Does the male reproductive performance depend on the early lactation milk in rats?

This study investigated the role of the early lactation milk (ELM) on the male reproductive performance and the participation of GnRH on this effect in Wistar rats. Newborn males were divided into three experimental groups: 1) ELM-deprived pups, 2) ELM-deprived pups treated with exogenous GnRH 1, 7, 25, and 31 h after birth, and 3) non-ELM-deprived and without exogenous GnRH. In relation to the other two groups, the ELM-deprived male rats exhibited as adults: reduced fertility, decreased weight of both vas deferens and seminal vesicle, and reduced levels of fructose in the seminal vesicle and prostate gland. We suggest that the intake of ELM during the neonatal period is important to the later sexual development of rats, and that GnRH is somehow involved in such an effect.

Growth curves for Macrobrachium rosenbergii in semi-intensive culture in Brazil

Four 0.02-ha earthen ponds at the UNESP Aquaculture Center, Jaboticabal, São Paulo, Brazil, were stocked with newly metamorphosed Macrobrachium rosenbergii post-larvae at 1.5 animals/m2. After 8 mo, prawn density at harvest ranged from 0.3/ m2 to 0.8/m2. Growth curves were determined for each population using von Bertalanffy growth functions. Asymptotic maximum length and asymptotic maximum weight increased as final population size decreased indicating that a strong density effect on prawn growth occurs in semi-intensive culture, even when populational density varies within a small range of less than 1 animal/m2.

Analytical functions for the calculation of hyperspherical potential curves of atomic systems

We present angular basis functions for the Schrödinger equation of two-electron systems in hyperspherical coordinates. By using the hyperspherical adiabatic approach, the wave functions of two-electron systems are expanded in analytical functions, which generalizes the Jacobi polynomials. We show that these functions, obtained by selecting the diagonal terms of the angular equation, allow efficient diagonalization of the Hamiltonian for all values of the hyperspherical radius. The method is applied to the determination of the 1S e energy levels of the Li + and we show that the precision can be improved in a systematic and controllable way. ©2000 The American Physical Society.

Duality of osculating developables of projective curves

We give a description of the dual varieties of all developables of osculating linear spaces to a projective curve in terms of the higher order dual varieties of the curve, in arbitrary characteristic. We also determine for these varieties the inseparable degrees of the projections from the conormal varieties onto their dual varieties.

Atenolol reduces salivary activity in pups of spontaneously hypertensive and normotensive rats treated during pregnancy and lactation

The salivary activity in pups of spontaneously hypertensive rats (SHR) and Wistar (W) rats treated with atenolol during pregnancy, and lactation was evaluated. Atenolol's anti-hypertensive effect on the SHR rats was noticed from the beginning of treatment. Atenolol-treated SHR and Wistar rat pups showed a decrease in salivary gland weight, salivary flow, and protein concentration, with no alteration in salivary amylase activity. Atenolol's effect on salivary glands can interfere with oral health maintenance. Copyright © Informa Healthcare USA, Inc.

Growth curves and genetic parameters in colombian buffaloes (Bubalus bubalis Artiodactyla, Bovidae): Curvas de crecimiento y parámetros genéticos en búfalos (Bubalus bubalis Artiodactyla, Bovidae) en Colombia

Non-linear mathematical functions proposed by Brody, Gompertz, Richards, Bertalanffy and Verhulst were compared in several buffalo production systems in Colombia. Herds were located in three provinces: Antioquia, Caldas, and Cordoba. Growth was better described by the curves proposed by Brody and Gompertz. Using the datasets from herds from Caldas, heritabilities for traits such as weaning weight (WW), weight and maturity at one year of age (WY and MY, respectively), age at 50% and 75% of maturity (A50% and A75%, respectively), adult weight (β0), and other characteristics, were also estimated. Direct and maternal heritabilities for WW were 0.19 and 0.12, respectively. Direct heritabilities for WY, MY, A50%, A75% and β0 were 0.39, 0.15, 0.09, 0.20 and 0.09, respectively. The genetic correlation for β0 and WY was -0.47, indicating that selection for heavy weight at one year of age will lead to lower weight at adult age. These data suggest that selection based on maturity traits can generate changes in characteristics of economic importance in beef-type buffalo farms. © 2012 Universidad de Antioquia.

A visual tool for building synchronous generator capability curves

Synchronous generators are essential components of electric power systems. They are present both in hydro and thermal power plants, performing the function of converting mechanical into electrical energy. This paper presents a visual approach to manipulate parameters that affect operation limits of synchronous generators, using a specifically designed software. The operating characteristics of synchronous generators, for all possible modes of operation, are revised in order to link the concepts to the graphic objects. The approach matches the distance learning tool requirements and also enriches the learning process by developing student trust and understanding of the concepts involved in building synchronous machine capability curves. © 2012 IEEE.

Growth curves for ostriches (Struthio camelus) in a Brazilian population

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genetic parameters for test-day milk yield, 305-day milk yield, and lactation length in Guzerat cows

Milk production in tropical environments requires the use of crossbreeding systems including breeds well adapted to harsh conditions, but with lower productivities when compared to specialized breeds. Besides the genetic improvement for milk production, lactation lengths also need to be studied for most of these breeds. Accordingly, genetic parameters were estimated for 305-day cumulative milk yield (MY305), test-day milk yield (TDMY), and lactation length (LL) using information from the first lactations of 2816 Guzerat cows selected for milk production in 28 herds in Brazil. Contemporary groups were defined as herd, year and season of the test for TDMY, and as herd, year and season of calving for MY305 and LL. Variance components were estimated with the restricted maximum likelihood method under a multi-trait animal model. Heritabilities estimated for TDMY ranged from 0.16 to 0.24, and were 0.24 and 0.12 for MY305 and LL, respectively. Genetic correlations were high and positive, ranging from 0.51 to 0.99 among TDMY records, from 0.81 to 0.98 between each TDMY and MY305, and from 0.71 to 0.94 between each TDMY and LL. Genetic parameters obtained in this study indicated the possibility of using test-day records for the prediction of breeding values for milk yield in this population of the Guzerat breed. The use of TDMY as selection criteria would result in indirect gains in MY305 and LL. However, the highest response to selection for MY305 would be obtained by direct selection for this trait. © 2012 Elsevier B.V.

Evaluation of von willebrand factor during pregnancy, lactation and oestrous cycle in bitches affected and unaffected by von willebrand disease

Plasmatic concentrations of von Willebrand Factor (vWF) increase during pregnancy in humans and dogs; however the mechanism of such increase is still not well defined. The aims of this study were: (i) to evaluate changes in vWF concentration during pregnancy and during the subsequent oestrous cycle in bitches affected and unaffected by von Willebrand Disease (vWD); (ii) to correlate the vWF levels and cortisol levels in both groups. Seven vWD affected (GI) and nine unaffected (GII) bitches were used. The animals were assessed during pregnancy, parturition, lactation and non-gestational oestrous cycle in 11 moments (Pregnancy 1, Pregnancy 2, Parturition, Lactation 1, Lactation 2, Lactation 3, Anestrus, Proestrus, Oestrus, Diestrus 1, and Diestrus 2). The following tests were performed; measurement of von Willebrand factor antigen (vWF:Ag), albumin and cortisol. In both groups, vWF concentration remained stable during the non-gestational oestrous cycle, but increased during pregnancy, with the highest value observed at parturition. Increases of 70% and 124% in vWF were seen in GI and GII, respectively, compared to anestrus. No correlation was found between vWF and cortisol. Values of vWF:Ag changed during pregnancy, with a peak at parturition, both in vWD affected and unaffected animals. Values of vWF were not altered in the different phases of the oestrous cycle following pregnancy in both groups. Evaluation of vWF during pregnancy can cause false negative results for vWD, but assessment can be performed at any point in the oestrous cycle of non-pregnant bitches. © 2012 Blackwell Verlag GmbH.

Genetic parameters for milk yield, lactation length and calving intervals of murrah buffaloes from brazil

The major objective of this study was to estimate heritability and genetic correlations between milk yield (MY) and calving interval (CI) and lactation length (LL) in Murrah buffaloes using Bayesian inference. The database used belongs to the genetic improvement program of four buffalo herds from Brazil. To obtain the estimates of variance and covariance, bivariate analyses were performed with the Gibbs sampler, using the program MTGSAM. The heritability coefficient estimates were 0.28, 0.03 and 0.15 for MY, CI and LL, respectively. The genetic correlations between MY and LL was moderate (0.48). However, the genetic correlation between MY and CI showed large HPD regions (highest posterior density interval). Milk yield was the only trait with clear potential for genetic improvement by direct mass selection. The genetic correlation between MY and LL indicates that indirect selection using milk yield is a potentially beneficialstrategy.Theinterpretation of the estimated genetic correlation between MY and CI is difficult and could be spurious. ©2013 Sociedade Brasileira de Zootecnia.

Nutrients balances and milk fatty acid profile of mid lactation dairy cows supplemented with unsaturated fatty acid

The objective was to evaluate the effect of unsaturated fatty acid sources supplementation on nutrients balances and milk fatty acid profile of mid lactation dairy cows. Twelve Brazilian Holstein cows in the mid lactation (mean of 128 days) and (580 ± 20kg of weight; mean ± SD) with milk yield of 25kg/d were assigned randomly into three 4 × 4 Latin square, fed the following diets: control (C); refined soybean oil; (SO); whole soybean raw (WS) and; calcium salts of unsaturated fatty acids (CSFA). Milk yield was 26.6; 26.4; 24.1 and 25.7 to the diets CO, SO, WS and CSFA respectively. Cows fed the WS treatment produced less milk (1.95kg/d of milk), fat and lactose than did cows fed the SO and CSFA. Cows fed the CSFA treatment showed less blood, urine (g/d) concentrations of N more energetic efficiency and intake of energy than did cows fed the SO treatment. Cows fed the unsaturated fatty acids sources showed more C18:2 cis-9, trans-11 CLA and trans-C18:1 FA concentration in milk than did cows fed the CO treatment. Diets with whole soybeans and soybeans oil provide more efficient digestive processes, and increase milk composition of unsaturated fatty acids.

The low predictive power of simple Phillips curves in Chile

This study uses some backward-looking versions of Phillips curves, estimated from both revised and real-time data, to explore the existence, robustness and size of the contribution that a variety of activity measures may make to the task of predicting inflation in Chile. The main results confirm the findings of the recent international literature: the predictive power of the activity measures considered here is episodic, unstable and of moderate size. This weak predictive contribution is robust to the use of final and real-time data.

Efeitos da exposição perinatal ao chumbo sobre a pressão arterial e a rea tividade vascular de ratos recém-desmamados e adultos, tratados ou não com DMSA, L-Arginina e/ou Enalapril: Andréia Fresneda Gaspar. -

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