Analysis of growth curves of fowl. III. Geese

1. Growth curves of two lines (S,D) and their reciprocal hybrids (in total,, n = 344) were evaluated by the Richards function. Geese were weighed at 7 d intervals to the ninth week, and then at 92, 154, 192 and 217 d of age. Food and water were supplied ad libitum.

2. The accuracy of curve fit measured by the coefficient of determination (R ²) for different genetic groups ranged from 0.9840 to 0.9918. The highest percentage deviations between observed and estimated live weights were recorded at hatching (on average 15.1%), while at the others points of curve they were significantly lower (from 0.6 to 6.8%).

3. The geese are characterised by an early maturing rate. The peak of the absolute growth rate (the inflection point of the curve) occurred at 18.7 to 23.5 d of age (t ⁺). The degree of maturity at a slaughter age of 63 d (u ₆₃ =y ₆₃/A) ranged from 0.69 to 0.76. Fitting the inflection point at the beginning of the linear growth phase significantly affects the maturing rate (k) and the ratio between the inflection (j ⁺ ) and the asymptotic (A) weights. The values of these correlated parameters were very low (j ⁺/A = 0.233 to 0.294, k= 0.0281 to 0.0373 ln0/d).

4. The live weights of geese from 28 d of age and the parameters of the Richards function were significantly higher (P<0.05, P<0.01) in the sire line (S) than in the dam line (D). A low. negative heterosis was observed at all points of the growth curves (— 0.01 to — 9.7%). The results indicated the effect of sex‐linked growth genes.

5. The phenotypic correlations between parameters of the Richards function within genetic groups are discussed.     

Analysis of growth curves of fowl. I. Chickens.

1. The Richards function was used to describe the growth curves (n = 989) of 9 broiler lines. Chickens were fed ad libitum and body weight was recorded every second week from hatching to 26 weeks of age. 2. The accuracy of curve fit measured by the coefficient of determination (R2) was better for males than for females (0.9986-0.9995 vs 0.9972-0.9988, respectively). 3. The estimation of the asymptotic final weight (A) for different lines enabled the degree of maturity (ut = yt/A) to be determined at any fixed point of the curve. At the age of 7 weeks this had a value of 0.318-0.369 for cockerels and 0.325-0.377 for pullets and represented the slaughter maturity of individual lines. The ratio of inflection/asymptotic weight (y+/A = 0.370-0.388) indicated that in some cases chicken growth can be described approximately by the Gompertz function (y+/A = 0.368). 4. It was found that the age at the inflection point of curves (t+ 48.2-55.7 d for cockerels and t+ = 47.8-52.8 d for pullets) roughly corresponds to the slaughter age of the chickens. 5. The interline differences in the parameters of maturation rate for weight (y+/A, k, t+, u7) are low in comparison with the differences in body weight (A, y+, y7) and absolute growth rate (v, v+). 6. The intragroup phenotypic correlation among growth parameters and the importance of the mathematical models are discussed.     

溧阳鸡生长曲线分析与拟合的研究

运用Logistic模型和Gompertz模型对溧阳鸡0~12周龄生长曲线进行了分析和非线性的拟合研究。结果表明,溧阳鸡公、母鸡在3周龄前生长曲线基本一致,之后公鸡则明显高于母鸡,且保持较长时间的快速生长状态。Logistic模型和Gompertz模型均能比较好地拟合溧阳鸡公鸡的生长曲线(R2分别为0.994 4和0.995 3)和母鸡的生长曲线(R2分别为0.996 7和0.997 9),但Gompertz模型在拟合度和预测体重效果方面相对较好。拟合曲线模型中代表极限体重的参数A,公鸡明显高于母鸡,其他参数接近或略有差异。     

太湖鸡生长发育与曲线拟合情况分析

运用Logistic、Gompertz和Bertallanffy3种曲线模型对太湖鸡母鸡0~12周龄生长情况进行了分析和非线性拟合研究。结果表明:3种曲线模型均能较好地拟合太湖鸡的早期生长曲线(R2均为0.999)。分析发现:Logistic生长曲线对禽类早期生长的拟合效果较佳,而对早期生长发育较慢的地方禽种的生长后期拟合效果较差。经比较,3种生长曲线中以Gompertz曲线模型对太湖鸡母鸡的生长拟合效果最佳。通过生长曲线的拟合还能发现饲养管理中存在的问题。     

商品乌骨鸡生长性能测定

目的：为了开发商品乌骨鸡的经济价值和遗传潜能，对商品乌骨鸡进行选育时可以针对公鸡和母鸡的质量特性及屠宰性能进行性状选择，以达到快速提高商品乌骨鸡体重的目的。方法：用单因素试验对公鸡和母鸡性能进行测定并比较。结果：在相同饲养条件下，公鸡生长速度比母鸡快，屠宰性能公鸡总优于母鸡。结论：商品乌骨鸡进行选育时可以侧重于公鸡，从而迅速提高乌骨鸡质量，以满足消费者对乌骨鸡的迫切需要。     

中畜草原白羽肉鸭与樱桃谷鸭的遗传差异分析

【目的】通过基因组重测序技术对中畜草原白羽肉鸭与樱桃谷鸭的遗传差异进行分析,追溯两个品种鸭在不同人工选择下的基因组变异机制,以此阐明优异性状形成的遗传基础。【方法】选择樱桃谷鸭商品代和中畜草原白羽肉鸭商品代各16只进行基因组重测序,过滤掉高缺失率与最小等位基因频率较低的位点,获得高质量SNPs用于后续分析;对两品种的基因型数据进行主成分分析(PCA)确定其遗传分化情况;采用群体遗传分化指数(Fst)和群体核酸多样性比值(Pi)两种分析方法综合筛选中畜草原白羽肉鸭和樱桃谷鸭的受选择信号。【结果】主成分分析结果显示,中畜草原白羽肉鸭和樱桃谷鸭分化显著。以10 kb窗口5 kb步长分别计算Fst与Pi分析值,取前1%作为阈值(Fst>0.177,Pi>0.885),在两种分析方法的信号重叠区域共筛选到410 kb候选区域,共注释到21个候选基因。对候选基因进行GO与KEGG富集分析发现,12个基因显著富集到细胞组分和分子功能两大类中(P<0.05),2个基因显著富集到代谢相关通路(P<0.05)。这些基因中,与脂质代谢、氨基酸代谢、免疫调控相关的基因包括PDE3A、P...     

Homoeothermy and growth rate in the fowl

Observations on growth rates and diurnal changes in colonic temperatures were made on seven groups of 30 to 50 White Plymouth Rock x Cornish chicks aged between 6 and 8 weeks. Ambient air temperature ranged from 22 °C to 35 °C.

Colonic temperatures in the morning (08.00 to 09.00 h) and growth rates were within the normal range. A slight hyperthermia was evident from 13.00 to 14.00 h.

Morning colonic temperatures were not correlated with the later increments in body temperatures. This suggests that the set‐point temperature for thermo‐regulatory control differs between individuals.

Growth rates were not correlated with the morning colonic temperature, except in one group; they were, however, significantly correlated with the diurnal fluctuation in colonic temperature in all groups. These results suggest that the maintenance of a constant body temperature is essential for a normal growth rate.

The variation in thermoregulatory ability accounted for 31 to 71% of the total variation in growth rate.     

Molecular characterization of MHC class II region in guinea fowl

1. The MHC class II gene was amplified, cloned and sequenced in guinea fowl. 2. The NumeMHC II sequence of 754 nucleotides included complete exon 1 (91 nt), exon 2 (270 nt), exon 3 (282 nt) and exon 4 (110 nt). 3. The size of β(1) and β(2), domains were 89 and 93 amino acids, respectively in guinea fowl. 4. High amino acid variability (38·2%) was observed within guinea fowl in β(1) domain, while in β(2) domain, amino acid variability (6·3%) was low. 5. Among poultry species, the percent amino acid identity between guinea fowl and chicken, quail, pheasant and duck was 38·8, 42·2, 44·4 and 58·8 in β(1) domain; and 13·8, 17·0, 13·8 and 27·6 in β(2) domain, respectively. 6. Sequence alignment with mammalian and avian MHC showed that many of the conserved features of MHC class II glycoprotein was conserved in guinea fowl. 7. Within-species genetic distances (Poisson correction) based on cumulative amino acid variability in β(1) domain and β(2) domains was 0·141 in guinea fowl. 8. Guinea fowl showed low and similar genetic distances with all the poultry species (0·255-0·268) except duck (0·456). 9. Guinea fowl made separate branch within the major cluster having chicken, quail and pheasant, showing equal distance from these poultry species, whereas duck MHC II clustered separately.     

白番鸭数量性状间相关性分析

对ＲＦ系白番鸭蛋重与受精率,孵化率及初生重;见蛋白龄、性成熟期和产蛋率;耗料量和产蛋率;产蛋率与周龄等数量性状间相关性进行观测分析。结果表明：蛋重大（８６～９０ｇ）受精率高（９７．７％）,但孵化率低（６７．４％）;中等蛋重（７６～８５ｇ）孵经率高（８１．０％）;蛋重与初生重呈强直线正相关（ｒ＝０．９４０８）。经观测各组ＲＦ系白番鸭从见蛋到产蛋率无显著差异（Ｐ〉０．０５）;产蛋期间母鸭群的耗料量与产     

Estimating parameters of growth curves of bulls

Parameters were estimated for nonlinear growth curves for bulls of five straightbred and 20 crossbred breed-types produced in two generations of a diallel. The primary intent of this study was to use the estimates obtained for mature size and maturing rate to define male growth in manner that would be appropriate for use in the Texas Agricultural Experiment Station (TAES) Beef Cattle Simulation Model. The results that were obtained from the nonlinear regressions made on the male growth data indicated that the relation between the mature sizes of males and females of the same breed-type is consistent with the assumption for that relation contained in the model (a ratio of 1.5). However, the inverse relationship between mature size and maturing rate that is assumed in the model was not consistent with the results of the present study. That contradiction presumably arose due to the different environment imposed on the males relative to their female counterparts. This condition prohibits direct application of the results of this study because live weights cannot be directly related to the principal growth curve contained in the model. However, such a relationship can be developed when information regarding the composition of bulls considered in this study becomes available.     

Caegal growth in the domestic fowl following surgical manipulation

1. Some effects of removing increasing proportions of the left caecum on the remaining caecal tissue and on the right caecum were studied in young chicks during a period of 35 d. The chicks were 22 d old when the operations were carried out.

2. No differences were detected between the gains in weight of the control and experimental groups of birds.

3. A marked negative linear relationship was observed between the dry weight of the amount of caecal tissue removed when the birds were 22 d old and the weight of the left caecum at the end of the experiment.

4. The average growth rate of the left caecum (g dry tissue/week) was found to be dependent on the estimated weight of caecal tissue remaining after surgery.

5. No evidence was obtained to indicate that the growth of the right caecum responded to the removal of the left caecal tissue.

6. The morphology and histology of the operated caeca were found to be similar to the equivalent regions of the unoperated caeca. Surgical interference was not followed by any major changes in mucosal architecture.

7. In birds which had experienced unilateral caecectomy, the discharge of caecal faeces usually stopped for about 2 d. When caecal defaecation was resumed, the pattern of defaecation appeared to be the same as that observed in sham‐operated birds with both caeca intact.     

Synthetic oestrogens in the production of roasting fowl. II. Dietary nutrient concentration and time of implantation

Three experiments have been carried out using broiler‐type birds reared beyond the normal broiler stage to 14 weeks of age. In the first experiment control cockerels were compared with birds injected with either a 15 mg. hexoestrol pellet or a 15 mg. pellet of diethylstilboestrol at 9 weeks of age: at this stage three diets of different nutrient density were offered. As the nutrient density was increased, food utilisation progressively improved and growth rates were raised. Hexoestrol implantation resulted in an increase in voluntary food intake of 23 per cent above the control whereas diethylstilboestrol implantation increased voluntary food intake by only 14 per cent. These increases in food intake were associated with proportional increases in live‐weight gain.

In a second experiment pullets received 15 mg. implants of hexoestrol at 64 days of age, and were then fed diets of different nutrient concentrations to 98 days of age. Live‐weight gain tended to improve as nutrient density was raised, and efficiency of food utilisation was inversely proportional to nutrient density.

In a third experiment male birds were reared from 70 to 119 days of age. Four different implantations with hexoestrol at various ages were compared: only in those receiving two implants was there any difference in performance. Six diets varying in energy level and protein level were offered. Growth rates improved as dietary protein levels were raised progressively from 13.3 to 16.3 per cent, though food utilisation was most efficient at 14.8 and 16.3 per cent crude protein. Growth rate was 7.6 per cent greater when the dietary energy level was raised from 3065 to 3275 kcal. metabolisable energy per kg.     

番鸭下丘脑组织的RNA-Seq特征分析

为筛选番鸭下丘脑组织中的基因组信息,本研究以NCBI数据库中已标注的绿头鸭基因组（登录号：BGI_duck_1.0）为参照,利用RNA-Seq技术对番鸭下丘脑组织基因表达水平,以及可变剪切事件、SNPs及InDel进行筛选。结果显示,共鉴定出14 619个基因表达（FPKM ≥ 1）,占筛选出总基因数的72.7%。共有5 034个基因发生了7 528次可变剪切,其中外显子跳跃占92.76%,第一个外显子可变剪切和内含子滞留所占比例最小,共占总数的0.027%。通过RNA-Seq技术,本研究还筛选到646 423个SNP位点和77 712个InDel位点。对SNPs和InDel所在的基因进行功能注释发现,这些基因主要参与分子功能、生物过程和细胞组成过程。通过KEGG通路分析发现,出现SNPs和InDel所在基因主要富集在内分泌调节和神经行为调节的相关通路上,表明下丘脑既可参与内分泌调节,又参与动物的神经行为调节。本研究筛选出的数据不仅丰富了番鸭的遗传信息,而且也建立了番鸭相关基因的SNPs和InDel的数据库,这为番鸭的遗传育种工作及相关功能基因的具体定位提供了可靠依据,同时也为以后番鸭行为的研究提供了一定的参考价值。     

北京鸭繁殖性能的遗传分析

采用动物模型和MTDFREML软件计算北京鸭繁殖性能性状的遗传参数、育种值和母体效应，结果表明：（1）北京鸭产蛋量的变异较大。（2）北京鸭产蛋量的遗传力主要由加性效应决定，母本效应的作用较小。（3）要综合选择北京鸭的体重、蛋重和产蛋量，以便达到三者共同提高的目的。（4）对北京鸭进行产蛋量的早期选择时，应剔除开产阶段的产蛋记录，选择才较为准确。（5）北京鸭产蛋量有上升趋势，蛋重和体重有下降趋势。     

黑羽与黄、白羽鹌鹑杂交后代生长曲线的拟合

运用Logistic、Gompertz、Bertalanffy和Brody等4种非线性拟合模型对黑羽母鹌鹑与黄羽、白羽公鹌鹑2组杂交后代0～10周龄的体质量生长数据进行曲线拟合与分析.结果显示,4种模型均能较好的拟合其生长曲线,但Gompertz模型对于2个试验组的拟合度均达到0.997 0以上,残差平方和(E)均较低,拐点周龄的拟合值分别为3.030 4周和3.206 4周,拐点体质量的拟合值分别为59.480 9 g和54.213 6 g,均最接近实际值,故Gompertz模型为最适宜描述2组杂交后代生长曲线的模型.     

乌鸡中氟喹诺酮类药物残留现状分析

乌鸡是我国特有的地方鸡种,具有特殊种质性状和经济价值的品种资源,是药、肉、蛋、观赏兼用型多用途鸡种。但近些年日常监测显示,乌鸡产品中氟喹诺酮类药物残留超标较为严重,影响了乌鸡产业的健康发展。因此,本文收集了2016年-2021年国家市场监督管理总局公布的乌鸡中氟喹诺酮类药物残留超标的监测结果,对不合格产品的分布地区进行了比较研究,以期为氟喹诺酮类在乌鸡体内的残留监管以及药物的合理使用提出建议,确保乌鸡产品质量安全。