It is generally presumed that allosucking brings benefits to the allosucking infants. Nevertheless, the data supporting such a presumption are rare. The aim of the study was to determine whether allosucking has any impact on growth rates of the allosucking calves. Fifty pregnant hinds were observed between 28 May (1st day of calving) and 2 September (abrupt weaning of all calves) on a red deer farm at Vimperk, South Bohemia, the Czech Republic. Of the 50 calves born the growth curve was calculated for 39 calves. During their 1st month of life these calves were observed in 1015 sucking bouts. In 690 cases the calves sucked from maternal hinds and in 325 cases non-maternal hinds. Only 25·64% of calves sucked exclusively from maternal hinds. The prevailing type of sucking behaviour was a combination of sucking from maternal hinds and allosucking (74·36%). Calves sucking from maternal and non-maternal hinds showed 1·6-fold higher sucking frequency than did calves feeding from maternal hinds only. Our results indicate that to some extend allonursing behaviour of the hind may affect their calves’ feeding behaviour. The more non-filial calves the maternal hind nursed, the higher frequency of the sucking by their calves occurred. The groups of calves did not differ in birth weight. With increasing age, the relative body weight increased faster in calves sucking maternal hinds only than in calves sucking maternal and non-maternal hinds. This gain in body weight was not essentially influenced by the fact whether or not the calf’s maternal hind nursed non-filial or exclusively filial calves. However, at weaning (99 days), the lowest body weight occurred in allosucking calves whose maternal hinds were allonursing. The results suggest that allosucking does not mean an extra profit to the allosucker. Instead, in our subjects, allosucking was rather attributed to compensation of nutritional requirements based on a combination of various factors, such as discrete differences in body weight at birth and also later and allonursing of the maternal hind.

Summary Starting with the consideration of a two‐locus system of a diploid organism, a general model for crossbreeding parameters, including additive, dominance, additive × additive, additive × dominance and dominance × dominance effects, is derived. A general procedure for the calculation of the coefficients of the crossbreeding parameters is described. As the number of parameters in the general model is high, reparametrization conditions must be introduced to reduce this number. The derivation of 13 models for two source populations known from the literature is demonstrated. Four new models for a detailed analysis of epistatic effects in crossbreeding plans with more than two source populations are presented. An example from cattle breeding is given. Problems connected with the reparametrization and the estimation of effects are discussed. Zusammenfassung Kreuzungszucht bei Nutztieren. V. Analyse von Kreuzungsplänen mit sekundären Kreuzungsgenerationen Ausgehend von der Betrachtung eines Zweilokus‐Systems eines diploiden Organismus wird ein allgemeines Modell für Kreuzungsparameter abgeleitet, das additive, dominante, additiv × additive, additiv × dominante und dominant × dominante Effekte enthält. Eine allgemeine Methode zur Berechnung der Koeffizienten der Kreuzungsparameter wird beschrieben. Da die Anzahl der Parameter im allgemeinen Modell hoch ist, müssen Reparametrisierungsbedingungen eingeführt werden, um diese Anzahl zu senken. Die Ableitung von 13 Modellen für zwei Ausgangspopulationen, die aus der Literatur bekannt sind, wird demonstriert. Vier neue Modelle für eine detaillierte Analyse von epistatischen Effekten in Kreuzungsplänen mit mehr als zwei Ausgangspopulationen werden vorgestellt. Ein Beispiel aus der Rinderzüchtung wird angeführt. Probleme, die mit der Reparametrisierung und der Schätzung der Effekte zusammenhängen, werden diskutiert.

This paper compares the growth patterns of chickens, turkeys, ducks and geese. The growth curves and their parameters were estimated by the Richards function. In this work, weight data of females of current sire lines (62 chickens, 47 ducks and 42 geese) and commercial medium-type hybrids (27 turkeys) were used. Birds were fed ad libitum and weighed at 7 or 14 d intervals up to 18-28 weeks of age. The accuracy of the curve fit was high in all species (R 2 = 0.9840 to 0.9994). The ratios y + /A (weight at the inflection point over mature weight), which determine the shape of the growth curve, were 0.370, 0.358, 0.407 and 0.261 in chickens, turkeys, ducks and geese, respectively. Only the growth pattern of the Galliforms did not significantly differ from the Gompertz type of growth (y + /A = 0.368). The age at the inflection point confirmed the high early growth of geese (t + = 21.1 d) and ducks (t + = 25.5 d). The chickens finished the autoacceleration phase of growth at 47.7 d and turkeys at 74.0 d of age. The phenotypic correlations between the inflection parameters t + and y + were higher in waterfowl than in chickens and turkeys. The inflection parameter t + and y + were positively associated with the maturing index k in ducks and geese, and negatively in chickens and turkeys. The evolutionary aspects of the interspecific differences are discussed. growth curve / turkey / waterfowl / chicken / evolution Résumé-Étude comparative des courbes de croissance de volaille. L'article compare les patrons de croissance du poulet, de la dinde, du canard et de l'oie. Les courbes de croissance et leurs paramètres ont été estimés selon l'équation de Richards. L'analyse a porté sur les poids de femelles de lignées paternelles courantes (62 poulets, 47 canards et 42 oies) et de 27 dindes (hybrides commerciaux de type moyen). Les oiseaux ont été nourris ad libitum et pesés régulièrement jusqu'à l'âge de 18 à 28 sem. La précision de l'ajustement des courbes est élevée pour les !! espèces (R 2 = 0,9840 à 0,9994). Le rapport y + /A (poids au point d'inflexion sur poids adulte) qui définit la forme de la courbe de croissance est de 0,370, 0,358, 0,407 et 0,261 pour le poulet, la dinde, le canard et l'oie respectivement. Seul le patron de croissance des Galliformes ne diffère pas significativement de la fonction de Gompertz (y + /A = 0, 368). L'âge au point d'inflexion confirme la précocité de croissance de l'oie (t + = 21, 1 j) et du canard (t + = 25, 5 j). La période d'auto-accélération de la croissance dure 47,7 j chez le poulet et 74 j chez la dinde. Les corrélations phénotypiques entre les paramètres d'inflexion t + et y + sont plus élevées chez le canard et l'oie que chez le poulet et la dinde. Les liaisons entre les paramètres d'inflexion t + et y + et l'index de maturation k sont positives chez le canard et l'oie et négatives chez le poulet et la dinde. Les aspects évolutifs des différences interspécifiques sont discutés dans l'article.

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.

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 (R2) 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 (u63 = y63/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 (y+) and the asymptotic (A) weights. The values of these correlated parameters were very low (y+/A = 0.233 to 0.294, k = 0.0281 to 0.0373 ln theta/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 th 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.

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1. Growth curves of nine selected lines and one random-bred control population (in total, n = 1070) were evaluated by the Richards function. The ducks were weighed at 7-d intervals and, after the tenth week, every second week (up to 18 weeks). Food and water were supplied ad libitum. 2. The predicted curves closely fitted the weight data points (R2 = 0.9991-0.9997). 3. The ducks are characterized by early maturity rate. The peak of the absolute growth rate (the inflection point of the curve) occurred at 24.1-27.6 d of age (t+). A higher ratio of the inflection to the asymptotic weights (y+/A = 0.380-0.424) was found in comparison to those from the Gompertz-type function of growth (y+/A = 0.368). 4. In the selected lines the degree of maturity at a slaughter age of 7 weeks (u7 = y7/A) ranged from 0.784 to 0.835 for males and from 0.819 to 0.889 for females. 5. Ducks within the non-selected control line had a significantly lower maturing rate than the selected lines. 6. Sexual dimorphism was recorded for all growth parameters analysed. Females have faster maturation rate than males (higher values of y+/A, u7, k and a shorter auto-acceleration phase of growth). 7. High interline differences were found for body weight (A, y+, y7) and for absolute growth rate (v, v+) and smaller ones for parameters of the maturation rate (y+/A, u7, k and t+). 8. The intragroup phenotype correlation between growth parameters and the use of weight data only up to 7 weeks of age for the estimation of parameters of the Richards function are discussed.

Summary A comparative analysis of chicken growth curves (n = 328) of White Cornish, Orpington, New Hampshire breeds and two lines of White Leghorn was based on the Richards function parameters. The accuracy of curve fit was expressed by percentage deviations of the observed and estimated weights in individual points of the curve and for a standardized period of 24 weeks. The greatest deviations were observed at the beginning of the growth period. The breeds differed distinctly in the parameters of the growth curve concerning live weights and the rate of gains, i. e. in the asymptotic final weight (A), the weight at inflection point (y*) and average and maximal rate of growth (v and v*). Significant differences were recorded also in the length of the autoacceleration phase of growth (t*). The shape of average breed growth curves approximated at most the Gompertz type of growth (n → 0, y*/A ≐ 0.368), but high individual variability was established (− 0.4 ≤ n ≤ 1.0, 0.279 ≤ y*/A ≤ 0.500) within the investigated set of individuals. In the present study relationships among individual parameters of the Richards function are considered. High intragroup phenotypic correlations among the shape parameter n and the k parameter characterizing the rate of maturing (rp = 0.89 up to 0.97), n and A(rp = −0.26 up to −0.82), and k and A (rp = −0.44 up to −0.87) are the expression of functional relations among the parameters. Résumé Les courbes de croissance des poussins de différent types de rendement L'analyse comparative des courbes de croissance des poussins (n = 328) des races White Cornish, Orpington, New Hampshire et de deux lignées White Leghorn a été effectuée sur la base des paramètres de la fonction de Richards. La précision de la «curve fit» a été déterminée à l'aide des déviations de pour cent du poids réel et évalué dans les différents points de la courbes et pour une période standarde de 24 semaines. Les déviations les plus grandes ont été enregistrées au début de la période de croissance. Les races différaient réciproquement sur les paramètres de la fonction de croissance concernant le poids vif ainsi que la vitesse de l'obtention des gains de poids, c'est à dire dans le poids final asymptotique (A), sur le poids au moment de l'obtention du point d'inflexion (y*) et sur la vitesse moyenne et maximale de croissance (v et v*). Les différences significatives ont pu être trouvées dans la durée de la phase de croissance d'autoaccélération (t*). La forme des courbes de croissance ressemblait le plus au type de croissance de Gompertz (n → 0, y*/A ≐ 0.368), mais dans le cadre du groupe contrôlé d'individus a pu être trouvée une haute variabilité individuelle (−0.4 ≤ n ≤ 1.0, 0.279 ≤ y*/A ≤ 0.500). Le présent travail traite des dépendances réciproques entre les paramètres de la fonction de Richards. Les hautes corrélations phénotypiques au sein des groupes entre la paramètre de forme n et celui k qui caractérise la vitesse de croissance (rp = 0.89–0.97), n et A (rp = −0.26‐−0.82) et k et A (rp = −0.44‐−0.87) expriment la rel...