The production of a healthy cloned calf is dependent on a multitude of successful steps, including reprogramming mediated by the oocyte, the development of a functional placenta, adequate maternal–fetal interaction, the establishment of a physiological metabolic setting and the formation of a complete set of well-differentiated cells that will eventually result in well-characterised and fully competent tissues and organs. Although the efficiency of nuclear transfer has improved significantly since the first report of a somatic cell nuclear transfer-derived animal, there are many descriptions of anomalies concerning cloned calves leading to high perinatal morbidity and mortality. The present article discusses some our experience regarding perinatal and neonatal procedures for cloned Zebu cattle (B. indicus) that has led to improved survival rates in Nellore cloned calves following the application of such ‘labour-intensive technology’.
The aim of this study was to investigate the effects of metabolic diseases on uterine involution and reproductive performance during the postpartum period. Multiparous Holstein dairy cows (n = 50) were divided into four groups based on whether they were healthy (n = 14), or had lipomobilization (n = 14), hypocalcemia (n = 11), and hyperketonemia (n = 11). Transrectal palpation and transrectal B-Mode sonography were carried out on days 7, 14, 21, 30, 45 and 60 after parturition. Cows with metabolic disease had a greater (p < 0.05) uterine size as assessed transrectally compared with cows without metabolic disease. Sonographic measurements revealed a greater (p < 0.05) horn diameter and endometrial thickness in cows of the metabolic disease groups than in the healthy cows. Metabolic disease affected (p < 0.05) the milk yield, percentage of service per pregnancy, days to first ovulation and days open. In conclusion, metabolic disease affected the uterine involution and fertility during the postpartum period.
1 November 2003 in Brazilian Journal of Microbiology
This study has detected BPV-1 DNA sequences in wart, blood and plasma samples collected from animals affected by papillomatosis, suggesting viral presence inside the cell. We sellected an animal in which we could detect BPV-1 DNA sequences in wart, blood, placenta and amniotic liquid samples and her offspring which presented BPV-1 DNA sequences in blood sample collected immediately after birth. These results show a possible vertical transmission of BPV-1. Neste estudo detectou-se DNA de BPV-1 em: verruga, sangue e plasma de animais afetados por papilomatose. Estes resultados trazem evidências sobre possível localização intracelular do BPV-1 no sangue. Avaliamos um animal afetado por papilomatose e positivo para BPV-1 em amostras de verruga, sangue, placenta e líquido amniótico e que teve sua cria recém-nascida também positiva para BPV-1 no sangue. Estes resultados indicam possível transmissão vertical do BPV-1
The main pathogenic treponemes causing bovine digital dermatitis were identified from 17 infected herds in southern Brazil for the first time in this study using PCR. We did not find a relationship between treponeme phylogroup composition and clinical classification. Treponema phagedenis was present in all lesions. Rumen fluid was implicated as a reservoir location for these pathogens.
Low efficiency of somatic cell cloning by nuclear transfer has been associated with alterations of placental vascular architecture. Placental growth and function depend on the growth of blood vessels; VEGF-A and bFGF are the most important factors controlling neovascularization and vascular permeability in the placenta. We hypothesize that the VEGF-A and bFGF systems are disrupted in placentomes from cloned animals, contributing to the placental abnormalities that are common in these clones. We determined mRNA expression and protein tissue localization of VEGF-A, bFGF, and their receptors in placentomes from cloned and non-cloned bovine fetuses at term. Real-time RT-PCR revealed that VEGFR-2 mRNA was increased in cloned male-derived placentomes, while mRNA of bFGF and its receptors were decreased in placentomes of cloned females. VEGF-A system proteins were found to be located in placentomal endothelial, maternal and fetal epithelial and stromal cells; there was a variable pattern of cellular distribution of these proteins in both cloned and non-cloned animals. Alterations in the expression of VEGF-A and bFGF systems suggest that angiogenic factors are involved in abnormal placental development in cloned gestations, contributing to impaired fetal development and poor survival rates.