ABSTRACT
Weaning weight (WW) is one of the most important information within production systems, as it is a reflection of management during the breastfeeding phase and will influence the performance of animals in subsequent phases. This study aimed to develop and evaluate linear, quadratic, and exponential models to predict WW using the body volume (BV) formula in Santa Inês lambs for meat. Eighty-five lambs at 90 days of age with WW 17.52 ± 3.79 kg and BV 13.29 ± 2.86 dm3 were evaluated. The quality of fit of the models was evaluated using the coefficient of determination (R2), mean squared error (MSE), and root MSE (RMSE). For the external evaluation of the models, an independent dataset from 43 lambs at 90 days of age was used. The first-degree linear model showed the lowest values of MSE (1.02) and RMSE (1.01). In the external evaluation, all models exhibited estimates of mean WW and standard deviation of this weight similar to the external dataset, as well as high values (above 0.89) for the R2 of predicted vs. observed data. Concordance correlation coefficient (CCC) analysis also revealed that all models showed accuracy and precision (CCC > 0.90). There was no difference between the models in terms of accuracy (P > 0.05). The comparison in terms of precision indicated that the linear model is more precise than the exponential model and that the quadratic model is as precise as the linear model. The first-degree linear model should be used due to its simplicity of interpretation and ease of estimation.
Subject(s)
Animal Husbandry , Body Weight , Models, Biological , Sheep , Animals , Body Composition , Meat , Sheep, Domestic , Weaning , Algorithms , Reproducibility of Results , Animal Husbandry/methodsABSTRACT
The objective of this study was to identify the main technologies used in the management of ruminant grazing. We developed a review protocol in which the search terms were previously tested and based on the PVO strategy to determine the guiding question (population [P]: domestic ruminants; variables [V] of interest: grazing management technologies; and outcomes [O]: intake, performance, and productivity of animals raised exclusively on pasture). The guiding question was the following: What technologies are used in the grazing management of domestic ruminants on pasture? The databases used were SCOPUS (Elsevier), SciELO Citation Index, Science Direct, and Wiley Online Library, and the search was carried out until October 15, 2021. The search identified 2683 research articles; however, only 43 were considered eligible and included due to their methodological robustness for data extraction. The most commonly used species were Lolium multiflorum and Lolium perenne (20%), Panicum maximum (18%), and Brachiaria brizantha (14%). The most widely used grazing methods were continuous grazing (53.4%) and intermittent grazing (39.5%). Among the technologies, the most widely adopted were pasture height (55.8%) and herbage allowance (11.6%). The most frequent sampling methods were the use of a ruler (37.2%) and measuring stick (13.9%) to measure the height, and clipping with a frame (18.6%) to measure herbage allowance. The animals used in the included studies were cattle (n = 1335), sheep (n = 839), and goats (n = 41). Pasture height and herbage allowance were the most widely used grazing management technologies, with the data concentrated mainly in Brazil, in studies with continuous grazing by cattle.
Subject(s)
Animal Feed , Animal Husbandry , Diet , Animals , Cattle , Animal Feed/analysis , Brachiaria , Brazil , Diet/veterinary , Lolium , Panicum , Ruminants , Sheep , Animal Husbandry/methodsABSTRACT
The aim of this study was to predict carcass traits of Santa Inês lambs finished in tropical pastures by using biometric measurements. Data originated from two experiments involving 56 lambs (32 in experiment I and 24 in experiment II). In both experiments, the sheep were finished in that were finished in pastures of Panicum maximum and Brachiaria brizantha, experiment I being conducted in the rainy season and experiment II in the dry season. The following biometric measurements were recorded before slaughter: body length (BL), withers height (WH), rump height (RH), thorax width (TW), rump width (RW), chest width (CW), heart girth (HG), thigh circumference (TC), rump circumference (RC) and leg length (LL), in addition to live weight at slaughter (SW). After slaughter, hot carcass weight (HCW), cold carcass weight (CCW) and the weights of primal cuts (shoulder, neck, loin, leg and rib) were recorded. In the equations generated to predict SW, HCW and CCW, R2 ranged from 0.58 to 0.91 and the measurements of WH, TC, CW, HG and RW were the most relevant. In the equations developed to predict the weight of primal cuts, in turn, R2 ranged from 0.26 to 0.99. In these models, SW, BL, CW, TC, LL and HG explained most of the variation in the weight of primal cuts. Biometric measurements can be used to accurately and precisely predict HCW, CCW and the weight of primal cuts from the carcass of Santa Inês sheep finished in tropical pastures, since the equations presented R2 and correlation coefficient and agreement above 0.8.
ABSTRACT
Chlamydia trachomatis é um parasita intracelular obrigatório e tem sido considerado como um dos problemas para a reprodução humana. Para o presente estudo, foi realizada uma busca referente aos principais fatores relacionados à infertilidade ou falhas em técnicas de reprodução assistida em virtude da infecção aguda ou crônica causada pela clamídia. Trata-se de uma revisão por levantamento retrospectivo de artigos científicos publicados nas últimas duas décadas (1984 - 2011). A maioria das infecções por clamídia em mulheres é assintomática e a infecção persistente pode ocasionar danos às tubas uterinas, infertilidade, parto prematuro, conjuntivites no recém-nascido, doença inflamatória pélvica e endometritepós-parto. Na infecção em seres humanos por C.trachomatis, as proteínas expressas da família HSP60(Chsp60) são reconhecidas como antígenos. HSP60 são também proteínas expressas pelo zigoto de mamíferos após a fertilização; portanto, nas mulheres com imunidade pré-existente induzida pelo Chsp60 pode ocorrer resposta imunológica secundária nos estágios iniciais da gravidez. O levantamento bibliográfico evidenciou a carência de artigos que comprovem que a falha de fertilização in vitro seja causada pela infecção por C. trachomatis.
