The objectives of this research were to evaluate breed differences for heat-stress resistance using age at first calving and first calving interval, and to assess breed by region interactions for seven regions of the United States for survival-related traits up to five years of age in Brown Swiss, Holstein, and Jersey cows. Age at first calving and first calving interval were studied in farms with two breeds, with Holstein and Brown Swiss or Holstein and Jersey cows. The survival-related traits were analyzed in farms with one or two breeds. Seven regions within the United States were defined: Northeast, Northwest, Central north, Central, Central south, Southwest and Southeast. The fertility traits were also analyzed in seven individual states: Wisconsin, Ohio, Oregon, California, Arizona, Florida, and Texas. Brown Swiss were older than Holsteins at first calving (833 ± 2.4 d vs. 806 ± 2.0 d in regions, and 830 ± 3.1 d vs. 803 ± 2.4 d in states), but Holsteins and Brown Swiss did not differ for first calving interval. Jerseys were younger than Holsteins at first calving and had shorter first calving intervals (P < 0.01). In data from individual states, Holsteins housed with Brown Swiss were older at first calving than Holsteins housed with Jerseys (800 ± 2.7 d vs. 780 ± 2.5 d). Holsteins housed with Jerseys had slightly shorter first calving intervals than Holsteins housed with Brown Swiss, and the interaction of "type of Holstein: with season of the first calving was highly significant (P < 0.01). Region and season effects were smaller for Jerseys than for Holsteins, thus, Jerseys showed evidence of heat-stress resistance with respect to Holsteins. Management modified age at first calving in Holsteins, depending on the type of herd they were located in. Longer calving intervals might have been partly due to voluntary waiting period to breed the cows. The survival-related traits were evaluated up to five years of age. They consisted of stayability, number of completed lactations, days lived, herd-life, and total days in milk. For herds with one breed, the order for stayability to five years of age, from longer to shorter-lived breed was: Brown Swiss, Jersey and Holstein, but for the ratio of days in milk to herd-life the order was: Holstein, Jersey and Brown Swiss, and for the ratio of days in milk to days lived, it was: Jersey, and Holstein and Brown Swiss tied. This last ordering was the same for number of lactations completed by five years of age. The results for two-breed herds were similar since Brown Swiss and Jerseys had larger (Chi-square P < 0.01) probabilities of living past five years of age than Holsteins, and for days in milk and number of lactations completed, Jerseys had higher values than Holsteins (P < 0.01), but Holsteins and Brown Swiss tied in some analyses. Breed by region interaction was always significant. If all other conditions were assumed equal, Jerseys would give fastest returns by five years of age. The overall conclusion is that Jerseys performed better for the traits analyzed, all of them highly influenced by environmental conditions. / Ph. D.

In presented thesis the chosen parameters of reproduction {--} days to first service, days open, calving interval, insemination index - were evaluated in dairy cattle. There were 222 of dairy cows observed (53 Czech Pied and 169 Holstein cows). The results of reproduction were evaluated as unsatisfactory. Length of calving interval overreached recommended 400 days in 56,25 % of Holstein and in 33,33% of Czech Pied cows. Also the mean value of insemination index 2,39 exceeds the optimum of 1,8-2,0.

With the objective of estimating genetic parameters for stayability to 48 and 60 months of age (STAY48 and STAY60) and their association with milk production in the first lactation (P305), age at first calving (AFC) and first calving interval (FCI) data from 3,344 cows from six herds located in the states of Minas Gerais, São Paulo and Paraiba were analyzed. The (co) variances were estimated by Bayesian approach, using bi-characteristics animal models. For STAY48, STAY60 and AFC systematic effects farm-year-season of birth were include with model. For P305 and FCI, the model used included the systematic effects of farm-year-season of calving and age at calving (linear and quadratic) as a covariable. In addition to these systematic effects for all traits were also included the effects of random additive genetic and residual. The mean estimates of heritability were 0.25 ± 0.08, 0.32 ± 0.07, 0.31 ± 0.05, 0.28 ± 0.05 and 0.08 ± 0.04 for STAY48, STAY60, P305, AFC and FCI, respectively. The a posteriori estimates of genetic correlations between STAY48 and P305 AFC and FCI were 0.90 ± 0.10, -0.55 ± 0.24 and 0.64 ± 0.33. The estimated genetic correlations between STAY60 and P305, AFC and FCI were 0.94 ± 0.07, -0.54 ± 0.21 and 0.83 ± 0.18. The genetic and phenotypic correlations estimated between stayability to 48 and 60 months of age and milk production in the first lactation indicate that production in the first lactation may be used as a selection criterion for longevity. Similarly, the selection to reduce the age at first calving can cause, for a correlated response female. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Com o objetivo de estimar parâmetros genéticos para stayability aos 48 e 60 meses de idade (STAY48 e STAY60) e suas associações com produção de leite na primeira lactação (P305), idade ao primeiro parto (IPP) e primeiro intervalo de partos (PIDP), foram analisados dados de 3.344 vacas pertencentes a seis rebanhos localizados nos estados de Minas Gerais, São Paulo e Paraíba. Os componentes de (co)variância foram estimados por abordagem Bayesiana em análises bi-características. Para as características STAY48, STAY60 e IPP, foram incluídos os efeitos sistemáticos de fazenda-ano-estação de nascimento. Para P305 e PIDP, o modelo utilizado incluiu os efeitos sistemáticos de fazenda-ano-estação de parto e idade da vaca ao parto com covariável (efeitos linear e quadrático) como covariável. Além desses efeitos sistemáticos, para todas as características estudadas, foram considerados os efeitos aleatórios genético aditivo direto e residual. As herdabilidades médias estimadas foram 0,25±0,08, 0,32±0,07, 0,31±0,05, 0,28±0,05 e 0,08±0,04 para STAY48, STAY60, P305, IPP e PIDP, respectivamente. As estimativas a posteriori das correlações genéticas obtidas entre STAY48 com P305, IPP e PIDP foram de 0,90±0,10, -0,55±0,24 e 0,64±0,33. As correlações genéticas estimadas entre STAY60 com P305, IPP e PIDP foram de 0,94±0,07,-0,54±0,21 e 0,83±0,18. As correlações genética e fenotípica estimadas entre a stayability aos 48 e 60 meses de idade e produção de leite na primeira lactação indicam que a produção na primeira lactação pode ser usada como critério de seleção para longevidade. De forma semelhante, a seleção para reduzir a idade ao primeiro parto pode provocar, por resposta correlacionada, em melhorias na longevidade das fêmeas.

Made available in DSpace on 2016-12-08T16:24:15Z (GMT). No. of bitstreams: 1 PGCA11MA116.pdf: 1391947 bytes, checksum: 452ae8e6b14145386d67ad7b97589c53 (MD5) Previous issue date: 2011-12-06 / The genetic improvement programs for dairy cattle give more focus in production traits, with negative consequences in the genetics for functional traits like fertility, longevity and health. Selection for conformation can minimize the negative effects for some characteristics, like the mammary health, with gains on longevity. Farmers and technicians have used selection for conformation, especially rump, aiming improve fertility, although without scientific evidence of its efficacy. In this way, this work aimed to study the influence of some linear type traits on calving interval in Holstein cows in South of Brazil. The Holstein Cattle Breeder´s Association of Paraná State (APCBRH) supplied the data for this study. Linear type traits with possible influence on fertility (width and rump angle, chest width, body depth, rear leg side view, foot angle and angularity) were studied using a scale from 1 to 9 points. Calving interval (CI) was used as fertility trait. After editing the data comprised linear classification of 23,014 cows, from 248 herds, classified from 2000 to 2010, daughters of 797 sires. Variance components for heritability and genetic correlation were estimated with Restricted Maximum Likelihood method (REML), using MIXED procedure of statistics package SAS. Heritability for type traits and CI were estimated, as well as genetic correlations among type traits and these with CI. For heritability evaluation for CI and genetic correlation of type traits with CI, information about 51,237 calving intervals of 24,740 cows, of 294 herds, calved between 2000 and 2010, daughters of 1,003 sires were utilized. To evaluate the effect of the conformation of the cows in the CI, the cows were divided in three scores for each trait type, with low score (linear classification 1 to 3), middle score (linear classification 4 to 6) and high score (linear classification 7 to 9). Heritability estimates ranged from 0,09 to 0,24, with the lower values for traits of the category legs and feets. Heritability estimation for CI too was of low magnitude (0,05). Genetic correlation estimations among type traits were also, in general, of low magnitude, with the higher value between chest width and body depth (0,52). Rump width and rump angle showed negative genetic correlation (-0,33), with selection for rump width can lead to an increasing in cows with high pins. Genetic correlation estimations between type traits and CI were, mostly, low. The ones with higher genetic correlation with CI were: foot angle (0,41), rear leg side view (-0,36), rump width (-0,33) and angularity (0,32). Rump angle did not show genetic correlation with CI, however, cows with high pins (score 1 to 3) showed phenotypically longer CI, although with discrete differences in relation to cows with intermediate rumps or low pins (2,5 and 4,7 days, respectively). Rump width did not affect the phenotypic value of CI. Selection for this character may lead to few gains for fertility, although with negative effects to rump angle and rear leg side view, due to negative genetic correlations (-0,33 and -0,35, respectively). For angularity, unfavorable genetic correlation with CI was observed and substantially longer CI were related to more angular cows too, particularly in older cows. We concluded that the estimated genetic correlations of some type traits with calving interval provided information for the practice of selection for type , with the purpose of providing improvements in in the reproductive efficiency of dairy herds. The selection order to avoid cows with inverted rump does not determine genetic gain for fertility. However, cows with high pins have reversed phenotypically calving interval slightly longer. Selection for increased width of rump may bring some increase in fertility, however, with negative consequences on the genetic merit of other type traits. Selection for high angularity should be prevent due the reduction of fertility / Os programas de melhoramento genético têm dado maior ênfase à seleção para as características produtivas, com consequências negativas sobre características funcionais, tais como fertilidade, longevidade e sanidade. A seleção para conformação tem conseguido minimizar parcialmente os efeitos negativos para algumas características, como, por exemplo, a sanidade da glândula mamária, com ganhos sobre longevidade. Produtores e técnicos tem utilizado a seleção para conformação, em especial da garupa, com o intuito de melhorar a fertilidade das vacas, faltando, entretanto, a devida comprovação científica de sua eficácia. Neste sentido, objetivou-se estudar a influência de algumas características lineares de tipo sobre o intervalo de partos em vacas da raça Holandesa no Sul do Brasil. Os dados utilizados foram fornecidos pela Associação Paranaense de Criadores de Bovinos da Raça Holandesa (APCBRH). Estudaram-se características lineares de tipo, com possível influência sobre fertilidade (largura e inclinação de garupa, largura de peito, profundidade corporal, pernas vista lateral, ângulo de casco e angulosidade), sendo as mesmas avaliadas na escala de 1 a 9 pontos. O indicador de fertilidade avaliado foi o intervalo de partos (IP). O arquivo utilizado continha 23.014 vacas classificadas no período de 2000 a 2010, oriundas de 248 rebanhos, filhas de 797 touros. Os componentes de variância para a estimativa das herdabilidades e das correlações genéticas foram obtidas pelo método da Máxima Verossimilhança Restrita (REML), utilizando-se o procedimento MIXED do pacote estatístico SAS. Foram estimadas as herdabilidades para características de tipo e IP, assim como as correlações genéticas entre características de tipo e destas com IP. Para estimativa da herdabilidade do IP e das correlações genéticas das características de tipo com o IP foram utilizadas informações de 51.237 intervalos de parto de 24.740 vacas, paridas entre 2000 e 2010, filhas de 1003 touros, pertencentes a 294 rebanhos. Para avaliar o efeito da conformação das vacas, as mesmas foram divididas em três escores de pontuação para cada característica de tipo, sendo escore baixo (pontuação linear de 1 a 3), escore intermediário (pontuação linear de 4 a 6) e escore alto (pontuação linear de 7 a 9). As estimativas de herdabilidade variaram de 0,09 a 0,24, sendo os valores mais baixos para as características da categoria pernas e pés. A estimativa de herdabilidade para IP foi de baixa magnitude (0,05). As estimativas das correlações genéticas entre as características de tipo foram, em geral, de pequena magnitude, sendo o maior valor observado entre largura de peito e profundidade corporal (0,52). As características largura e inclinação de garupa apresentaram correlação genética negativa (- 0,33), sendo que, a seleção para garupa larga poderá levar a um aumento na frequência de vacas com garupa invertida. As estimativas de correlações genéticas entre as características de tipo e IP foram, em sua maioria, baixas. Dentre as características de tipo as que apresentaram maior correlação genética com IP foram: ângulo de casco (0,41), pernas vista lateral (-0,36), largura de garupa (-0,33) e angulosidade (0,32). A inclinação de garupa não apresentou correlação genética com IP, entretanto, vacas com garupa invertida (escore 1 a 3) apresentaram fenotipicamente IP significativamente mais longos, porém com diferenças discretas em relação às vacas com garupa intermediária ou escorrida (2,5 e 4,7 dias, respectivamente). A largura de garupa não afetou o valor fenotípico do IP (P > 0,05). A seleção para esta característica poderia trazer pequenos ganhos para fertilidade, porém com efeitos negativos sobre a inclinação de garupa e pernas vista lateral, devido a correlações genéticas negativas com estas características (-0,33 e -0,35, respectivamente). Para angulosidade, além da correlação genética desfavorável com intervalo de partos, também foram observados IP substancialmente mais longos em vacas mais angulosas, especialmente em vacas mais velhas. Conclui-se que as correlações genéticas estimadas de algumas características de tipo com intervalo de partos fornecem subsídios para a prática de seleção para tipo, com a finalidade de proporcionar melhorias na eficiência reprodutiva dos rebanhos leiteiros. A seleção visando evitar vacas com garupa invertida não determina ganhos genéticos para fertilidade. Entretanto, vacas com garupas invertidas apresentam fenotipicamente intervalos de partos discretamente mais longos. A seleção para aumento da largura de garupa poderá trazer algum incremento em fertilidade, porém, com consequências negativas sobre o mérito genético de outras características de tipo. A seleção para elevada angulosidade deve ser evitada devida à redução da fertilidade

Made available in DSpace on 2016-12-08T16:24:22Z (GMT). No. of bitstreams: 1 PGCA15MA174.pdf: 1125115 bytes, checksum: debf2ea0252ff58d406adab80ac46300 (MD5) Previous issue date: 2015-06-25 / Improvement of animal nutrition and management, together with genetic selection for milk yeld, increased the productivity of the herds, especially Holstein cows. On the other hand, characteristics related to fertility, health and longevity were disadvantaged The aim was to compare the development, milk yeld and composition, the health of the mammary gland, the body condition score (BCS), reproductive performance and longevity of crossbred Holstein x Simmental cows with Holstein cows. To obtain the data set two farms were used, one in Bom Retiro in SC and another in Carambeí in PR. For growth evaluation, weight gain of the animals were evaluated monthly. For production and udder health data from the official Dairy Herds Improvement Programs of the farm were used. BCS and body weight estimation were made on the farm with an interval between 60 and 90 days within one year. Information concerning the date of birth, parity date, date and number of inseminations, were obtained from the management software of the farms, generating information regarding the calving interval, days between calving to first service, conception rate, age at first calving. In one of the farms, calving were monitoring to quantify the calving difficulty, in the same farm, information of culling were obtained to determine the survival rate of cows. Data were analyzed by statistical package of SAS, using the MIXED and GENMOD procedures. For growth curve, production and composition of milk, (BCS) and body weight nonlinear regression was used, using the NLIN procedure of SAS and the curves of Gompertz (growth) and Wood (production and composition) were used because of having the lowest mean square. Holstein x Simmental crossbred cows produced more milk 31,8 x 30,4 kg/day (P < 0,05), with higher content of lactose and protein, with no difference for fat content. Holstein cows had higher somatic cell score (SCS) 4.49 x 2.93 (P <0.0001) compared to crossbreed cows. Holstein x Simmental crossbred cows had better BCS during lactation 3.65 x 2.94 (P <0.0001) with no difference in body weight in relation to Holstein cows. For growth of calves and heifers there was no difference between the genetic groups. Crossbred cows Holstein x Simmental had better reproductive performance than the Holstein cows, characterized by lower calving interval (381 x 445 days), higher conception rate (37.31 x 33, 64%) and shorter interval calving to first service (65.6 x 89.3 days). Crossbred cows Holstein x Simmental had higher survival rate than Holstein cows (83 x 92 In conclusion, crossbred cows Holstein x Simmental produce more milk with higher content of lactose and protein, have less ECS and greater BCS without difference for growing of heifers and body weight in adult age. Crossbred cows still have better reproductive performance and have a higher survival rate than the Holstein cows / Melhorias na nutrição e no manejo dos rebanhos bem como a seleção genética para a produção de leite aumentaram a produtividade dos animais. Em contrapartida, características relacionadas a fertilidade, sanidade e longevidade foram prejudicadas. O objetivo foi comparar o desenvolvimento, a produção e composição do leite, a sanidade da glândula mamária, o escore de condição corporal o desempenho reprodutivo e a longevidade de vacas mestiças Holandês x Simental em relação as vacas puras Holandês. Foram utilizadas duas propriedades, uma localizada no município de Bom Retiro em SC e outra em Carambeí no PR. Para avaliação de crescimento o ganho de peso dos animais foi avaliado mensalmente. Para obter dados produtivos e de sanidade de úbere foram utilizados dados do controle leiteiro oficial da propriedade. As avaliações de escore e peso vivo foram realizadas na propriedade com intervalo entre 60 e 90 dias no período de um ano, informações estas obtidas em uma das propriedades. As informações referentes a data de nascimento, data de parto, data e número de coberturas, foram obtidas junto aos software de gerenciamento de ambas as propriedades, gerando informações referentes ao intervalo entre partos (IEP), período parto primeiro serviço, taxa de concepção, idade ao primeiro parto. Em uma das propriedades foi feito o acompanhamento dos partos para quantificar a dificuldade de parto, da mesma forma, foram obtidas informações referentes ao descarte de animais para determinar a taxa de permanência no rebanho das vacas. Os dados foram analisados pelo pacote estatístico SAS, utilizando-se os procedimentos MIXED e GENMOD Para curva de crescimento, de produção e composição do leite bem como escore de condição corporal (ECC) e peso vivo foi utilizada a técnica de regressão não linear, do pacote estatístico SAS sendo que foram utilizadas as curvas de Gompertz (crescimento) e de Wood (produção e composição) por apresentarem o menor quadrado médio do erro. Vacas mestiças Holandês x Simental produziram mais leite 31,8 x 30,4 ( P < 0,05), com maior teor de lactose e proteína, sem diferença para teor de gordura. Vacas Holandês obtiveram maior escore de células somáticas (ECS) 4,49 x 2,93 (P < 0,0001) em relação as mestiças. Vacas mestiças Holandês x Simental obtiveram melhor ECC durante a lactação 3,65 x 2,94 (P < 0,0001) sem diferença para peso vivo em relação as vacas Holandês. Para crescimento de bezerras e novilhas não houve diferença entre os grupamentos genéticos. Vacas mestiças Holandês x Simental obtiveram melhor desempenho reprodutivo em relação as vacas puras, caracterizado através do menor IEP (381 x 445 dias), maior taxa de concepção (37,31 x 33, 64 %) bem como menor intervalo parto primeiro serviço (65,6 x 89,3 dias). Vacas mestiças Holandês x Simental apresentaram maior taxa de permanência no rebanho em relação as vacas puras (83 x 92 %). Conclui-se que vacas mestiças produzem mais leite, com maior teor de lactose e proteína, possuem menos ECS e maior ECC sem diferença para crescimento de novilhas e peso vivo na idade adulta. Apresentam ainda melhor desempenho reprodutivo e maior taxa de permanência no rebanho em relação as vacas puras Holandês

Die Arbeit liefert eine umfassende Beschreibung der Managementmethoden von Milcherzeugerbetrieben unter dem Fokus Herdenfruchtbarkeit. Die Studie analysiert Einflüsse des Managements auf Reproduktions- und Milchleistung und verfolgt hierzu einen bio-sozialen Forschungsansatz. Die Daten wurden 2007 in Interviews mit Herdenmanagern und Stallrundgängen anhand von Fragebögen in 84 v.a. Brandenburger Milcherzeugerbetrieben erhoben. Die Fragen betrafen u.a. Haltungsumwelt, Stressvermeidung, Herden-, Reproduktions- und Personalmanagement. Die Leistungsdaten der Herden entstammen der Milchleistungsprüfung 2007. Die Datenanalyse umfasste qualitative und quantitative Methoden. Abhängige Variablen waren Zwischenkalbezeit (ZKZ) und 305-Tage-Milchleistung (ML). Im Mittel betrug die Herdengröße 306,3 Kühe (+/-238,3), die ZKZ 413,2d (+/-18,73) und die ML 8555kg (+/-1132,9). Die ZKZ sank tendenziell mit steigender ML (r=-0,188, p=0,10). Die ML stieg mit der Herdengröße (r=0,29, p=0,01). Die Laufgänge (LG) waren in 71,25% der Betriebe nass und rutschig. Hier war die ZKZ tendenziell länger (+16,6d, p=,055) als bei trockenen, rutschfesten LG. Die Liegeflächen (LF) waren in 29,9% der Betriebe trocken und elastisch. Hier war die ML höher (+1110kg, p=0,011) als bei nassen, harten LF. Eine eindeutige Zuordnung der Verantwortung für die Brunstkontrolle wirkte tendenziell positiv auf die ZKZ (-6,3d, p=0,129). Akademisch ausgebildete Herdenmanagerinnen erzielten eine höhere ML als gleichqualifizierte Männer (+752,9kg, p=0,005) bei gleicher ZKZ und damit eine günstigere Relation von Reproduktions- und Milchleistung. Motivierung durch materielle und soziale Anreize bzw. Verantwortungsübertragung und gute Kommunikation war mit einer höheren ML verbunden als Motivierung durch Leistungslohn (+ ca. 1000kg, p=0,009). Die Studie belegt die Notwendigkeit verbesserter Haltungsbedingungen und bietet eine Grundlage für vertiefende Studien zum Personalmanagement in Milchviehbetrieben. / This study provides a comprehensive characterization of current management methods of dairy farms, focusing on herd fertility. Relations of management factors to fertility and milk performance are analyzed following a bio-social approach. In 2007 a questionnaire survey including face-to-face interviews and direct observations was conducted in 84 East German dairy farms, mostly located in Brandenburg. Questions referred to housing, stress prevention, and management of herds, reproduction and personnel. Herd performance data stem from milk performance testing in 2007. Data analysis combined qualitative and quantitative methods. Calving interval (CI) and 305-day-milk yield (MY) were used as dependent variables. Mean values of herd size, CI and MY were, respectively, 306.3 cows (+/-238.3), 413.2d (+/-18.73d) and 8555kg (+/-1132.9). CI tended to decrease with increasing MY (r=-0.188, p=0.10). MY increased with rising herd size (r=0.29, p=0.01). Floors were wet and slippery in 71.25% of farms. In these farms CI tended to be longer (+16.6d, p=0.055) compared to farms with dry and non-slippery floors. Lying areas were in 29.9% of the farms dry and flexible. Here MY was higher (+1110kg, p=0.011) than in farms with wet and hard lying areas. A clear assignment of responsibility for heat detection showed a trend of decreasing CI (-6.3d, p=0.129). Female herd managers with academic qualification achieved a higher MY than likewise qualified men (+752.9kg, p=0.005), with no difference in CI. Thus, herds managed by highly qualified women showed a better MY:CI ratio. Employee motivation by material and social incentives or by allocating responsibility to workers and pursuing good communication was related to higher MY than motivation by performance pay alone (+1000kg, p=0.009); CI remained unaffected. Performance pay had no positive effect on targeted parameters. Results underscore the need for improved housing and recommend further study into personnel management in dairy farms.