共查询到20条相似文献,搜索用时 31 毫秒
1.
为了给红灯笼樱桃适时施肥和果实适期采收提供理论依据,并为制定科学的栽培技术和管理措施提供参考。定期调查4~5年生红灯笼樱桃新梢和果实生长发育动态及其相关性。结果表明:(1)新梢生长从3月上旬开始,一直生长到8月下旬停长,生长期达140天,在生长发育过程中出现一~四次生长高峰期,其中伸长生长一~四次,生长量四次,净生长量一次;叶片生长二~三次,生长量三次,净生长量二次;加粗生长四次,生长量和净生长量都四次。(2)果实生长从4月上旬为花谢幼果期开始,一直长到6月中旬停长期,生长期长达56~63天,果实纵横径在整个生长过程中出现次二~三次生长高峰期,其生长量三次;净增长量二~三次生长高峰:其中果实纵径二次;果实缝合线横径三次;果实非缝合线横径出现二次。(3)果实生长与新梢生长的相关性:果实生长量曲线和新梢生长量曲线都是逐步升高的单曲线,其新梢伸长生长和果实生长是一致的,呈双S曲线;果实净生长量有明显的二~三次生长高峰期,其生长曲线是S曲线或双S曲线,而新梢伸长生长的净生长量有一~四次生长高峰期,其中伸长生长是一次高峰,生长曲线呈凸曲线,加粗生长的净生长量有四次生长高峰期,其生长曲线呈三S曲线。(4)建议樱桃进行栽培管理时要求在头年加强水肥管理的同时,在4月下旬作为最佳施肥时期施肥,同时在果梢生长旺期加强根外追肥,来缓解养分的竞争。 相似文献
2.
促生长激素轴与铜促生长的关系 总被引:7,自引:0,他引:7
日粮中添加适量的铜可显著促进动物的生长,但其确切作用机理不明确,动物的生长受生长激素(GH)和胰岛素样生长因子(IGF)轴的调控,GH和IGF水平因铜的添加而显著升高,并与铜促生长发生密切相关,其机理可能是铜能调控促生长调节肽的合成和释放。 相似文献
3.
Evidence is discussed which indicates that nutrient partitioning between muscle and adipose tissue can be altered by growth hormone administration in meat animals. In the limited number of studies conducted with meat animals, growth rate, feed efficiency and carcass composition were improved by growth hormone administration. When insulin was administered to normally growing swine no improvement in growth performance was observed. The mechanisms by which growth hormone affects growth performance are not clear but considerable data from rodent studies exist to indicate that many of the growth promoting effects of this hormone are due to somatomedins. However, few data are available for meat animals to indicate whether the growth promoting effects of growth hormone are mediated by somatomedins. Knowledge about the mechanisms that regulate growth hormone synthesis, secretion and biological action is accumulating. It is apparent that growth hormone administration induces an insulin-resistant state in rodents and meat animals. It is not clear whether chronic growth hormone administration in meat animals induces a growth hormone resistant state. Based on the available information, manipulation of systemic hormone concentrations and(or) tissue sensitivity to hormones involved in growth and differentiation may result in means to manipulate fetal and postnatal growth and development. 相似文献
4.
5.
合作猪异地生长性能的初步研究 总被引:2,自引:0,他引:2
对异地饲养合作猪不同阶段体重的测定分析结果表明,合作猪体重的增长与月龄呈线性生长模式,绝对生长曲线呈钟状对称分布,在3~4月龄达到最大值242.563 g;相对生长曲线随月龄呈下降趋势,符合生物生长机理,其生长发育表现出良好的异地适应性和生长潜能。 相似文献
6.
G L Bennett 《Journal of animal science》1992,70(1):51-56
Lean tissue growth rate is usually estimated from indirect measurements including growth rate. A procedure to determine prediction equations for lean tissue growth rate is proposed. The procedure restricts the regression of fat growth rate on predicted lean growth rate to be equal to the regression of fat growth rate on actual lean growth rate. The restriction can be phenotypic or genetic if suitable parameter estimates are available. When applied phenotypically, selection on predicted lean tissue growth rate will result in selection differentials for both fat and lean tissue growth rates that are proportional to those obtained by direct selection for lean tissue growth rate. This restriction is desirable because expected correlated changes in fat are used to justify selection for lean tissue growth. Conventional prediction procedures have ignored correlated changes and obscured the original intent of using lean tissue growth rate as a biological selection criterion. When using conventional procedures to predict a biological selection criterion from indirect measurements, changes in important correlated traits may depend more on the choice of indirect measurements than on the choice of selection criterion. 相似文献
7.
Tomoaki ONODA Ryuta YAMAMOTO Kyohei SAWAMURA Harutaka MURASE Yasuo NAMBO Yoshinobu INOUE Akira MATSUI Takeshi MIYAKE Nobuhiro HIRAI 《Journal of Equine Science》2013,24(4):63-69
Percentile growth curves are often used as a clinical indicator to evaluate variations of
children’s growth status. In this study, we propose empirical percentile growth curves
using Z-scores adapted for Japanese Thoroughbred horses, with considerations of the
seasonal compensatory growth that is a typical characteristic of seasonal breeding
animals. We previously developed new growth curve equations for Japanese Thoroughbreds
adjusting for compensatory growth. Individual horses and residual effects were included as
random effects in the growth curve equation model and their variance components were
estimated. Based on the Z-scores of the estimated variance components, empirical
percentile growth curves were constructed. A total of 5,594 and 5,680 body weight and age
measurements of male and female Thoroughbreds, respectively, and 3,770 withers height and
age measurements were used in the analyses. The developed empirical percentile growth
curves using Z-scores are computationally feasible and useful for monitoring individual
growth parameters of body weight and withers height of young Thoroughbred horses,
especially during compensatory growth periods. 相似文献
8.
Studies on the pathogenesis of tibial dyschondroplasia in chickens. II. Growth rate of long bones. 总被引:3,自引:0,他引:3
C Riddell 《Avian diseases》1975,19(3):490-496
The growth rate of the tibiotarsus, tarsometatarsus, and humerus was studied in two strains of chickens selected for a high and low incidence of tibial dyschondroplasia. The proximal growth plates grew more rapidly than the distal growth plates. The proximal growth plate of the tibiotarsus grew fastest, while those of the tarsometatarsus and humerus had growth rates that were respectively 4 and 33% slower. The bones averaged slightly faster growth in the high-incidence strain than in the low-incidence strain. A slowed growth decreased the incidence of tibial dyschondroplasia. However, lack of correlation between growth rate and the development of tibial dyschondroplasia in individual chickens suggested that growth rate may be no more than a contributing factor. 相似文献
9.
Tomoaki ONODA Ryuta YAMAMOTO Kyohei SAWAMURA Yoshinobu INOUE Akira MATSUI Takeshi MIYAKE Nobuhiro HIRAI 《Journal of Equine Science》2011,22(2):37-42
Thoroughbred horses are seasonal mating animals, raised in northern regions or countries.
Foals born yearly in spring generally show a typical seasonal compensatory growth pattern,
in which their growth rate declines in the first winter and increases in the next spring.
In this study, a new empirical adjustment approach is proposed to adjust for this
compensatory growth when growth curve equations are estimated, by using 1,633 male body
weights of Thoroughbreds as an illustrating example. Based on general Richards growth
curve equation, a new growth curve equation was developed and fit to the weight-age data.
The new growth curve equation had a sigmoid sub-function that can adjust the compensatory
growth, combined with the Richards biological parameter responsible for the maturity of
animals. The unknown parameters included in the equations were estimated by SAS NLMIXED
procedure. The goodness of fit was examined by using Akaike’s Information Criterion (AIC).
The AIC values decreased from 13,053 (general Richards equation) to 12,794 (the newly
developed equation), indicating the better fit of the new equation to the weight-age data.
The shape of the growth curve was improved during the period of compensatory growth. The
proposed method is one of the useful approaches for adjusting seasonal compensatory growth
in growth curve estimations for Thoroughbreds, and for their management during the
compensatory period. Based on this approach, the optimal growth curve equations can be
estimated also for female body weight of Thoroughbreds or other growth traits affected by
seasonal compensatory growth. 相似文献
10.
11.
The objective of this study was to examine the effect of various growth factors such as the epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) either individually or in association, in the presence of follicle-stimulating hormone (FSH) on the in vitro growth and viability of caprine oocytes at pre-antral stage. Pre-antral follicles were disassociated enzymatically and mechanically from pre-pubertal caprine ovaries after the animals were anaesthetically ovariectomized. Caprine pre-antral follicles in group 1, 2, 3 and 4 were cultured in growth culture medium, growth culture medium + EGF, growth culture medium + IGF-I and growth culture medium + IGF-I + EGF, respectively, for 9 days. The results indicated that EGF (50 mg/l) increased the survival rate of oocytes, but decreased the growth rate of oocytes; IGF-I (100 mg/l) effectively maintained the survival of oocytes and stimulated their growth; IGF-I (100 mg/l) and EGF (50 mg/l) in combination produced a higher effect on both the survival and the growth rate of oocytes than IGF-I or EGF alone. Conclusively, the growth factors can effectively maintain the survival of caprine oocytes from pre-antral follicles and regulate their growth in culture. EGF and IGF-I in association could synergically meliorate the culture system of caprine pre-antral follicles. 相似文献
12.
13.
14.
为揭示马岗鹅的生长发育规律,挖掘马岗鹅的生长潜力,本研究通过测定马岗鹅0~12周龄的体重和体尺性状,并用Logistics、Von Bertalanffy和Gompertz 3种模型进行生长曲线拟合。结果表明:马岗鹅体重生长曲线最佳模型为Gompertz模型(R2=0.999),拐点周龄是4.31周龄,拐点体重是1459.01g,2~8周龄的周增重都在320 g以上,相对生长率都在16%以上,8周龄前为马岗鹅体重迅速增长时期。胸深、龙骨长、颈长的最佳拟合模型为Gompertz,拐点周龄分别为0.65、3.71、2.28周龄;体斜长、半潜水长的最佳拟合模型为Von Bertalanffy,拐点周龄分别为0.53、0.47周龄;胸宽、骨盆宽、胫长、胫围的最佳拟合模型为Logistic,拐点周龄分别为3.81、1.39、0.91、0.51周龄;7周龄前为马岗鹅体尺性状迅速增长时期。本研究结果可为马岗鹅的生产和饲养管理提供理论指导。 相似文献
15.
研究紫花苜蓿第1茬地上部干物质生长过程与有效积温的关系 总被引:1,自引:0,他引:1
对不同秋眠级数的4年生紫花苜蓿Medicago sativa品种第1茬干物质生长与≥5 ℃有效积温的研究结果表明:1)不同紫花苜蓿品种各器官干物质生长趋势一致,干物质生产潜力、最大生长速率、干物质生长盛期的平均生长速率均表现为全株>茎>叶,但是最大生长速率和平均生长速率所对应的有效积温值范围有差异。全株、茎和叶干物质最大生长速率分别出现在5 ℃初日后有效积温达504.72~609.45 ℃、574.47~643.91 ℃、444.53~543.25 ℃之时;平均生长速率转折点所对应的有效积温值范围为总干物质为384.61~716.54 ℃;茎干物质为424.48~773.36 ℃;叶干物质为320.42~642.48 ℃。2)不同苜蓿品种间干物质生长存在差异。半秋眠性品种路宝、牧歌401和美国杂交熊全株、茎、叶的干物质潜力大,最大生长速率较大,生长盛期内的平均生长速率较大,各转折点所对应的有效积温值相对较高,且其迟滞期的有效积温值也相对较高,秋眠性品种超级13R则相反。 相似文献
16.
夏秋季刈割能促进白三叶及杂草的高度生长,杂草的生长速度大于白三叶。刈割间隔时间是影响白三叶及杂草高度生长的主效因子,间隔时间越短,白三叶及杂草的高度生长越慢。高留茬频密刈割(15 d-10 cm)能使白三叶和杂草均保持较高的生长速率,低留茬每月刈割1次(30 d-5 cm)能使白三叶和杂草均保持较低的生长速率,低留茬频密刈割(15 d-5 cm)是控制杂草的最佳手段,但同时也抑制了白三叶的生长。既能较好地抑制杂草生长又不影响白三叶生长的最佳处理组合为30 d-5 cm,白三叶生长速度0.28 cm/d,杂草0.34 cm/d。 相似文献
17.
18.
生长率假说(GRH)是研究生物生长率与化学计量特征之间关系的理论。为了验证生长率假说,以北方草原重要建群种羊草(Leymus chinensis)为材料,将取自内蒙古和吉林省4个地点的羊草在相同的光照、水肥条件下盆栽土培,用称重法测定了羊草的生长率,用PCR的方法分析了羊草核糖体DNA基因间隔区(IGS)长度,研究了羊草生长率与羊草磷含量、氮磷比、IGS长度及取样地土壤中氮、磷含量之间的关系。结果表明,羊草生长率与羊草全磷含量存在正相关关系,与羊草氮磷比存在负相关关系,生长率较高的羊草具有较长的IGS,符合生长率假说的预测。不同来源的羊草种植在相同环境下,来自氮、磷含量较高土壤的羊草具有较高的生长率,这可能是羊草对特定地域生境条件长期适应的结果。高的生长率和长的IGS可能是植物对较高氮、磷含量环境的适应。 相似文献
19.
20.
Samuel E. Aggrey 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2004,121(4):260-268
This study was undertaken to use the spline linear regression to model pre‐asymptotic body weight measurements from an unselected random‐bred chicken population fed two different protein diets. The spline linear regression model is a compound function comprising of series of linear models. It was used to compartmentalize growth into segments. The birds raised under the low‐protein diet had four compartments, whereas those raised under the high‐protein diet had three compartments. Whereas the protein level defined the number of splines or compartments, the growth potential demonstrated by the sexes were different. The males under low‐protein diet grew faster than the females under high‐protein diet. Even though both sexes responded to high‐protein diet, a high‐protein diet in females was not enough to raise their growth potential to that of males under low protein levels. The efficiency of growth under the two protein levels were assessed with relative growth. Relative growth rate is the increase in body weight per unit of body weight per unit of time, and it represents the efficiency of an animal as a producer of new body mass material. The maximum relative growth modeled by the Gompertz function for both sexes under the two protein levels were observed at day 6 and hereafter, declined proportionally to a proponent of the amount of growth remaining. Despite the high absolute growth of the birds fed a high‐protein diet compared with their counterparts fed a low‐protein diet, the relative growth rates of the two groups were comparable. Modelling both absolute and relative growth show that the maximum absolute and relative growth rates occur within different time frame, as a result, selecting on absolute growth rate for improved relative growth within the same time frame or vice versa may not achieve the desired selection goal. The use of the spline regression and relative growth models would have practical application for commercial broilers and broiler breeders where growth is either truncated before the asymptote or controlled by dietary and other environmental factors to prevent excessive obesity. 相似文献