Breeding objectives were developed for Targhee sheep at different levels of prolificacy and triplet survival. Economic weights (EW) were derived for estimated breeding values (BV) from National Sheep Improvement Program genetic evaluations for 120 d weaning weight (WW), maternal milk (MM), yearling weight (YW), fleece weight (FW), fiber diameter (FD), staple length (SL), and prolificacy (PLC; lambs born/100 ewes lambing). A commercial flock was simulated, accounting for nonlinear relationships between performance and profit. Ewes were assumed mated to sires of specified BV and profit was derived from lifetime performance of lambs and replacement females from that lamb crop. Economic weights were determined as change in profit from use of sires with BV that were one additive standard deviation above the mean for each trait [1.98 kg for WW, 1.62 kg for MM, 2.90 kg for YW, 0..36 kg for FW, 0.99 microns for FD, 0.74 cm for SL, and 17.58 lambs/100 ewes for LC], while holding all other BV at breed average. Separate breeding objectives were derived for different ways of meeting increased nutrient needs (P = purchase hay, R = rent pasture, and L= limited flock size) and for different market lamb values (D = discounting lamb value for heavy weights, ND = no discount for heavy lambs). Based on replicated simulations, relative EW did not vary with prolificacy or triplet survival (P > 0.15) but were affected by feed costs and lamb market values (P < 0.01). Selection indexes were derived within and across simulated scenarios, and correlation (r) among indexes of > 0.90 indicated that an index could be used across multiple scenarios with little loss of selection efficiency. Indexes derived within feed cost scenarios (P, R, and L) and lamb value scenarios (D, ND) were strongly intercorrelated (r > 0.97). Correlations among average indexes for feed cost scenarios (0.97 for R and P, 0.70 for R and L; 0.85 for P and L) indicated that two feed cost scenarios could be used depending on whether winter forage was limited (L) or not (NL). The correlation between average indexes for these two scenarios was 0.78. Indexes were presented for combinations of feed cost and lamb value scenarios. Two indexes were suggested, representing the scenarios that apply to a large portion of Targhee producers. These indexes were for discounting heavy lambs with limited winter forage (D-L: 1.0 WW + 0.14 MM __ 0.76 YW + 1.22 FW __ 0.36 FD - 0.09 SL + 0.25 LC) and discounting heavy lambs with additional available forage (D-NL: 1.0 WW + 0.24 MM __ 0.34 YW + 1.65 FW __ 0.41 FD - 0.14 SL + 0.33 LC). For a standardized selection differential of one for the index, the expected changes in mean index value were $2.17 and $1.92 per ewe per generation for D-L and D-NL, respectively. / Master of Science

O objetivo do presente estudo foi estimar valores econômicos para características componentes de índices de seleção em bovinos de corte na fase de cria. Os dados produtivos analisados foram simulados e representativos de sistemas de produção que fazem uso dos programas de melhoramento genético animal. Os valores de custos e receitas aplicados foram coletados de empresas ligadas ao setor econômico da pecuária de corte nacional. As características assumidas como critérios de seleção, para as quais estimaram-se valores econômicos, foram: probabilidade de prenhez aos 14 meses (PP14), habilidade de permanência (HP) e peso a desmama (PD). Para a estimação de valores econômicos, foi aplicada a metodologia de Modelo Bioeconômico, a qual estima o lucro adicional a partir da alteração no desempenho produtivo da característica de influência genética, enquanto mantendo constante todas as demais variáveis analisadas. O valor econômico da PP14 foi de R$0,71 por percentual de prenhez, avaliado por novilha e de R$1,16 por kg bezerro(a) desmamado, para a característica de PD. Os valores econômicos da HP, avaliados por vaca, foram de R$1,37, R$1,87, R$2,37 e R$2,87, considerando-se o custo de compra da novilha a R$450,00, R$500,00, R$550,00 e R$600,00, respectivamente. Os resultados econômicos obtidos foram padronizados para o valor genético-econômico, medida resultante do produto entre o desvio padrão genético aditivo da característica e o respectivo valor econômico. A HP, apesar de, em valores absolutos, ser a característica de maior importância econômica para o sistema produtivo analisado, apresenta o valor genético-econômico inferior em relação às características de PP14 e PD, as quais têm maior herdabilidade e variabilidade genética. O valor genético-econômico da soma das características PP14 e HP foi maior do que PD, sugerindo serem as características de fertilidade as mais economicamente importantes para o sistema produtivo simulado, específico ao comércio de bezerros desmamados para o mercado. / The objective of the present study was to estimate economic values for component of selection indexes in beef cattle herds during suckling phase. Analyzed productive data was simulated and representative of production systems assisted by breeding program. Values of costs and incomes were collected from companies related to the economical study of national cattle raising. Selection criteria, for which economic values was estimated, were: heifer pregnancy at 14 months (PP14), stayability (HP) and weight weaning (PD).) The methodology of Bioeconomic Model was applied to estimation of economic values (VE). This methodology estimates the impact in the profit from the alteration in performance for each trait of genetic influence, keeping constant all the others variables analyzed. The VE for PP14 was R$0.71 for percentage of heifer pregnant, evaluated for heifer, and R$1.16 for kg of calves weaned analyzed for PD. The VE of the HP, analyzed for cow, were R$1.37, R$1.87, R$2.37 and R$2.87 considering the heifer cost purchase of R$450.00, R$500.00, R$550.00 and R$600.00, respectively. The VE were standardized for the genetic-economic value, result of multiplication of additive genetic standard deviation of the trait by respective VE. Although HP, in absolute values, was the trait of larger economic importance to the analyzed productive system, it presents inferior genetic-economic value compared PP14 and PD. This inversion is due to greater heritability and genetic variability of PP14 and PD. The genetic-economic value of the PP14 and HP together, was more important than WW, showing that the traits of fertility are the most economically important for this simulated productive system, specific to the commerce of calves weaned for the market.

Made available in DSpace on 2014-07-29T15:13:42Z (GMT). No. of bitstreams: 1 Tese Fernando Brito Lopes.pdf: 2440791 bytes, checksum: e2b0f0d68c27ff72334b6e2591e57e68 (MD5) Previous issue date: 2011-08-05 / The objectives and selection criteria used for dairy goats in Brazil are determined empirically. Brazil has climate, soil and environmental diversity, as well as distinct socioeconomic and political realities, producing distinctions among the political administrative regions of the country. The aim of this study was to obtain spatial distribution of physical, climatic and socioeconomic aspects that best discriminate the Brazilian dairy goats production, identifying the characteristics of higher socio-economic relevance for intensive or semi-intensive rearing of dairy goats, derive economic weights for selection objectives and propose selection indices whose criteria are easy to be collected by breeders of dairy goats in Brazil. The spatial analysis was performed using local climatic variables, physical and socioeconomic. The selection objectives were defined by their relative economic importance to farming systems. The economic value of each characteristic was calculated as the difference between the average profit before and after the upgrade, after increasing by 1% each feature, keeping the average remaining unchanged. It was proposed eight selection indices. The traits included in each indice were: I and V indices, milk production (MP) and lactation length (LL); II and VI indices, MP, LL, and age at first calving (AFC); III and VII indices, MP , LL, AFC and calving interval (CI) and IV and VIII indices, MP, LL, AFC, CI, somatic cell count (SCC) and total solids (TS). To test the selection indices were simulated dairy goats herds using selection intensities of 10%, 25% and 50%. For each herd, were simulated MP, LL, AFC, CI, SCC and TS. To compare the means was used the Tukey test (p<0.01). Multivariate analysis revealed distinctions between the Brazilian Regions. Climatic factors were most important for discrimination between the regions of Brazil. Thus, animal breeding programs should be implemented according to the specificities of each region. The average profit of the semi-intensive system was higher than the intensive system, R $ 0.18 and $ 0.14, respectively. Productive and reproductive traits were improved by selecting animals for PL, DL, IPP and IDP simultaneously. Having differentiated payment for milk of better quality, for the levels of EST and SCC, we suggest the use of indices with these selection criteria. The choice and use of these indices depend on the definition of the objectives of selection and ease of measurement of selection criteria to be used. / Os objetivos e critérios de seleção utilizados para caprinos leiteiros no Brasil são determinados empiricamente. Há diversidade edafoclimática e realidades socioeconômicas e políticas distintas no Brasil. Isto contribui para diferenciar as regiões político administrativas do país. Assim, Objetivou-se espacializar os fatores físicos, climáticos e socioeconômicos que melhor discriminam a produção de caprinos leiteiros no Brasil; identificar as características de maior relevância sócio-econômica para sistemas intensivo e semi-intensivo de criação de caprinos leiteiros, derivar ponderadores econômicos para os objetivos de seleção e propor índices de seleção cujos critérios sejam fáceis de serem coletados por criadores de caprinos leiteiros no Brasil. As análises de espacialização municipal foram realizadas utilizando variáveis climáticas, físicas e socioeconômicas. Os objetivos de seleção foram definidos por meio de sua importância econômica relativa aos sistemas de criação. O valor econômico de cada característica foi calculado pela diferença entre o lucro médio antes e depois do melhoramento, após aumentar cada característica em 1%, mantendo a média das demais inalterada. Foram propostos oito índices de seleção. As características incluídas em cada índice foram: índices I e V, produção de leite (PL) e duração da lactação (DL); índices II e VI, PL, DL e idade ao primeito parto (IPP); índices III e VII, PL, DL, IPP e intervalo de partos (IDP); e, índices IV e VIII, PL, DL, IPP, IDP, contagem de células somáticas (CCS) e extrato seco total (EST). Para testar os índices de seleção propostos, foram simulados rebanhos de caprinos leiteiros, utilizando intensidades de seleção de 10%, 25% e 50%. Em cada rebanho, foram simuladas PL, DL, IPP, IDP, CCS e EST. Para comparação das médias utilizou-se o teste de Tukey (p<0,01). As análises multivariadas evidenciaram distinções entre as regiões político administrativas do Brasil. Os fatores climáticos foram os mais importantes na discriminação entre as regiões brasileiras. Assim, programas de melhoramento genético animal devem ser implementados de acordo com as especificidades de cada região. O lucro médio do sistema semi-intensivo foi maior que o sistema intensivo, R$ 0,18 e R$ 0,14, respectivamente. Características produtivas e reprodutivas foram melhoradas ao selecionar os animais para PL, DL, IPP e IDP, simultaneamente. Havendo pagamento diferenciado por leite de melhor qualidade, em relação aos teores de EST e CCS sugere-se a utilização dos índices com estes critérios de seleção. A escolha e utilização destes índices dependerão da definição dos objetivos de seleção e da facilidade de mensuração dos critérios de seleção a serem utilizados.

O objetivo do presente estudo foi estimar valores econômicos para características componentes de índices de seleção em bovinos de corte na fase de cria. Os dados produtivos analisados foram simulados e representativos de sistemas de produção que fazem uso dos programas de melhoramento genético animal. Os valores de custos e receitas aplicados foram coletados de empresas ligadas ao setor econômico da pecuária de corte nacional. As características assumidas como critérios de seleção, para as quais estimaram-se valores econômicos, foram: probabilidade de prenhez aos 14 meses (PP14), habilidade de permanência (HP) e peso a desmama (PD). Para a estimação de valores econômicos, foi aplicada a metodologia de Modelo Bioeconômico, a qual estima o lucro adicional a partir da alteração no desempenho produtivo da característica de influência genética, enquanto mantendo constante todas as demais variáveis analisadas. O valor econômico da PP14 foi de R$0,71 por percentual de prenhez, avaliado por novilha e de R$1,16 por kg bezerro(a) desmamado, para a característica de PD. Os valores econômicos da HP, avaliados por vaca, foram de R$1,37, R$1,87, R$2,37 e R$2,87, considerando-se o custo de compra da novilha a R$450,00, R$500,00, R$550,00 e R$600,00, respectivamente. Os resultados econômicos obtidos foram padronizados para o valor genético-econômico, medida resultante do produto entre o desvio padrão genético aditivo da característica e o respectivo valor econômico. A HP, apesar de, em valores absolutos, ser a característica de maior importância econômica para o sistema produtivo analisado, apresenta o valor genético-econômico inferior em relação às características de PP14 e PD, as quais têm maior herdabilidade e variabilidade genética. O valor genético-econômico da soma das características PP14 e HP foi maior do que PD, sugerindo serem as características de fertilidade as mais economicamente importantes para o sistema produtivo simulado, específico ao comércio de bezerros desmamados para o mercado. / The objective of the present study was to estimate economic values for component of selection indexes in beef cattle herds during suckling phase. Analyzed productive data was simulated and representative of production systems assisted by breeding program. Values of costs and incomes were collected from companies related to the economical study of national cattle raising. Selection criteria, for which economic values was estimated, were: heifer pregnancy at 14 months (PP14), stayability (HP) and weight weaning (PD).) The methodology of Bioeconomic Model was applied to estimation of economic values (VE). This methodology estimates the impact in the profit from the alteration in performance for each trait of genetic influence, keeping constant all the others variables analyzed. The VE for PP14 was R$0.71 for percentage of heifer pregnant, evaluated for heifer, and R$1.16 for kg of calves weaned analyzed for PD. The VE of the HP, analyzed for cow, were R$1.37, R$1.87, R$2.37 and R$2.87 considering the heifer cost purchase of R$450.00, R$500.00, R$550.00 and R$600.00, respectively. The VE were standardized for the genetic-economic value, result of multiplication of additive genetic standard deviation of the trait by respective VE. Although HP, in absolute values, was the trait of larger economic importance to the analyzed productive system, it presents inferior genetic-economic value compared PP14 and PD. This inversion is due to greater heritability and genetic variability of PP14 and PD. The genetic-economic value of the PP14 and HP together, was more important than WW, showing that the traits of fertility are the most economically important for this simulated productive system, specific to the commerce of calves weaned for the market.

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.