Genome wide scan for quantitative trait loci affecting tick resistance in cattle (Bos taurus × Bos indicus)

Abstract Background In tropical countries, losses caused by bovine tick Rhipicephalus (Boophilus) microplus infestation have a tremendous economic impact on cattle production systems. Genetic variation between Bos taurus and Bos indicus to tick resistance and molecular biology tools might allow for the identification of molecular markers linked to resistance traits that could be used as an auxiliary tool in selection programs. The objective of this work was to identify QTL associated with tick resistance/susceptibility in a bovine F2 population derived from the Gyr (Bos indicus) × Holstein (Bos taurus) cross. Results Through a whole genome scan with microsatellite markers, we were able to map six genomic regions associated with bovine tick resistance. For most QTL, we have found that depending on the tick evaluation season (dry and rainy) different sets of genes could be involved in the resistance mechanism. We identified dry season specific QTL on BTA 2 and 10, rainy season specific QTL on BTA 5, 11 and 27. We also found a highly significant genome wide QTL for both dry and rainy seasons in the central region of BTA 23. Conclusions The experimental F2 population derived from Gyr × Holstein cross successfully allowed the identification of six highly significant QTL associated with tick resistance in cattle. QTL located on BTA 23 might be related with the bovine histocompatibility complex. Further investigation of these QTL will help to isolate candidate genes involved with tick resistance in cattle.

Diferentes ofertas de forragem e a produção de leite em vacas mestiças Holandês x Gir

Objetivou-se avaliar o efeito de diferentes ofertas de forragem em pastagem de estrela africana (Cynodon nlemfuensis Vanderyst var. nlemfuensis), sobre a taxa de desaparecimento de forragem (TDF) e a produção de leite de vacas mestiças Holandês x Gir. Trinta animais foram submetidos a três ofertas de forragem (OF) distintas, sendo 10,0 12,5 e 15,0% do peso corporal. Houve influência da OF sobre a TDF (P<0,001). Para cada unidade de acréscimo da OF, a TDF aumentou 140,0kg ha-1 dia-1. Houve efeito da relação folha:colmo sobre a produção de leite (P<0,05). O aumento da oferta não refletiu em incremento da produção de leite em função do manejo empregado para obtenção das ofertas e estádio de crescimento das plantas.

Metabolic changes in ruminant calves fed cation-anion diets with different proportions of roughage and concentrate

Two experiments were carried out with twenty-four male weaned Holstein calves to verify the influence of different dietary cation-anion concentrate and roughage proportions on calves metabolism. In the first experiment, calves were fed rations with -100, +200 and +400 mEq cation-anion balance/kg of dry matter, containing 60% of roughage and 40% of concentrate. In the second experiment, calves (117.6±20.8 kg average weight) received rations with similar dietary cation-anion balance but in diets of 40% roughage and 60% concentrate. As the dietary cation-anion balance became more positive, there was a quadratic response of blood pH in both diets with 60 and 40% roughage. A linear increase following increased dietary cation-anion balance was observed on bicarbonate concentration, carbon dioxide tension, carbon dioxide partial pressure and urine pH on both experiments, while anion gap decreased linearly. Blood urea nitrogen and base excess increased quadratically according to increased dietary cation-anion balance on 60% roughage, whereas those same parameters showed a linear increase on 40% roughage. Growing ruminant metabolism both in cationic and anionic diets was modified when the roughage:concentrate ratio was altered.

Validação de modelos de predição das concentrações de nitrogênio ureico no leite do rebanho de vacas holandesas

Objetivou-se, no presente trabalho, validar modelos de predição de nitrogênio ureico no leite no intuito de contribuir para avaliação da adequação nutricional de dietas de rebanhos de vacas leiteiras. Foram utilizadas 8.833 observações de vacas da raça Holandesa de um rebanho comercial, registraram-se produção de leite, peso corporal, número de dias em lactação e número de lactações. Dos dados coletados, foram tiradas médias mensais a fim de se estudar o rebanho. O modelo 1 foi desenvolvido por Jonker et al. (1998) e os modelos 2 e 3 por Kauffman & St-Pierre (2001). Para a avaliação dos modelos, foram medidas a acurácia, a precisão e a robustez. Notou-se falta de acurácia para os modelos 1 (viés=2,60mg/dL) e 2 (viés=-1,95mg/dL), enquanto o modelo 3 foi acurado (-0,89mg/dL). Contudo, os modelos 1, 2 e 3 não diferiram entre si quanto à precisão (erro residual=3,72, 2,68 e 2,64mg/dL, respectivamente). Os modelos 1 e 2 não apresentaram robustez para o número de dias em lactação, tampouco o modelo 1 para a concentração de gordura. O modelo 3 foi o melhor avaliado, quando se desejou estimar as concentrações de nitrogênio ureico no leite de um rebanho de vacas Holandesas nas condições de campo estudadas.

Nutrients balances and milk fatty acid profile of mid lactation dairy cows supplemented with monensin

The aim of this study was to evaluate the nutrients balance and milk fatty acids profile of dairy cows supplemented with monensin. Twelve Brazilian Holstein dairy cows were distributed into four balanced 3x3 Latin squares, and fed with the following diets: control (C), basal diet without addition of monensin, monensin 24 (M24), addition of 24mg/kg DM of monensin, and monensin 48 (M48), addition of 48mg/kg DM. The experimental diets influenced the efficiency of net energy of lactation utilization. A quadratic effect was observed for the energy balance. It was observed effect of diets on nitrogen balance. It was observed effect of monensin in the milk yield, composition and in the milk fatty acids profile. Monensin in diets of dairy cows in mid lactation, using corn silage, improved the nutrients balance and milk fatty acid profile with 24mg/kg DM.

Condição corporal ao parto e produção de leite sobre o desempenho reprodutivo de vacas holandesas em lactação

O objetivo, neste estudo, foi avaliar os efeitos da condição corporal ao parto e da mudança de condição corporal sobre o desempenho reprodutivo de vacas leiteiras após o parto. Para tanto, 51 vacas holandesas, de 30 dias pré-parto até 150 dias após o parto, foram distribuídas aleatoriamente de acordo com a condição corporal ao parto nas classes 1 (condição corporal maior ou igual a 3,25) e 2 (condição corporal menor ou igual a 3,0). Dentro das classes de condição corporal ao parto, os animais foram distribuídos quanto à mudança de condição corporal (Categoria 1, igual ou menor que -0,50 e Categoria 2, igual ou maior que -0,75) e à média da produção de leite ajustada para 3,5% aos 150 dias (Grupo 1 = 22,61 e Grupo 2 = 31,65 kg/dia). Não houve diferenças da condição corporal ao parto e da produção de leite ajustada para 3,5% sobre o intervalo parto primeiro estro, intervalo parto primeiro serviço, período de serviço, número de serviço / concepção e taxa de gestação aos 150 dias de lactação. Vacas que ao parto apresentaram média de escore de condição corporal de 3,40 e 2,79 tiveram semelhante desempenho reprodutivo pósparto. Em relação à produção de leite ajustada para 3,5%, vacas com produção média de 22,61 e 31,65 apresentaram similares resultados. A mudança de condição corporal não influenciou o intervalo parto primeiro serviço, o período de serviço e o número de serviço por concepção, mas apresentaram maior intervalo parto primeiro estro e menor taxa de gestação

Palynologie und Sedimentologie der Interglazialprofile Döttingen, Bonstorf, Munster und Bilshausen

Palynologie und Sedimentologie der Interglazialprofile Döttingen, Bonstorf, Munster und Bilshausen Zusammenfassung In der vorliegenden Dissertation wurden vier dem Holstein-Interglazial zugehörige Bohrkerne sowie ein rhumezeitlicher Bohrkern palynologisch und sedimentologisch bearbeitet. Die holsteinzeitlichen Bohrkerne stammen aus Kieselgurlagerstätten der Lüneburger Heide (Bonstorf und Munster) und aus einem Trockenmaar (Döttingen) in der Eifel. Der rhumezeitliche Kern stammt aus der Typlokalität Bilshausen im Harzvorland. Neben Prozentwertdiagrammen werden Pollendichte- und wenn möglich Polleninfluxwerte vorgestellt, die insbesondere für die Lokalitäten Hetendorf/Bonstorf und Munster/Breloh bisher nicht verfügbar waren. Mit dem Profil Döttingen konnte erstmals eine sowohl vollständige als auch nicht innerhalb des klassischen Aufkommens holsteinzeitlicher Fundstellen im norddeutschen Tiefland positionierte Holsteinsequenz aus dem deutschen Mittelgebirge dokumentiert werden. Das erhaltene Pollendiagramm bestätigt die aus den norddeutschen Profilen bekannte holsteintypische Vegetationsabfolge, durch die das Holstein gegenüber anderen Interglazialen wie Holozän, Eem oder Rhume palynologisch definiert ist. Neben der grundsätzlichen Übereinstimmung der Pollensequenz unterscheidet sich das Profil Döttingen aber deutlich im prozentualen Aufkommen der beteiligten Taxa von den norddeutschen Profilen. So wird eine hohe Alnus-Präsenz als Merkmal deutscher Holsteinprofile bestätigt, jedoch ist die, in den norddeutschen Lokalitäten durchhaltend hohe oder dominante Beteiligung von Pinus im deutschen Mittelgebirge nicht vorhanden und muss daher auf die Standortbedingungen Norddeutschlands zurückgeführt werden. Abies dagegen ist im Holstein der Mittelgebirge wesentlich präsenter als im norddeutschen Flachland. Im Profil Döttingen wurden insgesamt 10 Tephralagen gefunden. Auf eine dieser Tephren folgt ein „Birken-Kiefern-Gräser Vorstoß“, der palynostratigraphisch dem älteren „Birken-Kiefern Vorstoß“ in Munster/Breloh entspricht. Als eine Typologie des Holstein kann das in den Profilen Döttingen und Munster bestätigte intraholsteinzeitliche Carpinus-Minimum verstanden werden. An Hand sedimentologischer und palynologischer Befunde aus dem Bohrkern MU 2 muss die Existenz zweier, in der Literatur postulierter, postholsteinzeitlicher, „Nachschwankungen“ in Munster/Breloh in Frage gestellt, wenn nicht abgelehnt werden. In Kern MU 2 fallen palynostratigraphische Grenzen häufig mit Sandeinschaltungen zusammen. Eine dieser Sandeinschaltungen, nämlich unmittelbar vor dem älteren „Birken-Kiefern-Vorstoß“, korreliert in ihrer stratigraphischen Position mit der den „Birken-Kiefern-Gräser-Vorstoß“ im Profil Döttingen einleitenden Tephralage. Es gelang die Dauer des intraholsteinzeitlichen Carpinus Minimums auf etwa 1500±100 Jahre zu bestimmen und eine interne Zweigliederung zu dokumentieren. Im rhumezeitlichen Kern von Bilshausen (BI 1) konnten zahlreiche Störungen nachgewiesen werden. Insbesondere im Teufenbereich des Bilshausener „Birken-Kiefern-Vorstoßes“ deuten diese auf eine möglicherweise verfälschte Überlieferung. Der palynologisch markante „Lindenfall“ von Bilshausen liegt im Bereich einer isoklinalen Schichtenverfaltung. Die in der Literatur im Horizont des „Lindenfalls“ beschriebene „Bilshausentephra“ wurde nicht gefunden. Warvenzählungen an den Kernen MU 1, MU 2 und BI 1 ermöglichten Pollenzonendauern in Holstein- und Rhume-Interglazial zu bestimmen. Dabei wurde mittels den Warvenzählungen, unter zu Hilfenahme von Literaturdaten und von Schätzwerten eine Dauer für das Holstein-Interglazial sensu stricto (Pollenzonen I-XIV) von 15400-17800 Jahren und für das Rhume-Interglazial von wahrscheinlich 22000 Jahren bis maximal 26000 Jahren ermittelt.

Cristalli organici semiconduttori: proprietà di trasporto elettronico e applicazioni

In questo lavoro saranno inizialmente discusse le tecniche medianti le quali sono cresciuti i monocristalli organici confrontando le tecniche di crescita proprie dell’elettronica organica con quelle utilizzate comunemente in quella inorganica. Successivamente si introdurrà il problema del trasporto elettronico con particolare riguardo verso alcune molecole come il rubrene o il pentacene. Tramite il modello microscopico verranno studiate le interazioni elettrone-fonone, locale e non locale, in particolare nei cristalli di rubrene e DMQtT–F4TCNQ attraverso la teoria del piccolo polarone di Holstein. Dopo aver sottolineato i limiti di questa teoria ne verrà proposta una alternativa basata sui lavori di Troisi e supportata da evidenze sperimentali. Tra le tecniche utilizzate per l’analisi dei campioni verranno discusse le basi della teoria del funzionale di densità. L’attenzione sarà rivolta ai cristalli ordinati mentre una breve descrizione sarà riservata per quelli disordinati o amorfi. Nel capitolo 3 verrà trattato il ruolo degli eccitoni all’interno dei semiconduttori organici, mentre nell’ultimo capitolo si discuterà di diverse applicazioni dei semiconduttori organici come la costruzione di FET e di detector per raggi X. Infine verranno mostrati il setup sperimentale e il procedimento per l’estrazione di parametri di bulk in un semiconduttore organico tramite analisi SCLC.

Compartment pressure of the rectus sheath accurately reflects intra-abdominal pressure in a porcine model

To investigate whether the compartment pressure of the rectus sheath (CPRS) reflects the intra-abdominal pressure (IAP) under various conditions of intra-abdominal hypertension (IAH) in a pig model.

Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), after slipped capital femoral epiphysis

OBJECTIVE: The aim of this study was to assess the glycosaminoglycan (GAG) content in hip joint cartilage in mature hips with a history of slipped capital femoral epiphysis (SCFE) using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC). METHODS: 28 young-adult subjects (32 hips) with a mean age of 23.8+/-4.0 years (range: 18.1-30.5 years) who were treated for mild or moderate SCFE in adolescence were included into the study. Hip function and clinical symptoms were evaluated with the Harris hip score (HHS) system at the time of MRI. Plain radiographic evaluation included Tonnis grading, measurement of the minimal joint space width (JSW) and alpha-angle measurement. The alpha-angle values were used to classify three sub-groups: group 1=subjects with normal femoral head-neck offset (alpha-angle <50 degrees ), group 2=subjects with mild offset decrease (alpha-angle 50 degrees -60 degrees ), and group 3=subjects with severe offset decrease (alpha-angle >60 degrees ). RESULTS: There was statistically significant difference noted for the T1(Gd) values, lateral and central, between group 1 and group 3 (p-values=0.038 and 0.041). The T1(Gd) values measured within the lateral portion were slightly lower compared with the T1(Gd) values measured within the central portion that was at a statistically significance level (p-value <0.001). HHS, Tonnis grades and JSW revealed no statistically significant difference. CONCLUSION: By using dGEMRIC in the mid-term follow-up of SCFE we were able to reveal degenerative changes even in the absence of joint space narrowing that seem to be related to the degree of offset pathology. The dGEMRIC technique may be a potential diagnostic modality in the follow-up evaluation of SCFE.

Delayed gadolinium-enhanced magnetic resonance imaging of cartilage in the long-term follow-up after Perthes disease

Aim of this study was to assess the glycosaminoglycan content in hip joint cartilage in mature hips with a history of Legg-Calvé-Perthes (LCPD) disease using delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC).

MRI morphometry, cartilage damage and impaired function in the follow-up after slipped capital femoral epiphysis

To assess rotation deficits, asphericity of the femoral head and localisation of cartilage damage in the follow-up after slipped capital femoral epiphysis (SCFE).

Assessment of early cartilage degeneration after slipped capital femoral epiphysis using T2 and T2* mapping

T2 and T2* mapping are novel tools to assess cartilage quality.

Intestinal atresia and ectopia in a bovine fetus

A 2-year-old Red Holstein cow was presented with uterine torsion at 235 days of pregnancy. The fetus extracted by cesarean section had weak vital signs and marked abdominal distention. An edematous pouch that contained tubular structures with peristaltic activity was associated with the umbilical cord. Because of poor prognosis, both dam and fetus were euthanized. At necropsy, the fetus had severe distention of the forestomachs, abomasum, and proximal small intestine; absence of distal small intestine, cecum, and proximal colon; atresia of the 2 blind ends of the intestine; and atrophy of distal colon and rectum. The tubular structures associated with the umbilical cord were identified as the segments of intestine that were absent in the fetus. Intestinal atresia combined with ectopia may be caused by local ischemia during temporary herniation and rotation of the fetal gut into the extraembryonic coelom. The close connection between ectopic intestine and amniotic sheath of the umbilical cord in this case may have facilitated vascularization and allowed development and viability of the ectopic intestine.