Evaluación de resistencia a ixodicidas y efectividad de la vacuna Bm86 en el grado de infestación por garrapata Boophilus SP. en las razas de ganado bovino charolais, simmental, brangus negro y comercial.

Tesis (Maestría en Ciencia Animal) UANL, 2013.

Heat tolerance and the effects of shade on the behavior of Simmental bulls on pasture

The objectives were to assess the degree of thermolysis capacity as a characteristic of heat tolerance of the Simmental beef cattle and evaluate the effects of shade and shade type (artificial: AS, trees: TS, or no shade: NS) on daily behavior patterns during summer. Black globe temperature (BGT) was different under the two types of shade (P < 0.05) and was lower under the TS (P < 0.01) and under AS (P > 0.01) than average BGT in the sun. Animals when in AS used more intensely the shade (P = 0.002) mostly lying down under it (10.00-14.00 hours), while time standing was similar (P = 0.107) between TS and NS. Bulls without shade (NS) spent significantly more time at the water trough and most part of the day standing idle (72.4%, 10.1 h/14 h). TS bulls spent more time grazing/standing (P < 0.001). The Simmental bulls that were in TS and AS spent more time ruminating than bulls that stay without shade (NS). The availability of shade changes grazing, rumination and idling behavior of cattle in response to environmental conditions. Shade provided by trees can be more efficient than artificial shading as cattle spent more time grazing when tree shade was available. Thermolysis capacity can be used to select heat-tolerant animals.

Synaptonemal complex analysis of the Holstein-Friesian, Piemontese and Simmental breeds of Bos taurus taurus

The synaptonemal complex (SC) of specimens of Sos taurus taurus from the Holstein-Friesian, Piemontese, and Simmental breeds, was analysed. The analysis included quantification of the frequency of various types of abnormalities in the SC, and the frequency of calls with SC abnormalities. All animals had 29 autosomal bivalents and one sexual bivalent and the most frequently recorded abnormality was pairing failure. The number of cells with abnormalities in the Holstein-Friesian breed was 29.41%, in the Piemontese breed was 30.00% and in the Simmental breed it was 29.54%. The subspecies Bos taurus taurus had 29.63% of cells showing abnormalities with 57.33% of these abnormalities occurring in zygotene and 42.67% occurring in pachytene. Statistical analyses showed that there were no significant differences in the number of cells with SC abnormalities among the breeds studied. The frequency of cells with abnormalities, and the efect on the fertility of the Holstein-Friesian, Piemontese and Simmental breeds are discussed.

Genetic evaluation using multi-trait and random regression models in Simmental beef cattle

The Brazilian Association of Simmental and Simbrasil Cattle Farmers provided 29,510 records from 10,659 Simmental beef cattle; these were used to estimate (co)variance components and genetic parameters for weights in the growth trajectory, based on multi-trait (MTM) and random regression models (RRM). The (co)variance components and genetic parameters were estimated by restricted maximum likelihood. In the MTM analysis, the likelihood ratio test was used to determine the significance of random effects included in the model and to define the most appropriate model. All random effects were significant and included in the final model. In the RRM analysis, different adjustments of polynomial orders were compared for 5 different criteria to choose the best fit model. An RRM of third order for the direct additive genetic, direct permanent environmental, maternal additive genetic, and maternal permanent environment effects was sufficient to model variance structures in the growth trajectory of the animals. The (co)variance components were generally similar in MTM and RRM. Direct heritabilities of MTM were slightly lower than RRM and varied from 0.04 to 0.42 and 0.16 to 0.45, respectively. Additive direct correlations were mostly positive and of high magnitude, being highest at closest ages. Considering the results and that pre-adjustment of the weights to standard ages is not required, RRM is recommended for genetic evaluation of Simmental beef cattle in Brazil. ©FUNPEC-RP.

Reproductive efficiency of Nellore cows nursing Nellore or crossbred Simmental x Nellore calves

The objective of this study was to analyze the influence of genetic group (GG) of the calf during gestation, mobilization of body reserves and period of postpartum anestrus in Nellore cows. Thirty-seven primiparous and multiparous cows were used: 24 gave birth to Nellore (NEL), and 13 gave birth to 1/2 Simmental x 1/2 Nellore (SIM) calves. According to the date of calving, cows were divided into three blocks, with intervals of 20 days between blocks. The body condition (BC) of the cows was estimated subjectively on a scale from 0 to 5 points, with intermediate grading of 0.5 points. We measured the thickness of subcutaneous fat (SF) between the 12th and 13th ribs and rump by ultrasound. Blood samples from each cow were collected weekly from the third week after birth until weaning, to analyze the level of progesterone; in the samples collected until 16 weeks postpartum, we analyzed the concentration of nonesterified fatty acids(NEFA). The gestation period of mothers of NEL calves was eight days longer, on average. The variables relating to the mobilization of body reserves (NEFA, BC and SF) were not influenced by calf GG, with the only significant effects being the number of days postpartum, witha peak in the concentration of NEFA between the sixth and eighth weeks and linear decrease in BC and NF. Mothers of NEL calves remained in anestrus for 4.6 weeks longer than the mothers of crossbred calves.

Vom Simmental bis Spitzbergen. Albrecht von Haller als europäischer Vermittler regionaler Kultur und Ökonomie

Albrecht von Haller sah die Nützlichkeit des Reisens respektive der Reiseberichte einerseits in der Menschenbildung mittels Horizonterweiterung und andererseits im Vergleich und im Transfer regionaler Formen der Naturaneignung. In diesen beiden Dimensionen bewegte sich Hallers vielfältige Mittlertätigkeit, namentlich als Dichter der Alpen, als Schlüsselfigur im sich globalisierenden Pflanzentransfer sowie als Rezensent von Reiseberichten und Landesbeschreibungen. Seit seiner ersten Alpenreise vereinte er in seiner Person den idealisierenden Blick auf die fremde Kultur mit dem wissenschaftlichen Forscherdrang nach der unbekannten Natur. Gerade beim Transfer von Kulturpflanzen waren Natur und Kultur eng miteinander verknüpft, ging es doch nicht nur um den Austausch von Samen, Wurzeln und Setzlingen, sondern ebenso um Praktiken und Wissensbestände der regionalen Kultur und Ökonomie

Ceco-cecal intussusception in a Simmental heifer

This report describes the clinical, laboratory and ultrasonographic findings in a Simmental heifer with a ceco-cecal intussusception. The general condition of the heifer was moderately reduced and it showed mild colic signs. Physical examination revealed a firm longish mass visible and palpable in the right flank. Findings upon rectal examination, fecal output und defecation were normal. Ultrasound examination of the mass revealed features typical for an intussusception. Based on the slow development of symptoms, normal fecal output and ultrasonography findings, a ceco-cecal intussusception was diagnosed. Right flank laparatomy was performed under general anaesthesia, and an end-to-side anastomosis between the jejunum and the spiral colon was made after resection of the intussuscepted intestines. Recovery was uneventful.

Hereditäre Thrombozytopathie beim Simmental Rind.

Der Wiederkäuerklinik oder dem Institut für Genetik der Universität Bern wurden zwi-schen 2012 und 2014 insgesamt 5 Rinder der Rasse Simmental vorgestellt, die je-weils nicht sistierende Blutungen nach Trauma zeigten. Alle betroffenen Tiere waren homozygote Träger für die seit 2007 bekannte RASGRP2 Mutation. Die verfügbaren Eltern wurden als heterozygote Anlageträger genotypisiert, was somit einen rezessi-ven Erbgang bestätigt. Drei erkrankte Tiere sind an den Folgen der unstillbaren Blu-tungen verstorben. Ein Tier konnte stabilisiert werden und wurde einen Monat nach der Entlassung aus der Klinik geschlachtet. Bei einem weiteren Fall wurden wieder-holt andauernde Blutungen sowie mehrmals Hämatome festgestellt und nach der genetischen Analyse wurde das Rind euthanasiert. Die Genotypisierung einer Stich-probe von 145 Stieren, die im Jahr 2013 in der Schweiz in der künstlichen Besamung zum Einsatz kamen, zeigte, dass 10% der getesteten Stiere in der Schweiz Anlage-träger für die assoziierte Mutation sind. Diese Stiere werden mit TP carrier gekenn-zeichnet und sollten zukünftig nicht mehr unkontrolliert eingesetzt werden. Die Zuchtverantwortlichen in der Schweiz nutzen heute den Gentest systematisch zur Selektion von anlagefreien Stieren.

Selección genómica de toros simmental con base al sistema austriaco-aleman, una posibilidad para la asociación colombiana de criadores de ganado simmental para mejorar su genética

Tesis (Zootecnista). -- Universidad de La Salle. Facultad de Ciencias Agropecuarias. Programa Zootecnia, 2014

Stayability in Italian Simmental dual-purpose cows: phenotypic and genetic associations

In recent years, dairy farmers have observed a substantial decrease in cows’ survival, with a direct negative consequence on the profitability. Shorter lifespan raises questions about animal welfare and farming conditions at which cows are exposed to. However, the length of productive life depends also on voluntary culling due to low productivity and, in dual-purpose breed, to low price of carcasses (meat). The general aim of the thesis was to investigate the genetic and phenotypic relationship of functional longevity with morphological features like muscularity and body condition score (BCS) and productive traits within Italian Simmental dual-purpose dairy cattle raised in Emilia-Romagna herds.

Preweaning performance and body composition of calves from straightbred Nellore and Bos taurus x Nellore crosses

The objectives were to evaluate preweaning performance, body composition, and efficiency of calves representing straightbred Nellore (NL), F(1), and 3-breed-cross systems. Energy requirements, milk production, and efficiency of 39 cow-calf pairs were recorded from straightbred NL calves from NL cows (10), crossbred (Angus-sired) calves from NL cows (ANL: 9), and crossbred calves (CC; Canchim-sired: 5/8 Charolais, 3/8 Zebu) from ANL (10) and Simmental x NL (10) cows. Cows and their respective calves were individually fed from birth to weaning (17 to 190 d postpartum). At 38 d of age, corn silage (7.8% CP, 2.19 Mcal of ME/kg of DM) was available to calves ad libitum. Milk production at 42, 98, 126, and 180 d postpartum was recorded by weighing calves before and after suckling. The ratio between GE and ME of milk was considered 1:0.93. Calves were slaughtered at weaning and the 9th-, 10th-, and 11th-rib section was removed for body composition estimation. The ANL calves were lighter (P < 0.01) at birth than the CC calves; the NL calves were intermediate. At weaning, the CC calves were heavier (P = 0.04) than the NL and ANL calves (230 +/- 5.5 vs. 172 +/- 8.1 and 209 +/- 8.6 kg, respectively). The ANL calves had greater (371 +/- 27 Mcal; P = 0.01) silage intake than the NL (270 +/- 25 Mcal) and CC (279 +/- 17 Mcal) calves. Milk energy intake was greater for the CC calves (970 +/- 38 Mcal of ME; P = 0.005) than the NL (670 +/- 57 Mcal of ME) and ANL (743 +/- 61 Mcal of ME) calves. The ANL calves compensated for the reduced milk production of the NL cows, which supplied less of their energy requirement for growth by increased silage intake. Calves from crossbred cows received a greater proportion of their total energy intake from milk. Crossbred calves had greater (P < 0.03) retained energy (retained energy = weaning body energy - birth body energy) than the NL calves (388 +/- 23 for ANL, and 438 +/- 15 for CC vs. 312 +/- 22 Mcal for NL calves). Percentages of water (P = 0.74) and chemical fat (P = 0.51) were similar among groups (63.7 +/- 0.6 and 14.3 +/- 0.7% for ANL calves, 63.1 +/- 0.4 and 14.7 +/- 0.5% for CC calves, and 63.3 +/- 0.6 and 13.7 +/- 0.7% of empty BW for water and chemical fat, respectively, for NL calves). Energetic efficiency (kcal of retained energy/Mcal of ME intake) was similar (P = 0.52) among groups (358 +/- 22 for ANL calves, 355 +/- 14 for CC calves, and 327 +/- 22 for NL calves). The greater BW gains and the differences in empty body composition at weaning were not enough to compensate for the greater ME intake of crossbreds. In this study, the crossbreeding systems evaluated increased preweaning calf performance but did not affect gross or energetic calf efficiency.