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ABSTRACT We aimed to evaluate the impact of using embryo transfer (ET) information on weaning weight estimated breeding values (EBV) and its accuracy. Data from Hereford and Braford cattle, raised under extensive conditions in Southern Brazil, were used. A model that included ET information in addition to maternal (genetic and permanent environmental) effects as a function of foster dams was compared to a model without ET information. Accuracy of both bulls and calves increased due to inclusion of ET records in 0.04 and 0.12 points, respectively. In general, the inclusion of ET records provided a greater amount of phenotypic variance and most accurate EBV for sires and progeny. The results obtained in this study encourage the use of ET phenotypic records in large-scale genetic evaluation programs, especially for bulls that have most of their progeny coming from ET. Most of the Brazilian genetic evaluation programs do not use phenotypic records of ET animals. Therefore, breeding values are predicted based only on parentage average, which implies in underestimated accuracies. Considering that ET has been widely used in Brazil and that such information improves genetic predictions, we suggest modifying the traditional adopted models by considering ET information in the Brazilian genetic evaluations.

This study evaluated animal performance, carcass characteristics and meat quality of 36-month old Nellore steers finished in pastures (n = 10) and 20-month old Angus vs. Nellore bulls finished in feedlot (n = 10). Final body weight, carcass weight, characteristics, conformation and fat thickness, were higher (p < 0.001) for the Nellore steers than for Angus vs. Nellore bulls. Water losses during chilling (24 hours, 4oC) were lower (p < 0.05) for Nellore steers than for the Angus vs. Nellore bulls. Muscle percentage on the 6th rib was higher (p < 0.05) for the Nellore steers than for Angus vs. Nellore bulls; while bone percentage was lower (p < 0.05) for Nellore steers. After 7 and 14 days of ageing, the L* meat value was higher for the Nellore steers than for the Angus vs. Nellore bulls; the L* meat value was similar (p > 0.05) throughout the ageing period for the Angus vs. Nellore bulls, but higher in meat from the Nellore steers (p < 0.05). Genetic group had no effect (p > 0.05) on meat a* value (redness). Likewise, ageing time had no effect on a* in both genetic groups, and genetic group had no effect (p > 0.05) on meat b* value (yellowness). On the other hand, b* was increased after day 7 of ageing for the bulls from the two genetic groups. Thawing and cooking losses were lower for Nellore steers after day 7 of aging (p < 0.05). The meat of the Angus vs. Nellore bulls was more tender (p < 0.05) at all ageing times studied (1, 4, 7 and 14 days) than the meat of the Nellore steers. Genetic group had no effect (p > 0.05) on lipid oxidation; however, lipid oxidation increased after day7. Meat from Nellore steers contained a higher percentage of saturated fatty acids (SFA), a lower percentage of unsaturated (UFA) and monounsaturated fatty acids (MUFA) and a similar percentage of polyunsaturated fatty acids (PUFA) than the meat from Angus vs. Nellore bulls. Intramuscular fat from Nellore steers had a more favourable n-6:n-3 fatty acid ratio than that from Angus vs. Nellore bulls (4.37 vs. 11.45, respectively). Tenderness, flavour and overall acceptability were higher (p < 0.001) for meats of the Nellore steers, regardless of ageing time (1, 4, 7 and 14 days).

The objective of this study was to verify the performance and carcass quality of pigs from four genetic lines and to correlate these data with the number and diameter of muscle fibers. A total of48 pigs were used and distributed into four treatments: high-lean commercial crossbred line; prolificacy commercial crossbred line; (Landrace X Large White) crossbred animals; and undefined genetic line. The experimental design consisted of a complete randomized design with a 4 x 2 factorial arrangement (4 genetic lines and 2 genders). Daily weight gain, daily feed intake and the feed conversion were evaluated. At slaughtering, the carcasses were evaluated and the number and the diameter of the muscle fibers of longissimus dorsi were assessed. The high-lean commercial line presented the greatestnumber of muscle cells (P

In genetic evaluations, the definition of unknown parent groups (UPG) is usually based on time periods, selection path and flows of foreign founders. The definition of UPG may be more complex for populations presenting genetic heterogeneity due to both, large national expansion and coexistence of artificial insemination (AI) and natural service (NS). A UPG definition method accounting for beef bull flows was proposed and applied to the French Charolais cattle population. It assumed that, at a given time period, unknown parents belonged to the same UPG when their progeny were bred in herds that used bulls with similar origins (birth region and reproduction way). Thus, the birth period, region and AI rate of a herd were pointed out to be the three criteria reflecting genetic disparities at the national level in a beef cattle population. To deal with regional genetic disparities, 14 regions were identified using a factorial approach combining principal component analysis and Ward clustering. The selection nucleus of the French cattle population was dispersed over three main breeding areas. Flows of NS bulls were mainly carried out within each breeding area. On the contrary, the use and the selection of AI bulls were based on a national pool of candidates. Within a time period, herds of different regions were clustered together when they used bulls coming from the same origin and with an estimated difference of genetic level lower than 20% of genetic standard deviation (σg) for calf muscle and skeleton scores (SS) at weaning. This led to the definition of 16 UPG of sires, which were validated as robust and relevant in a sire model, meaning numerically stable and corresponding to distinct genetic subpopulations. The UPG genetic levels were estimated for muscle and SS under sire and animal models. Whatever the trait, differences between bull UPG estimates within a time period could reach 0.5 σg across regions. For a given time period, bull UPG estimates for muscle and SS were generally larger by 0.30 to 0.75 σg than those of cows. Including genetic groups in the evaluation model increased the estimated genetic trends by 20% to 30%. It also provoked re-ranking in favor of bulls and cows without pedigree.

Abstract The implementation of genetic groups in BLUP evaluations accounts for different expectations of breeding values in base animals. Notwithstanding, many feasible structures of genetic groups exist and there are no analytical tools described to compare them easily. In this sense, the recent development of a simple and stable procedure to calculate the Bayes factor between nested competing models allowed us to develop a new approach of that method focused on compared models with different structures of random genetic groups. The procedure is based on a reparameterization of the model in terms of intraclass correlation of genetic groups. The Bayes factor can be easily calculated from the output of a Markov chain Monte Carlo sampling by averaging conditional densities at the null intraclass correlation. It compares two nested models, a model with a given structure of genetic groups against a model without genetic groups. The calculation of the Bayes factor between different structures of genetic groups can be quickly and easily obtained from the Bayes factor between the nested models. We applied this approach to a weaning weight data set of the Bruna dels Pirineus beef cattle, comparing several structures of genetic groups, and the final results showed that the preferable structure was an only group for unknown dams and different groups for unknown sires for each year of calving.

Objetivou-se determinar o tempo necessário para adaptação às dietas e avaliar o efeito de quatro níveis de uréia na ração (0; 0,65; 1,3 e 1,95% na matéria seca [MS]), sobre os consumos e as digestibilidades aparentes totais da MS, matéria orgânica (MO), proteína bruta (PB), extrato etéreo (EE), carboidratos totais (CHO), fibra em detergente neutro (FDN), carboidratos não-fibrosos (CNF) e o consumo de nutrientes digestíveis totais (NDT) em novilhos holandeses, ½Holandês-Guzerá, ½Holandês-Gir e puros Zebu. Os animais foram distribuídos em quatro quadrados latinos (grupos genéticos) 4 x 4, constituído por quatro animais, quatro períodos experimentais e quatro tratamentos (rações). Os animais foram alimentados com dieta composta por 50% de feno de capim-tifton 85 e 50% de concentrado, contendo 12% PB, com níveis crescentes de uréia. O primeiro período experimental teve duração de 19 (13 para adaptação à dieta e seis para a coleta de fezes). A partir da avaliação do consumo diário de MS no período de adaptação, avaliou-se a possibilidade de redução na adaptação às dietas nos períodos subseqüentes. A fibra em detergente ácido indigestível (FDAi) foi utilizada como indicador do fluxo de matéria seca fecal. Uma vez que as médias para o consumo de MS, para cada nível de uréia utilizado, desde o 1º até o 12º dia do período de adaptação, não diferiram da média padrão (do 13º dia), o período de adaptação às dietas dos períodos experimentais subseqüentes foi reduzido para 10 dias. O consumo, em kg/dia, foi maior para os animais holandeses, seguido pelos mestiços e pelos animais Zebu. A digestibilidade total da MS não foi influenciada pelos grupos genéticos nem pelos níveis de uréia nas rações.The effects of diet adaptation protocol by steers and of feeding four dietary urea levels (0, 0.65, 1.3, and 1.95%, dry matter - DM basis) on intake and total apparent digestibility of DM, organic matter (OM), crude protein (CP), ether extract (EE), total carbohydrates (CHO), neutral detergent fiber (NDF), nonfiber carbohydrates (NFC) and total digestible nutrients intake (TDN) for Holstein, ½ Holstein-Guzera, ½ Holstein-Gir and Zebu steers were evaluated in this trial. The animals were assigned to four 4x4 latin squares (genetic groups): four animals, four experimental periods and four treatments (diets). The animals were fed diets (12% CP, with increasing urea levels) with 50% tifton-85 bermudagrass hay and concentrate. The first experimental period lasted 19 days, 13 days for adaptation and 6 days for feces collection. The possibility of reducing diet adaptation in the subsequent periods was investigated by evaluating daily DM intake in the adaptation period. The indigestible acid detergent fiber (FDAi) was used as marker of fecal dry matter flow. The adaptation to diets of the subsequent experimental periods was reduced by 10 days, because DM intake means, for each urea level, from 1st to 12th day of adaptation did not differ from the standard mean (13th day). The intake, expressed as kg/day, was higher for Holstein animals, followed by the crossbreds and Zebu. Total DM digestibility was affected nor by the genetic groups, neither by the dietary urea levels.

O potencial de produção de trinta e cinco cabras mestiças - 12 ½Pardo-alpina + ½Moxotó (½PA-M), 11¾ Pardo-alpina + ¼Moxotó (¾PA-M) e 12 Tricross (½Anglo-nubiana + ¼Pardo-alpina + ¼Moxotó) - foi avaliado em um experimento foi conduzido na Embrapa Caprinos. Os cabritos foram separados das respectivas mães ao nascimento. As cabras foram ordenhadas duas vezes ao dia e o controle leiteiro procedido semanalmente. Os animais foram confinados em baias coletivas e receberam dieta para produção de 2,5 kg de leite/dia, composta de silagem de sorgo ad libitum e concentrado. Os animais foram pesados em intervalos de 14 dias. A produção de leite, como coletada, não foi influenciada pelo genótipo. No entanto, quando foi corrigida para 4% de gordura, o genótipo ½ PA-M foi superior aos ¾ PA-M e Tricross. Não houve diferença significativa entre genótipos para gordura, proteína e extrato seco total do leite.The objective of this trial was to study the production of thirty-five crossbred goats: ½Brown Alpine x 12 ½Moxoto (½BA-M), 11 ¾Brown Alpine x ¼Moxoto (¾BA-M), and 12 Tricross (½Anglo Nubian x ¼Moxoto x ¼Brown Alpine). After birth, the kids were separated from their mothers. Goats were milked twice a day and milk composition determined weekly. Animals were housed in collective pens and received a diet composed of sorghum silage (ad libitum) plus concentrate that were formulated to allow 2.5 kg/d of milk yield. Animals were weighted every 14 days. Milk production did not differ among genotypes. However, 4% fat corrected milk was greater for ½BA-M than the remaining groups. No significant differences were observed for milk composition (fat, protein, and total solids) across genotypes in the current trial.

Foram avaliadas as características de carcaça de bovinos Indubrasil e cruzados F1 Holandês-Gir e F1 Holandês-Guzerá, nas fases de recria e terminação. Foram determinados os rendimentos de carcaça e porcentagens dos cortes básicos, comprimento de carcaça, espessura de gordura subcutânea, área de olho de lombo, proporções de músculo, gordura e ossos. Os grupos genéticos não influenciaram os rendimentos de carcaça quente, em relação ao peso vivo e ao peso corporal vazio, e dos cortes básicos, dianteiro, traseiro total e especial, nas fases de recria e terminação. Animais Indubrasil podem atingir, com pesos inferiores aos dos animais F1 Holandês-Gir e F1 Holandês-Guzerá, os mesmos patamares de gordura na carcaça. Animais F1 Holandês-Guzerá apresentaram maior área de olho de lombo na fase de recria, mas não houve diferenças na fase de terminação.The carcass characteristics of bovine Indubrasil and crossbred F1 Holstein-Gir and Holstein-Guzera in the growing and finishing phases were evaluated. The carcass yield and the percentages of the basic cuts, carcass length, subcutaneous fat thickness, loin eye area, muscle, fat and bones percentages were also determined. The genetic groups showed no influence on hot carcass yield in relation to live weight and empty body weight, as well as in yields of the basic cuttings, the hindquarter, the forequarter and pistol style cut, at the growing and finishing phases. Indubrasil animals can reach, in inferior weights than animals F1 Holstein-Gir and F1 Holstein-Guzera, the same fat levels in the carcass. F1 Holstein-Guzera presented higher area of the loin at growing, but no differenceswere observed in the finishing phase.

Este estudo foi realizado para avaliar a diferença entre grupos genéticos e efeitos de dietas com diferentes níveis de energia metabolizável para frangos de corte. O desempenho e a qualidade da carcaça de sete grupos genéticos (M1C1, C1C1, C2C2, M1C2, C2F1, C1F1 e M1F1) de frangos de corte, obtidos a partir do cruzamento entre dois genótipos desenvolvidos pela UFV (M1 e F1) e de duas das principais marcas comerciais (C1 e C2), foram determinados. As aves foram distribuídas ao acaso em 84 boxes (15 aves/boxe e 12 repetições), onde permaneceram até o 42º dia de vida. No período inicial (1º ao 21º dia de idade), as aves receberam ração com 3000 kcal de EM/kg e, no período final (22º ao 42º dia de idade), rações com quatro diferentes níveis de energia metabolizável (2900, 3050, 3200 e 3350 kcal EM/kg). As características avaliadas foram: peso vivo no 42º dia de idade, peso ao abate e rendimento de carcaça e de cortes nobres. Encontrou-se diferença entre grupos genéticos e sexo, independente do nível de energia, sobre peso vivo, peso ao abate, peso de carcaça e cortes nobres, destacando-se os grupos genéticos C1C1 e C2C2. Os machos apresentaram melhores resultados para todas as características. No estudo de rendimentos de carcaça e cortes nobres expressos em relação ao peso ao abate, verificou-se diferença entre grupos genéticos apenas para rendimento de peito.This study was conducted to evaluate the difference among genetic groups and the effects of diets with different levels of metabolizable energy for broilers. The performance and carcass quality of seven genetic groups (M1C1, C1C1, C2C2, M1C2, C2F1, C1F1 and M1F1) of broilers obtained from the cross among two lines developed by UFV (M1 and F1) and two mainly trade mark lines (C1 and C2) were determined. The chickens were randomly allocated to 84 different boxes (15 birds/box and 12 replicates), where they were kept up to 42 days of age. In the initial period (1st to the 21st day of age) the birds were fed diet with 3000 kcal of ME/kg, and in the final period (22nd to the 42nd day of age) the birds were fed diets with four different levels of energy (2900, 3050, 3200 and 3350 kcal ME/kg). The analyzed characteristics were: live weight at 42nd day of age, slaughter weight and carcass and prime cut yields. Significant difference was observed among genetic groups and sex, independent of the energy level, on live weight, slaughter weight, carcass weight and prime cuts, standing out the genetic groups C1C1 and C2C2. The males presented the best results for all traits. In the study of carcass and prime cut yields, in function of the slaughter weight, there was difference among genetic groups only for breast yield.

Este experimento foi realizado com o objetivo de avaliar o rendimento de carcaça de três grupos genéticos de frangos de corte, produzidos na UFV, denominados UFV1, UFV2 e UFV3, alimentados com ração única na fase inicial e rações isoenergéticas contendo 16,5; 18,0; 19,5; e 21,0% de proteína bruta (PB) na fase final. Duzentos e quarenta pintos de cada grupo genético, no total de 720 pintos, foram alojados em 48 boxes até 42 dias de idade. No 43º dia, dois machos e duas fêmeas, de cada box, foram pesados e abatidos para determinação do rendimento de carcaça. O delineamento experimental usado foi o inteiramente casualizado em arranjo fatorial 3 x 4 x 2 (grupo genético, nível de proteína e sexo), com quatro repetições, num total de 192 aves. Os valores dos dados de duas aves por sexo foram usados para o cálculo da média. Houve diferença entre grupos genéticos para rendimentos de carcaça, peito e coxa, e o grupo UFV1 apresentou os melhores resultados. Entre sexo, os machos foram superiores nos rendimentos de coxa e sobre-coxa, porém observaram-se maiores rendimentos de peito e gordura abdominal para as fêmeas. À medida que o nível de PB da ração aumentou, o rendimento de carcaça e gordura abdominal reduziu e o de coxa aumentou (efeito linear). Não foi verificado efeito significativo de interação simples dos fatores grupo genético, níveis de proteína e sexo.The objective of this experiment was to evaluate the carcass yield of three genetic groups of broilers chickens, obtained at UFV, called UFV1, UFV2 and UFV3. The chicks were fed an unique diet during the initial phase period and isocaloric diet containing 16.5, 18.0, 19.5, and 21.0% of crude protein (CP) at the finishing phase. Two hundred and forty chicks of each genetic group, totaling 720 chicks, were allotted to 48 floor pens up to 42 days of age. At43rd day, two males and two females of each pen were weighed and slaughtered for the determination of the carcass yield. A completely randomized experimental design was used in a 3x4x2 factorial arrangement (genetic group, protein level and sex) with four replications, totaling 192 chicks. The values of two chickens data per sex were used in the mean calculation. There were differences among genetic groups for yields of carcass, breast and thigh, and UFV1 group showed the best results. Males had higher yields of thigh and drumstick, however, higher breast and abdominal fat yields were observed for females. As dietary CP levels increased, carcass yield and abdominal fat reduced and thigh yield increased (linear effect). No significant effect was observed for single interaction involving genetic group, protein levels and sex.

O objetivo deste experimento foi avaliar o desempenho de três grupos genéticos de frangos de corte obtidos na UFV, denominados UFV1, UFV2 e UFV3, alimentados com rações contendo diferentes níveis de proteína bruta (PB). Duzentos e quarenta pintos de cada grupo genético, no total de 720 pintos, foram alojados em 48 boxes até 42 dias de idade. Na fase inicial (1 a 21 dias), foi fornecida ração única para todas as aves. Na fase final (22 a 42 dias), as aves passaram a receber rações isoenergéticas (3.100 kcal EM/kg), com diferentes níveis de PB (16,5; 18,0; 19,5; e 21,0%). As características estudadas foram: consumo de ração (CR), ganho de peso (GP) e conversão alimentar (CA) nos períodos de 1 a 21, 22 a 42 e 1 a 42 dias de idade. O delineamento experimental no período inicial foi inteiramente casualizado, com três grupos genéticos e 16 repetições, e para o período final, arranjo fatorial 3x4 (grupo genético e nível de proteína), com quatro repetições. Houve diferenças entre grupos genéticos para GP e CR. O grupo UFV1 apresentou os melhores resultados. A conversão alimentar não diferiu entre os grupos. O aumento do nível de PB influenciou o desempenho das aves. Efeito linear positivo entre níveis de PB, GP e CA foi observado. Consumo de ração não foi influenciado pelos níveis de PB. Não se observou interação entre grupos genéticos e níveis de proteína.The objective of this experiment was to evaluate the performance of three genetic groups of broiler chicks, obtained at UFV, called UFV1, UFV2 and UFV3, fed diets with different crude protein (CP) levels. Two hundred and forty chicks of each genetic group, totaling 720 chicks, were allotted to 48 floor pens up to 42 days of age. At the initial phase (1 to 21 days), all chicks were fed an unique diet. At the final phase (22 to 42 days), the chicks were fed isocaloric diets (3.100 kcal ME/kg) with different CP levels (16.5, 18.0, 19.5, and 21.0%). The studied traits were: feed intake (FI), weight gain (WG) and feed:gain ratio (FG) in the periods from 1 to 21, 22 to 42 and 1 to 42 days. The experiment design at the initial phase was a completely randomized design, with three genetic groups and sixteen replicates, and for the final phase, a 3x4 factorial arrangement (genetic group and protein level) with four replicates. There were differences among genetic groups for FI and WG. The UFV1 group showed the best results. The feed:gain ratio did not differ among the groups. The increase in the protein levels affected the broiler chicks performance. A positive linear effect of CP levels on WG and FG was observed. Protein levels did not influenced FI. No interaction was observed between genetic group and protein level.

Abstract Comparing predicted breeding values (BV) among animals in different management units (e.g. flocks, herds) is challenging if units have different genetic means. Unbiased estimates of differences in BV may be obtained by assigning base animals to genetic groups according to their unit of origin, but units must be connected to estimate group effects. If many small groups exist, error of BV prediction may be increased. Alternatively, genetic groups can be excluded from the statistical model, which may bias BV predictions. If adequate genetic connections exist among units, bias is reduced. Several measures of connectedness have been proposed, but their relationships to potential bias in BV predictions are not well defined. This study compares alternative strategies to connect small units and assesses the ability of different connectedness statistics to quantify potential bias in BV prediction. Connections established using common sires across units were most effective in reducing bias. The coefficient of determination of the mean difference in predicted BV was a perfect indicator of potential bias remaining when comparing individuals in separate units. However, this measure is difficult to calculate; correlated measures such as prediction errors of differences in unit means and correlations among prediction errors are suggested as practical alternatives.