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1.
规模化养殖罗曼粉商品蛋鸡产蛋率和累计产蛋数曲线拟合分析 《畜牧与饲料科学》2021,42(4):54-60
[目的]探索规模化养殖罗曼粉商品蛋鸡的产蛋特点和规律。[方法]选择9万羽罗曼粉蛋鸡,统计18~85周龄的产蛋率和累计产蛋数,采用分室模型、杨宁模型、伍德模型对产蛋率进行拟合分析,采用Bertalanffy、Gompertz、Logistic模型对累计产蛋数进行拟合分析,并与实际观测值进行比较。[结果]分室模型、杨宁模型和伍德模型的产蛋率曲线拟合度分别为0.935、0.997和0.450,杨宁模型的预测值与实测值最接近;Gompertz模型拟合累计产蛋数曲线效果最好,拟合度为0.996,预测拐点周龄为47.38周,拐点产蛋数为166.36枚,极限产蛋数为365.12枚,比实际低11.64枚。[结论]杨宁模型和Gompertz模型分别对规模化养殖罗曼粉商品蛋鸡产蛋率和累计产蛋数的拟合效果最佳,适用于评估和预测规模化养殖条件下罗曼粉商品蛋鸡的产蛋性能。 相似文献
2.
Three strains of commercial leghorns vaccinated at 17 to 22 weeks of age with F strain Mycoplasma gallisepticum (MG) were maintained through 117 weeks of age. The three strains differed in both mortality and percent egg production per hen housed; however, the strains did not differ in egg weight (EW), eggshell strength (ESS), or percent daily egg production. Results of this study indicate EW and ESS for F strain MG-vaccinated hens follow patterns previously reported for uninfected layers. Further, mortality may account, in part, for differences in percent egg production per hen housed between strains of F strain MG-vaccinated hens. 相似文献
3.
《The Journal of Applied Poultry Research》2009,18(2):348-354
The US egg industry has grown dramatically in the past, with a significant component of that growth focusing on alternative production systems such as cage-free or range egg production. Constituents of this growth involving intensive egg production create uncertainty in relation to the future because of concerns about the impact of the cage environment on laying hen well-being. Both the commercial egg production sector and small producers using heritage strains of chickens, in flocks ranging in size from 100 to 3,000 hens, are responding by producing eggs in both cage-free and range settings. However, one of the current issues is that our knowledge base of how these alternative production methods influence egg performance and quality characteristics is limited to research studies that were conducted in the late 1940s and early 1950s. This information was collected with specific breeds, and not with modern lines of poultry that have been selected for very high rates of egg production. Therefore, an examination of alterative laying hen husbandry practices in the context of the current knowledge base would provide beneficial information to identify how these husbandry and feeding practices translate to modern strains of laying hens under cage-free or range production. Research on range or cage-free production done in controlled settings is limited, and additional studies relevant to egg producers wishing to expand cage-free and range egg production are needed. 相似文献
4.
为探索"豫粉1号"商品代的产蛋性能和蛋品质等生产特性的变化规律,采用Wood模型、杨宁模型和McMillan模型对产蛋率曲线进行拟合分析;并对32、36、40周蛋品质进行分析。结果显示,3种模型的非线性方程为：Wood模型：yt=0.327×2.2t×e－0.067t;McMillan模型：yt=159.19×（1－e－0.199×（t－17.612））×e－0.019t;杨宁模型：yt=0.284×e－0.284t/（1+e－0.302×（t－20.779））,拟合度分别为0.885、0.987和0.991。与实际生产数据相比,杨宁模型拟合值与观测值最为接近,拟合效果最佳。蛋品质分析结果显示,"豫粉1号"商品代蛋品质的哈氏单位达到82.61,为AA级;蛋壳强度达到4.77 kg/m2,具有较高的强度;蛋黄颜色为8.72,色泽比普通鸡蛋深。在实际生产中可以利用杨宁模型对该品系产蛋率的变化规律进行估计与预测,为地方蛋鸡新品系的育种及管理提供参考,蛋品质可在后期配套系运用中进行优化。 相似文献
5.
Salle CT Guahyba AS Wald VB Silva AB Salle FO Nascimento VP 《British poultry science》2003,44(2):211-217
1. Although the poultry industry uses state-of-the-art equipment and up-to-date services, in Brazil it generally makes decisions involving all its production variables based on purely subjective criteria. This paper reports the use of artificial neural networks to estimate performance in production birds belonging to a South Brazilian poultry farm. 2. Recorded data from 22 broiler production breeder flocks were obtained, from April, 1998 to December, 1999, which corresponded to 689 data lines of weekly recordings. 3. These data were processed by artificial neural networks using the software NeuroShell 2 version 4.0 (Ward Systems Group). The artificial neural network models generated were compared and selected based on their largest determination coefficient (R2), lowest Mean Squared Error (MSE), as well as on a uniform scatter in the residual plots. The authors conclude that it is possible to explain the performance variables of production birds, with the use of artificial neural networks. 4. The method allows the decisions made by the technical staff to be based on objective, scientific criteria, allows simulations of the consequences related to these decisions, and reports the contribution of each variable to the variables under study. 相似文献
6.
1. We investigated the use of monthly production records for genetic evaluation of laying hens, derived from a test day model with random regression in dairy cattle and compared it with other models. 2. Records of 6450 hens, daughters of 180 sires and 1335 dams, were analysed using a model with restricted maximum likelihood (REML): traits considered were monthly and cumulative egg production. Five models were studied: (1) random regression with covariates derived from the regression of Ali and Schaeffer (Canadian Journal of Animal Science, 67: 637-644, 1987) (RRMAS), (2) random regression with covariates derived from quartic polynomial (RRMP4), (3) fixed regression with covariates derived from Ali and Schaeffer (FRM), (4) multiple trait (MTM) and (5) cumulative (CM). 3. The models were compared on the basis of Spearman rank correlations of individual breeding values and sire breeding values estimated from subsets of full-sib split data. The hens (about 10% per generation) which ranked highest on their estimated breeding values from different models were compared phenotypically with their full records. 4. The estimates of heritability resulting from RRMP4 were biased upward from the estimates obtained from MTM, so this model was discarded. The heritabilities for monthly productions from RRMAS and MTM showed a similar pattern. They were high for the 1st month of production, decreased to their lowest value at about month 5 of production and increased again to the end of lay. 5. Spearman rank correlations between animal breeding values estimated by monthly models (RRMAS, FRM and MTM) were high, between 0.91 and 0.98, whereas those between estimates of monthly models and CM were lower, from 0.85 to 0.87. The correlations estimated either from intermittent months of measurements (odd vs even months) or full records were generally high, from 0.93 to 0.99. Information from odd months of production could be sufficient for cost-efficient recording schemes. The RRMAS generally had the highest correlation of sire breeding values between subsets of full-sib records, followed by MTM, RM and CM. Monthly models selected hens with higher productivity than the cumulative model. 6. In conclusion, genetic evaluation based on monthly production may be better than using cumulative production and RRMAS appeared to be the best among the models tested here. 相似文献
7.
Luara Afonso de Freitas Rodrigo Pelicioni Savegnago Natalia Vinhal Grupioni Salvador Boccaletti Ramos Nedenia Bonvino Stafuzza Elsio Antônio Pereira de Figueiredo 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2018,68(2):81-86
The aims of this study were to compare the suitability of the multi-trait (MUT) model to estimate genetic parameters with that of 13 reduced-rank principal component models (PC1 to PC13), and then to explore the additive genetic patterns of the breeding values obtained from these using clustering analyses of egg production traits. A total of 1,212 records were used to estimate genetic parameters using the MUT and PC models. The PC4 model was the best representation of the data since it had a lower AIC value and was more parsimonious than the MUT model. The estimated heritability of the age at the first egg (AFE) trait from this model was 0.28?±?0.06, and the estimated genetic correlation between AFE and total egg production (TP) was ?0.52?±?0.23. Potentially animals from cluster 2 are more likely to be in the selected group to help improve the egg production. 相似文献
8.
1. Field data on the reproductive performance of parent stock and grandparent female line and male line broiler breeders were extracted from a commercial database covering the years of hatch from 1989 to 2002. The data were from the UK, Western Europe, Central and South America and Japan. Quadratic regression curves were fitted to the data to estimate the long-term phenotypic trends in total egg production, hatching egg production, chick numbers, hatchability and female mortality. 2. Changes in performance over time were similar in the UK, Western Europe and Central and South America and are consistent with the suggestion that genetic selection in separate breeding programmes in the UK (supplying the UK and Western Europe) and Brazil (serving Central and South America) was associated with similar improvements in the performance of commercial parent stock and grandparent flocks. Changes in performance in Japan (supplied from the UK) were different but recent performance was similar to those in the other regions. 3. The mean annual improvements over 10 years to 2002 for male line, female line and parent stock, respectively, were 0.4, 1.7 and 1.7 for total egg number; 0.5, 1.8 and 1.6 for hatching egg number; 0.6, 1.8 and 1.3 for total chick production; 0.25, 0.47 and 0.09% for hatchability; and -0.69, -0.05 and -0.41% for female mortality. 4. The results are consistent with claims that significant genetic change in pedigree selection (nucleus) flocks by the primary breeding company are reflected in substantial improvements in reproductive performance in commercial flocks. The presence of similar rates of improvement in different geographical regions as a result of genetic selection in two continents representing tropical and temperate regions suggests that genotype-environment interactions for reproduction traits are not important. 相似文献
9.
Six strains under long-term selection for egg production and other economically-important traits were crossed in a full diallel, and tested with two commercial stocks and two control strains at two stocking rates (1 bird per 20.3-cm cage and 3 birds per 30.5-cm cage) and two diets (with and without an oyster shell supplement). The mean of the 30 strain crosses exceeded the mean of the six selected strains for egg production and egg quality traits, sexual maturity and viability, which in turn exceeded the performance of both of the control strains. The performance of several of the 30 strain crosses was similar to the commercial stocks. The only significant genotype X environment interaction was for Haugh units at 450 d. Performance at the lower stocking rate was generally superior to that at the higher stocking rate. General combining ability was important for the complete array of traits measured. Specific combining ability was important for the majority of traits. Heterosis was important for all traits except specific gravity, Haugh units, blood spots and laying house viability to 272 or 496 d at the higher stocking rate. The magnitude of heterotic effects was generally greater at the higher stocking rate. Reciprocal effects were important for egg production traits, sexual maturity, egg quality traits and viability. The dietary oyster shell supplement resulted in an improvement in shell quality as measured by specific gravity. 相似文献
10.
祁连山冰沟流域地形复杂,积雪深度较浅且破碎化严重,针对MODIS标准积雪面积比例产品在该地区监测精度较差的问题,本研究基于冰沟流域浅雪光谱特征分析及结合野外实测经验,探索浅雪的光谱特征对MODIS浅雪面积比例提取精度的影响;然后通过线性回归法、线性混合像元分解法及BP神经网络模型3种方法分别构建了针对研究区的MODIS积雪制图算法,并利用同时相的Landsat 8OLI二值积雪数据作为真值对上述3种制图方法进行精度验证。结果表明,1)浅雪的光谱反射率对基于NDSI阈值法的MODIS浅雪提取精度几乎没影响,MODIS提取浅雪精度差的主要原因为该地区复杂的地形而导致的积雪分布破碎化,即混合像元的大量存在;2)利用BP神经网络模型反演积雪面积比例的最佳输入参数组合为(ρ_1~ρ_7)+NDSI+DEM;3)线性混合像元分解模型在该研究区的积雪面积比例提取精度较低,BP神经网络模型精度最好;4)在地形复杂区域,多因素模型(BP神经网络模型)相对于单因素模型(一元线性回归模型)具有较好的积雪面积比例提取精度和稳定性,可以为研究区MODIS积雪面积比例的反演提供一种理想的方法。 相似文献
11.
《The Journal of Applied Poultry Research》2015,24(2):267-282
Poultry nutritionists should constantly evaluate their feeds and feeding programs in view of the changes that continue to be made to the potential growth rate of broilers and egg production in laying hens with the objective of providing the birds with the optimum economic level of nutrients at all times. In this review, the models generated at Universidade Estadual Paulista (UNESP) Jaboticabal, to estimate the optimum intake of amino acids (AA) for broilers and laying hens are presented. These models were used to estimate the variation in AA intake within a broiler population making use of coefficients of variation that represent the real situation in a commercial broiler operation. The range of AA intakes obtained was compared to some commonly applied feeding programs and recommendations. Based on results of our developed models and other feeding programs, feeds were formulated and growth was predicted using a growth simulation model (Avinesp). The prediction of growth showed that these models are reliable and useful tools to assist the nutritionists in decision making. In a study with laying hens, the Reading model (RM) was used to establish optimum economic AA intakes in a flock of hens. The input variables were the means and standard deviations of egg output and BW, and the relationship between the marginal cost of the AA and the marginal revenue for eggs. Based on this model, the optimum intake of each AA can vary with each of the variables considered. The models proposed in our study enable important decisions to be made regarding AA intakes to be used to obtain optimum economic performance from a population of broilers and laying hens. 相似文献
12.
为了研究二郎山山地鸡的产蛋规律,试验以二郎山山地鸡SD02与SD03品系一世代300日龄产蛋量建立产蛋曲线,并采用伍德模型、分室模型与杨宁模型对两品系进行产蛋率曲线拟合,然后对实际产蛋率曲线进行分析。结果表明:品系SD03的产蛋性能优于SD02。经过拟合分析,SD02品系的伍德模型、分室模型、杨宁模型的拟合度(R2值)分别是0.811 7,0.906 2,0.967 7,SD03品系拟合度分别是0.796 9,0.910 2,0.954 8;杨宁模型拟合效果最佳。 相似文献
13.
The efficacy of three commercial Mycoplasma gallisepticum (MG) immunizing agents-a bacterin, a recombinant fowlpox-MG vaccine, and a live F-strain vaccine-was compared in specific-pathogen-free hens in egg production. Three groups of 25 chickens were vaccinated with one of the vaccines at 10 wk of age and 25 birds were not vaccinated. At 25 wk of age (and approximately 50% egg production), 20 birds from each of the three vaccinated groups and 15 nonvaccinated controls were challenged with virulent R-strain via aerosol; the birds were necropsied and evaluated at 10 days post-challenge. The MG bacterin and live F-strain vaccinations were both protective and resulted in significant differences in air sac lesions, tracheal lesions, and ovarian regression compared to the nonvaccinated controls and the recombinant fowlpox-MG vaccine (P < or = 0.05). The evaluation of ovarian regression is a useful method of testing the efficacy of MG vaccines in laying hens. 相似文献
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The aim of the experiment was to examine the efficiency of pedigreed random‐bred control populations. It was argued that it was difficult to achieve this aim by the study of the parameters of a single control population, but that a comparison of the contemporaneous performance of two or more control strains over several generations would be more appropriate.
Six pedigreed randombred control populations with a planned size of 50 males and 150 females and derived from different base populations representing strains involved in a commercial poultry breeding programme were recorded for eight generations. Some difficulty was experienced in maintaining the populations to the size planned, particularly the Wyandotte strain, and this was associated with low semen production from males and low egg production from females rather than from poor fertility or hatchability. Analysis of data on sexual maturity, 25‐week body weight and 300 days’ egg production indicated no obvious regular changes in mean or variance except for sexual maturity for which the within strain variance increased markedly. The differences between strain means stayed relatively constant and there were few changes of rank order. The intra class correlation, corrected for changes in variance, for strains between years was 0–92, 1.00 and 0.96 for sexual maturity, body weight and egg production respectively.
Heritability estimates on four of the base populations indicated large differences between strains but also that additive genetic variation for some traits in some strains was approximately zero. For such traits and strains, genetic drift cannot occur which is a most desirable feature of a genetic control population. Some data were available on crosses of the control strains, which had been recorded for egg production and laying house mortality on many farms in each of eight years. There were no regular changes between years in mean egg production but mortality 相似文献
16.
A K Sheridan 《British poultry science》1986,27(4):541-550
The heterosis inheritance backcross evaluation technique (HI-BET) is proposed as a selection strategy for developing a pair of complementary strains from a crossbred population descended from a F1 population possessing considerable heterosis. These complementary strains are expected to produce a strain cross superior to the F1 population from which they were derived. In the first stage of an experimental evaluation of HI-BET, Australorp and White Leghorn hens were compared with their F1, F2 and F1 by parental breed backcross populations for a range of egg production traits. The substantial heterosis for survivors' egg production and total egg mass was largely lost in the F2 and backcross populations indicating that this heterosis was mainly due to parental epistasis. The uneven distribution of residual heterosis in the backcross populations suggests that about two-thirds of this parental epistasis was inherited from the White Leghorn line. As the Australorp line was substantially superior to the White Leghorn line for survivors' egg production and total egg mass, it most likely contained additive genes for both these traits that were not present in the White Leghorn line. It is suggested that HI-BET should be an effective strategy for incorporating these additive genes into the White Leghorn line, together with some brown egg shell genes if also desired, as a means of further improving the performance of the F1 cross. 相似文献
17.
1. The aim of the present study was to estimate genetic parameters for average egg weight (EW) and egg number (EN) at different ages in Japanese quail using multi-trait random regression (MTRR) models.
2. A total of 8534 records from 900 quail, hatched between 2014 and 2015, were used in the study. Average weekly egg weights and egg numbers were measured from second until sixth week of egg production.
3. Nine random regression models were compared to identify the best order of the Legendre polynomials (LP). The most optimal model was identified by the Bayesian Information Criterion. A model with second order of LP for fixed effects, second order of LP for additive genetic effects and third order of LP for permanent environmental effects (MTRR23) was found to be the best.
4. According to the MTRR23 model, direct heritability for EW increased from 0.26 in the second week to 0.53 in the sixth week of egg production, whereas the ratio of permanent environment to phenotypic variance decreased from 0.48 to 0.1. Direct heritability for EN was low, whereas the ratio of permanent environment to phenotypic variance decreased from 0.57 to 0.15 during the production period.
5. For each trait, estimated genetic correlations among weeks of egg production were high (from 0.85 to 0.98). Genetic correlations between EW and EN were low and negative for the first two weeks, but they were low and positive for the rest of the egg production period.
6. In conclusion, random regression models can be used effectively for analysing egg production traits in Japanese quail. Response to selection for increased egg weight would be higher at older ages because of its higher heritability and such a breeding program would have no negative genetic impact on egg production. 相似文献
18.
T. C. Carter 《British poultry science》1968,9(3):265-271
One hundred eggs were used, from hens of seven widely differing strains: two commercial brown‐egg hybrids (one British, one American), two commercial white‐egg hybrids (one British, one Canadian), one broiler strain, one highly inbred strain of laboratory White Leghorns and one laboratory strain of Brown Leghorns. The volume occupied by the shell of each egg was estimated from its surface area—itself estimated by means of a three‐parameter model (Carter, 1968)— and its mean thickness, measured with an anvil micrometer. The volume occupied by the egg contents was estimated by subtracting the shell volume from the egg volume, which was also estimated by means of the three‐parameter model. Mean overall shell density (counting as “shell” all mineral matter and spaces between the outer surface of the mineral shell and a surface through the tips of the mammillae) was estimated, by regressing shell weight on shell volume, to be 2.241 ±0.004 g./cm.3; covariance analysis showed that the strains were homogeneous in this respect. Mean incremental shell density (i.e. the density of shell distal to the mammillary region) was estimated, by regressing shell weight per unit surface area on shell thickness, to be 2.386±0.004 g./cm.3; the strains were homogeneous in this respect too. The mean depth of the intermammillary spaces was estimated to be 19.9 μ. All the residual deviation from the common regression line can be attributed to measurement error. The estimated density of incremental shell is lower than that of calcite; the packing fraction of the crystals in the shell aggregate and/or the atoms in the crystals was estimated to be 92.8 per cent. The density of the egg contents (at the temperature of the bird) was estimated by regressing weight of contents on volume of contents; covariance analysis revealed significant differences between strains, one of the brown‐egg hybrids having the highest density of egg contents, 1.045 g/cm.3, and the laboratory Brown Leghorns the lowest, 1.033; both commercial white‐egg hybrid strains gave a value of 1.040 g./cm.3. 相似文献
19.