The objective of this study was to evaluate the production, consumption, and energy balance parameters of primiparous 3/4 and 7/8 Holstein × Gir (HG) dairy cows fed two diets of differing energy levels during the postpartum period. At the beginning of the study, 28 days prepartum, the average weight of both genetic groups was 498?±?12 kg and body condition score (BCS) was 3.5?±?0.05. At the end of the study, 61 days postpartum, the 3/4 HG cows had higher weight and body condition scores than the 7/8 HG (456?±?8 and 429?±?8 kg and 3.13?±?0.03 and 2.94?±?0.03 BCS for 3/4 HG and 7/8 HG, respectively). Milk from cows fed the high-energy diet had higher percentages of fat, protein, lactose, and total dry extract than cows fed the low-energy diet. Cows fed the high-energy diet had higher net energy intake (95.3?±?1.9 vs. 88.1?±?2.1 MJ/day) and higher energy balance (3.64?±?2.13 vs ??6.02?±?2.30 MJ/day). The 3/4 HG cows displayed higher energy for maintenance (33.1?±?0.4 MJ/day) than the 7/8 HG (31.5?±?0.5 MJ /day). In conclusion, although the primiparous 3/4 HG were heavier than the 7/8 HG and had a higher body condition score, no differences in milk produced up to 60 days postpartum were observed. The higher energy diet during the postpartum period increased energy balance, resulting in higher production of milk fat, protein, and lactose.
Tropical Animal Health and Production - The objective of this study was to evaluate the ruminal parameters (pH, N-NH3, and microbial protein) and morphometry of the rumen and intestine of sheep fed... 相似文献
This study aimed to compare feed efficiency measures of Nellore beef cattle on different residual intake and gain (RIG) classes. We used data from 610 animals weighing on average 236.33 kg and average of 283 days of age from feedlot performance tests carried out between 2005 and 2012. Animals were grouped based on RIG into three different classes: high RIG (>?mean?+?0.5 standard deviation (SD), most efficient; n?=?193), medium RIG (mean?±?0.5 SD; n?=?235), and low RIG (<?mean – 0.5 SD, least efficient; n?=?182). Residual feed intake (RFI), residual gain (RG), feed conversion ratio (FCR), feed efficiency (FE), relative growth rate (RGR), and Kleiber ratio (KR) of animals in each RIG class were compared by Tukey test at 1% of probability. Phenotypic correlations between variables were evaluated as well. Animals on high RIG class showed lower dry matter intake (P?<?0.01) and higher average daily gain (P?<?0.01) than low RIG animals. Consequently, high RIG animals had lower FCR (P?<?0.01) and higher FE (P?<?0.01) than those animals in low RIG class. The most efficient animals based on RIG were also the most efficient animals based on RG and RFI. RIG was negatively correlated to dry matter intake (P?<?0.01) and FCR (P?<?0.01), and a positive correlation was found between RIG and FE (P?<?0.01). Therefore, RIG appears to be a good parameter to select animals with reduced dry matter intake and high productive performance.
Bovine tuberculosis is a major problem in Brazil. The intradermal tuberculin test is the standard test for detection of bovine tuberculosis in Brazil but can lack both sensitivity and specificity. The purpose of this study was to compare a bovine γ-IFN assay with the tuberculin test under field conditions in Brazil. A total of 1632 animals from 13 dairy farms were tested using the single cervical tuberculin test (SCTT). Among those animals, about 15% of each herd, 220 in total, represented a high-risk group and were selected to be tested using the γ-IFN test. Of the 1632 animals tested, 207 presented significant reactions representing 12.7% of the cattle studied. In the selected group the number of animals positive by the γ-IFN assay was 126/220 (57.3%) and the total number of reactive cows on SCTT was 106/220 (48.2%). The real number of infected cattle, following standards, was 120/220 (54.5%). From these results the relative sensitivity rate of γ-IFN test was 100% including the false-positive results and 88.3% for the SCTT — a significant (P < 0.01) difference in favour of the γ-IFN test of 11.7%. The γ-IFN assay also identified some positive animals 60–120 days earlier than the SCTT. In conclusion, we believe that the γ-IFN assay can be used alone or in combination with the SCTT, as a valuable tool for the control of bovine tuberculosis in the Brazilian national herd. 相似文献
This study hypothesised that different elephant grass genotypes respond differently in terms of their morphological development to irrigation. The objective of this study was to evaluate how water availability could affect the morphological development of different genotypes of elephant grass. The treatments consisted of four genotypes of elephant grass [Cenchrus purpureus (Schumach.) Morrone], managed under irrigation or not, during a two-year field trial. The experiment was arranged in a randomised block design in a split-plot, with four replicates per treatment (n = 4). Between the genotypes, two of them were classified as tall-sized (IRI 381 and Elephant B), and two as dwarfs (Taiwan A-146 2.37 and Mott). A three-way interaction between season, irrigation, and genotype affected the variables plant height, stem diameter, number of dead tillers, light interception (LI), and leaf area index (LAI) (p < .05). The morphological development of all genotypes was negatively impacted by the dry season. All genotypes grew taller during the rainy season (p < .05) and had a greater light interception (62%–80%) compared to the dry period (28%–59%). The genotype Mott, showed comparable LI and LAI to the tall-sized genotypes, whilst Taiwan A-146 2.37 was characterized by the lowest values, despite being the genotype with the greatest tiller density (60 tillers m−2) (p < .05). The use of irrigation mitigated the negative effects of the dry season on the plants, however, the type and size (tall vs. dwarf) of the elephant grass genotypes defined the extent of the responses to the use of the irrigation during the dry period. 相似文献
Cylindrospermopsin (CYN) is a cyanotoxin that is cytotoxic to a wide variety of cells, particularly to the hepatocytes. In this study, the toxic effects of purified CYN were investigated in primary cultured hepatocytes of Neotropical fish Hoplias malabaricus. After isolation, attachment, and recovery for 72 h, the cells were exposed for 72 h to 0, 0.1, 1.0, 10, and 100 μg l?1 of CYN. Then, cell viability and a set of oxidative stress biomarker responses were determined. Catalase, superoxide dismutase, glucose-6-phosphate dehydrogenase, and glutathione S-transferase activities were not affected by exposure to CYN. Concentration-dependent decrease of glutathione reductase activity occurred for most CYN-exposed groups, whereas non-protein thiol content increased only for the highest CYN concentration. Lipid peroxidation, protein carbonylation, and DNA damage levels were not altered, but reactive oxygen species levels increased in the cells exposed to the highest concentration of CYN. Cell viability decreased in all the groups exposed to CYN. Thus, CYN may cause a slight change in redox balance, but it is not the main cause of cell death in H. malabaricus hepatocytes. 相似文献
Phytotherapy can replace antibiotic administration as an alternative to control Aeromonas hydrophila, one of the main bacteria involved in the aetiology of farmed fish diseases. Given that plants of the Lippia spp. genus show biological potential for antimicrobial activity, this study evaluated the chemical composition of essential oils extracted from Lippia alba, Lippia origanoides and Lippia sidoides and their activity against A. hydrophila. The oils were obtained by steam distillation in a Clevenger‐type apparatus and their composition determined by gas chromatography and mass spectrometry (CG/MS). Antibacterial activity was assessed by calculating the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) using broth microdilution method. The main compounds identified were geranial (25.4%) and neral (16.6%) in L. alba oil, carvacrol (40.4%) and p‐cymene (11.4%) in L. origanoides oil and thymol (76.6%) and ortho‐cymene (6.3%) in L. sidoides oil. The three Lippia species showed bacteriostatic and bactericidal action against A. hydrophila, with MICs and MBCs ranging from 1250 to 5000 μg mL?1. Of the species tested, the best performance was obtained with essential oil of L. sidoides. 相似文献
The objective of this study was to verify the direct and indirect correlation between morphometric measures, ratios, body weight and yield in two lambari species Astyanax lacustris and Astyanax fasciatus and whether the discriminant analysis is capable of separating and allocating the species. We used 102 lambari yellow tail and 60 lambari red tail. The fish were weighed and submitted to the evaluation of the morphometric measurements. The direct and indirect effects were evaluated by the method of track analysis, considering weight at slaughter, weight of body parts and body yields as dependent variables and measures and morphometric ratios as explanatory variables. Astyanax lacustris presented higher height and body width, carcass yield and trunk, while A. fasciatus presented higher head yield and viscera weight. The discriminant analysis was able to classify 79.5% of the two species. Track analysis demonstrated that the morphometric measurements can be used for estimation of body and body components’ weight in A. lacustris and A. fasciatus. However, regarding the corporal yield; the morphometric measures were insufficient to explain the yield variations of the species. 相似文献
Infrastructure development and overfishing in the Amazon make it imperative to define adequate scales for the ecosystem‐based management of commercial fisheries and the wetlands on which they depend. We mapped fisheries and fish ecology data from Brazil, Peru, Bolivia and Colombia to an explicit GIS framework of river basins and mainstems. Migratory species account for more than 80% of the known maximum catches of commercial fisheries across the Amazon. Of these migratory species, we nominated six long‐distance migratory fish taxa as flagship species to define the two main commercial fishery regions. The migrations of at least one goliath catfish species define a large‐scale longitudinal link joining the Andes, Amazon Lowlands and Amazon River estuary. Migratory Characiforms demonstrate interbasin wetland connectivity between nutrient‐rich and nutrient‐poor rivers over at least 2 million km2, or about one‐third of the Amazon Basin. We show that flooded forest area is the most important wetland variable explaining regional variations in migratory characiforme biomass as indicated by maximum annual fishery catches. The sustainable management of Amazon fisheries will require transnational cooperation and a paradigm shift from local community management alone to a more integrated approach that considers both rural and urban consumers and challenges, and the realistic life histories of migratory species. 相似文献
We evaluated the use of MALDI-TOF MS for the identification of 3 major, dairy-associated Prototheca species, namely, Prototheca bovis (formerly P. zopfii genotype 2), P. blaschkeae, and P. ciferrii (formerly P. zopfii genotype 1). The MALDI-TOF MS spectra established for those species were introduced into the reference spectra library of the Bruker Biotyper MALDI-TOF MS analysis software. Next, 31 Prototheca isolates from Holstein cows with mastitis, from herds located in the midwestern area of São Paulo State, Brazil, were subjected to MALDI-TOF MS profiling. MALDI-TOF MS allowed identification of 22 of 27 P. bovis and 3 of 4 P. blaschkeae isolates with scores >2.0, with 5 of 27 P. bovis and 1 of 4 P. blaschkeae isolates identified only to the genus level. With our extended algae database, MALDI-TOF MS can contribute to quick and effective speciation of Prototheca from mastitis cases. 相似文献