547 research outputs found
Sustainability of poultry meat production: growth performance and carcass traits of slow-growing genotypes fed low input diets
No full textThe development of alternative and sustainable poultry meat production, consistently with the objectives of the European Green Deal and the F2F strategy, requires the use of resilient chicken breeds and low input diets (based on national and local raw materials). Thus, the present study compared performance and carcass traits of a fast-growth genotype (Ross 308) with those of two local breeds (Bionda Piemontese, BP; Robusta Maculata, RM) and their crosses with a moderate-growth genotype (Sasso, Sa). A total of 441 chickens were housed in 40 pens with 2 pens/genotype/sex, i.e. Ross (51 females and 52 males), BP (37 and 38), RM (25 and 47), BP×Sa (49 and 48), and RM×Sa (47 and 47). Within genotype, half of the pens received a standard diet (diet S: ME 3,050 kcal/kg; CP 18.5%) and half a low input diet (diet LI: ME 2,921 kcal/kg; CP 17.5%) from 20 d
of age until slaughtering (47 d for Ross and 105 d for other genotypes). Data were submitted to ANOVA with genotype, diet, and sex as main effects with interactions and pen as random effect. At the end of the trial, BP showed the lowest live weight followed by RM and BP×Sa, RM×Sa, and Ross (1620 g vs. 2024 g and 2037 g vs. 2376 g vs. 2643 g, respectively; P<0.001). Daily weight gain and feed intake changed accordingly which affected feed conversion (3.37 and 3.28 for BP and BP×Sa vs. 3.09 and 3.01 for RM and RM×SA vs. 1.85 for Ross; P<0.001). At slaughtering, BP showed the lowest dressing out percentage followed by BP×Sa, RM, RM×Sa and Ross chickens (58.3% vs. 64.7% vs. 70.1%, 68.8% and 71.1%; P<0.001) with corresponding changes of breast proportion (24.3% and 25.5% in BP and BP×Sa vs. 26.7% and 26.9% in RM and RM×Sa vs. 33.6% in Ross; P<0.001). Chickens fed diet S presented a higher growth rate (28.5 g/d vs. 23.8 g/d; P<0.001) and feed intake (69.4 g/d vs. 65.7 g/d; P<0.001) compared to those fed diet LI, and a lower feed conversion ratio (2.80 vs. 3.03; P<0.001). Differences in growth rate and feed conversion between chickens fed the two diets were small in the case of BP and BP×Sa and larger in the case of RM, RM×Sa and, especially, Ross chickens. In conclusion, growth results and carcass traits of local breeds were far lower compared to those of Ross chickens. As for pure breeds, RM performed better than BP especially when crossed with Sa. In addition, most performant chickens (Ross, RM and RM×Sa) suffered the use of a low input diet, whereas BP and BP×Sa chickens were more resilient to dietary changes
Combined analysis of data from two granddaughter designs: A simple strategy for QTL confirmation and increasing experimental power in dairy cattle
No full textA joint analysis of five paternal half-sib Holstein families that were part of two different granddaughter designs (ADR- or Inra-design) was carried out for five milk production traits and somatic cell score in order to conduct a QTL confirmation study and to increase the experimental power. Data were exchanged in a coded and standardised form. The combined data set (JOINT-design) consisted of on average 231 sires per grandsire. Genetic maps were calculated for 133 markers distributed over nine chromosomes. QTL analyses were performed separately for each design and each trait. The results revealed QTL for milk production on chromosome 14, for milk yield on chromosome 5, and for fat content on chromosome 19 in both the ADR- and the Inra-design (confirmed within this study). Some QTL could only be mapped in either the ADR- or in the Inra-design (not confirmed within this study). Additional QTL previously undetected in the single designs were mapped in the JOINT-design for fat yield (chromosome 19 and 26), protein yield (chromosome 26), protein content (chromosome 5), and somatic cell score (chromosome 2 and 19) with genomewide significance. This study demonstrated the potential benefits of a combined analysis of data from different granddaughter designs.Jörn Bennewitz, Norbert Reinsch, Cécile Grohs, Hubert Levéziel, Alain Malafosse, Hauke Thomsen, Ningying Xu, Christian Looft, Christa Kühn, Gudrun A. Brockmann, Manfred Schwerin, Christina Weimann, Stefan Hiendleder, Georg Erhardt, Ivica Medjugorac, Ingolf Russ, Martin Förster, Bertram Brenig, Fritz Reinhardt, Reinhard Reents, Gottfried Averdunk, Jürgen Blümel, Didier Boichard and Ernst Kal
Dietary supplementation with grape seed extract: effects on growth performance and gut response of broiler chickens
No full textIn recent years, dietary additives coming from plants are becoming attractive for keeping and improving gut health in broiler chickens. To this purpose, tannins can be supplemented in diets due to their anti-microbial, anti-oxidant, and antiinflammatory activities, but their effects can differ according to their origin. Thus, the present study evaluated the effects of a grape seeds extract (GSE) containing tannins on growth performance, and gut morphology and immune response of broiler chickens. A total of 800 chickens (half females and half males) were housed in collective pens (25 birds/pen, 8 pens/group) and fed a control diet (C) or the same diet added with 0.1% (diet GSE01) or 0.2% (diet GSE02) or 0.4% GSE (diet GSE04) from 0 (hatching) to 41 d of age (commercial slaughter). At 14 d and 28 d of age, 8 chickens per dietary treatment were slaughtered to sample jejunum mucosa. Serial sections were stained with hematoxylin/eosin for morphometric evaluation and with antibodies against intraepithelial CD3+ T-cells and CD45+ leukocytes to evaluate the anti-inflammatory activity. Data were submitted to ANOVA using a mixed model with diet as the main effect and pen (growth data) or
animal (gut mucosa data) as a random effect. Final live weight averaged 3,179 kg,- which corresponded to a daily growth rate of 76.1 g/d and a feed intake of 113 g/d, for a feed conversion ratio at 1.49, without any significant difference due to the dietary GSE supplementation or level. As for the GSE supplementation, villi height tended to decrease when chickens were fed diet GSE02 compared to those fed diets C, GSE01 and GSE04 (965 μm vs. 1,046 μm, 1,059 μm and 1,058 μm, respectively; P=0.07), the density of CD45+ increased (2497 vs. 1867, 2067, and 1858 cells/10,000 μm2; P<0.05). As for slaughtering age, villi height (968 to 1096 μm; P<0.01), goblet cells density (18.4 to 20.1 cells/300 μm; P<0.05) and CD3+ (1,812 to 2,193 cells/10,000 μm2; P<0.05) increased from 14 to 28 d of age. In conclusion, under the condition of the present study, GSE dietary supplementation did not affect chicken performance, but somewhat impaired gut mucosa status (as for reduced villi height) which was associated to a pro-inflammatory gut response (as for the higher density of inflammation cells) when using intermediate supplementation level (0.2%)
Evaluation of adaptability response, through a behavioural observation, of four different chicken genotypes reared in a free-range system
No full textAlternative poultry rearing systems such as organic and free range should be developed following the “One Welfare” concept, a link between animal and human welfare. Thus, the choice of chicken genotypes should take into account their adaptabiliy to environmental conditions strictly linked in turn to animal welfare. The aim of this study was to assess the adaptability through a behavioural observation, of four different Slow Growing (SG) chicken genotypes: RedjA (A), Lhomann Dual (LD) Necked Neck (NN) and a Crossbreed (CB, Robusta Maculata x Sasso) free range reared. At hatching 400 chickens were randomly housed into 8 pens (2 pens per genotype; 50 animals each, 25 females and 25 males) and given outdoor access from 35 days of age, (0.10 m2/bird indoor and 4 m2/bird outdoor). The behavioural pattern of each pen was video-recorded from 42 d of age during 5 weeks, 2 times week and 2 hours per recording (9:00 to 11:00 am). Static, active, eating, comfort and social behaviours were then scanned every 30 minutes to record the percentage of animals expressing each specific behaviour. Data were analyzed by ANOVA with genotype, day, and their interactions as fixed effects and pen as a random effect. Static behaviours were more frequently observed in A chickens followed by NN chickens compared to LD and CB genotypes (55.4% 46.3% vs. 34.8% and 35.4% of chickens; P<0.001), which depended on differences in chickens resting (13.5% and 11.9% vs. 8.5% and 9.9%; P<0.05) and roosting (41.8% and 34.4% vs. 26.3% and 25.5%, P<0.001). Conversely, LD and CB chickens showed more active behaviours compared to A and NN genotypes (33.9% and 32.0% vs 16.3% and 23.9%; P<0.001), which is determined by the number of birds walking (21.8% and 24.8% vs. 10.0% and 20.9% P<0.001). On the contrary, the number of birds hiding was lower in A, NN and CB chickens compared to LD (2.3%, 0.6% and 1.9% vs. 8.7%; P<0.001). Concerning the eating behavior a higher number of A and NN chickens were found eating grass as compared to CB and LD (15.7% and 18.9% vs. 14.8% and 10.3%; P=0.001). A lower number of A and NN birds showed comfort behaviours respect to CB and LD genotypes (7.0% and 5.1% vs. 7.9% and 11.3%; P<0.001), which was due to the lower percentage of birds scratching and dust bathing (P<0.001). In conclusion, the A genotype showed the less adaptive response, while LD chickens likely fitted better to free range systems based on their higher overall outdoor activity and a more complete ethogram
Effects of the dietary supplementation with grape pomace and chestnut extracts on growth performance and intestinal mucosa of broiler chickens
No full textDuring the last years, poultry production has been moving towards antibiotic-free production systems in which tannins can be used as feed additives to improve animal immune response and health, due to their anti-microbial, anti-oxidant, and anti-inflammatory activities. Results widely vary according to tannins source and structure, however. Thus, the present study assessed the effects of the dietary supplementation in broiler chickens with two vegetal extracts containing tannins, from grape pomace (GP) or chestnut (CN), on growth performance and morphology and immune response of intestinal mucosa. A total of 864 chickens (both sexes) in collective pens (24 birds/pen, 12 pens/group) were assigned to three experimental groups fed a control diet (C) or the same diet added with 0.2% CN extract (diet CN) or 0.2% GP extract (diet GP). At 14 d and 34 d of age, 12 chickens per diet were slaughtered to sample jejunum. Serial sections of 4 μm were stained with hematoxylin/eosin for morphometric evaluation and with antibodies against intraepithelial CD3+ T-cells and CD45+ leukocytes (only samples of the first slaughtering) to evaluate the anti-inflammatory activity. Data were submitted to ANOVA using a mixed model with diet as the main effect and pen (growth data) or animal (intestinal mucosa data) as a random effect. The diet GP significantly increased daily weight gain (DWG) in the whole trial (70.5 g/d vs. 69.4 g/d and 67.1 g/d; P<0.01) and final live weight (3148 g vs. 3099 g and 3084 g; P<0.01) compared to diets C and CN, with no effect on feed intake (on average 111 g/d), feed conversion ratio (1.59), and mortality (3.4%). Indeed, the diet GP promoted DWG in the second (+1.7%, P<0.001; 14-28 d) and in the third period of growth (+2.1%, P<0.05; 28-45 d) compared to diet C and, mostly, diet CN. The diets CN and GP decreased villi height compared to diet C (954 μm and 934 μm vs. 1033 μm; P<0.01), whereas crypt depth and villi-to-crypt ratio did not change. Regarding intestinal immune status, chickens fed diet GP showed higher densities of both CD3+ (2302 vs. 2116 cells/mm2; P<0.001) and CD45+ (2198 vs. 2040 cells/mm2; P<0.05) compared to those fed diet CN, whereas chickens fed diet C exhibited intermediate results. In conclusion, GP dietary supplementation improved chicken performance and promoted immune response in intestinal mucosa. Further insights are required to define the action mechanisms at the intestinal level
Cryptic patterning of avian skin confers a developmental facility for loss of neck feathering
No full textVertebrate skin is characterized by its patterned array of appendages, whether feathers, hairs, or scales. In avian skin the distribution of feathers occurs on two distinct spatial levels. Grouping of feathers within discrete tracts, with bare skin lying between the tracts, is termed the macropattern, while the smaller scale periodic spacing between individual feathers is referred to as the micropattern. The degree of integration between the patterning mechanisms that operate on these two scales during development and the mechanisms underlying the remarkable evolvability of skin macropatterns are unknown. A striking example of macropattern variation is the convergent loss of neck feathering in multiple species, a trait associated with heat tolerance in both wild and domestic birds. In chicken, a mutation called Naked neck is characterized by a reduction of body feathering and completely bare neck. Here we perform genetic fine mapping of the causative region and identify a large insertion associated with the Naked neck trait. A strong candidate gene in the critical interval, BMP12/GDF7, displays markedly elevated expression in Naked neck embryonic skin due to a cis-regulatory effect of the causative mutation. BMP family members inhibit embryonic feather formation by acting in a reaction-diffusion mechanism, and we find that selective production of retinoic acid by neck skin potentiates BMP signaling, making neck skin more sensitive than body skin to suppression of feather development. This selective production of retinoic acid by neck skin constitutes a cryptic pattern as its effects on feathering are not revealed until gross BMP levels are altered. This developmental modularity of neck and body skin allows simple quantitative changes in BMP levels to produce a sparsely feathered or bare neck while maintaining robust feather patterning on the body. © 2011 Mou et al
Les anomalies génétiques : définition, origine, transmission et évolution, mode d’action
No full textThis article presents an overview of the concepts and principles relative to genetic abnormalities, for which outbreaks are regularly observed in farm animal populations. These genetic defects originate from natural mutations and the frequency of some of them increases under the effect of genetic drift and sometimes of selection. When they are dominant, they are rapidly counter-selected and tend to disappear. But when they are recessive, the affected cases represent only a very small fraction of carrier individuals. Genetic defects are usually monogenic. However, this rule has many exceptions, either because the abnormality is more complex than initially assumed, or because the phenotype presents a variability caused by modulator genes in addition to the major factor. The recessive defects are mainly caused by loss of function mutations, whereas the dominant mutations often result from interactions between genes or between proteins, or from the loss of function of a repressor gene. Chromosomal abnormalities, when they are not lethal, cause syndromes which may vary between the different types of unbalanced caryotypes. Finally, genetic defects sometimes present very peculiar mechanisms, e.g. when the mutated gene is located on a sex chromosome or when it is imprinted.Cet article rappelle les notions et principes relatifs aux anomalies génétiques dont on observe régulièrement des émergences dans les populations animales d’élevage. Ces anomalies proviennent de mutations naturelles et certaines d’entre elles voient leur fréquence augmenter du fait principalement de la dérive génétique, parfois de la sélection. Lorsqu’elles sont dominantes, elles sont généralement rapidement contre-sélectionnées et tendent à disparaître. Mais lorsqu’elles sont récessives, les cas observables ne représentent qu’une toute petite fraction des individus porteurs. On définit généralement les anomalies génétiques comme des syndromes monogéniques. Toutefois, cette règle a beaucoup d’exceptions, soit parce que l’anomalie se révèle plus complexe qu’initialement supposé, soit parce que le syndrome présente une variabilité phénotypique due à des gènes modulateurs. Les anomalies récessives sont principalement dues à des mutations de type perte de fonction, tandis que les mutations dominantes résultent souvent d’interactions entre gènes ou entre protéines, ou de l’altération d’un gène répresseur. Les anomalies cytogénétiques conduisent à des phénotypes anormaux généralement différents entre types de caryotypes déséquilibrés. Enfin, les anomalies présentent parfois des déterminismes particuliers, par exemple dans le cas de gènes portés par les chromosomes sexuels ou soumis à empreinte parentale
Dossier : Anomalies génétiques - Avant-propos
No full textDossier : Anomalies génétiques - Avant-propo
Les anomalies génétiques : définition, origine, transmission et évolution, mode d’action
No full textThis article presents an overview of the concepts and principles relative to genetic abnormalities, for which outbreaks are regularly observed in farm animal populations. These genetic defects originate from natural mutations and the frequency of some of them increases under the effect of genetic drift and sometimes of selection. When they are dominant, they are rapidly counter-selected and tend to disappear. But when they are recessive, the affected cases represent only a very small fraction of carrier individuals. Genetic defects are usually monogenic. However, this rule has many exceptions, either because the abnormality is more complex than initially assumed, or because the phenotype presents a variability caused by modulator genes in addition to the major factor. The recessive defects are mainly caused by loss of function mutations, whereas the dominant mutations often result from interactions between genes or between proteins, or from the loss of function of a repressor gene. Chromosomal abnormalities, when they are not lethal, cause syndromes which may vary between the different types of unbalanced caryotypes. Finally, genetic defects sometimes present very peculiar mechanisms, e.g. when the mutated gene is located on a sex chromosome or when it is imprinted.Cet article rappelle les notions et principes relatifs aux anomalies génétiques dont on observe régulièrement des émergences dans les populations animales d’élevage. Ces anomalies proviennent de mutations naturelles et certaines d’entre elles voient leur fréquence augmenter du fait principalement de la dérive génétique, parfois de la sélection. Lorsqu’elles sont dominantes, elles sont généralement rapidement contre-sélectionnées et tendent à disparaître. Mais lorsqu’elles sont récessives, les cas observables ne représentent qu’une toute petite fraction des individus porteurs. On définit généralement les anomalies génétiques comme des syndromes monogéniques. Toutefois, cette règle a beaucoup d’exceptions, soit parce que l’anomalie se révèle plus complexe qu’initialement supposé, soit parce que le syndrome présente une variabilité phénotypique due à des gènes modulateurs. Les anomalies récessives sont principalement dues à des mutations de type perte de fonction, tandis que les mutations dominantes résultent souvent d’interactions entre gènes ou entre protéines, ou de l’altération d’un gène répresseur. Les anomalies cytogénétiques conduisent à des phénotypes anormaux généralement différents entre types de caryotypes déséquilibrés. Enfin, les anomalies présentent parfois des déterminismes particuliers, par exemple dans le cas de gènes portés par les chromosomes sexuels ou soumis à empreinte parentale
Illustration of plumage phenotypes associated with different genotypes at the <i>Inhibitor of gold</i> locus in chicken on different genetic backgrounds.
No full textThe birds in (A) and (B) carry the bottom recessive wheaten allele (e) at the MC1R locus and shows red pheomelanin-based pigmentation. The birds in (C) and (D) carry the brown allele (eb) at the same locus that allows expression of both eumelanin and pheomelanin and IG dilution is apparent as regards pheomelanin pigmentation. (A) and (B) depict F2 birds from the mapping pedigree with the wild-type phenotype or the recessive IG phenotype (IG/IG), respectively. (C) and (D) depict two IG/IG birds from the Lemon Millefleur Sabelpoot (Fig 1C) and Sebright-Lemon (Fig 1D) breeds, respectively. Photo by Michèle Tixier-Boichard (A and B) and C and D were taken by Nicolas Bruneau, INRAE (C and D).</p
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