Temperamento e comportamento materno-filial de ovinos das raças Corriedale e Ideal e sua relação com a sobrevivência dos cordeiros

O experimento foi conduzido na Estação Experimental da Embrapa, Bagé, Rio Grande do Sul, entre março de 2005 e fevereiro de 2006. O objetivo foi avaliar o comportamento materno-filial e o temperamento de ovelhas e cordeiros e relacioná-los com a sobrevivência dos cordeiros. Foram utilizadas 47 ovelhas da raça Corriedale, com peso médio de 52,1kg, e 45 ovelhas da raça Ideal, com peso médio de 49,5kg, em um delineamento inteiramente casualizado. O temperamento foi avaliado por meio dos testes: escore de comportamento materno (ECM), tempo de fuga, tipo de marcha e distância de fuga. As ovelhas da raça Corriedale apresentaram maiores valores no teste tipo de marcha que as ovelhas da raça Ideal. Os cordeiros da raça Corriedale eram os mais pesados e tinham maior índice de sobrevivência, quando comparados com os da raça Ideal. A raça não afetou o escore de comportamento materno. Ovelhas reativas (ECM=1), que fogem e não retornam aos seus cordeiros, se isolaram menos do rebanho antes do parto, protegeram menos suas crias, desmamaram-nas mais cedo e tiveram menor peso em relação às não-reativas. A reatividade das ovelhas prejudicou o cuidado materno com os cordeiros e essa característica deve ser considerada pelo setor produtivo.

Calagem e adubação boratada na produção de feijoeiro

Objetivou-se avaliar os efeitos da aplicação de calcário e boro nos atributos químicos de um Latossolo, estado nutricional e produtividade da cultura do feijoeiro. As doses de calcário empregadas foram crescentes, considerando-se a saturação por bases igual a 70%, correspondendo às doses: zero; 0,6; 1,2 (v = 70%); 1,8 e 2,4 t ha-1. O calcário utilizado apresentava poder relativo de neutralização total (PRNT), poder de neutralização (PN) e reatividade (RE) de 131; 137 e 95%, respectivamente. As doses de boro estudadas foram iguais a 0 (zero); 0,6; 1,2; 1,8; e 2,4 mg dm-3 de B, sendo a referência para definição das mesmas a de 1,2 mg dm-3 de B (ou 1,2 kg ha-1 de B). Utilizou-se como fonte o ácido bórico (H3BO3) p.a. (17% B). Na época do florescimento foi avaliado o estado nutricional das plantas e, aos 90 dias foram avaliadas a fertilidade do solo e a produção de grãos. No solo houve melhoria dos atributos pH, SB, V e na concentração de Ca e Mg, e do B com o emprego da adubação boratada. A interação da calagem com a adubação boratada promoveu maior acúmulo de Ca, Mg e B nas plantas. Os dados apresentados demonstram que o feijoeiro foi responsivo à calagem e à adubação boratada, tendo atingido bons índices de produção com a utilização de 1,8 kg ha-1 de B com doses crescentes de calcário.

Electrochemical behavior of parent and photodegradation products of some selected pesticides

Electrochemical behavior of pesticides is extensively studied, but little attention has been given to the study of their degradation products (by-products) by electrochemical methods. However, the degradation products of pesticides can be even more toxic then the parent products and such studies should be encouraged. Therefore, the objective of this work was to evaluate the electroactivity of by-products of imazaquin, methylparathion, bentazon and atrazine, generated by UV irradiation and measured using cyclic and differential pulse voltammetry and UV-visible absorption spectrophotometry. Results have shown that several by-products exhibit electroactivity, allowing, in some cases, the simultaneous determination of both parent and degradation products.

Associação da medroxiprogesterona ao protocolo Ovsynch para inseminação artificial em tempo fixo de búfalas cíclicas (Bubalus bubalis) criadas na Amazônia Oriental

O presente estudo visou avaliar os efeitos da associação da medroxiprogesterona (análogo sintético da progesterona) ao protocolo Ovsynch sobre o crescimento folicular, a ovulação e a taxa de concepção de búfalas criadas na Amazônia Oriental (Tracuateua-PA). Vinte e sete fêmeas adultas (G1 n=14 e G2 n=13), cíclicas, sem bezerro ao pé e com ECC 3,5 foram submetidas a Ovsynch. Os animais do G2 receberam 60 mg de medroxiprogesterona entre D0 e D7 (D0=início do tratamento). A ultra-sonografia ovariana foi realizada nos D 0, 7, 9 e 10. O contingente de folículos pequenos diferiu no D7 (G1: 4,57±0,60 versus G2: 6,54±0,67; P=0,05). Tempo e tratamento influenciaram o diâmetro folicular no D7. O crescimento do folículo dominante entre D7 e D9 foi maior nos animais tratados (G1: 2,05±0,49 mm/dia versus 3,48±0,41 mm/dia; P<0,05). Mais animais do G1 ovularam precocemente (35,71% versus 30,77%), porém isso não afetou as taxas de concepção (G1: 50,00% e G2: 30,77%; P>0,05). Os achados sugerem que a medroxiprogesterona (1) aumenta recrutamento folicular e retarda o crescimento dos folículos com diâmetro maior que 5,0 mm entre D0 e D7; (2) sua retirada incrementa em 1,7 vezes o crescimento folicular do D7 ao D9; (3) pode contribuir para a ovulação de folículos maiores e, em tese, para maior formação de tecido luteínico; (4) não promove ovulação precoce após o Ovsynch; (5) não eleva as taxas de concepção após sincronização de fêmeas cíclicas e com bom escore corporal, devendo ser avaliada para uso em fêmeas acíclicas ou com ECC mais baixo.

SELECTION OF TRICHOGRAMMA PRETIOSUM LINEAGES FOR CONTROL OF GRAPHOLITA MOLESTA IN PEACH

Grapholita molesta (Lepidoptera: Tortricidae) is one of the main pests of peach trees in Brazil, causing fruit losses of 3-5%. Among possible biological control agents, Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) has been found in peach orchards. Our objectives were to study the rearing of T pretiosum in eggs of G. molesta and Anagasta kuehniella (Lepidoptera: Pyralidae), and select lineages of this parasitoid that have the potential to control G. molesta. Selection of best lineages was made from 5 populations of T pretiosum collected from organically-cultivated peach orchards. The study was done under controlled temperature (25 +/- 2 degrees C), relative humidity (70 +/- 10%) and 14:10 h (light:dark) photoperiod conditions. Grapholita molesta eggs were found to be adequate hosts for the development of T pretiosum, and the parameters for number of parasitized eggs, percent parasitized eggs, and sex ratio were similar to those for A. kuehniella eggs. The highest rate of parasitism of G. molesta eggs occurred in eggs with up to 48 h of embryonic development. Among the lineages of T pretiosum that were collected, HO8, PO8, PEL, and L3M showed the best biological performance and are therefore indicated for semi-field and field studies for biological control of oriental fruit moth.

Precision of distances and ordering of microsatellite markers in consensus linkage maps of chromosomes 1, 3 and 4 from two reciprocal chicken populations using bootstrap sampling

Some factors complicate comparisons between linkage maps from different studies. This problem can be resolved if measures of precision, such as confidence intervals and frequency distributions, are associated with markers. We examined the precision of distances and ordering of microsatellite markers in the consensus linkage maps of chromosomes 1, 3 and 4 from two F 2 reciprocal Brazilian chicken populations, using bootstrap sampling. Single and consensus maps were constructed. The consensus map was compared with the International Consensus Linkage Map and with the whole genome sequence. Some loci showed segregation distortion and missing data, but this did not affect the analyses negatively. Several inversions and position shifts were detected, based on 95% confidence intervals and frequency distributions of loci. Some discrepancies in distances between loci and in ordering were due to chance, whereas others could be attributed to other effects, including reciprocal crosses, sampling error of the founder animals from the two populations, F(2) population structure, number of and distance between microsatellite markers, number of informative meioses, loci segregation patterns, and sex. In the Brazilian consensus GGA1, locus LEI1038 was in a position closer to the true genome sequence than in the International Consensus Map, whereas for GGA3 and GGA4, no such differences were found. Extending these analyses to the remaining chromosomes should facilitate comparisons and the integration of several available genetic maps, allowing meta-analyses for map construction and quantitative trait loci (QTL) mapping. The precision of the estimates of QTL positions and their effects would be increased with such information.

High-throughput SNP genotyping in the highly heterozygous genome of Eucalyptus: assay success, polymorphism and transferability across species

Background: High-throughput SNP genotyping has become an essential requirement for molecular breeding and population genomics studies in plant species. Large scale SNP developments have been reported for several mainstream crops. A growing interest now exists to expand the speed and resolution of genetic analysis to outbred species with highly heterozygous genomes. When nucleotide diversity is high, a refined diagnosis of the target SNP sequence context is needed to convert queried SNPs into high-quality genotypes using the Golden Gate Genotyping Technology (GGGT). This issue becomes exacerbated when attempting to transfer SNPs across species, a scarcely explored topic in plants, and likely to become significant for population genomics and inter specific breeding applications in less domesticated and less funded plant genera. Results: We have successfully developed the first set of 768 SNPs assayed by the GGGT for the highly heterozygous genome of Eucalyptus from a mixed Sanger/454 database with 1,164,695 ESTs and the preliminary 4.5X draft genome sequence for E. grandis. A systematic assessment of in silico SNP filtering requirements showed that stringent constraints on the SNP surrounding sequences have a significant impact on SNP genotyping performance and polymorphism. SNP assay success was high for the 288 SNPs selected with more rigorous in silico constraints; 93% of them provided high quality genotype calls and 71% of them were polymorphic in a diverse panel of 96 individuals of five different species. SNP reliability was high across nine Eucalyptus species belonging to three sections within subgenus Symphomyrtus and still satisfactory across species of two additional subgenera, although polymorphism declined as phylogenetic distance increased. Conclusions: This study indicates that the GGGT performs well both within and across species of Eucalyptus notwithstanding its nucleotide diversity >= 2%. The development of a much larger array of informative SNPs across multiple Eucalyptus species is feasible, although strongly dependent on having a representative and sufficiently deep collection of sequences from many individuals of each target species. A higher density SNP platform will be instrumental to undertake genome-wide phylogenetic and population genomics studies and to implement molecular breeding by Genomic Selection in Eucalyptus.

Characterization of mitochondrial genotypes in the foundation herd of the Canchim beef cattle breed

The Canchim (5/8 Charolais + 3/8 Zebu) beef cattle breed was developed at Southeast-Embrapa Cattle to take advantage of hybrid vigor and to combine the higher growth rate and beef quality of Charolais with tropical adaptations of Zebu. The development of three lineages (old, new, and crossbred) has increased its genetic basis. The genotypic origin (Bos taurus or Bos indicus) of the mitochondrial DNA (mtDNA) of the Canchim breed was unknown. We characterized the mtDNA genotype of this founder herd by allele-specific polymerase chain reaction. The 173 founder Zebu females (62 Indubrasil, 3 Guzerat, and 108 Nellore) and their 6749 offspring were identified. The frequency of B. indicus mtDNA ranged from 1.15 to 2.05% among the descendants (N = 6404) of each maternal line with available DNA, and among animals that were alive (N = 689) in December 2007 among the three lineages. Though mtDNA characterization can be used to direct animal selection, the low frequency of B. indicus mtDNA impairs the evaluation of its effects on production traits in these animals. The high prevalence of B. taurus mtDNA in Canchim proves that the founder Zebu females from the Indubrasil, Guzerat and Nellore breeds were obtained from crosses of Zebu sires with local B. taurus dams.

Sensor arrays to detect humic substances and Cu(II) in waters

The interaction between poly(o-ethoxyaniline) (POEA) adsorbed onto solid substrates and humic substances (HS) and Cu(2+) ions has been investigated using UV-vis spectroscopy and atomic force microscopy (AFM). Both HS and Cu(2+) are able to dope POEA and change film morphology. This interaction was exploited in a sensor array made with nanostructured films of POEA, sulfonated lignin and HS, which could detect small concentrations of HS and Cu(2+) in water. (C) 2009 Elsevier B.V. All rights reserved.

Effectiveness of two systems for the spraying of pesticides in citrus trees

Citriculture normally uses high application volumes in pesticide solutions (of 2.000 to 5.000 L ha(-1)) to control pests and diseases that affect the crop, which generates an increase in operational costs. For this reason, diverse systems of application are being developed to reduce application volumes and improve the uniformity of pesticide deposition. The goal of this work was to evaluate the efficiency of two application systems of pesticides in citrus trees. One system used a prototype for terrestrial application with rotary disc atomizers that are widely used in agricultural aviation, and the other system used hollow cone tip hydraulics. For the treatment of the trees the insecticide Metidation was used at the dose of 180 gr per hectare. To study the droplet spectrum, water-sensitive papers were installed at different positions in the trees canopy, and for the study of insecticide deposition leaves of the treated plants were collected. The water-sensitive papers were collected and analyzed using a computerized image analysis system (e-Sprinkle, EMBRAPA, Sao Paulo, Brazil), and the leaves analyzed by the technique of gas chromatography. Pesticide deposition was similar in both application system, although the solution volume used by the application system equipped with rotary disc atomizers was one quarter of the volume used by the application system equipped with hydraulic tips, reducing considerably the cost of the phytosanitary treatments.

Host suitability of Avena spp. genotypes to Meloidogyne incognita race 4

Host suitability of Avena spp. genotypes to Meloidogyne incognita race 4 The black oat (Avena strigosa), the white oat (A. sativa) and the Algerian oat (A. byzantina) have been widely used as cover crops under succession with soybean, cotton, bean, potato and carrot, which are crops highly damaged by Meloidogyne incognita. The management of M. incognita may have as a component the use of oat genotypes that reduce the nematode population density. Three greenhouse experiments were carried out in order to evaluate the host suitability of five genotypes of black oat (`CPAO 0010`, `Common`, `Embrapa 29`, `Embrapa 140` and `IPFA 99006`), one of white oat (`UFRGS 17`) and one of Algerian oat (`Sao Carlos`) to three isolates of M. incognita race 4 (BA, SP and MT). The black oats increased the population density of the nematode. The oats `UFRGS 17` and `Sao Carlos` reduced or caused a small increase in the population of M. incognita race 4, and neither differentiated from Crotalaria spectabilis. Therefore, the white oat `UFRGS 17` and the Algerian oat `Sao Carlos` should be used in preference to black oats as cover crops in areas infested with M. incognita race 4.

Effect of follicular wave synchronization on in vitro embryo production in heifers

Aiming to achieve the ideal time of ovum pick-up (OPU) for in vitro embryo production (IVP) in crossbred heifers, two Latin square design studies investigated the effect of ovarian follicular wave synchronization with estradiol benzoate (EB) and progestins. For each experiment, crossbred heifers stage of estrous cycle was synchronized either with a norgestomet ear implant (Experiment 1) or a progesterone intravaginal device (Experiment 2) for 7d, followed by the administration of 150 mu g D-cloprostenol. On Day 7, all follicles >3 mm in diameter were aspirated and implants/devices were replaced by new ones. Afterwards, implant/device replacement was conducted every 14 d. Each experiment had three treatment groups. In Experiment I (n = 12), heifers in Group 2X had their follicles aspirated twice a week and those in Groups 1X and 1X-EB were submitted to OPU once a week for a period of 28 d. Heifers from Group 1X-EB also received 2 mg EB i.m. immediately after each OPU session. In Experiment 2 (n = 11), animals from Group 0EB did not receive EB while heifers in Groups 2EB and 5EB received 2 and 5 mg of EB respectively, immediately after OPU. The OPU sessions were performed once weekly for 28 d. Therefore, in both experiments, four OPU sessions were performed in heifers aspirated once a week and in Experiment 1, eight OPU sessions were done in heifers aspirated twice a week. Additionally, during the 7-d period following follicular aspiration, ovarian ultrasonography examinations were conducted to measure diameter of the largest follicle and blood samples were collected for FSH quantification by RIA. In Experiment 1, all viable oocytes recovered were in vitro matured and fertilized. Results indicated that while progestin and EB altered follicular wave patterns, this treatment did not prevent establishment of follicular dominance on the ovaries of heifers during OPU at 7-d intervals. Furthermore, the proposed stage of follicular wave synchronization strategies did not improve the number and quality of the recovered oocytes, or the number of in vitro produced embryos. (C) 2009 Elsevier B.V. All rights reserved.

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.

Reproductive cycles in Bos indicus cattle

Several studies using transrectal ovarian ultrasonic scanning in Bos taurus (B. taurus) cattle and more recently in Bos indicus (B. Indicus) females evaluated the reproductive cycles of heifers and cows under different conditions. In general, B. indicus cattle have more follicles and more follicular waves during the estrous cycle and ovulate from smaller follicles than B. taurus. Consequently B. indicus females have smaller corpora lutea and it is assumed circulating concentrations of estradiol and progesterone are also less. However, these findings may vary depending on the nutritional status and regimen in which the animals are managed. Moreover, there are significant differences between B. taurus and B. indicus regarding follicle size at the time of deviation of the dominant follicle. These differences in ovarian function between B. indicus and B. taurus, e.g. greater antral follicle population are, probably, the main reasons for the great success of in vitro embryo production programs in Zebu cattle, especially in Brazil. (C) 2011 Elsevier B.V. All rights reserved.

mRNA profile of Nellore calves after primary infection with Haemonchus placei

Haemonchus parasites are responsible for many losses in animal production. However, few studies are available, especially of zebu cattle. In this study, we investigated mRNA differences of immune response genes in naive Nellore calves infected with Haemonchus placei, relating these differences to patterns of cellular infiltrate. Calves were infected with 15,000 H. placei 13 larvae and after 7 days lymph node and abomasum tissues were collected. IL-2, IL-4, IL-8, IL-12, IL-13, IFN-gamma, MCP-1, lysozyme, pepsinogen and TNF-alpha genes were evaluated by qPCR. Mast cells, eosinophils and globular leukocytes were counted by abomasum histology. In the infected group, IL-4, IL-13 and TNF-alpha were up-regulated in the abomasal lymph node. In the abomasum, IL-13 increased and TNF-alpha was down-regulated (p < 0.05). No differences were detected for mast cells and eosinophil counts in abomasal tissue (p > 0.05). We conclude that for this infection time, there was Th2 polarization but that cellular infiltrate in abomasal tissue takes longer to develop. (C) 2010 Elsevier B.V. All rights reserved.