Key Aroma Compounds in Roasted White Koluda Goose.

Aroma-active compounds in the roasted leg meat of White Koluda goose were assayed by gas chromatography-olfactometry, using aroma extract dilution analysis and solvent-assisted flavor evaporation. Quantitation, recombination-omission tests, and sensory evaluation were carried out. Thirty aroma compounds, for which odor activity values (OAVs) were calculated and for which the flavor dilution factors were greater than or equal to 1, were identified. The concentration of aroma compounds ranged from 0.06 to 633 (µg/kg). The highest OAVs (>1024) were for 2-furfurylthiol, 2-acetyl-1-pyrroline, and 1-octen-3-one. Nine key aroma compounds were: 2-furfurylthiol, 2-acetyl-2-thiazoline, 1-octen-3-one, 2-phenylethanethiol, 4,5-dimethyl-3-hydroxy-2(5H)-furanone, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, (E,E)-2,4-decadienal, 2-acetyl-1-pyrroline, and 3-(methylthio)propanal. The intensity of the dominating roasted, meaty/broth, and fatty notes in the recombination model consisting of the key odorants were rated (10-point scale) at 4.6-5.8 points, relative to the original roasted goose (5.2-6.2). The aroma compounds defined predominantly the meaty, roasted, and fatty flavors during the descriptive sensory evaluation of the roasted goose meat.

Animal-Based Measures for the On-Farm Welfare Assessment of Geese.

Currently, no specific animal-based measures (ABMs) protocols are available for geese in commercial meat production systems. Following a critical review of the literature and consultation of experts, seven ABMs, potentially valid and feasible for the on-farm welfare assessment of geese, were identified and then tested in 12 farms in Poland to assess their inter-observer reliability. Two observers conducted the assessment, which was divided into two phases. First, a handling test assessed the human-animal relationship (HAR), and a 100% inter-observer reliability was achieved by the observers when evaluating the attitudes of stockpeople and the reactions of geese to humans. Next, an animal inspection was conducted, and the observers simultaneously and independently visually evaluated 100 randomly selected geese per farm and assessed whether the selected ABMs could be identified. In terms of inter-observer reliability, high correlation coefficients were found for plumage dirtiness (ρ = 0.745; p < 0.01), twisted wings (ρ = 0.890; p < 0.001), and broken/twisted wings (ρ = 0.858; p < 0.001). The results showed that plumage dirtiness, twisted wings, and broken/twisted wings are valid and reliable measures. Further research should address the reliability of ABMs of geese in other types of production systems.

Genetic variability of body weight in two goose strains under long-term selection.

Body weight is one of the most important traits in any genetic improvement program in geese for at least 2 reasons. First, measurements of the trait are very easy. Second, body weight is correlated with a number of other meat performance traits. However, the genetic background of body weight shows considerable complexity. Three genetic models (with direct, maternal genetic and permanent maternal environmental effects) were employed in this study. Records of 3076 individuals of maternal strain W11 and 2656 individuals of paternal strain W33 over 6 consecutive generations, kept in the pedigree farm of Koluda Wielka, were analysed. Body weight (in kilograms) was measured in weeks 8 (BW8) and 11 (BW11). The inbreeding levels in both populations were relatively low (0.14% and 0.02% for W11 and W33, respectively), therefore these effects were not included in the linear models to estimate genetic parameters. Three fixed effects (hatch period, sex and year) were included in each linear model. Two criteria (AIC, BIC) were used to check the goodness of fit of the models. The computations were performed by WOMBAT software. In general, the genetic parameter estimates varied across the traits, models and strains studied. Direct additive heritability estimates ranged from 0.0001 (for BW11 of W33) to 0.55 (for BW11 of W33). Maternal and total heritabilities were also variable. Estimates of ratios of direct-maternal effect covariance in phenotypic variance were both positive and negative, but they were negligible, whereas ratios of the permanent environmental maternal variance to phenotypic variance were close to zero. Both of the applied criteria of model adequacy indicate that the model with maternal genetic and environmental effects should be considered as optimal. Genetic trends were close to zero. It seems that they were influenced by long-term selection. Similar tendencies have been observed for phenotypic trends, as well.

Analysis of the laying rhythm and reproductive traits of geese.

The aim of the performed investigations was to analyse the laying rhythm and reproductive traits of Koluda white geese from the W11 reproduction strain and to determine the heritability of these traits as well as correlations between the laying rhythm traits and reproductive traits. The total number of geese participating in the experiment included 383 one-year old layers from the control flock (the first year of reproductive utilisation). The following traits characterizing the laying rhythm were assessed individually for each layer: the number of 2 and 3-egg clutches or more, length (in days) of 2- or more egg clutches as well as the length of intervals between the laid eggs during the entire laying period. The following reproductive traits were also assessed individually for each bird: age at sexual maturity, initial number of eggs (eggs laid during the period from January, 1st to April, 30th), number of eggs during the whole laying period, laying intensity (the total number of eggs x 100/length of the laying period in days) as well as the length of the reproductive period. It was found that Koluda white geese laid most of their eggs (on average 70.2%) singly and not in clutches. With regard to egg clutches, it was found that 2-egg clutches constituted 85.3% of eggs laid in clutches. Moderate or high variability of traits associated with the laying rhythm and reproduction were demonstrated. The observed moderate heritability of the laying rhythm traits indicate that they may be utilised in the selection programs for geese. On the other hand, the reported high, positive genetic correlation coefficients between the number of egg clutches and the initial and total egg number as well as laying intensity confirm the existence of interactions between these traits. This fact may be helpful in breeding programs for determining the optimal selection systems for geese.