Female condition, egg shape and hatchability: a study on the grey partridge

Effects of tea residues-fermented feed on production performance, egg quality, antioxidant capacity, caecal microbiota, and ammonia emissions of laying hens

This study was to assess the effects of tea residues-fermented feed (TR-fermented feed) on production performance, egg quality, serum antioxidant capacity, caecal microbiota, and ammonia emissions of laying hens. A total of 1,296 Lohmann laying hens have randomly distributed four groups with six parallels and fed with diets TR-fermented feed at the rates of 0 (control), 1, 3, and 5%. The inclusion of 1% (TR)-fermented feed resulted in a significant increase in egg-laying rate and average egg weight of birds, and a reduction in the feed-to-egg ratio when compared to the control group (p < 0.05). The addition of 1 and 3% of (TR)-fermented feed significantly improved the Haugh unit of eggs (p < 0.05). The eggshell thickness was observed to increase by almost one-fold upon the inclusion of 3 and 5% (TR)-fermented feed in the basal diet (p < 0.05). The supplementation of 3% (TR)-fermented feed significantly increased the content of methionine, tyrosine, proline, essential amino acids (EAA), alpha linoleic acid (C18:3n6), docosanoic acid (C22:0), docosahexaenoic acid (C22:6n3), twenty-three carbonic acids (C23:0), ditetradecenoic acid (C24:1) and total omega-3 polyunsaturated fatty acids (∑ω-3 PUFA) in the eggs (p < 0.05). The addition of a certain amount of (TR)-fermented feed can enhance the activity of glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD) in chicken serum, and reduce the level of malondialdehyde (MDA) (p < 0.05). The ammonia concentration in the hen house of laying hens in the treatment groups decreased significantly (p < 0.05). Bacteroidetes and Firmicutes, the main phyla in the cecal bacterial community, were differentially abundant in each group, comprising greater than 55 and 33%, respectively. Collectively, this research indicates that (TR)-fermented feed supplementation improves the performance of laying hens and reduces ammonia emissions and can be used in industry-scale layer production.

Reproductive performance in houbara bustard is affected by the combined effects of age, inbreeding and number of generations in captivity

Although captive breeding programs are valuable for conservation, they have been shown to be associated with genetic changes, such as adaptation to captivity or inbreeding. In addition, reproductive performance is strongly age-dependent in most animal species. These mechanisms that potentially impact reproduction have often been studied separately, while their interactions have rarely been addressed. In this study, using a large dataset of nine male and female reproductive parameters measured for 12,295 captive houbara bustards (Chlamydotis undulata undulata) over 24 years, we investigated the relative and interactive effects of age, inbreeding and number of generations in captivity on reproduction. We clearly identified (1) senescence patterns in all parameters studied; (2) negative effects of inbreeding on sperm characteristics, display behavior, egg weight, egg volume and hatching probability; and (3) changes in phenotypic values for seven parameters according to number of generations in captivity. However, the effect sizes associated with age were substantially greater than those associated with inbreeding and number of generations in captivity. Beyond the independent effects of these three factors on reproductive parameters, the results highlighted their interactive effects and thus the importance of integrating them in the design of genetic management plans for conservation breeding programs.

How the egg rolls: a morphological analysis of avian egg shape in the context of displacement dynamics

Very little is known about how morphology affects the motion, spatial stability, and resulting viability of avian eggs. The limited existing research focuses on the uniquely pyriform egg shapes found in the Alcidae bird family. This unusual shell shape was originally thought to suppress displacement and prevent egg loss on the cliffside nesting habitat of the Uria genus. Unfortunately, these early studies never isolated or quantified the specific morphological features (elongation, asymmetry, and conicality) of these pyriform eggs, which limits their applicability to other taxa and has hampered a robust proof of concept. We isolated each feature as an enumerated variable, produced model 3D printed eggs with incremental expressions of a single variable and then with all three features covarying simultaneously. Recorded motion (egg-rolling) trials were conducted to test the individual and combined effects of each morphological characteristic on displacement over a range of inclines representative of the conditions found in nesting habitats. Increasing elongation and asymmetry significantly increased displacement, whereas increased conicality decreased displacement in the single-variable egg models. In the multivariable egg models, only conicality consistently suppressed displacement, while lower levels of asymmetry significantly increased displacement. Our findings broadly support previous studies’ assertions of the adaptive value of the pyriform eggs while providing methodology and comparative data for future analyses of the interactions between nesting habitat, behavior, and egg shape, beyond the confines of a handful of focal species.

Exploratory and descriptive study on nutritional characteristics and quality of eggs from Chilean partridge (Nothoprocta perdicaria)

This work aims to contribute more information on tinamou eggs by performing an exploratory and descriptive study of some of their nutritional and quality characteristics. The chemical composition of tinamou egg showed a high protein content in white (85% dry basis) and high lipid concentration in yolk (52% db). The iron (Fe) content in white was higher than hen egg (0.47 mg/100 g) and this could be associated with the observed pinkish color of the white. As in the hen egg, the major fatty acids in tinamou yolk were: oleic (39%), linoleic (23%) and palmitic (20%). The cholesterol content of tinamou was 21.2 mg/g of yolk, and 100 g of whole egg provides 589 mg of cholesterol. As in the hen egg, tinamou egg white showed high levels of lysine, sulfur-containing amino acids, threonine and valine with respect to the recommended allowance for an adult man. All essential amino acids with the exception of histidine cover the adult requirements. The shell inorganic composition of these eggs is calcium carbonate and the morphology was similar to other avian eggs. Tinamou egg is small and elongated, with a dark brown color. The eggshell is thinner and experiences more deformation but less breaking strength than hen eggshell.