J. R. B. Sereno

Using nonlinear models to describe height growth curves in Pantaneiro horses.

Height at withers data mostly from birth to 36 months of age of 26 Pantaneiro horses were used to fit Brody, Richards, Gompertz, Logistic, Weibull and Morgan-Mercer-Flodin nonlinear response functions. Based on measures of average curvature and combined mean square error, the Weibull model was chosen. The asymptote of this curve, representing the average height at maturity, was higher for males than females. The maturity index, however, was more elevated for females than males. There was indication of a negative association between the maturity index and height at maturity only for females. These results indicate that females mature earlier. After checking for normality and homogeneity of variances within groups (sex) the analysis investigated sex differences via t-tests. A significant difference was detected only for height at birth.

Parâmetros e tendência genética de peso de bovinos criados á pasto no Brasil

espanolParâmetros e tendencias geneticas para os pesos aos 120 (P120: n= 86 852), 205 (P205: n= 86 852), 365 (P365: n= 61 637) e 550 (P550: n= 36 187) dias de idade foram estimados para animais da raca Nelore criados a campo nas regioes Centro-Oeste e Sudeste no Brasil. Os dados sao provenientes da ABCZ/EMBRAPA e foram obtidos no periodo entre 1975 a 2001. Os parâmetros foram obtidos utilizando o programa MTDFREML, em analise unicaracteristica. Os efeitos fixos foram grupo de contemporâneos (combinacao de estacao (agua e seca), ano, sexo e fazenda) e a covariavel idade da vaca ao parto (linear e quadratico). Como efeito aleatorio utilizou- se o efeito aditivo direto, aditivo materno, e de ambiente permanente. As estimativas das variâncias geneticas, direta e materna, ambientais e fenotipicas e as covariâncias entre o efeito direto e materno foram 51,1; 17,9; 190,5; 280,4 e -12,0 para P120; 128,6; 47,2; 695,7; 932,4 e -25,9 para P205; 435,9; 32,2; 2934,0; 3604,9 e -27,4 para P365; 607,9; 177,7; 5637,7; 6602,5 e -117,6 para P550. Os valores de herdabilidades direta encontram-se na faixa de 0,09 a 0,18; herdabilidade materna variaram de 0,01 a 0,06, correlacao direta materna entre -0,23 a -0,36 e o efeito de ambiente permanente igual a 0,05 a 0,12. As estimativas das tendencias geneticas, direta materna, e ambientais no periodo de 1975 a 2001 foram 10,4; -1,6 e 18,4 kg para P120; 16,6; -2,8 e 23,0 kg P205; 21,7; -1,3 e 23,6 kg para P365; 25,5; -3,6 e -8,1 kg para P550, respectivamente. As tendencias geneticas diretas foram positivas e as maternas pequenas e nega- tivas. O desempenho materno tem influencia im- portante sobre os pesos aos 120 e 205 dias de idade e esse baixo valor obtido sugere que se deve considerar para este efeito nos programas de melhoramento, mesmo se tendo correlacao direta materna adversa. EnglishGenetic parameters and trends of weights were estimated for Nellore cattle from Central west and South East in Brazil. ABCZ/EMBRAPA provided weights (kg) at 120 (W120), 205 (W205), 365 (W365) and 540 (W540) for 86 852, 86 852, 61 637, 36 187 animals, respectively, from 1975 to 2001. Parameters were obtained using MTDFREML in single trait analyses. Fixed effects were contemporary group (dry or wet season), year, sex and farm and age of dam (linear and quadratic covariate). Random effects were direct and maternal genetic effects, their covariance, and the uncorrelated maternal permanent environmental effect. The analysis was restarted until twice the logarithms of the likelihoods changed no more than two decimal places. Estimates of direct and maternal genetic variances, direct-maternal covariance, and environmental and phenotypic variances were [51.1, 17.9, -12.0, 190.5 and 280.4] for W120; [128.6, 47.2, -25.9, 695.7 and 932.4] for W205; [435.9, 32.2, -27.4, 2934.0 and 3604.9] for W365; and [607.9, 177.7, -117.6, 5637.7 and 6602.5] for W540. Direct heritabilities ranged from 0.09 to 0.18, maternal heritabilities from 0.01 to 0.06, direct-maternal genetic correlations from -0.23 to -0.36, and permanent environmental effects from 0.05 to 0.12. Direct and maternal genetic and environmental trends from 1975 to 2001 were 10.4, -1.6 and 18.43 kg for W120; 16.6, -2.8; and 23.0 kg for W205; 21.7, -1.3 and 23.6 kg for W365, and, 25.5, -3.6, and -8.1 kg for W540, respectively. The direct genetic trends were positive and maternal trends were small. The importance of maternal performance for W120 and W205 suggests it should be considered in breeding programs although it has a low heritability and modestly adverse genetic correlation with direct genetic effects.

Cytogenetic and molecular analysis of the Pantaneiro cattle breed

The objective of this work was to characterize Pantaneiro cattle genetically through its paternal ancestry by the morphology of the Y chromosome, whether submetacentric or acrocentric, as well as to identify the maternal ancestry through mitochondrial DNA. The karyotype and mitochondrial DNA of 12 bulls of Pantaneiro breed were analyzed. The Y chromosome was analyzed in lymphocyte metaphases and the mitochondrial DNA by diagnosing its haplotype (Bos taurus and Bos indicus). Among Pantaneiro animals analyzed three had a taurine (submetacentric) Y and nine had a zebuine (acrocentric) Y chromosome, suggesting breed contamination by Zebu cattle, once Pantaneiro is considered to be of European origin. The mitochondrial DNA was exclusively of taurine origin, indicating that the participation of zebuines in the formation of the breed occurred entirely through the paternal line.

Nascimento de bezerros normais após inseminação artificial utilizando espermatozóides criopreservados obtidos de epidídimos refrigerados de bovinos após a morte

The objective of this study was to evaluate the morphological and functional characteristics of bovine spermatozoa retrieved from chilled epidydimides for long periods and cryopreserved. Bovine testicles were collected in abattoir, transported to the laboratory and stored at 5°C for 0, 24, 48h e 72 hours (n=10 for each storage time treatment group). The spermatozoa were retrieved from each epidydimides, evaluated and diluted in tris-egg yolk-glycerol 7% medium and cryopreserved in liquid nitrogen. The morphological and functional characteristics of the spermatozoa were analyzed in vitro, by microscopic evaluation and in vivo, using artificial insemination. Morphological alterations as sperm immaturity and motility reduction decreased after 72h of epididymides refrigeration and after thaw sperm were observed. The membrane and acrosome integrity were only affected in G48 and G72 groups after cryopreservation. However, the sperm capacity of fertilization post-cryopreservation was sufficient to promote two pregnancies and birth of healthy calves from G24 h and G72h groups. These results indicated that recovery and cryopreservation of chilled epididymal sperm until 72h from dead animals is a viable option to preserve male gametes to compose a germplasm bank.

Indicação geográfica na conservação e agregação de valor ao gado Curraleiro da comunidade Kalunga

EnglishThe objective of this study was to show the importance of geographical indications, as a strategy of maintaining and aggregating value to the Curraleiro cattle, and as a basis for future registration of the denomination of origin Kalunga Meat of Curraleiro, by the remaining Kalunga qui- lombo community in Cavalcante situated in the State of Goias, Brazil. Recognition of the denomination of origin Kalunga Meat of Curraleiro, will make establishment of a modality of sustainable exploration in the Cerrado possible, as well as promote preservation of a bovine race well adapted to adverse conditions of this biome, improve their food availability and increase family income. portuguesEste trabalho objetivou mostrar a importância das indicacoes geograficas, como estrategia de conservacao e agregacao de valor ao gado Curraleiro e, propor estrategias para o futuro registro da denominacao de origem Carne de Curraleiro Kalunga, pela comunidade remanescente de quilombo Kalunga do municipio de Cavalcante, Goias, Brasil. O reconhecimento da denominacao de origem Carne de Curraleiro Kalunga, viabilizara o estabelecimento de uma modalidade de exploracao sustentavel para o Cerrado, com a preservacao de uma raca bovina adaptada as condicoes adversas deste bioma e proporcionara as familias quilombolas, melhoria na disponibilidade de alimento e aumento da renda familiar.

DNA testing for parentage verification in a conservation nucleus of Pantaneiro horse

We investigated the genealogy of the in situ conservation nucleus of the Pantaneiro horse using DNA microsatellites by evaluating 101 horses, the group consisting of 71 adult horses (3 stallions, 40 male and 31 mares) and 27 foals (14 colts and 13 fillies). Genomic DNA was extracted from hair roots and genotyped using 12 microsatellite markers (AHT4, AHT5, ASB2, ASB17, ASB23, HMS3 HMS6, HMS7, HTG4, HTG10, LEX33 and VHL20). The number of alleles per locus varied from 6 to 13, with a mean of 7.8 and the expected heterozygosity ranged from 0.544 to 0.734 (mean 0.644). The VLH20, ASB2, HTG10, ASB23 markers had a high (> 0.8) polymorphism information content and the total exclusion probability of the 12 microsatellite loci was 0.99. The genealogical study of the Pantaneiro horse using genetic markers was efficient in detecting mistakes during paternity and maternity designation and is an important tool which can be used together with traditional systems of animal identification. The use of genetic markers is recommended in the systematic control of the genealogical registrations and conservation plans to improve genetic aspects of the Pantaneiro horse.

Redução da proporção touro:vaca no Pantanal brasileiro

(4) Abstract - This work was conducted to study alternatives for reduction of the bull:cow ratio in the Brazilian lowland and, therefore, lower the production costs for the local beef cattle industry. The ratios 1:10, 1:25, and 1:40 were used in native pastures with a mean stocking rate of 0.27 mature animal unit per hectare over two consecutive breeding seasons. Statistical analysis did not show any effect (P>0.05) of year (P = 0.2097), animal category (P = 0.0773), bull:cow ratio (0.8134) on reproductive performance. However, the pregnancy rate in a multiple bull system was higher (P = 0.0228) than in the individual bull system. An evaluation of the economic impact of this management system in the extensive Lowland herds showed that at the ratio of 1:10 the bulls were sub utilized.

Weight and age at puberty and their correlations with morphometric measurements in crossbred breed Suffolk ewe lambs

The objective of this study was to identify and to correlate parameters that characterize puberty and estimate the age and weight of Suffolk ewe lambs in Mato Grosso do Sul. This study was carried out with twenty-two Suffolk ewe lambs for 256 days. Blood samples were collected from the jugular vein and centrifugated and the plasma were stored at -20°C until analysis of progesterone (P4) concentration by radioimmunoassay (RIA). The morphometric measurements included: head length and width, body length, elbow height, chest perimeter, back-sternal diameter, croup length, width and height, cannon bone perimeter and shoulder and hip width, using a tape. The animals became pubertal when the plasma progesterone concentration was >1.0 ng/mL, at 34.1 ± 5.2 kg and 39.5 ± 8.5 weeks of age. Meanwhile, the lambs that did not reach puberty (37.7 ± 11.4 weeks of age) were lighter. The morphometric measurements has medium to low correlations with age and weight at puberty.

Maternal offspring behaviour in Curraleiro Pé Duro naturalized cattle in Brazil

The objective of the present study consisted of describing dam and calf suckling behaviour of Curraleiro Pe Duro cattle. In this study, 38 mother-offspring pairs and one mother-offspring-orphan trio were observed for 10 hours daily during three consecutive days spaced every four months over a period of one year. After identification, the animals were observed under field conditions where calf posture and the number of suckling episodes (NS), mean suckling duration (MSD), total suckling duration per day (TSD) as well as natural weaning of these animals were recorded. The model assessed the effects of calf sex and age as well as feeding time. Suckling episodes (70.6%) had a duration of one to five minutes and the calf that suckled in the inverted parallel position had greater chances of success during suckling (99.5%); the younger animals had a shorter mean suckling duration (4.0±0.6 minutes) than the older ones (7.5±1.2 minutes) but they showed a higher number of suckling episodes (6.29±1.00 vs. 1.33±0.04 feeds in 10 hours for young and older calves). Only the factor age in the first three months was significant for NS, MSD, and TSD; males and females had similar suckling episode length and distribution. While these animals show some traits similar to other cattle breeds such as feeding their calves early in the morning and late in the afternoon, the dams spend large periods of the day away from their calves and suckling is more frequent but for shorter periods of time compared with other breeds. Other unique features such as allo-suckling and formation of day-long creches are observed in this breed.

Caracterização fenotípica de ovelhas dos humedales de ite, sul do peru: dados preliminares

Sheep farming is an important socioeconomic activity in Peru, being one of the main sources of income for many rural families. The objective of the present study was to characterize the phenotype of adult ewes, from local flocks farmed in the Ite Wetlands, southern coast of Peru. These animals were reared in a semi extensive system, on native pastures. Thirteen morphometric traits were measured and analyzed using MEANS, CORR, GLM, DISCRIM and CLUSTER procedures of the statistical program SAS. Three morphologic traits were also registered and three zoometric indices calculated. The results indicated that these ewes are smaller than specialized breeds, but had tendency for meat production and different body sizes, showing variability of biotypes between flocks, according to the management, geographical location and apparent racial miscegenation.