朝鲜鹌鹑的生长发育性能研究

选择300只10日龄的朝鲜鹌鹑(公、母各半),在相同的饲养管理条件下饲养4周,系统测定了各周的体重和体斜长、胸骨长、胸宽、胸深、胫长等体尺指标,并拟合了公、母鹑体重的Logistic生长曲线。结果表明,朝鲜鹌鹑公、母鹑38日龄体重为109.38 g和117.92 g,母鹑的生长速度明显高于公鹑,所拟合的公、母鹑体重的生长曲线方程分别为yt=122.5/[1+e-0.1200×(t-20.0921)](R2=0.9914)和yt=134.5/[1+e-0.1154×(t-21.0727)](R2=0.9933),鹑群生长发育均匀整齐。     

Influence of strain and flock age on geometrical and mechanical attributes of eggs produced from Japanese quail birds

We investigated how the geometrical and mechanical properties of eggshell of Japanese quail are affected by strain and flock age. Two strains of quail (white and gray) were used in the current experiment. The results showed that there was no significant difference for all geometric measurements due to strain effect. Eggs produced from the older birds showed significantly higher (P < 0.01) values compared with younger age for all studied traits. Eggs produced from quails at 22 weeks had a significantly (P < 0.01) darker yolk color than that of the younger age. Superiority in shell thickness, shell weight, and breaking force was detected in eggs of gray quails compared with white quails. On the other hand, the eggs from white quails had significantly higher values for static stiffness and Young's modulus as compared with those of gray counterparts. A significant decrease (P < 0.01) was found for fracture toughness and Young's modulus in eggs of aged birds. A significant negative relationship was found between the breaking force and both static stiffness and Young's modulus. A significant positive relationship was observed between breaking force and both shell thickness and shell percentage. The phenotypic correlation between eggshell breaking force and toughness was relatively high.     

A genetic investigation of various growth models to describe growth of lambs of two contrasting breeds

This study compared the use of various models to describe growth in lambs of 2 contrasting breeds from birth to slaughter. Live BW records (n = 7559) from 240 Texel and 231 Scottish Blackface (SBF) lambs weighed at 2-wk intervals were modeled. Biologically relevant variables were estimated for each lamb from modified versions of the logistic, Gompertz, Richards, and exponential models, and from linear regression. In both breeds, all nonlinear models fitted the data well, with an average coefficient of determination (R2) of > 0.98. The linear model had a lower average R2 than any of the nonlinear models (< 0.94). The variables used to describe the best 3 models (logistic, Gompertz, and Richards) included estimated final BW (A); maximum ADG (B); age at maximum ADG (C); position of point of inflection in relation to A (D, for Richards only). The Richards and Gompertz models provided the best fit (average R2 = 0.986 to 0.989) in both breeds. Richards estimated an extra variable, allowing increased flexibility in describing individual growth patterns, but the Akaike's information criteria value (which weighs log-likelihood by number of parameters estimated) was similar to that of the Gompertz model. Variables A, B, C, and D were moderately to highly heritable in Texel lambs (h2 = 0.33 to 0.87), and genetic correlations between variables within-model ranged from -0.80 to 0.89, suggesting some flexibility to change the shape of the growth curve when selecting for different variables. In SBF lambs, only variables from the logistic and Gompertz models had moderate heritabilities (0.17 to 0.56), but with high genetic correlations between variables within each model (< -0.88 or > 0.92). Selection on growth variables seems promising (in Texel more than SBF), but high genetic correlations between variables may restrict the possibilities to change the growth curve shape. A random regression model was also fitted to the data to allow predictions of growth rates at relevant time points. Heritabilities for growth rates differed markedly at various stages of growth and between the 2 breeds (Texel: 0.14 to 0.74; SBF: 0.07 to 0.34), with negative correlations between growth rate at 60 d of age and growth rate at finishing. Following these results, future studies should investigate genetic relationships between relevant growth curve variables and other important production traits, such as carcass composition and meat quality.     

藏猪体重非线性生长曲线分析

藏猪是我国青藏高原特有的高原型地方猪种,本研究用logistic、Gompertz和Richards模型拟合了藏猪体重生长曲线,并以成华猪为对照分析了藏猪的生长规律。结果表明logistic、Gompertz和Richards模型均适宜拟合藏猪和成华猪的生长曲线,其中Richards模型最好,Gompertz模型优于logistic模型。Richards模型拟合的藏猪极限体重为71.91kg,生长拐点为9.45月龄,最大生长速度为180.0g;说明藏猪存在体重小、生长速度慢、生长拐点迟等特点。     

藏猪体重非线性生长曲线分析

藏猪是我国青藏高原特有的高原型地方猪种,本研究用logistic、Gompertz和Richrds模型拟合了藏猪体重生长曲线,并以成华猪为对照分析了藏猪的生长规律.结果表明logistic、Gompertz和Richards模型均适宜拟合藏猪和成华猪的生长曲线,其中Richards模型最好,Gompertz模型优于logistic模型.Richrds模型拟合的藏猪极限体重为71.91kg,生长拐点为9.45月龄,最大生长速度为180.0g;说明藏猪存在体重小、生长速度慢、生长拐点迟等特点.     

高邮鸭生长发育与曲线拟合研究

为了研究高邮鸭的早期生长发育规律,本试验运用Gompertz、Logistic和Von Bertalanffy 3种非线性生长模型对高邮鸭1~10周龄生长情况进行了分析和曲线拟合。结果表明,高邮鸭早期生长迅速,3周龄时体重增加最大;3种模型均能较好地拟合高邮鸭早期生长,其中Gompertz曲线模型的拟合度为0.99902,拟合估计值与实际观测值最接近,拟合效果最佳,更适合早期生长发育较快的高邮鸭。     

Comparison on accuracy of different nonlinear models in predicting growth of Podolica bulls

Animal growth does not follow a linear pattern, being explained mathematically by functions that have parameters with biological meaning. These parameters are used to estimate the expected weight of animals at specific ages. Several nonlinear models have been used to describe growth. This study was carried out to estimate the parameters of logistic, Gompertz, Richards and von Bertalanffy growth curve models in a sample of Podolica young bulls to determine the goodness of fit. Animals were weighed every 3 months from birth to 810 days of age. The results indicate that all the growth models used were easily fitted to the observed data with Gompertz and logistic functions presenting less computational difficulty in terms of number of iterations to achieve convergence. Moreover, logistic and Richards equations provided the best overall fit being useful to describe the growth of Podolica bulls. Considering that the literature lacks information on growth curves in Podolica breed, the study of a mathematical model for growth describing the developmental pattern of a specific population within a peculiar environment is a useful tool to improve Podolica breed production.     

文昌鸡生长模型拟合的研究

试验旨在通过生长曲线的拟合来了解文昌鸡生长发育的规律。用Logistic、Gompertz和Bertallanffy 3种非线性生长模型对公母文昌鸡的生长发育进行拟合。3种模型均能较好地拟合文昌鸡生长曲线,但是Gompertz模型在公母鸡上拟合效果均最佳。公母鸡在4周前生长较一致,4周后,公鸡生长速度明显快于母鸡。运用3种模型对文昌鸡进行生长曲线的拟合和分析是可行的,对及时了解文昌鸡的生长发育规律提供了参考。     

西藏藏鸡生长曲线拟合及分析

为探究西藏藏鸡早期的生长发育规律,本研究采用Logistic、Bertalanffy和Gompertz非线性模型对公、母鸡从出生到24周龄的体重进行拟合分析。结果显示:3种生长曲线模型的拟合度均能达到0.99以上;进一步从统计和生物学意义角度评价3种模型发现,Gompertz模型拟合效果最好;Gompertz方程拟合公鸡和母鸡的生长拐点周龄分别为10.28周和10.65周;公鸡的拐点体重、最大周增重和最大体重分别为577.20、80.81、1569 g,母鸡分别为465.80、55.90、1266.18 g。研究表明3种模型对西藏藏鸡生长曲线的拟合和分析是可行的,可为管理藏鸡生长发育关键点提供参考。     

人工养殖东北林蛙生长曲线的拟合与分析

为了解东北林蛙的生长规律,运用Gompertz、Logistic和Von Bertalanffy3种非线性模型分别对东北林蛙一龄和二龄生长期间体重数据进行了曲线拟合和分析。结果表明:3种模型都能很好地模拟东北林蛙的生长曲线,但Logistic曲线模型的拟合效果最好。结果显示,运用3种模型对东北林蛙进行生长曲线的拟合和分析是可行的。     

渝东白山羊与波尔山羊杂交F1生长发育规律研究

采用Logistic、Von Bertalanffy和Gompertz 3种典型非线性生长模型分别对渝东白山羊与波尔山羊F,0-6月龄体重数据进行曲线拟合分析。结果表明,Logistic、Von Bertalanffy和Gompertz3种模型均能很好地拟合杂交F．生长曲线,但VonBertalanffy在拟合效果和预测体重效果方面更佳。分析Yon Bertalanffy模型拟合参数,发现拐点体重为6．501kg,拐点月龄为1．292月,最大月增重为2．955kg,成熟体重为21．994kg。     

新疆褐牛种公牛体重生长发育曲线拟合

为探究新疆褐牛种公牛生长发育规律,利用SAS 8.1软件中的Logistic、Gompertz、Brody和Bertallanffy 4种常用的生长曲线模型对344头次新疆褐牛种公牛体重生长曲线进行拟合。结果表明,4种模型均能较好的拟合新疆褐牛种公牛体重生长,拟合度R²分别为 0.9217、0.9263、0.9176和0.9261,其中Gompertz模型对新疆褐牛种公牛体重生长发育的拟合效果较好,Logistic、Gompertz和Bertallanffy模型生长曲线的拐点分别为(0.4937岁、502.10 kg)、(1.3168岁、379.54 kg)和(1.0477岁、311.25 kg)。本研究对实际生产具有一定的参考价值。     

浙东白鹅生长曲线及拟合分析

运用Logistic、Gompertz和Von Bertalanffy 3种非线性模型对浙东白鹅0~8周龄的生长曲线进行分析及拟合比较。结果表明,浙东白鹅公、母鹅在3周龄前生长曲线基本一致,之后一直到8周龄公鹅明显高于母鹅;3种曲线模型拟合度均达到0.99以上,其中Gompertz曲线模型在拟合度和预测极限生长量拐点周龄和最大周增重等方面相对较好。进一步分析结果表明,浙东白鹅公鹅的拐点体重高于母鹅,拐点周龄性别间差异不大。本研究对不同性别浙东白鹅的生长模式及其对营养环境的需求进行了初步探讨,为开展浙东白鹅的规模化养殖提供参考。     

Modelling cumulative egg production in laying hens and parent stocks of broiler chickens using classical growth functions

ABSTRACT

1. The objective of the present study is to introduce fresh insight into modelling of egg production by applying classical growth functions to egg production records reported by Aviagen Management Guide to laying hens and the parent stock of broiler chickens.

2. The functions (monomolecular, logistic, Gompertz, Richards and Morgan) were fitted using nonlinear regression procedures of SAS software, and their performance was assessed using goodness-of-fit statistics (coefficient of determination, residual mean squares, Akaike information criterion and Bayesian information criterion).

3. Overall, except for the logistic and Gompertz, the growth functions evaluated gave an acceptable fit to the cumulative egg production curves, with the Morgan equation ranking first followed by the Richards equation. The Morgan and Richards equations provided satisfactory predictions of weekly egg yield at different egg production stages, from early to late production, whereas the least accurate estimates were obtained with the logistic equation.

4. In conclusion, classical growth functions proved feasible alternatives to fit cumulative egg production curves of laying hens and parent stock of broiler chickens, resulting in suitable statistical performance and accurate estimates of production.     

不同水平甘露寡糖对肉鹑生长性能和血清胆固醇的影响

为了探讨不同水平甘露寡糖对肉鹑生产性能和血清胆固醇的影响。将240只1日龄鹌鹑随机分成4组,每组设4个重复,每个重复15只鹌鹑,Ⅰ组为对照组,饲喂基础日粮,Ⅱ~Ⅳ组为试验组,在基础日粮中分别添加0.5%、1%、2%的甘露寡糖,进行为期50 d的饲养试验。结果表明,与对照组相比,Ⅲ、Ⅳ组的35日龄和50日龄的肉鹑的体重分别提高2.02%、2.66%,7.36%、7.90%。血清胆固醇含量:Ⅱ组35日龄肉鹑胆固醇含量比对照组升高22.22%,Ⅱ组50日龄肉鹑胆固醇含量比对照组降低12.20%;Ⅲ组35日龄肉鹑和50日龄肉鹑的胆固醇含量分别降低3.70%、9.76%,Ⅳ组35日龄肉鹑胆固醇含量比对照组升高7.41%,50日龄肉鹑的胆固醇含量降低21.95%。试验研究表明:在肉鹑生产中,适量添加甘露寡糖可增加肉鹑体重并且降低胆固醇含量。     

边鸡生长曲线拟合和比较分析的研究

运用Logistic, Gompertz, Bertallanffy 3种非线性模型分别对边鸡进行曲线拟合和分析。研究结果表明,3种模型均能较好的模拟边鸡生长曲线,拟合度（R2）均高于0.99,其中以Bertallanffy模型的拟合度最高（公、母鸡分别为0.9974和0.9984）。因此,运用3种模型对边鸡进行生长曲线的拟合和比较分析是可行的,为及时了解边鸡的生长发育规律提供了参考。     

马冈鹅胚胎生长曲线拟合与比较分析

运用Logistic、Gompertz和von Bertalanffy 3种非线性模型分别对马冈鹅的胚重和胚长进行了曲线拟合和分析。结果表明,3种模型均能较好地拟合马冈鹅胚胎的生长曲线,拟合度(R²)均高于0.99,其中以von Bertallanffy模型拟合胚重的效果最好,Gompertz模型拟合胚长的效果最好(拟合度分别为0.995和1.000)。本研究结果为及时了解马冈鹅胚胎时期的生长发育规律提供了参考依据。     

P and Ca requirements for Japanese quail

Four experiments were conducted to estimate the phosphorus and calcium requirements for weight maintenance and weight gain in Japanese quails during their growth phase from 16 to 36 days. Japanese quails aged 16 days were used for estimating the phosphorous and calcium requirements for weight maintenance or weight gain, with these quails composing each reference slaughter group and the others distributed in a completely randomized design, housed in cages of galvanized wire (33 × 33 × 16 cm) that were stored in acclimatized chambers with specific environmental temperatures. The light programme used during the 20‐day experimental period was 24 h of artificial light. Analysis of the data showed that the prediction equations for estimating the phosphorus and calcium requirements for weight maintenance and weight gain of Japanese quails between 16 and 36 days of age were P (g/quail/day) = P^0.75*(9.3695 + 7.7397*T) + 9.70*WG, in which P is the phosphorus requirement, and Ca (g/quail/day) = P^0.75*(363.99 – 8.0262*T) + 28.15*WG, in which Ca is the calcium requirement, P is BW (kg), T is temperature (°C) and WG (g/quail/day).     

合作猪生长曲线分析和拟合研究

对在异地舍饲的高原型小型猪种——合作猪的生长发育规律进行了研究,并利用Logistic、Gompertz和R ichards三种曲线拟合了其生长模型。研究结果表明,三种模型中,Gompertz模型拟合效果最理想(R2=0.999 5);公、母猪在150日龄前生长基本一致,但150日龄后母猪明显快于公猪;公、母猪的生长拐点分别为118.32、146.75日龄,母猪的成年体重明显快于公猪,但达到生长拐点的日龄比公猪迟。     

Comparative Study on Analysis and Fitting of Pudong Chicken Growth Curve

The objective of this paper was to study the growth and development laws of Pudong chicken. The growth curve of Pudong chicken(cock and hen) from 0 to 20 weeks was analyzed and fitted with three models(Gompertz, Logistic and Bertalanffy). It was concluded that the growth curves were appropriately fitted with three models, and fitness degree(R2)in growth data of Pudong chicken were all above 0.992. The Bertalanffy model was the most effective with the highest R2 for cock(R2=0.995) and hen(R2=0.999), respectively. With further analysis of fitted parameters for Logistic model of cock, 0-3 weeks' fitted values were significantly greater than measured values and 4-8 weeks ' fitted values were lower than measured values. Compared with Logistic model, the values calculated by Gompertz model and Bertalanffy model were more coincident with the practical measuring values. For hens, 0-3 weeks ' fitted values of Logistic model were significantly greater than measured values and 0-2 weeks ' fitted values of Gompertz model were slightly greater than measured values, while the values calculated by Bertalanffy model best matched the observed val-ues from actual measure. The results showed that Bertalanffy model used to estimate the growth weight of Pudong chicken was the best while Logis-tic model was the worst. So the fitness and analysis of growth curves of Pudong chicken are valid, which may be adopted to predict growth and de-velopment laws of Pudong chicken and provide reliable data for precise feeding and breeding.