partum reaching a nadir at calving and thereafter increased gradually. The distribution of adiponectin molecular weight forms was neither affected by time, parity nor treatment. Cows receiving CLA had decreased serum adiponectin concentrations whereby primiparous cows responded about 4 weeks earlier than multiparous cows. The time course of adiponectin concentrations in sc AT (corrected for residual blood) was similar to serum concentrations, without differences between CLA and CON. CLA supplementation attenuated the post partum increase of circulating adiponectin thus acting towards prolongation of peripartal IR and drain of nutrients towards the mammary gland.


Assuntos
Adiponectina/metabolismo , Tecido Adiposo/metabolismo , Suplementos Nutricionais , Lactação/efeitos dos fármacos , Lactação/metabolismo , Ácidos Linoleicos Conjugados/administração & dosagem , Leite/metabolismo , Animais , Bovinos , Feminino , Leptina/metabolismo , Ácidos Linoleicos Conjugados/farmacologia , Paridade/efeitos dos fármacos , Período Pós-Parto/efeitos dos fármacos , Gravidez
11.
J Dairy Res ; 81(3): 257-66, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24594287

RESUMO

Subclinical ketosis is a metabolic disorder which often goes undiagnosed and leads to constricted performance and an impairment of general condition. In the current study subclinical ketosis was characterised by a ß-hydroxybutyrate (BHB) concentration of >1·2 mmol/l in blood serum. To generate this metabolic situation, an animal model was created. The model, based on group-specific interaction of dietary energy supply and body condition, is appropriate for testing the medical effectiveness of treating this kind of ketosis and its concomitants. During the trial, 18 dairy cows (primiparous and pluriparous) were assigned, according to their body condition score (BCS) 6 weeks before expected parturition, to a normal [6.78 MJ net energy for lactation (NEL)/kg dry matter; 20% concentrate] or to a high-energy feeding group (7·71 MJ NEL/kg dry matter; 60% concentrate). Therefore cows with the highest BCS were allocated to the high-energy group to enhance the contrast with the control group. Statistical analysis was done using the MIXED procedure of SAS. Effects were declared significant when P-values were ⩽0.05. Owing to the higher energy concentration and dry matter intake, the energy intake and balance was significantly higher in the high-energy feeding group, with strong effects on lipid metabolism and health in blood and liver post partum. Within the first 2 weeks after calving, 8 out of 9 cows (89%) of the high-energy group had BHB values indicative of subclinical ketosis. These cows also had significantly higher values of non-esterified fatty acids (NEFA), aspartate transaminase (AST) and glutamate dehydrogenase (GLDH) post partum, as well as a raised total lipid content of the liver. RQUICKI, a calculated parameter which is based on serum concentrations of glucose, insulin and NEFA to assess the insulin sensitivity, was not affected by treatment. Therefore, RQUICKI does not seem to be the right parameter for diagnosing decreased insulin sensitivity in cows affected by subclinical ketosis. The milk fat and the fat:protein ratio of the high-energy group was also higher, even though there was no decrease in milk yield for cows with subclinical BHB values.


Assuntos
Doenças dos Bovinos/metabolismo , Ingestão de Energia/fisiologia , Metabolismo Energético/fisiologia , Cetose/veterinária , Lipólise/fisiologia , Prenhez/metabolismo , Ácido 3-Hidroxibutírico/sangue , Fenômenos Fisiológicos da Nutrição Animal , Animais , Constituição Corporal/fisiologia , Bovinos/metabolismo , Bovinos/fisiologia , Doenças dos Bovinos/fisiopatologia , Feminino , Cetose/metabolismo , Cetose/fisiopatologia , Lactação/metabolismo , Lactação/fisiologia , Gravidez , Prenhez/fisiologia
12.
Arch Anim Nutr ; 68(6): 492-506, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25348458

RESUMO

A long-term feeding experiment with dairy cows was performed to investigate the effects of feeding a Fusarium toxin contaminated (FUS) and a background-contaminated control (CON) ration with a mean concentrate feed proportion of 50% during the first 11 weeks after parturition (Groups FUS-50, CON-50, Period 1), and with concentrate feed proportions of 30% or 60% during the remaining 17 weeks (Groups CON-30, CON-60, FUS-30 and FUS-60, Period 2), on zearalenone (ZEN) residue levels in blood serum, milk, urine and bile. ZEN, α-zearalenol (α-ZEL) and ß-zearalenol (ß-ZEL), zearalanone (ZAL), α-zearalanol (α-ZAL) and ß-zearalanol (ß-ZAL) were determined by HPLC with fluorescence detection. The ZEN concentrations of the rations fed to Groups CON-50, FUS-50 (Period 1), CON-30, CON-60, FUS-30 and FUS-60 (Period 2) amounted to 53.1, 112.7, 35.0, 24.4, 73.8 and 72.5 µg/kg dry matter, respectively. The concentrations of ZEN, α-ZEL, ß-ZEL, ZAN, α-ZAL and ß-ZAL in serum, urine and milk were lower than 1, 1, 4, 100, 50 and 200 ng/g, respectively, while ZEN, α-ZEL and ß-ZEL were detected in bile. Their levels changed with oral ZEN exposure in the course of the experiment and in a similar direction with concentrate feed proportion (Period 2 only). Thus the proportions of the individual ß-ZEL, α-ZEL and ZEN concentrations of their sum varied only in narrow ranges of 68-76%, 6-13% and 12-20%, respectively. Interestingly, the bile concentrations of ß-ZEL, α-ZEL and ZEN of Groups CON-60 and FUS-60 amounted to only approximately 50%, 45% and 62%, respectively, of those of Groups CON-30 and FUS-30 despite a similar or even lower ZEN exposure. The results indicate that conversion of ZEN to its detectable metabolites was not changed by different dietary concentrate feed proportions while their absolute levels were decreased. These findings might suggest concentrate feed proportion-dependent and rumen fermentation-mediated alterations in ZEN/metabolite degradation, and/or liver associated alterations in bile formation and turnover.


Assuntos
Ração Animal/análise , Bovinos/metabolismo , Dieta/veterinária , Zearalenona/metabolismo , Animais , Relação Dose-Resposta a Droga , Esquema de Medicação , Resíduos de Drogas , Feminino , Leite/química , Zearalenona/sangue , Zearalenona/química , Zearalenona/urina , Zeranol/análogos & derivados , Zeranol/química , Zeranol/metabolismo
13.
Arch Anim Nutr ; 68(6): 460-77, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25348551

RESUMO

Physiological consequences of adaptation to and continued feeding of a high-energetic diet were studied in eight non-pregnant, non-lactating dairy Holstein cows over a period of 16 weeks. The first six weeks served as an adaptation period from the low energetic straw-based diet (3.8 MJ NEL/kg DM) to the high-energetic ration (7.5 MJ NEL/kg DM). Intake of dry matter (DM) increased with dietary energy concentration from 9 to 20 kg/d up to week 9 to 12 and decreased thereafter. The initial live weight (LW) of 550 ± 60 kg was increased linearly and corresponded to an average daily LW gain of 2.3 ± 0.3 kg. Energy balance increased approximately nine-fold to a maximum of 114 MJ NEL/d in week 10. Ruminal fermentation pattern was completely changed from an acetate dominating profile to a propionate based one, which was paralleled by a marked increase in the rumen fluid endotoxin concentration. Unlike blood glucose concentration, which increased continuously, that of cholesterol and triglycerides started to increase after an initial stagnation. In conclusion, both ruminal adaptation to a high-energetic diet and the continued feeding of such a diet induced digestive and metabolic adaptations in non-pregnant, non-lactating cows characterised by a progressing positive energy balance.


Assuntos
Ração Animal/análise , Bovinos/fisiologia , Dieta/veterinária , Digestão/fisiologia , Metabolismo Energético/fisiologia , Adaptação Fisiológica , Fenômenos Fisiológicos da Nutrição Animal , Animais , Ingestão de Líquidos , Ingestão de Alimentos , Feminino , Abrigo para Animais , Umidade , Fígado/química , Fígado/metabolismo , Nitrogênio/metabolismo , Rúmen/química , Temperatura , Fatores de Tempo , Aumento de Peso
15.
Front Immunol ; 13: 784046, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35370999

RESUMO

In early lactation, an energy deficit leading to a negative energy balance (NEB) is associated with increased susceptibility to disease and has been shown to be an important factor during transition in dairy cows. L-carnitine as a key factor in the mitochondrial transport of fatty acids and subsequently for ß-oxidation and energy release is known to modulate mitochondrial biogenesis and thus influence metabolism and immune system. In the current study, we characterized hematological changes around parturition and investigated the potential effects of dietary L-carnitine supplementation on immune cell functions. For this approach, dairy cows were assigned either to a control (CON, n = 30) or an L-carnitine group [CAR, n = 29, 25 g rumen-protected L-carnitine per cow and day (d)]. Blood samples were taken from d 42 ante partum (ap) until d 110 post-partum (pp), with special focus and frequent sampling from 0.5 to72 h post-calving to clarify the impact of L-carnitine supplementation on leukocyte count, formation of reactive oxygen species (ROS) in polymorphonuclear cells (PMN) and peripheral mononuclear cells (PBMC) and their phagocytosis activity. Blood cortisol concentration and the capacity of PBMC proliferation was also investigated. All populations of leukocytes were changed during the peripartal period, especially granulocytes showed a characteristic increase up to 4 h pp. L-carnitine supplementation resulted in increased levels of eosinophils which was particularly pronounced one day before to 4 h pp, indicating a possible enhanced support for tissue repair and recovery. Non-supplemented cows showed a higher phagocytic activity in PBMC as well as a higher phagocytic capacity of PMN during the most demanding period around parturition, which may relate to a decrease in plasma levels of non-esterified fatty acids reported previously. L-carnitine, on the other hand, led to an increased efficiency to form ROS in stimulated PMN. Finally, a short period around calving proved to be a sensitive period in which L-carnitine administration was effective.


Assuntos
Carnitina , Leite , Animais , Carnitina/farmacologia , Bovinos , Suplementos Nutricionais , Feminino , Contagem de Leucócitos , Leucócitos Mononucleares , Parto/metabolismo , Gravidez , Espécies Reativas de Oxigênio
16.
Animals (Basel) ; 11(1)2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-33435209

RESUMO

l-carnitine plays an important role in energy metabolism through supporting the transport of activated fatty acids to the subcellular site of ß-oxidation. An acute phase reaction (APR) is known as an energy consuming process. Lipopolysaccharides (LPS) are often used in animal models to study intervention measures during innate immune responses such as APR. Thus, the aim of the study was to investigate the effects of dietary l-carnitine supplementation during an LPS-induced APR in mid-lactating German Holstein cows. Animals were assigned to a control (CON, n = 26) or l-carnitine group (CAR, n = 27, 25 g rumen-protected l-carnitine/cow/d) and received an intravenous injection of LPS (0.5 µg/kg body weight) at day 111 post-partum. Blood samples were collected from day 1 pre-injection until day 14 post-injection (pi). From 0.5 h pi until 72 h pi blood samplings and clinical examinations were performed in short intervals. Clinical signs of the APR were not altered in group CAR except rumen motility which increased at a lower level compared to the CON group after a period of atonia. Group CAR maintained a higher insulin level compared to group CON even up to 72 h pi which might support glucose utilization following an APR.

17.
Front Vet Sci ; 7: 649, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33102562

RESUMO

Babesia divergens, transmitted by the tick Ixodes ricinus, is the most common cause of bovine babesiosis in northern Europe and plays a role as a zoonotic pathogen. However, several studies have indicated a decline of B. divergens prevalence in Europe during the last decades. Here, we investigate the epidemiology of bovine babesiosis on a beef production farm in northern Germany, which had not been affected by babesiosis until an initial outbreak in 2018. In June 2018, 21 adult cattle died, showing classical symptoms of babesiosis. Babesia divergens merozoites were detected in blood smears of clinically affected animals and the species was confirmed by PCR and sequencing of a part of the 18S rRNA gene. In 2018, screening of the farm's entire stock by PCR revealed that Babesia-positive animals were present in only one of five herds grazing on different pastures. In the following year, further babesiosis cases occurred in multiple herds. In March 2020, 95 cattle were tested for anti-B. divergens antibodies and 36 of them (37.89%) had positive titres. To investigate the local Babesia prevalence in ticks, 1,430 questing I. ricinus ticks (555 larvae, 648 nymphs, 227 adults) were collected on the farm's pastures and subjected to PCR for Babesia detection. Babesia divergens DNA could not be detected, but Babesia microti showed an overall prevalence of 0.49% (7/1,430; 0.88% [2/227] of adult ticks, 0.77% [5/648] of nymphs, 0.00% [0/555] of larvae). Babesia venatorum was detected in 0.42% (6/1,430) of ticks (0.44% [1/227] of adult ticks, 0.77% [5/648] of nymphs, 0.00% [0/555] of larvae) and B. capreoli in 0.07% (1/1,430) of ticks (0.00% [0/227] of adult ticks, 0.15% [1/648] of nymphs, 0.00% [0/555] of larvae). Despite the fact that no B. divergens-positive ticks were found, the collected data suggest a geographical spread of the pathogen on the farm. Bovine babesiosis remains a disease of veterinary importance in Europe and may cause considerable economic losses when (re-)emerging in non-endemic areas, especially as awareness for the disease among veterinarians and farmers declines.

18.
PLoS One ; 15(1): e0227117, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31923267

RESUMO

Hypospadias, disorder of sex development (DSD), is a sporadic congenital abnormality of the genital region in male ruminants, which is characterized by a non-fused urethra during fetal development. Detailed clinical examination classified the hypospadias phenotype of a male Holstein calf studied here as the perineal type. In combined use of cytogenetic analysis and whole genome sequencing, a non-mosaic, pseudo-monosomy 59, XY + tan(18;27) was detected. This chromosomal aberration had its origin in a tandem fusion translocation of the bovine autosomes (BTA) 18 and 27 with an accompanying loss of genomic sequences mainly in the distal end of BTA 18 and the proximal end of BTA 27. The resulting phenotype included hypospadias, growth retardation and ventricular septal defect.


Assuntos
Doenças dos Bovinos/genética , Aberrações Cromossômicas , Comunicação Interventricular/genética , Hipospadia/genética , Translocação Genética/genética , Animais , Bovinos , Análise Citogenética/métodos , Comunicação Interventricular/veterinária , Hipospadia/veterinária , Masculino , Monossomia/genética , Sequenciamento Completo do Genoma/métodos
19.
Animals (Basel) ; 10(2)2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32098123

RESUMO

Dairy cows are metabolically challenged during the transition period. Furthermore, the process of parturition represents an energy-consuming process. The degree of negative energy balance and recovery from calving also depends on the efficiency of mitochondrial energy generation. At this point, L-carnitine plays an important role for the transfer of fatty acids to the site of their mitochondrial utilisation. A control (n = 30) and an L-carnitine group (n = 29, 25 g rumen-protected L-carnitine per cow and day) were created and blood samples were taken from day 42 ante partum (ap) until day 110 post-partum (pp) to clarify the impact of L-carnitine supplementation on dairy cows, especially during the transition period and early puerperium. Blood and clinical parameters were recorded in high resolution from 0.5 h to 72 h pp. L-carnitine-supplemented cows had higher amounts of milk fat in early lactation and higher triacylglyceride concentrations in plasma ap, indicating increased efficiency of fat oxidation. However, neither recovery from calving nor energy balance and lipomobilisation were influenced by L-carnitine.

20.
PLoS One ; 14(12): e0226823, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31877171

RESUMO

Cataracts are focal to diffuse opacities of the eye lens causing impaired vision or complete blindness. For bilateral congenital cataracts in Red Holsteins a perfectly cosegregating mutation within the CPAMD8 gene (CPAMD8:g.5995966C>T) has been reported. We genotyped the CPAMD8:g.5995966C>T variant in Holstein calves affected by congenital bilateral congenital cataracts, their unaffected relatives and randomly selected herd mates. Ophthalmological examinations were performed in all affected individuals to confirm a congenital cataract. Whole genome sequencing was employed to screen variants in candidate genes for the Morgagnian cataract phenotype. In the present study, 3/35 cases were confirmed as homozygous mutated and 6/14 obligate carriers. Further 7/46 unaffected animals related with these cases were heterozygous mutated for the CPAMD8:g.5995966C>T variant. However 32 cases with a congenital cataract showed the wild type for the CPAMD8 variant. We did not identify variants in the candidate genes CPAMD8 and NID1 or in their close neighborhood as strongly associated with the congenital cataract phenotype in Holstein calves with the CPAMD8 wild type. In conclusion, the CPAMD8:g.5995966C>T variant is insufficient to explain the majority of Morgagnian congenital cataract phenotypes in Holsteins. It is very likely that congenital bilateral cataracts may be genetically heterogeneous and not yet known variants in genes other than CPAMD8 and NID1 are involved.


Assuntos
Catarata/veterinária , Doenças dos Bovinos/congênito , Doenças dos Bovinos/patologia , Bovinos/genética , Animais , Catarata/genética , Catarata/patologia , Doenças dos Bovinos/genética , Complemento C3/genética , Feminino , Masculino , Polimorfismo de Nucleotídeo Único , Inibidor da Tripsina Pancreática de Kazal/genética , alfa-Macroglobulinas/genética
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