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ABSTRACT: Ducks (common, Muscovy and mule ducks) are the third most important bird species in animal production for human consumption worldwide. Our study aimed to improve the efficiency of mule duck breeding, thus contributing to the efficiency of food production in general. In the common duck, females can be bred either with males of the same species (i.e. in pure breeding (PB) subscript p) or in inter-generic crossbreeding (CB; subscript c) with Muscovy drakes to produce the hybrid mule duck. The aim of the present study was to estimate the genetic parameters of several indicators of duration of fertility, considered to be a trait of the female duck, within and between breeding schemes and, in particular, to estimate the purebred-crossbred genetic correlation (rg pc). These indicators were maximum duration of fertility (MD), that is, the time interval between insemination and the last fertilised egg, the number of fertile eggs (F) and of hatched ducklings (H) after a single artificial insemination (AI), and the fertility rate over days 2 to 12 after AI (F 2,12), taking three sub-periods (F 2,4, F 5,8, F 9,12) into account. A total of 494 females and 2655 inseminations were involved. PB resulted in longer duration of fertility (MD p = 8.1 v. MD c = 6.4 days). Heritability (h 2) was higher for MD p (estimate ± s.e.: 0.27 ± 0.04) than for MD c (0.15 ± 0.04), but both traits were highly correlated with each other (rg pc = 0.85 ± 0.07). F p and F c had similar heritability (h 2 around 0.24) and displayed a high genetic correlation (0.78 ± 0.07). The same was true for H p and H c (h 2 around 0.17 and rg pc = 0.88 ± 0.05). The heritability estimates were 0.24 ± 0.03 for F 2,12p and 0.20 ± 0.04 for F 2,12c, with a 0.80 ± 0.07 genetic correlation between each other. Permanent environmental effects influenced MD p far less than MD c, F p less than F c, but H p and H c to the same extent. The high values for rg pc (>0.78) indicated that the same genes are involved in the duration of fertility for both PB and CB. Unlike CB, initial fertility for PB (F 2,4p) was not correlated to overall fertility rate and to duration of fertility and probably involves different genes, if any. In both breeding schemes, indirect selection on F would be better than direct selection on H to improve H, and easier to implement than selection on MD. Moreover, any gain in one breeding scheme will have its correlated counterpart in the other one, because of the high values of rg pc.
animal 11/2012; 6(11):1731-7. · 1.74 Impact Factor
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ABSTRACT: The aim of the study was to evaluate the impact of 2 isoenergetic growing diets with different CP (17 vs. 23%) on the performance and breast meat quality of 2 lines of chicken divergently selected for abdominal fatness [i.e., fat and lean (LL) lines]. Growth performance, breast and abdominal fat yields, breast meat quality parameters (pH, color, drip loss), and muscle glycogen storage at death were measured. Increased dietary CP resulted in increased BW, increased breast meat yield, and reduced abdominal fatness at slaughter regardless of genotype (P < 0.001). By contrast, dietary CP affected glycogen storage and the related meat quality parameters only in the LL chickens. Giving LL chickens the low-CP diet led to reduced concentration of muscle glycogen (P < 0.01), and as a result, breast meat with a higher (P < 0.001) ultimate pH, decreased (P < 0.001) lightness, and reduced (P < 0.001) drip loss during storage. The decreased muscle glycogen content observed in LL receiving the low-CP diet compared with the high-CP diet occurred concomitantly with greater phosphorylation amount for the α-catalytic subunit of adenosine monophosphate-activated protein kinase and glycogen synthase. This was consistent with the reduced muscle glycogen content observed in LL fed the low-CP diet because adenosine monophosphate-activated protein kinase inhibits glycogen synthesis through its action on glycogen synthase. Our results demonstrated that nutrition is an effective means of modulating breast meat properties in the chicken. The results also highlighted the need to take into account interaction with the genetic background of the animal to select nutritional strategies to improve meat quality traits in poultry.
Journal of Animal Science 02/2012; 90(2):447-55. · 2.10 Impact Factor
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ABSTRACT: Improving the fowl's natural ability to clear Salmonella from their body is important in reducing disease prevalence in poultry flocks, as recommended by a recent regulation of the European Commission. It may be efficient, as expected from estimation of heritability coefficients : 0.16 in chicks and 0.18 for global contamination of hens. The animal's age has to be considered since the genetic correlation between resistances at the two ages is negative. Selecting two series of divergent lines for increased or decreased resistance, after inoculation at one week of age (chick resistance) or at the peak of lay (adult resistance) confirmed the efficiency at least of selection for the adult resistance. In parallel, genes controlling variations to Salmonella resistance were researched and several QTLs identified in crosses between experimental lines and, for some of them, confirmed in commercial lines. Thanks to the derivation of a model of Salmonella propagation within a flock, it has been shown that a combination of vaccination and genetic selection can result in very low percentage of contamination.
World's Poultry Science Journal 05/2010; 66(02):251 - 260.
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ABSTRACT: The ability of chickens to carry Salmonella without displaying disease symptoms is responsible for Salmonella propagation in poultry stocks and for subsequent human contamination through the consumption of contaminated eggs or meat. The selection of animals more resistant to carrier state might be a way to decrease the propagation of Salmonella in poultry stocks and its transmission to humans. Five QTL controlling variation for resistance to carrier state in a chicken F(2) progeny derived from the White Leghorn inbred lines N and 6(1) had been previously identified using a selective genotyping approach. Here, a second analysis on the whole progeny was performed, which led to the confirmation of two QTL on chromosomes 2 and 16. To assess the utility of these genomic regions for selection in commercial lines, we tested them together with other QTL identified in an [Nx6(1)] x N backcross progeny and with the candidate genes SLC11A1 and TLR4. We used a commercial line divergently selected for either low or high carrier-state resistance both in young chicks and in adult hens. In divergent chick lines, one QTL on chromosome 1 and one in the SLC11A1 region were significantly associated with carrier-state resistance variations; in divergent adult lines, one QTL located in the major histocompatibility complex on chromosome 16 and one in the SLC11A1 region were involved in these variations. Genetic studies conducted on experimental lines can therefore be of potential interest for marker-assisted selection in commercial lines.
Animal Genetics 05/2009; 40(5):590-7. · 2.40 Impact Factor
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ABSTRACT: A total of 540 common duck dams were used for a comparison of duration of fertility and hatchability between eggs issued from common dams inseminated with sperm (175 x 10(6) dose(-1)) from either common (pure-breeding or PB) or Muscovy (crossbreeding or CB) drakes. Artificial inseminations (AI) were performed at 3 periods of the reproductive season (27-35, 39-43 and 49-56 weeks) with 2 alternate inseminations/period at 3-week intervals (one with semen from common and the other from Muscovy). Fertility was estimated from egg candling while early embryo mortality (EEM), medium embryo mortality (MEM) and late embryo mortality (LEM) was estimated on Days 0-6 (PB+CB), Days 7-25 (PB) or Day 28 (CB) of incubation, and after, respectively. Overall fertility from Days 2-12 after AI was 61.1% in PB and 42.8% in CB. The maximum duration of fertility (time interval between AI and last fertile egg) was 8.1 days in PB versus 6.4 days in CB (p<0.05). The age of the dam influenced this interval, particularly in PB, with a longer duration at 40 weeks compared to 50 (p<0.05). On average, EEM represented 2.5% of fertile eggs while MEM accounted for 5% of surviving embryos on Day 6 and LEM, for 11.5% of hatched eggs. MEM was significantly higher in CB (6.3%) compared to PB (3.9%; p<0.05). Overall, an increase in EEM and MEM was observed in both types of eggs at and after 50 weeks of age. An increase in EEM (regardless of dam's age) and in MEM (only in the oldest females) was observed with sperm storage duration. Sex ratio at hatching (49.2% males in PB vs. 53.0% in CB) was particularly unbalanced on the first fertile day (54.7% and 57.1%, respectively).
Theriogenology 06/2008; 69(8):983-9. · 1.96 Impact Factor
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C Beaumont,
F Lecerf,
J Protais,
F Calenge,
K Prevost,
A C Lalmanach,
H Chapuis,
F Pitel,
T Burlot, N Sellier,
P Fravalo,
A Vignal,
P Velge
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ABSTRACT: Increasing resistance to acute Salmonellosis (that is, contamination level shortly after infection) is not sufficient to reduce the risk for consumers to be contaminated by Salmonella. Indeed, animals may remain contaminated at a low level for weeks or months. Increased resistance to the Salmonella carrier state, i.e., animals' ability to clear bacteria, is needed; it involves measuring bacterial contamination several weeks after inoculation with a low dose. To study such resistance traits, three convergent approaches were used. A quantitative trait loci (QTL) study was performed, taking advantage of inbred lines differing in resistance. Several QTLs controlling resistance at a younger age were identified and are currently being confirmed in a new cross before finer mapping, using advanced intercross lines. These inbred lines are also presently being compared using functional genomics. In parallel, a selection experiment for increased or decreased resistance at a younger and a later age was undertaken. Besides providing genetic models differing in their levels of resistance, it underlined the importance of the choice of selection criterion, whether marker assisted or not. Indeed, genes controlling resistance are strongly dependant on age; selecting for resistance at a younger age might result in increased susceptibility at an older age. Finally, the results of this experiment were used in a model of the intra-flock propagation of Salmonella. It showed that introducing a proportion of resistant animals within a flock of susceptible hens could dramatically change the evolution of contamination. Moreover, it demonstrated the magnitude of synergy between selection and vaccination, which should enhance the interest of increased resistance. The results show that selection for increased resistance to the Salmonella carrier state may be efficient, providing that the appropriate criteria of selection are used.
Developments in biologicals 02/2008; 132:353-7.
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ABSTRACT: The experiment consisted of a 2 × 2 × 2 factorial design testing the two D+ and D- chicken lines selected for divergent digestion efficiency (fifth selection generation), xylanase (with or without) and ampicillin and collistin (with or without) supplementations. From 8 to 22 days, 144 chickens (18 birds per treatment) were fed a diet containing 55% wheat from a high-viscosity cultivar (Rialto). Effects of treatments were evaluated on individual growth performance (8 to 19 days), digestibilities of lipids and dry matter, dietary energy value (apparent metabolisable energy corrected to zero-nitrogen retention (AMEn)), digestive organ and breast sizes, and intestinal bile acids at 3 weeks of age. Individual variabilities were much lower in D+ than in D- birds for feed : gain ratios, digestibilities and AMEn values. In all cases, feed : gain ratios were lower in the D+ than in the D- line (P < 0.001), and D+ birds showed 22% to 86% higher values than in D- birds (P < 0.001) for digestibilities and AMEn. In D- birds, antibiotics but not xylanase supplementation had significant effects on lipid digestibility (P < 0.01) and AMEn (P < 0.05), whereas both supplements improved these parameters in D+ birds (P < 0.001 for both additives on lipids digestibility, P < 0.05 for xylanase and P < 0.01 for antibiotics on AMEn). Relative weights of gizzard and proventriculus, and gizzard : intestine weight ratio were higher in D+ than in D- birds, while relative weight of intestine was increased in D- birds compared with D+ birds. Antibiotics reduced intestine relative weight in D+ (P < 0.001) and D- (P < 0.01) lines. AMEn variations were efficiently predicted by the gizzard : intestine weight ratio. In conclusion, antibiotics were very efficient for improving growth performance, AMEn and digestibility values in both chicken lines. Xylanase was less efficient than antibiotics. Because of their low individual variabilities, D+ birds were much more efficient than D- ones for the detection of significant effects induced by xylanase supplementation. Differences between lines in feed : gain ratio, digestibilities and AMEn were reduced when xylanase and antibiotics were added together. Effects of xylanase supplementation and animal genetics on lipid digestibility could not be entirely explained in terms of intestinal bile acids. Other factors should be involved, especially for the lipid digestibility difference induced by animal genetics. The gizzard : intestine weight ratio was an efficient parameter for predicting AMEn variations due to animal genetics and additives.
animal 11/2007; 1(10):1435-42. · 1.74 Impact Factor
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ABSTRACT: 1. The repeatability and heritability of growth inhibition by egg albumen of two major pathogenic bacteria, a Gram-negative (Salmonella Enteritidis) and a Gram-positive (Staphyloccocus aureus) and of two antimicrobial albumen proteins, lysozyme and ovotransferrin, were estimated in commercial pedigree hens. 2. Repeatability was evaluated in 100 egg-type hens at the beginning, middle and end of the laying cycle on eggs collected for 3 weeks. Heritabilities were estimated at 36 to 40 weeks of age on 400 pedigree hens (2 eggs/hen), which were the offspring of 25 sires each mated with 4 dams. Ovotransferrin and lysozyme were quantified by ELISA. Salmonella Enteritidis (S.E.) and Staphyloccocus aureus (S.A.) were inoculated into a sample of sterilised albumen and enumerated after incubation. 3. Total protein content in albumen decreased with age of laying hens, whereas there were increases in lysozyme or ovotransferrin concentrations and in the bacteriostatic effect of albumen. 4. Repeatability for bacterial growth in albumen ranged from 0.29 to 0.39 for the number of S.E. (log cfu/ml) one day post inoculation (p.i.) but was lower and more variable at 5 d p.i. or for S.A. number. It ranged from 0.27 to 0.38 for S.E. and S.A. number at the mid period of the laying cycle. Repeatabilities were low and variable for total egg albumen protein or lysozyme and ovotranferrin concentrations (0 to 0.22). 5. Negative phenotypic correlations were observed between lysozyme concentrations and S.E. number but that between lysozyme and S.A. number was not significant. 6. Heritabilities were low (0.01 to 0.09) for protein traits. They were 0.11 for S.A. number and 0.16 for S.E. number one day p.i. 7. It appears to be more efficient to select on global bacterial growth than on specific antimicrobial proteins. The most promising trait is the number of S.E. one day p.i.
British Poultry Science 11/2007; 48(5):559-66. · 1.00 Impact Factor
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ABSTRACT: 1. Relationships between feed conversion ratio, growth curve parameters and carcase composition were investigated on 1061 chickens from a slow-growing line of label-type chickens. The growth curve was modelled with the Gompertz function. Individual feed conversion ratio (FCR) was recorded between 8 and 10 weeks of age and residual feed consumption (RES) was calculated over the same interval. Abdominal fat yield (AFY), breast yield (BRY) and leg yield (LY) were also measured on the birds following slaughter at 75 d of age. 2. The means for FCR and RES were 3.15 and 0.62 g, respectively. Growth curve parameters were 0.141/d for initial specific growth rate (L), 0.031/d for maturation rate (K) and 48.9 d for age at inflexion (TI). Mean values for BRY, LY and AFY were 166, 306 and 40 g/kg, respectively. 3. Heritability of FCR and RES were moderate to high (0.33 and 0.38 to 0.45). Growth curve parameters and LY were moderately heritable (0.22 to 0.34) and BRY and AFY were highly heritable (0.50 and 0.66). Genetic correlations between growth curve parameters and either FCR or RES were low to moderate (-0.31 to 0.51). LY and AFY were highly correlated with FCR (-0.70 and 0.44) and RES (-0.32 and 0.44) but BRY was not (0.00 and -0.35). These results show that indirect selection for feed conversion ratio is possible by using growth curve parameters and abdominal fatness, which do not require rearing the chickens in cages.
British Poultry Science 07/2006; 47(3):273-80. · 1.00 Impact Factor
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ABSTRACT: The aim of the experiment was to study the effects of 2 wheat cultivars (Baltimor and Scipion) with different hardness values (75 and 5, respectively) on 2 divergent lines (D+ and D-) of broiler chickens selected on the basis of their digestion ability assessed by AME(n). Wheat was incorporated at 54.6% in diets. The other main ingredients were soybean meal (35.3%) and rapeseed oil (5.5%). Diets were given as pellets from 7 to 26 d. The experimental design was a 2 x 2 factorial design testing 2 wheat cultivars (soft or hard) on 2 selected lines of broiler chickens (high AME(n) or low AME(n)). From 7 to 16 d, D+ line showed lower (P < 0.0001) feed intake and feed:gain ratio than the D- line. At 3 wk of age, the D+ chickens resulted in increased digestibility values (P < 0.01) and 9% increased AME(n) value (P < 0.0001) compared with D-. Wheat cultivar effects on feed efficiency and AME(n) differed between lines. In the D+ line, their values were about 6% higher (P < 0.05) with soft than with hard wheat, whereas they did not differ in the D- line. However, wheat cultivar effect on starch digestibility did not differ between lines; soft instead of hard wheat resulted in about 6% improvement (P < 0.0001) in both lines. In the D- line, soft instead of hard wheat tended to reduce lipid and protein digestibilities, which explained why the starch digestibility improvement due to soft wheat was not converted into a significant AME(n) improvement in D birds. Study of digestive organ size revealed that increased proventriculus and gizzard weight (P < 0.05) could be one of the causes for the better digestion capacity of the D+ line. The pancreas was bigger (P < 0.01) in D- than in D+ birds, which probably came from an adaptation to a digestive disorder in D- birds.
Poultry Science 03/2006; 85(3):462-9. · 1.73 Impact Factor
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M Debut,
C Berri,
C Arnould,
D Guemené,
V Santé-Lhoutellier, N Sellier,
E Baéza,
N Jehl,
Y Jégo,
C Beaumont,
E Le Bihan-Duval
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ABSTRACT: 1. The aim of this study was to compare the behavioural and physiological responses to hanging and acute heat stress in three different chicken breeds. Chicks were obtained from a slow-growing French 'Label Rouge' line (SGL), a fast-growing standard line (FGL) and a heavy line (HL). The SGL, FGL and HL birds were slaughtered at their respective market ages of 12, 6 and 6 weeks, in an attempt to achieve similar body weights. Before stunning, birds were either shackled by their legs on the moving line for 2 min (shackling stress: SH) or placed in a room at 35 degrees C and 60% of humidity for 3.5 h and then shackled for 2 min (acute heat stress plus shackling: H + SH) or subjected to minimal stress by shackling for 10 s before stunning (control group: C). 2. Bird physiological responses to the three pre-slaughter treatments were estimated by measuring blood corticosterone, glycaemia, creatine kinase activity, acid-base status and electrolyte concentration as well as lactate content and glycolytic potential in the breast (Pectoralis major) and thigh (Ilio tibialis) muscles. Behavioural responses to shackling stress were evaluated by measuring wing flapping duration, straightening up attempts and vocalisations. 3. Blood corticosterone was higher in SH and H+SH groups than in the C group, regardless of genotype. The struggling activity on the shackle line differed among chicken breeds. It was more intense and occurred more rapidly after hanging in the SGL birds than in both other breeds. Furthermore, SGL struggling activity was not affected by hanging duration while it increased with hanging duration in FGL and HL birds. 4. Wing flapping duration was negatively correlated with blood pH, bicarbonate concentration and positively correlated with breast muscle lactate content, indicating that struggling stimulated antemortem glycolysis activity in breast muscle. Acute heat stress affected blood Ca2+ and Na+ concentration and increased glycaemia and glycolytic potential of thigh muscle. 5. Both acute heat stress and shackling before slaughter were experienced as stressful events by all types of birds.
British Poultry Science 11/2005; 46(5):527-35. · 1.00 Impact Factor
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C Beaumont,
O Roussot,
K Feve,
F Vignoles,
S Leroux,
F Pitel,
J M Faure,
A D Mills,
D Guémené, N Sellier,
S Mignon-Grasteau,
P Le Roy,
A Vignal
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ABSTRACT: A quantitative trait loci (QTL) study was undertaken to identify genome regions involved in the control of fearfulness in Japanese quail (Coturnix japonica). An F2 cross was made between two quail lines divergently selected over 29 generations on duration of tonic immobility (DTI), a catatonic-like state of reduced responsiveness to a stressful stimulation. A total of 1065 animals were measured for the logarithm of DTI (LOGTI), the number of inductions (NI) necessary to induce the immobility reaction, open-field behaviour including locomotor activity (MOVE), latency before first movement (LAT), number of jumps (JUMP), dejections (DEJ) and shouts (SHOUT), corticosterone level after a contention stress (LOGCORT) and body weight at 2 weeks of age (BW2). A total of 310 animals were included in a genome scan using selective genotyping with 248 AFLP markers. A total of 21 suggestive or genome-wide significant QTL were observed. Two highly significant QTL were identified on linkage group 1 (GL1), one for LOGTI and one for NI. In the vicinity of the QTL for LOGTI, a nearly significant QTL for SHOUT and a suggestive QTL for LAT were also identified. On GL3, genome-wide significant QTL were observed for JUMP and DEJ as well as suggestive QTL for LOGTI, MOVE, SHOUT and LAT. A significant QTL for BW2 was observed on GL2 and a nearly significant one on GL1. These results may be useful in the understanding of fearfulness in quail and related species provided that fearfulness has the same genetic basis.
Animal Genetics 11/2005; 36(5):401-7. · 2.40 Impact Factor
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C Berri,
M Debut,
V Santé-Lhoutellier,
C Arnould,
B Boutten, N Sellier,
E Baéza,
N Jehl,
Y Jégo,
M J Duclos,
E Le Bihan-Duval
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ABSTRACT: 1. Pectoralis major (P. major) muscle pH and meat quality traits were studied in relation to bird response to ante-mortem stress in three chicken lines: a fast-growing standard line (FGL), a slow-growing French 'Label Rouge' line (SGL) and a heavy line (HL). Ninety-nine birds of the three genetic types were slaughtered at their usual marketing age (6, 12 and 6 weeks for FGL, SGL and HL birds, respectively) on the same day. The birds of each line were divided into three different ante-mortem treatment groups: minimum stress (shackling for 10 s) (C), shackling for 2 min (SH) and acute heat plus shackling stress (exposure to 35 degrees C for 3.5 h and shackling for 2 min before stunning) (H + SH). 2. Regardless of chicken line, wing flapping duration (WFD) between hanging and stunning was strongly negatively related to P. major muscle pH at 15 min post-mortem. It was also moderately negatively related to P. major muscle glycolytic potential (GP), which represents glycogen level at death. Increasing WFD induced an increased ultimate pH (pHu) only in HL. The consequences of increased WFD for breast meat traits were dependent on the chicken line: it induced lower L* and b* and higher a* and drip loss in SGL while it only increased breast a* in HL birds. By contrast, WFD variations did not alter breast meat quality traits of FGL birds. Regardless of the chicken line, increased GP was associated with lower pHu and higher L* and drip loss. In SGL, it also increased b* and decreased curing-cooking yield of breast meat. 3. Struggling activity on the shackle line and muscle glycogen content at death could partly explain line and pre-slaughter variations in breast meat pH and quality traits. The water holding capacity of the raw and cooked meat was impaired by long shackling in the case of SGL birds while it was barely affected by ante-mortem conditions in the two standard lines. In conditions which minimised bird struggling (C), SGL and FGL birds had meat with a better water holding ability than that of broilers from the heavy line. However, when broilers were subjected to SH or H + SH conditions, the breast meat water holding capacity of SGL birds was lowered to the same level as that of the heavy line birds.
British Poultry Science 11/2005; 46(5):572-9. · 1.00 Impact Factor
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Theriogenology 01/2005; 64(2):429-439. · 1.96 Impact Factor
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ABSTRACT: The genetic parameters of digestibilities for a wheat-based diet were estimated on 864 broilers. Two divergent lines (D+ and D-) were developed based on AMEn. The Rialto wheat variety was used as it is known to result in low digestibility values. Digestibility of lipids (DL), starch (DS), and proteins (DP) were measured individually using Near Infrared (NIR) analysis of freeze-dried excreta. Body weight, feed consumption (FC), feed conversion ratio (FCR) and residual feed consumption (RES) were recorded to evaluate their correlation with AMEn. The mean AMEn value was 3,093 kcal/kg DM (CV = 9.0%), with a range of 1,001 to 4,022 kcal/kg DM, and was highly heritable (0.36 to 0.38) based on the Restricted Maximum Likelihood method. Genetic correlations with BW were low (-0.10 to -0.15). Selection for AMEn can thus be performed without modifying BW. In contrast, the estimated genetic correlations between AMEn and the other traits were highly negative (-0.53 to -0.60 for FC, -0.77 to -0.80 for RES, and -0.77 to -0.84 for FCR). Finally, digestibilities of feed components were moderately to highly heritable (0.33 to 0.47) and highly correlated with AMEn (0.91 for DL, 0.83 for DS, and 0.86 for DP). Selecting for improved AMEn should thus improve digestibility of proteins, starch, and lipids. The first generation of divergent selection on AMEn confirmed these results, D+ and D- lines showing a 13% difference in AMEn (P < 0.0001) and similar BW.
Poultry Science 06/2004; 83(6):860-7. · 1.73 Impact Factor
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ABSTRACT: Mule duck hatcheries have long reported varying degrees of unbalance in the sex ratio, with a preponderance of male mules at hatching. The aim of the present study was to assess the distributions of sex ratios at various stages of development in embryos originating from intra- and intergeneric crosses between parental lineages (Muscovy male x Muscovy female, Pekin male x Pekin female, Muscovy male x Pekin female or Mule, and Pekin male x Muscovy female or Hinny). In Experiment I, embryo sexing was performed on Days 1 and 5 of incubation (by multiplex PCR) and at hatching (by vent observation). The sex ratio was not significantly modified during the early stages of embryo development whatever the genetic origin (P>0.05, Days 1 and Day 5) but our results in mule and hinny ducklings confirmed the preponderance of males among normally hatched ducklings originating from the intergeneric lineage (58.9 and 55.4% males in mules and hinnies, respectively; P<0.05 in both cases). Sex ratio (vent sexing) in second grade (cull) ducklings revealed that 68% of these ducklings were females (P<0.05). In Experiment II, the distribution of sex ratio was also performed in mule duck eggs from 6 batches (400,000 eggs/batch) first examined for fertility (candling) on Day 18 of incubation. These results indicate that the percentage of males present in the population of normally hatched ducklings increases when fertility decreases. In addition, this experiment also revealed that 83.7-90.5% of viable male mule embryos develop up to hatching, compared to only 43.0-51.0% of female mule embryos. Given that a deviation in sex ratio during the first stages of incubation is unlikely (Experiment I), it is concluded that the skewed sex ratio of mule ducks at hatching is primarily due to increased late mortality in female mule embryos occurring between egg transfer and hatching. This mortality originated, at least in part, from the intergeneric origin of female mules, and was marked to a greater or lesser extent depending on the initial success of fertilization in a given batch, a possible indication that the initial quality of gametes may selectively exert its influence at the later stages of embryo development.
Theriogenology 01/2004; 61(2-3):573-80. · 1.96 Impact Factor
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British Poultry Science 01/2004; 44(5):791-2. · 1.00 Impact Factor
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M Debut,
C Berri,
E Baéza, N Sellier,
C Arnould,
D Guémené,
N Jehl,
B Boutten,
Y Jego,
C Beaumont,
E Le Bihan-Duval
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ABSTRACT: The present study was aimed at estimating the genetic variability between lines of breast and thigh meat quality (pH decline, color, drip loss, and curing-cooking yield) by comparing a slow-growing French label-type line (SGL) and a fast-growing standard line (FGL) of chickens exposed to different preslaughter stress conditions. The birds were slaughtered under optimal conditions or after exposure to 2 h of transport or acute-heat stress (2 h at 35 degrees C). Relationships between meat quality and stress sensitivity were investigated by measuring struggle during shackling and tonic immobility (TI) duration, 1 wk before slaughter, as an indicator of the basal level of fear of the birds. Although most of the meat quality indicators varied between the 2 lines, differences were muscle dependent. In concordance with a lower ultimate pH, curing-cooking yield of thigh meat was decreased for the FGL birds. In contrast, these birds had a higher curing-cooking yield and a lower drip loss of breast meat resulting from a less rapid pH decline in this muscle compared with SGL birds. Thigh meat characteristics were influenced by both preslaughter stresses, but no significant effects were detected for breast meat. The main effect of heat stress in thigh meat was a decrease of the ultimate pH and led to paler color and lower curing-cooking yield; opposite effects were obtained for transport. Breast meat was much more sensitive to physical activity of birds on the shackle line. Longer durations of wing flapping on the shackle line gave more rapid initial pH decline. Whatever the line, no relationship between TI duration and meat quality characteristics or activity was observed. The present study suggested that SGL birds could be at disadvantage due to more struggle during shackling and accelerated postmortem glycolysis, which is detrimental to the quality of breast meat.
Poultry Science 01/2004; 82(12):1829-38. · 1.73 Impact Factor
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ABSTRACT: In this study we have characterized four of the principle goose apolipoproteins and compared their physicochemical properties with human and avian counterparts. Goose ApoB-100 and ApoAI amino acid compositions were very similar to their chicken and human homologous proteins. The partial N-terminal sequence from goose ApoAI was 91% and 82% similar to the corresponding duck and chicken proteins, respectively. Most of the observed amino acid changes detected between the ApoAI sequences were amino acid replacements having the same characteristics and could be the result of a single base mutation. The N-terminal portion of two ApoC-like apolipoproteins were also studied. Goose ApoCa had an electrophoretic mobility of 0.31 and exhibited a nine-residue motif that was well conserved between ApoCIII sequences from different species. We therefore suggest that ApoCa is the equivalent of mammalian ApoCIII. The N-terminal portion of goose ApoCb, the second major ApoC in high-density apolipoprotein, showed no similarity to proteins previously described in the literature. This protein displayed two isomorphs in alkaline urea gel electrophoresis called ApoCb1 and ApoCb2 with Rf values of 0.36 and 0.39, respectively. A genetic polymorphism was detected in the population whereby 25% of the animals carried only one isomorph and 50% exhibited both ApoCb isomorphs. These frequencies were similar in females and males. The transmission mode of these ApoCb isomorphs was consistent with two segregating alleles from a single codominantly expressed gene.
European Journal of Biochemistry 01/1996; 234(2):586-91. · 3.58 Impact Factor
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ABSTRACT: Semen quantitative (sperm production) and qualitative parameters (percentage of live and normal spermatozoa, sperm motility, egg fertility and hatchability), as well as hormonal parameters (LH and testosterone plasma concentrations) were compared for landais ganders, which were treated or not, with an LH-RH agonist prior to being sexually active. Treatment with the LH-RH agonist at this physiological stage delayed the onset of sperm production in some of the treated males. Although, comparable data were obtained during the first half of the reproductive period, treatment with the LH-RH agonist maintained sperm output at higher levels during its second half. Although the percentage of normal and live spermatozoa, sperm motility and true hatchability did not differ, the LH-RH agonist treatment had a positive effect on gosling production because of the higher fertility of the treated birds during the second part of the reproductive period. Treatment induced a large short-term decrease in testosterone levels followed by a rebound, leading to higher levels during the second half of the reproductive period. We conclude that treatment of ganders with an LH-RH agonist partially prevented the naturally occurring decline in sperm production and induced an increase in the rate of fertility rates during the second half of the productive period.
Theriogenology 11/1995; 44(6):793-809. · 1.96 Impact Factor
