Genetic parameters for body weights,egg traits and antibody response against Newcastle Disease Virus (NDV) vaccine among two Tanzania chicken ecotypes

Genetic parameters were estimated for production traits and primary antibody response (Ab) against Newcastle diseases virus (NDV) vaccine among two Tanzania chicken ecotypes viz. Kuchi and Tanzania Medium (Medium). Production traits studied were body weights at 8 (Bwt8), 12(Bwt12), 16(Bwt16), and 20 (Bwt20) weeks of age, age at first egg (AFE), egg number in the first 90 days after sexual maturity (EN-90), egg weight (EW), egg shell thickness (STH), and egg shape index (ESI). Heritability estimates for Bwt8, Bwt12, Bwt16, Bwt20, AFE, EN-90, EW, STH, ESI and Ab for Kuchi chicken were 0.38 ± 0.10, 0.41 ± 0.07, 0.44 ± 0.08, 0.45 ± 0.09, 0.42 ± 0.10, 0.31 ± 0.05, 0.43 ± 0.08, 0.53 ± 0.11, 0.48 ± 0.13 and 0.27 ± 0.06, respectively. Corresponding estimates for Medium ecotype were 0.39 ± 0.09, 0.43 ± 0.10, 0.42 ± 0.08, 0.43 ± 0.07, 0.52 ± 0.11, 0.32 ± 0.06, 0.50 ± 0.07, 0.61 ± 0.13, 0.52 ± 0.10 and 0.29 ± 0.05, respectively. Genetic (r _g) and phenotypic (r_p) correlations in both ecotypes were highest among body weights (i.e. r_g = 0.60 to 0.93 and r_p = 0.54 to 0.78), and were lowest (around 0.10 and below, ranging from positive to negative) among primary antibody response against NDV vaccine and production traits, and among eggshell thickness, egg shape index and other production traits. The magnitudes of heritability estimates obtained in this study indicate good prospects of improving these traits in both ecotypes through selection.     

Pasture,multi-enzymes,benzoic acid and essential oils positively influence performance,intestinal organ weight and egg quality in free-range laying hens

1. The objective of this study was to investigate the effect of range type, multi-enzyme applications, and a combination of benzoic acid (BA) and essential oils (EO) on the productive performance, organ weight and egg quality of free-range laying hens.

2. Three hundred laying hens were evaluated for the short-term (6 weeks) and long-term (12 weeks) effects of range type (G = no pasture, P = pasture) and feed additives (T1 = control; T2 = betaglucanase/pectinase/protease; T3 = BA/EO). Body weight, feed intake (FI), feed conversion ratio (FCR), egg production (EP), digestive organ weight, and egg quality (EQ) were evaluated. Data were analysed using SPSS 2.2 in a 2×2×3 factorial arrangement.

3. Hens that ranged on pasture were significantly heavier (2043 g vs. 1996 g; p < 0.001), laid heavier eggs (61.9 g vs. 60.3 g; p < 0.001) and produced darker yolk colour (4.3 vs. 7.0; p < 0.001) compared to hens ranged on gravel. Hens fed T2 were significantly heavier (2050 g) compared to hens fed T1 (2005 g) or T3 (2008 g). Organ weights (gizzard, liver and pancreas) were significantly heavier in hens ranged on pasture (16.8 g/kg BW, 22.3 g/kg BW and 1.89 g/kg BW, respectively) compared to hens ranged on gravel (14.2 g/kg BW, 21.7 g/kg BW and 1.83 g/kg BW, respectively). Over time, body weight (1970–2070 g; p < 0.001) and egg weight (59.5–62.8 g; p < 0.001) increased, FI (123–120 g; p = 0.024) was reduced and FCR (2.36–2.10; p = 0.002) improved

4. In conclusion, hens housed on pasture and fed multi-enzyme supplemented diets had significantly heavier body weight and produced heavier eggs with darker yolk colour. Pasture intake and enzyme supplementation increased digestive organ weight significantly.     

Endocrine Gland and Brain Weights of Market Weight Bulls and Steers Representing the Shorthorn Breed and Several Breed Crosses

Thyroid, adrenal, pituitary and brain weights were first determined in 1971 in 492 market weight cattle representing purebred Shorthorns and crosses of “foreign” breeds, Charolais, Simmental and Limousin with Hereford, Angus and Shorthorn. Thyroid weights were also determined in a similar group of 433 cattle the following year. The data were reported on a per 100 kg body weight basis and analyzed within the subgroups of breed of sire, breed of dam and location.

The average thyroid weight per 100 kg of body weight for males within subgroups over the two years ranged from 3.99 to 8.71 g, while that for steers ranged from 3.81 to 4.41 g. The average thyroid weight for a group of 18 Limousin sired heifers was 3.71 g. The average adrenal weight per 100 kg of slaughter weight ranged from 3.66 to 4.20 g in the males and from 3.66 to 3.86 g in the steers. Pituitary weight per 100 kg body weight at slaughter ranged from 486-511 mg in bulls and from 469-510 mg in steers. Average brain weight ranged from 85.5 to 97.3 g in males and from 92.2 to 94.1 g in steers.

Breed differences existed only for the pituitary gland, with Simmental sired males and steers having heavier glands than Charolais sired males and steers.

Sex differences were significant for the thyroid and the brain. Thyroids of males were generally heavier than those of steers, while brains of steers were heavier than those from males.

Thyroid, adrenal and brain weights were significantly different between two genetically similar purebred herds of Shorthorns.

     

Selection with restriction in a poultry breeding scheme with different selection procedures in both sexes: Correlated responses

1. Mass selection in two replicate lines of Leghorn chickens was practiced for low 20‐week body weight in males and by an index designed to reduce age at first egg, body weight at 20 weeks and maintain a constant early egg size in females.

2. Selection responses in body weights of hens at 40 and 60 weeks of age, as well as in average egg weight of all eggs, egg number, egg mass and feed conversion at the above ages are given for 5 generations of selection.

3. Estimation of genetic responses were made separately for selection on males (M _i ) and females (F _i ) using control groups of hens from matings between females with an index near the population average and either males with body weight near the population average (Cl) or the selected males within lines (C2).

4. Total genetic response to selection of both parents (CR _i ) showed an expected decline in body weights of hens, small changes in egg weights and egg numbers, and an improved feed efficiency.     

Different Serum Haemolytic Complement Levels in Indigenous Chickens from Benin,Bolivia, Cameroon,India and Tanzania

Titres of classical (CPW) and alternative (APW) complement pathways were measured in clinically healthy local chicken populations (ecotypes) from Africa (Benin, n = 78; Cameroon, n = 299; Tanzania, n = 101), Asia (India, n = 96) and South America (Bolivia, n = 64). A wide variation was found in haemolytic complement levels between the various ecotypes. Distributions of the classical and alternative complement titres were not normal but were skewed to the right. Differences in complement were found both within and between ecotypes. Furthermore, CPW titres of the indigenous chickens were lower than those determined in commercial layer chickens. This suggests that complement levels background and husbandry. The relationships between complement levels, the chicken MHC(B) complex, environmental antigenic pressure, and survival of the scavenging local chickens are discussed.     

Egg production,fertility, hatchability and immune responses of some chicken strains under high ambient temperatures

This experiment was designed to investigate and compare the egg production, fertility, hatchability and immune responses of some local developed Egyptian chicken strains under high ambient temperatures. A total of 108 (26 weeks old) laying hens of Matrouh, Silver Montazah, Mandarah and Inshas (9 hens × 3 replicates × 4 strains) were used to evaluate the impact of thermal stress (24-34ºC) during summer season (June, July and August) on egg production, fertility, hatchability and immune responses. The obtained results revealed that final body weight (FBW/g) and body weight change (BWC/g) among different chicken strains were not affected. The daily feed consumption (FC/g) and feed conversion ratio (FCR) for Silver Montazah and Inshas strains were significantly (p ≤ .05) higher than those of Matrouh and Mandarah strains. The mean egg production (EP/%) and egg mass (EM) for Silver Montazah and Inshas strains were significantly (p ≤ .05) higher than those of Matrouh and Mandarah strains. The highest percentages of hatchability of total eggs (HTE) and fertile eggs (HFE) were recorded in Inshas chickens, while the lowest value was recorded in Mandarah chickens. Also, the highest embryonic mortalities (p ≤ .05) and lowest chick weight at hatch (CWH/g) were recorded in Mandarah chickens compared with the other strains. The highest values for antibody titres against phytohemagglutinin-P (PHA-P) were recorded in Mandarah chickens, while the least values were recorded in Inshas chickens.     

Age, genotype and sex effects on growth performance of local chickens kept under improved management in Ghana

Characterisation of animal genetic resources has been recognised globally as an important step towards their sustainable use. Body weight data of local chickens (213 forest and 160 savannah chickens) and 183 French free-ranging SASSO T44 chickens kept under improved management were collected from hatch to 40 weeks of age and analysed to determine the effects of age, genotype and sex on their growth performance. At all ages, SASSO T44 chickens had significantly (P < 0.05) higher weights (2.6–3.2 kg at 28 weeks) than the local chickens (1.2–1.7 kg at 28 weeks). The rate of growth at the earlier ages in the local genotypes (5.57–7.80 g/day) was lower than the range of 13.81–15.42 in SASSO T44 chickens. Except at hatch, savannah chickens were significantly heavier (P < 0.05) than the forest chickens at all ages. Male chickens had significantly (P < 0.05) superior growth rates than females across all genotypes except from the 20th to the 28th week. Growth trends in both sexes depicted linear increase in body weights; however, the rate of increase in body weights was higher in males as compared to females, thus showing clear sexual dimorphism. There were no significant (P > 0.05) differences in the growth rates of SASSO T44 chickens and local genotypes at the later ages (20–28 weeks). Local chickens from the savannah zone had better growth rate than forest chickens. The significant effect of ecozone on the growth potential of local chickens is an indication that their productive potential could be improved through interventions in the environment such as provision of feed and some veterinary care.     

Comparative analysis of meat quality and chemical composition among three weight groups of Chinese Ningdu yellow chicken: Implications for customer choice

The aim of this study was to compare the meat quality and evaluate the chemical composition of Chinese Ningdu yellow chicken of different weights once they have reached market age. Thirty hens at the day of age 118 were selected and divided into three groups according to their weight: light weight (1288.00 ± 69.78 g, n = 10), medium weight (1407.17 ± 39.40 g, n = 10), heavy weight (1581.6 ± 46.59 g, n = 10), and the differences in weight among these three groups are significant. Biochemical, histological, and metabonomic approaches were used to obtain index values of meat quality and chemical composition. Compared with meat from lighter chickens, muscle fiber density was significantly lower in heavier chickens, and meat pH was positively correlated with chicken weight. Though the amount of all measured amino acids were not different among three weight groups of chicken, the levels of several kinds of fatty acids exhibited significant differences or correlations, including linolenic acid, arachidonic acid, myristic acid, oleic acid, and docosahexaenoic acid (DHA). These results contribute to help customers choose the optimal chicken weight depending upon the food to be cooked.     

Farmers’ breeding practices and traits of economic importance for indigenous chicken in RWANDA

Data on breeding practices and traits of economic importance for the indigenous chicken (IC) were collected through personal interviews using structured questionnaires and direct observations of chicken management practices. The study was conducted from November 2015 to January 2016 in Rwamagana, Rulindo, Ruhango, Kicukiro and Muhanga districts of Rwanda. Data were collected and analysed through computation of indices, which represented a weighted average of all rankings of a specific trait. Spearman’s non-parametric rank correlation was calculated for ranking of traits of economic importance to indicate the directional effects. The results on chicken ecotypes and their attributes showed that prolificacy, mature weight, disease tolerance, egg number and heat tolerance were highly preferred. The dwarf ecotype was most abundantly reared (38.84%) and considered to be significantly smaller and to have poorer growth rate, but to have better prolificacy than other indigenous chicken ecotypes. Selection of breeding cock and hen was based on disease tolerance, body weight at sexual maturity, body size and growth rate. In addition, for hen, mothering ability and egg fertility (Fer) were considered. Indices for the traits perceived by farmers as of primary economic importance were egg yield (0.093), disease tolerance (0.091), high growth rate (0.089), prolificacy (0.088), high body weight (0.087) and egg fertility (0.083). The most important traits considered by the marketers were body weight (BW), disease tolerance (Dtol), plumage colour (Pcol), egg yolk colour (EYC), meat quality (MQ), growth rate (GR) and egg yield (EY) whereas for consumers, meat quality, egg yolk colour, egg yield, body weight and growth rate were considered. Among traits perceived as important by farmers, a positive and significant correlation was found between BW and GR and Fer. Correlation was moderate for BW and prolificacy, drought tolerance (Drtol), Dtol and EYC. BW was negatively correlated with temperament (Temp), heat tolerance, Pcol and egg shell colour (ESC). Regarding marketers and consumers’ preference rank correlation, positive and significant correlation was between BW and GR and MQ. As such, appropriate ecotypes (indigenous chicken) which have these characteristics need to be identified and utilised more based on their performance and adaption to the environment conditions to ensure efficient IC production.     

Estimation of maintenance energy requirements in German shepherd and Labrador retriever dogs in Bangalore,India

Maintenance energy requirements (MERs) were calculated for 17 German shepherd and 20 Labrador retriever adult dogs using an in‐home prospective dietary trial. The dogs were fed the same dry pet food and body weight, food intake, body condition score and physical activity were monitored for 10 weeks. Labrador retrievers were significantly heavier and had higher body condition scores than German shepherd dogs, but there was no difference between males and females within each group. Body weights remained stable over the study period, with an average daily gain of 9.1 g. Mean (SD) MER was 103.4 (16.3) kcal/kg BW^0.75, which was some 20% lower than that currently suggested for moderately active young adult dogs. Individual MER ranged from 66.8 to 141 kcal/kg BW^0.75. There were no significant differences in MER between the two breeds, or between males and females within and between the two breeds. There was a significant inverse relationship between MER and body condition score, reflecting the lower energy expenditure of adipose tissue. The lower MER of dogs in this study, relative to previous observations, may reflect climatic and environmental differences and highlight the necessity for accurate estimates of MER in relation to the production and feeding of pet foods.     

Effect of hexoestrol implantation and body size on the chemical composition and body components of chickens

Two groups of meat‐type cockerels, 56 d of age, from the same hatch but of different mean live‐weights (1135 g ± SD 96.2 and 544 g ± 72.0) due to differences in earlier nutritional treatments were implanted with hexoestrol to determine the effects on food consumption, live‐weight gain, carcass gain, chemical composition of carcass and offal, and weight of some body components. Replicate groups were slaughtered prior to implantation and at the end of the 28‐d experimental period.

Implantation with a single 15 mg hexoestrol pellet resulted in the following significant differences compared with untreated controls: increases in food consumption, live‐weight gain, carcass weight and weight of offal of 21.5, 14.2, 8.2 and 16.6 per cent respectively; poorer food conversion, higher total fat in the carcass, offal and total body and, relative to body weight, heavier livers and lighter hearts, gizzards, legs and necks. The increased fat in treated chickens accounted for all the increased body weight and carcass weight.

In comparisons of small and large chickens there was no significant difference in live‐weight gain during the 28‐d experimental period. At both 56 and 84 d of age the dressing percentages were lower and the weights relative to body weight of offal, liver, shanks and gizzards were higher in small than in large chickens. Percentage moisture was significantly higher in the total bodies and carcasses of small chickens, while percentage fat was significantly lower in the carcasses of small chickens at both 56 and 84 d and in the total bodies and offals at 56 d.     

Egg production and quality under three housing systems in the tropics

The aim of this study was to evaluate egg production and quality of Rhode Island Red (RIR) laying hens in an outdoor system in the subhumid tropic. Eighty RIR laying hens were measured in two periods and housed randomly under three treatments: outdoor (O), indoor (I) and in conventional cages (C). Egg weight (55.88, 53.76 and 57.16 g, for O, I and C, respectively), food intake/hen/day (138.94, 129.74 and 162.90 g, for O, I and C, respectively) and food efficiency (3.13, 3.22 and 3.96 for O, I and C, respectively) were significantly (P < 0.05) influenced by housing system; however, both egg production and final body weight were not different (P > 0.05). Yolk colour (10.76, 9.94 and 10.08 colour scale, for O, I and C, respectively), albumen weight (92.63, 92.28 and 90.08 g, for O, I and C, respectively) and yolk weight (15.19, 14.61, 15.48 g for O, I and C, respectively) were significantly (P < 0.05) influenced by housing system, but albumen height, Haugh units and egg shell weight remained similar (P > 0.05). Under the conditions of this study, outdoor egg production seems to be a sustainable system comparable to the commercial type based on wired cages.     

Growth performance of Nigerian local chickens in crosses involving an exotic broiler breeder

Six-hundred-and-seven-day-old chicks were generated from Nigerian local chickens consisting of three genotypes (Normal-feathered; Frizzled-feathered; Naked neck) and an exotic broiler breeder (Anak Titan) to evaluate growth performance for possible meat-type chicken development. Growth parameters measured were body weight, breast girth and keel length on weekly basis for 20 weeks. Effects of sire, dam and chick genotypes were significant (P < 0.001) on growth traits. At week 20, chickens sired by the Anak Titan weighed 1,614.82 g followed by Normal-feathered local chickens with body weight of 1,211.32 g. Progenies of Anak Titan and Naked neck dams weighed 1,761.96 and 1,292.80 g at week 20, respectively. Among purebreds, Anak Titan weighed 35.05 g at day-old and had heaviest body weight of 2,360.29 g at 20 weeks compared to the three local strains. The average body weights for the crossbred, Normal-feathered×Anak Titan at day-old and week 20 were 36.39 and 1,577.63 g, respectively. This was followed by Anak Titan×Naked neck with 33.32 g at day-old and 1,514.14 g at week 20. Sex had significant effect (P < 0.05) at weeks 16 and 20 with the males having higher mean values than their female counterparts. This study revealed that crosses involving Anak Titan sire×Naked neck dam had highest growth performance, and there was no strain differences among the growth performance of purebred Nigerian local chickens.     

Polymorphisms of the PNPLA3 gene and their associations with chicken growth and carcass traits

1. An F₂ resource population of Gushi chickens crossed with Anka broilers was used to investigate the genetic effects of the chicken PNPLA3 gene on growth and adipose accumulation.

2. Associations between three SNPs (g.40006G?>?T, g.42344T?>?C and g.42404A?>?T) and broiler traits were determined using linkage disequilibrium, haplotype construction and association analysis.

3. The g.40006G?>?T mutation was associated with body weights at 4, 6, 8, 10 and 12 weeks of age, carcass weight, evisceration weight and semi-evisceration weight (P? 4. Haplotypes of the g.42344T?>?C and g.42404A?>?T mutations were associated with body weight at 12 weeks, carcass weight, evisceration weight, and semi-evisceration weight (P? 5. The results suggest that the PNPLA3 gene may be in linkage with the causative mutation or a QTL controlling growth traits in chickens. In contrast to human studies, the polymorphisms were not associated with fat related traits.     

仙居三黄鸡产蛋期的生产性能

笼养条件下观察产蛋期的仙居三黄鸡不同体重对产蛋性能的影响。结果表明,体重最大组的只日产蛋量、产蛋率、蛋重、产蛋数、蛋长和蛋宽等指标均为最大;蛋重和蛋宽出现显著性差异,其余指标差异不显著;蛋重、蛋长和蛋宽与母鸡体重呈显著正相关。该研究结果可为仙居三黄鸡及其他蛋鸡的品质改良和开发利用提供理论依据。     

Genotype X environment interaction in two breeds of chickens kept under two management systems in Southern Ethiopia

Rhode Island Red (RIR) and Fayoumi chickens were evaluated on-station in a college farm and on-farm in village farms, whereas local chickens were only tested under on-farm condition. Traits recorded are egg production and egg quality, body weight and feed efficiency at 4, 8 and 12 months of age. Significant age effect was found for most traits except for shell thickness, albumen height and egg length. Also, significant breed by management system interactions were found for all traits measured in both systems. Fayoumi chickens were higher in egg production in both management systems. Moreover, they were higher than RIR in feed efficiency. RIR were higher in most egg quality traits and had higher weight gain. Local chickens performed below the two exotic breeds in most of the traits, but had higher weight gain than Fayoumi. Chickens kept on-farm had poorer performance than those kept on-station in all traits except for yolk colour.     

Egg production response of laying chickens to feather clipping,cool water and aspirin during hot weather conditions

An 8-week trial was conducted between March and May (hot-dry season) to determine effects of water temperature, feather clipping and aspirin on egg production of chickens. The treatments tested were hens given ordinary drinking water (control), cool water (100 g ice block per L) and aspirin (0.3 mg per L of ordinary water) and hens whose feathers were clipped (about two thirds of body feathers clipped). At 32 weeks of age, 120 Lohmann brown layer chickens of similar live weights were randomly divided into 12 groups of ten hens each and assigned to the treatments in triplicate using a completely randomized design. Feed and water were given ad libitum. Data included feed intake, water consumption, hen-day egg production and egg weight. Ambient house temperature, hen’s cloacal temperature and water temperature were monitored daily during the experimental period. Mean daily ambient temperature increased from 28.4 to 35.0 °C during the study period with consequent increase in cloacal temperatures (40.31 to 41.18 °C) of hens, ordinary drinking water and cool water. None of the treatments had any significant (P?>?0.05) effects on feed intake and water consumption of the birds. Hens given cool water produced more (P?P?P?>?0.05). It is concluded that the provision of cool water in a hot-dry climate had a beneficial effect on egg laying performance of chickens.     

康县太平鸡早期生长曲线拟合及体重与体尺相关性分析

为研究太平鸡早期生长发育规律,提高品种选育效果,采用Logistic、Von Bertalanffy、Gompertz三种非线性生长模型对其体重进行拟合,并对13周龄的体重与体尺进行相关性分析。结果表明：Gompertz模型对太平鸡0～15周龄体重的拟合效果最佳,拟合所得的太平公、母鸡的拐点周龄分别为7.08周、6.84周,拐点体重分别为572.24 g、482.74 g,成熟体重分别为1 555.34 g、1 312.09 g;13周龄太平鸡体重与体尺之间存在不同程度的相关性,公鸡的体重与体斜长、龙骨长、胫长、胫围、骨盆宽呈极显著正相关（P<0.01）;母鸡的体重与龙骨长、胫长、胫围、胸围、骨盆宽呈极显著正相关（P<0.01）。     

Genetics of immunocompetent traits in a synthetic broiler dam line

Three hundred and three chicks of both sexes, from a synthetic dam line (SDL) of broiler chickens, were studied for economic traits (body weights at 4, 5 and 6 weeks of age) and immunological traits (humoral and cell mediated immune responses, and serum lysozyme concentration). The objective was to evaluate these traits and to estimate their genetic and non-genetic parameters. The humoral immune response was assessed by estimating the antibody response to sheep red blood cells using the haemagglutination (HA) test and serum IgG concentration using single radial immunodiffusion (SRID). The cell mediated immune (CMI) response was estimated as in vivo response to a mitogen (PHA-P). Serum lysozyme was measured by lysoplate assay. Least squares means for body weight at 4, 5 and 6 weeks were 684 +/- 20, 920 +/- 19 and 1205 +/- 28 g, HA titre was 6.289 +/- 0.246, CMI was 0.438 +/- 0.015 mm, lysozyme was 1.860 +/- 0.047 microg/ml and IgG was 6.287 +/- 0.194 mg/ml. There was an effect of sire on HA titre and on body weight at 4, 5 and 6 weeks of age; males were heavier than females. Heritability estimates were high for body weights but low for immunological traits. Phenotypic correlations (rp) among body weights were high and positive but were very low between body weights and most immunological traits. Among the immunological traits all rp were very low. Genetic correlations (rg) of body weights were positive and medium to high with CMI and HA and negative with serum IgG.     

Relationship between egg‐shell colour and two measurements of shell strength in the Vasca breed

1. Egg‐shell colour, egg specific gravity, shell thickness and egg weight were determined for 2080 eggs from three varieties of the Vasca, a Spanish brown‐egg‐laying hen.

2. Intermediate, positive and significant (P < 0·01) correlation coefficients were found between egg‐shell colour and specific gravity (0·25), or shell thickness (0·21). There was a very high (0·84), significant (P < 0·01) correlation between the measures of shell strength.

3. Shell thickness was accurately predicted with both specific gravity and egg weight as independent variables (determination coefficient 0·74); eggshell colour did not explain any further variation.

4. All traits showed considerable departure from normality in the form of negative kurtosis (shell colour and specific gravity), positive kurtosis (shell thickness and egg weight), negative skewness (shell thickness) or positive skewness (egg weight).

5. Egg‐shell colour, specific gravity and shell thickness were less in July, in old birds and in eggs laid in the morning. Differences in egg quality traits between the three varieties were not significant.