Complete replacement of the mitochondrial genotype in a Bos indicus calf reconstructed by nuclear transfer to a bos taurus oocyte

Due to the exclusively maternal inheritance of mitochondria, mitochondrial genotypes can be coupled to a particular nuclear genotype by continuous mating of founder females and their female offspring to males of the desired nuclear genotype. However, backcrossing is a gradual procedure that, apart from being lengthy, cannot ascertain that genetic and epigenetic changes will modify the original nuclear genotype. Animal cloning by nuclear transfer using host ooplasm carrying polymorphic mitochondrial genomes allows, among other biotechnology applications, the coupling of nuclear and mitochondrial genotypes of diverse origin within a single generation. Previous attempts to use Bos taurus oocytes as hosts to transfer nuclei from unrelated species led to the development to the blastocyst stage but none supported gestation to term. Our aim in this study was to determine whether B. taurus oocytes support development of nuclei from the closely related B. indicus cattle and to examine the fate of their mitochondrial genotypes throughout development. We show that indicus:taurus reconstructed oocytes develop to the blastocyst stage and produce live offspring after transfer to surrogate cows. We also demonstrate that, in reconstructed embryos, donor cell-derived mitochondria undergo a stringent genetic drift during early development leading, in most cases, to a reduction or complete elimination of B. indicus mtDNA. These results demonstrate that cross-subspecies animal cloning is a viable approach both for matching diverse nuclear and cytoplasmic genes to create novel breeds of cattle and for rescuing closely related endangered cattle.

Observações clínicas, anatomopatológicas e tratamento de seis casos de dermovilite exsudativa vegetante crônica (cancro da ranilha) de cqüinos

Chronic hypertrophic pododermatitis cases in six horses of different breeds, aging 14 months to 19 years are described. The lesion begun with a infiltrative tissue in the frog and sole regions of the hoof, characterized by a fast and disorganized growth, with a papillary aspect, white colored in the roots and dark on the extremity, with a necrotic secretion and an extremely fetid odor. Microscopically, an exuberant epidermic proliferative tissue was observed, intermingled with little connective tissue. The horses were divided into two treatment groups. In the first group, including three young mares and a foal, showing lesions in only one limb, a surgical resection of the invasive mass was performed, followed by cauterization of the remaining edges and subsequent daily local application of antiseptic substances. In three of these horses, recurrence of the initial lesion occurred, with fast growth of hyperplasic tissue, affecting almost all the frog and half of the sole. Two horses developed contraction deformities of the hoof. In the second group, one male and one female, each with lesions in two limbs, after surgical debridement of the tissue, the animals received daily applications of picric acid 5%, associated to local use of oxitetracyclin. Although one of these cases required a second surgical intervention for removal of the mass, the horses showed after a period of two to three months total absence of the infiltrative tissue. The use of local picric acid 5% and oxitetracyclin associated to previous surgical debridement showed to be more efficient than the use of antiseptic substances in the treatment of chronic hypertrophic pododermatitis.

Estimates of covariance functions for growth from birth to 630 days of age in Nelore cattle

Weight records of Brazilian Nelore cattle, from birth to 630 d of age, recorded every 3 mo, were analyzed using random regression models. Independent variables were Legendre polynomials of age at recording. The model of analysis included contemporary groups as fixed effects and age of dam as a linear and quadratic covariable. Mean trends were modeled through a cubic regression on orthogonal polynomials of age. Up to four sets of random regression coefficients were fitted for animals' direct and maternal, additive genetic, and permanent environmental effects. Changes in measurement error variances with age were modeled through a variance function. Orders of polyno-mial fit from three to six were considered, resulting in up to 77 parameters to be estimated. Models fitting random regressions modeled the pattern of variances in the data adequately, with estimates similar to those from corresponding univariate analysis. Direct heritability estimates decreased after birth and tended to be lowest at ages at which maternal effect estimates tended to be highest. Maternal heritability estimates increased after birth to a peak around 110 to 120 d of age and decreased thereafter. Additive genetic direct correlation estimates between weights at standard ages (birth, weaning, yearling, and final weight) were moderate to high and maternal genetic and environmental correlations were consistently high. © 2001 American Society of Animal Science. All rights reserved.

Growth hormone mRNA expression in the pituitary of Bos indicus and Bos taurus x Bos indicus crossbred young bulls treated with recombinant bovine somatotropin

The effects of breed and of recombinant bovine somatotropin (rbST) treatment on growth hormone gene expression were studied in young bulls. The experiment was completely randomized in a [2 × 2]-factorial arrangement, using two levels of rbst (0 or 250 mg/animal/14 days), and two breed groups (Nelore and Simmental x Nelore crossbred). A CDNA encoding Bos indicus growth hormone was cloned and sequenced for use as a probe in Northern and dot blot analyses. Compared to the Bos taurus structural gene, the Bos indicus CDNA was found to begin 21 bases downstream from the transcription initiation site and had only two discrepancies (C to T at position 144-His and T to C at position 354-Phe), without changes in the polypeptide sequence. However, two amino acid substitutions were found for Bubalus spp., which belong to the same tribe. The rbst treatment did not change any of the characteristics evaluated (body and pituitary gland weights, growth hormone MRNA expression level). Crossbred animals had significantly higher body weight and heavier pituitaries than Nelore cattle. Pituitary weight was proportional to body weight in both breed groups. Growth hormone MRNA expression in the pituitary was similar (P>0.075) for both breed and hormonal treatment groups, but was 31.9% higher in the pure Nelore group, suggesting that growth hormone gene transcription regulation differs among these breeds.

Características anátomo-estruturais da pelé de ovinos (ovis áries L.) lanados e deslanados, relacionadas com o aspecto físico-mecânico do couro

The objective of the study was establishing the anatomical-structural differences between the skin of non-wool sheep of the Morada Nova breed and wool-on sheep of the Polwarth or Ideal breeds and their relations to the physical-mechanical characteristics of their leather after tanning. Ten animals of both breeds were used, with five animals of approximately one and four years of age of each breed. The animals were slaughtered, and immediately after skinning, samples were taken viewing the microtomy of the skin in the dorsal, lateral, ventral, hind and palette regions, parallel and perpendicular to the head-tail axle, and perpendicular to the grain of the skin. The skins were depilated, chromium-tanned and re-tanned. From the leather, three samples were taken from the two directions considered from the regions studied for physical-mechanical analysis, for tension and tear resistance and distension on the lastometer. The average of the results of the physical-mechanical analysis were compared by Tukey test at the levels of 1 and 5% probability. The breed, the age, the region and the position exerted a positive effect on the values of the resistance of the leather to tension for the Morada Nova four year old sheep, reaching a minimum of 200 kg/cm . The region and the position exerted a positive effect on the values of tear-resistence of the leather for both breeds studied, reaching a minimum of 40 kg/cm. The resistance of the leather on distension was superior to 8 mm, for all the animals studied, not influenced by breed, age, region or position. The skin of the Ideal sheep presented a thermostatic skin layer greater than the reticular layer with great folicular and glandular density, contrary to the skin of the Morada Nova sheep where the thermostatic and reticular layers are of approximately the same thickness, with less folicular and glandular density.

Espécies do gênero Eimeria Schneider, 1875 (Apicomplexa: Eimeriidae) em caprinos leitros mantidos em sistema intensivo na região de São Jose do Rio Preto, estado de São Paulo, Brasil.

Were examined 58 dairy goats, 41 kids and 17 adults, Saanen and Alpine breeds, males and females, in intensive system, in the São José do Rio Preto region, São Paulo state, for detection and identification of Eimeria spp. oocysts. The 58 feces samples analyzed by the Centrifugal-flotation technique, were positive for, at least, one Eimeria species. The Eimeria species found in this research were: E. ninakohlyakimovae (77,6%), E. jolchijevi (72,4%), E. alijevi (63,8%), E. christenseni (63,8%), E. arloingi (62,1%), E. caprovina (56,9%), E. hirci (50,0%) and E. caprina (48,3%). It follows that the high rate of the positive animals and the high frequency of the Eimeria species among the animals demonstrated that the disease is common in dairy goats, kids and adults, in intensive system.

Desenvolvimento morfolôgico dos ovários em embriões e fetos bovinos da raça Nelore

The morphologic events related to the prenatal development of the ovaries in 81 Nelore breed embryos and fetuses gathered in a local slaughterhouse, with age range from 26 to 240 days following fecundation were studied. The age of fetuses was estimated from measures taken in the cranium-caudal direction. The sex was identified from macroscopic observations and using Polymerase Chain Reaction (PCR) technique. For histology the gonads were fixed in Bourn's fluid for 24 hours and 5 μm thick section's were stained with hematoxylin-eosin. Formation of gonadal ridge and presence of germinal cells were found within it at 29 and 34 days, respectively. Oogonia and primordial follicles, unlike the growing follicles, exhibited significant differences in diameter in the various periods studied. Positive correlation (P<0.05) was found between the diameter of oogonia and their nucleus as well as between primordial and growing follicles with their oocytes and respective nuclei. The gonad was fully formed at 40 days. Primordial follicles, in the growing stage, and antral follicles first appeared, approximately at 95, 140, and 180 days, respectively. Despite the onset and duration of oogenesis being similar to that of taurine breeds, folliculogenesis initiates at an early stages in the Nelore breed.

Investigação soroepidemiológica de leptospirose canina na área territorial urbana de Botucatu, São Paulo, Brasil

Leptospirosis was seroepidemiologically investigated in 775 dogs from Botucatu, state of Sao Paulo, in blood samples collected during the annual anti-rabies vaccination campaign. The samples were collected from 14 out of the 45 vaccination stations geographically distributed in five different municipal districts, with a territorial urban area of 31Km2. Samples were taken from 449 males and 326 females; 564 were of undetermined breed, and 211 were pedigree animals; ages ranged from 3 months to 20 years. Diagnosis included the microscopic serum agglutination tests using 12 Leptospira spp serovars. Serological results and epidemiological variables were compared using Goodman and chi-square tests, with χ=0.05. There were 119 (15.3%) positive samples for 11 serovars; the most important was canicola with 48 (40.3%), followed by pyrogenes 41 (34.5%). Statistical analysis showed significant difference for: breed, 17.7% positive in undetermined breeds and 9.0% in pedigrees; and sex, 18.4% positive in males and 11.0% in females. There was no statistically significant difference in relation to age with uniform distribution of positives.

Prolapso de glândula de terceira pálpebra em cäes: Avaliação cito e histopatológica

The present experiment was carried out in ten animals with third eyelid prolapsed gland. All of the prolapsed glands were surgically excised. The age of the dogs ranged from two month to ten years old, and the breeds were Beagle (20%), Teckel (10%), Pinscher (10%), Poodle (10%) and other mongrel dogs. Aspirative citology was made in all the removed glands, after that they were fixed in 10% formalin and stained with Hematoxiline and Eosine. It was observed a focal mononuclear inflamatory infiltrate in the conjunctive and periacinal tissues. Ductal dilatation and metaplasia were noted on cells of the ducts. Cyitologic examination showed similar inflamatory infiltrate to histopatologic findings. The glands showed a chronic adenitis. The absence of histo and cytologic significance changes justify the tissue function observed during surgical excision.

Avaliação da capacidade imunoestimulante e da estabilidade de um probiótico empregado em rações de cães

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Leitões lactentes e desmamados alimentados com dietas farelada ou extrusada seca e umida

This work was conducted throughout three phases of swine's growth (7 days from birth till the weaning age; from weaning until 7 days later and from 8 to 21 days after weaning); taking as objective the evaluation of the development of suckling and weaned piglets fed with a bran or extruded, dried and wet diet. We've used, for this paper, a total number of 31 pigs breeds, weaned and in average 21 day's lifetime and 3 different rations: dried bran; dried extruded bran and wet extruded bran (2 volumes of water to one volume of ration). During the 8th and 21st day after weaning all the animals received the same bran dried ration. Water and ration were supplied ad libitum. The experimental delimitation was totally random, with 3 treatments and eleven repetitions in the two first phases and five repetitions in the third phase, the multivariate variance analysis applied in the inferences about the results and from this we could conclude that the weight daily gain and the ration daily consumption were significantly not affected, i.e. by the processing, by the dry material ration content. However, we could observe a tendency to increase ration consumption and weight gaining when the animals were fed with bran extruded wet ration.

Effects of the density, aviary type, breed, and age on the behaviors of laying hens kept in cages

An experiment was carried out in order to investigate the behaviors of laying hens due to the environmental factors of: density inside of the cage, aviary type, breed, and age. The experiment was configured as a factorial 4x2x2x2 study, with treatments being four different ages, two different breeds, two different cage densities, and two different aviaries. The birds' behaviors were recorded using video cameras installed in the cages, using samples of 15 minutes recorded from 12 PM to 4 PM. The observed behaviors, frequency and duration of behaviors (measured in seconds) were identified and noted related to each bird. The study was initiated in March 2007, during four non-consecutive weeks. The observed behaviors were: opening wings, stretching, threatening, ruffling feathers, drinking water, aggressive pecking, eating, running, lying down, stretching head out of the cage, preening, mounting, prostrating, and doing nothing (inactivity). Due to the non-normality of the data recorded, the Kruskal-Wallis statistical test of the MINITAB Statistical Software® was used to compare the medians of the variables. For breed factor, only the durations of the eating presented significant differences (p-value< 0.05). For cage density, there was a significant median difference (p-value< 0.05) for almost all behaviors observed. The average length of time of behaviors was higher for the lowest cage density. However, the frequency of behaviors was lmerfor the lowest cage density. The frequency of the behaviors to preen feathers, to lie down, to drink water and to stretch the head were higher in the aviary, where the groups of birds were smaller. The observed behaviors were particularly affected by experimental factors cage density, and aviary type, which directly affects the available space for each bird.

Inferência bayesiana na predição de valores genéticos do peso aos 365 dias de bovinos de corte

Data from purebred Simmental, Nellore and Canchim cattle breeds obtained from the respective Brazilian Associations of Breeders were used to estimate variance components and to predict genetic values for 365 days weight. The results obtained by Bayesian inference were compared to those from Restricted Maximum Likelihood (REML) and Best Linear Unbiased Prediction (BLUP), which are the most commonly used methods of estimation and prediction in animal breeding. The two methods presented similar point estimates but the study of the marginal posterior distributions in the Bayesian approach yields more detailed information about the parameters and other unknowns in the model.

Relações materno-filiais e sua influência no peso pré-desmama de animais Nelore da Bahia

The aim of this study was to investigate the maternal-offspring relationships in the bovine breeds Nellore PO (Pure Breed) and Nellore CL (Cara Limpa) in Bahia State. The genetic composition of breeds did not affect LP (latency time to stand); this variable showed mean values of 71 min and 52 min, respectively, for Nellore PO and Nellore CL. The variable LPTM (latency time to begin suckling after standing) was significantly higher for Nellore PO (mean values of 39 min) tham for Nellore CL (18 min). The variable TCC (time in contact with the calf) was classified as class 4 (60 to 80% of the time was spent with the calves). The P120 (weight at 120 days) had mean values of 122.3 kg and 122.7 kg respectively, for Nellore PO and Nellore CL. In conclusion, the maternal-offspring behaviour had little influence of the genetic composition of the breeds. These results suggest that more studies are necessary to define technological parameters for cattle raising in Bahia State.

Physiological bases for understanding estrous cycle differences between bos taurus and bos indicus

Background: Although there is some information in the literature discussing differences of the estrous cycle of Bos taurus and Bos indicus cattle, most of the data derive from studies performed in temperate climate countries, under environmental and nutritional conditions very different than those found in tropical countries. Moreover, the physiological basis for understanding the differences between Bos taurus and Bos indicus estrous cycles are still unknown. This review explores the physiological and metabolic bases for understanding the key differences between the Bos taurus and Bos indicus estrous cycle. Moreover, it presents recent results of studies that have directly compared reproductive variables between Zebu and European cattle. Review: The knowledge of reproductive physiology, especially the differences between Bos taurus and Bos indicus, is important for the development and application of different techniques of reproductive management in cattle. In this regard, overall, Bos indicus have a greater number of small ovarian follicles and ovulatory follicles are smaller as compared to Bos taurus. Consequently, Zebu cattle also have smaller corpus luteum (CL). Nevertheless, circulating concentrations of steroid and metabolic hormones are not necessarily higher in European cattle. In fact, some studies have shown that despite ovulating smaller follicles and having smaller CL, Bos indicus cows or heifers have higher circulating concentrations of estradiol, progesterone, insulin and IGF-I compared to Bos taurus females. In addition, there are also substantial differences between Bos indicus and Bos taurus cattle in relation to follicle size at the time of selection of the dominant follicle. Conclusion: Data from very recent studies performed in Brazil have corroborated results from previous reports that have observed substantial differences in the estrous cycle variables of Bos indicus versus Bos taurus cattle. Those differences are probably related to distinct metabolism and metabolic hormone concentrations between Zebu and European cattle. This increased knowledge will allow for the establishment of more adequate reproductive management protocols in both breeds of cattle.