Poultry production systems are currently dealing with some important issues like animal welfare, environmental impacts of soy imports from overseas, and the decline of genetic diversity. Therefore, an alternative approach to poultry production was tested in this study using six dierent chicken genotypes in terms of fattening performance of males and laying performance of females. Two traditional chicken breeds, Vorwerkhuhn (VH) and Bresse Gauloise (BG), and a commercial layer genotype, White Rock (WR) as well as crossbreds thereof were fed diets containing either 20% vicin-rich or vicin-poor faba beans. The genotype BG and the crossing genotypes with BG exhibited the best growth performance. WR and BG × WR cross showed the best performance regarding the egg production and egg quality. Taken together, the dietary effect revealed only small negative impacts of vicin. In terms of dual-purpose usage, crossing BG with WR seems to be the most promising variant studied here.

Skeletal disorders, including fractures and osteoporosis, in laying hens cause major welfare and economic problems. Although genetics have been shown to play a key role in bone integrity, little is yet known about the underlying genetic architecture of the traits. This study aimed to identify genes associated with bone breaking strength and bone mineral density of the tibiotarsus and the humerus in laying hens. Potentially informative single nucleotide polymorphisms (SNP) were identified using Random Forests classification. We then searched for genes known to be related to bone stability in close proximity to the SNPs and identified 16 potential candidates. Some of them had human orthologues. Based on our findings, we can support the assumption that multiple genes determine bone strength, with each of them having a rather small effect, as illustrated by our SNP effect estimates. Furthermore, the enrichment analysis showed that some of these candidates are involved in metabolic pathways critical for bone integrity. In conclusion, the identified candidates represent genes that may play a role in the bone integrity of chickens. Although further studies are needed to determine causality, the genes reported here are promising in terms of alleviating bone disorders in laying hens.

The quality of chicken eggs is an important criterion for food safety and the consumers' choice at the point of sale. Several studies have shown that egg quality can be influenced by the chickens' genotype and by the composition of the diet. The present study aimed to evaluate the effect of faba beans as a substitute for soybeans in the diet of chickens originating from traditional low-performance breeds in comparison with high-performing laying type hens and their crosses on egg quality parameters. Chickens of six different genotypes were fed either with a feed mix containing 20% faba beans with high or low vicin contents or, as a control, a feed mix containing soybeans. The genotypes studied were the local breeds Vorwerkhuhn and Bresse Gauloise, as well as commercial White Rock parent hens and their crosses. Yolk weight, Haugh units, yolk and shell color, the frequency of blood and meat spots and the composition of the eggs were significantly influenced by the genotype. The feeding of faba beans had an effect on yolk and shell color, Haugh units and shell portion, while there was no significant influence on the frequency of blood and meat spots.

Keel bone damage is an important animal welfare problem in laying hens. Two generations of four layer lines, differing in phylogenetic background and performance level and kept in single cages or floor pens were weighed and scored for keel bone deformities (KBD) during the laying period. KBD, keel bone fractures (KBF) and the bone mineral density (BMD) of the keels were assessed post mortem. For BMD, relationships to laying performance and body growth were estimated. Caged hens showed more deformities, but fewer fractures and a lower BMD of the keel bone than floor-housed hens. White-egg layers had a lower BMD (0.140–0.165 g/cm2) and more KBD than brown-egg layers (0.179–0.184 g/cm2). KBF occurred more often in the high-performing lines than the moderate-performing ones. However, in the high-performing lines, BMD was positively related to total egg number from 18 to 29 weeks of age. The adult body weight derived from fitted growth curves (Gompertz function) had a significant effect (p < 0.001) on keels’ BMD. The study contributes to the understanding of predisposing factors for keel bone damage in laying hens. It showed that the growth rate has a rather subordinate effect on keels’ BMD, while the BMD itself greatly affects KBD.

The faba bean (Vicia faba L.) is a native protein crop and considered a promising alternative to soybeans. Due to its anti-nutritive substances such as vicin and convicin (VC) its use in animal nutrition has been restricted. In the present study, two consecutive experiments were conducted to analyse the effects of feeding 20% faba beans, which differ in their VC content on fattening performance and slaughter traits of different chicken genotypes. In a first trial, purebred male chickens of the local breeds Bresse Gauloise and Vorwerkhuhn as well as of a high-performance White Rock line were tested. In a second trial, crossbreds of them were evaluated: Vorwerkhuhn x Bresse Gauloise, Vorwerkhuhn x White Rock, Bresse Gauloise x White Rock. Daily weight gain and feed intake were recorded until slaughter at approximately 2100 g. At slaughter the final live weight, carcass yield and the weights of the valuable parts (breasts and legs) were measured. For the genotypes studied, no adverse or undesirable effects of both VC−rich and VC−poor faba beans in the feedstuff were detected regarding body weight development, carcass quality, and fattening parameters. Furthermore, there was no indication that the birds’ health was impaired.

The authors wish to make the following corrections to this paper [...]

Poultry production is raising concerns within the public regarding the practice of culling day-old chicks and the importation of soy from overseas for feedstuff. Therefore, an alternative approach to poultry production was tested. In two consecutive experiments, two traditional chicken breeds, Vorwerkhuhn and Bresse Gauloise, and White Rock as a commercial layer genotype as well as crossbreds thereof were fed diets containing either 20% vicin-rich or vicin-poor faba beans, though addressing both subjects of debate. Hen performance traits and bone stability were recorded. All parameters were considerably influenced by the genotype with White Rock showing the significantly highest (p < 0.05) laying performance (99.4% peak production) and mean egg weights (56.6 g) of the purebreds, but the lowest bone breaking strength (tibiotarsus 197.2 N, humerus 230.2 N). Regarding crossbreds, the Bresse Gauloise × White Rock cross performed best (peak production 98.1%, mean egg weight 58.0 g). However, only limited dietary effects were found as only the feeding of 20% vicin-rich faba beans led to a significant reduction of egg weights of at most 1.1 g (p < 0.05) and to a significant reduction of the shell stability in the crossbred genotypes. In terms of dual-purpose usage, crossing of Bresse Gauloise with White Rock seems to be the most promising variant studied here.

Laying hens have undergone strong selection pressure for traits related to productivity in recent decades. This has led to an impressive increase in egg production but is also assumed to cause undesirable side effects, such as behavioural changes or increased bone damage. Resource trade-offs resulting from egg production might trigger such changes. Our hypothesis was that hens from lines selected for high levels of egg production need to conserve energy to maintain productivity by reducing locomotor activity. We further assumed that the reduced locomotor activity is accompanied by poorer motor coordination abilities. In addition to the performance level, phylogenetic origin has potential implications for behavioural and physiological differences. Thus, we compared hens from four purebred layer lines in a 2 x 2 model that differed in productivity levels (a line with high egg production (320 eggs/year) and a line with moderate egg production (200 eggs/year)) and phylogenetic origins (white and brown egg layer lines). Furthermore, hens of each line were kept in compartments of two different sizes (large, with stocking densities of 3.19 hens/m(2); and small, with stocking densities of 5.94 hens/m(2)), to examine the effect of space and stocking density on the behaviour and bone strength of the hens. In total, we tested 742 chickens from the four different layer lines. We recorded their general locomotor activity in their home compartments and tested their motor coordination using a rotarod test. After the laying period, we examined the bone breaking strength of the tibiotarsi and the humeri from chickens of all four lines. The hens from both highly productive lines possessed poorer motor coordination than the hens from the moderately productive lines of corresponding phylogenetic origin. Furthermore, the hens from the brown egg-laying lines performed better than the hens from the white egg-laying lines. Compartment size had a positive effect on the motor coordination of the hens from the moderately productive lines and interacted with productivity. However, general locomotor activities were not different between the hens from lines with different productivities or of different phylogenetic origins. The hens from the moderately productive lines possessed higher bone breaking strengths than the hens from the highly productive lines within the phylogenetic groups. Our results show that the hens from the lines with high productivity have poorer motor coordination and lower bone breaking strength than the hens with moderate productivity. These results can help to gain further understanding of practical problems, such as the high prevalence of bone damage in laying hens.

The authors wish to make the following corrections to this paper [...].

In modern laying hybrids, calcium (Ca) homeostasis is immensely challenged by daily eggshell calcification. However, excessive mobilization of Ca from bones may lead to osteoporosis, which then manifests in a high incidence of poor bone quality. The aim of this study was to characterize the hens’ adaptation response to an alternating dietary Ca restriction. The animal model consisted of four purebred layer lines, differing in laying performance (high vs. moderately performing lines) and phylogenetic origin (white- vs. brown-egg lines). According to the resource allocation theory, hens selected for high egg production were assumed to show a different response pattern to cope with this nutritive challenge compared to moderately performing lines. Data collected included egg number, egg quality traits, body weight and bone characteristics. The Ca depletion led to a temporary drop in egg production and shell quality and a loss of bone stability due to Ca mobilization. The white-egg lines response was more pronounced, whereas the brown-egg lines were less sensitive towards reduced Ca supply. Our study shows that the hens’ responsiveness to coping with a nutritive Ca depletion is not ultimately linked to genetic selection for increased egg production but rather to phylogenetic origin.

The current practices of the poultry industry have raised concerns among consumers. Among these is the culling of day-old male chicks of laying hybrids; a suitable alternative for this could be the use of dual-purpose breeds where both sexes are used. Another practice that causes concern is the import of large quantities of soybeans for feedstuff production. Substitutes for these soybean-based products are regional protein crops, such as faba beans (Vicia faba L.; FBs). The objective of this study was to test the suitability of FB as a locally produced soybean meal replacement for two local dual-purpose chicken breeds and one high-performing layer line. The breast and leg meat of male Bresse Gauloise (BG), Vorwerkhuhn (VH), and White Rock (WR) animals was evaluated for different meat quality parameters: pH, color, water holding capacity, and tenderness. Sensory properties of the samples were evaluated by a trained panel with a conventional descriptive analysis. Results show different effects of FB diets on meat quality parameters in the different breeds. The attributes mostly affected by the diet are related to aroma, flavor, and texture, particularly in VH and WR. Overall, faba beans appear to be an acceptable dietary protein source for rearing these breeds for meat production.

Impaired animal welfare due to skeletal disorders is likely one of the greatest issues currently facing the egg production industry. Reduced bone stability in laying hens is frequently attributed to long-term selection for increased egg production. The present study sought to analyse the relationship between bone stability traits and egg production. The study comprised four purebred layer lines, differing in their phylogenetic origin and performance level, providing extended insight into the phenotypic variability in bone characteristics in laying hens. Data collection included basic production parameters, bone morphometry, bone mineral density (BMD) and bone breaking strength (BBS) of the tibiotarsus and humerus. Using a multifactorial model and regression analyses, BMD proved to be of outstanding importance for bone stability. Only for the tibiotarsus were morphometric parameters and the bone weight associated with BBS. Within the chicken lines, no effect of total eggshell production on BBS or BMD could be detected, suggesting that a high egg yield itself is not necessarily a risk for poor bone health. Considering the complexity of osteoporosis, the estimated genetic parameters confirmed the importance of genetics in addressing the challenge of improving bone strength in layers.

The flagellar beating of a spermatozoa's axoneme is caused by the varying activation and inactivation of dynein molecules. Dynein, axonemal, light chain 4 (DNAL4) is a functional candidate gene for sperm motility as it encodes a small subunit of the dyneins. We resequenced the porcine DNAL4 using three artificial insemination (AI) boars each with high (>68%) or low (<60%) motility, and detected 23 SNP. These were then genotyped for 82 AI boars. Using spermatological records, significantly negative genetic correlations between ejaculate volume (VOL) and the further spermatological parameters concentration (CONC) (r = -.43), motility of undiluted semen (MOTUD) (r = -.09), motility after 24 h (MOT1) (r = -.17) and after 48 hr (MOT2) (r = -.23) were estimated. Significantly positive correlations existed between CONC and MOT1 (r = .07) as well as MOT2 (r = .10), between MOTUD and MOT1 (r = .33), between MOTUD and MOT2 (r = .36), and finally between MOT1 and MOT2 (r = .70). Significantly negatively correlated were all motility traits with the parameters abnormal acrosome (AA) (MOTUD r = -.06; MOT1 r = -.08, and MOT2 r = -.1) and presence of cytoplasmic droplet (CD) (MOTUD r = -.07; MOT1 r = -.08; MOT2 r = -.07). Association analyses (single marker regression model; SMR) propose that SNP g.1007A>G, located in the second intron, reduces motility significantly (MOTUD -4.59%; MOT1 -10.33%; MOT2 -19.37%). According to the dominant-recessive model (DRM), genotype AA is always superior compared to genotypes AG and GG (i.e. MOTUD 67.67%, 64.16% and 53.91%; MOT1 54.17%, 43.75% and 28.44%; MOT2 44.12%, 24.91% and 4.97%). The average effect of gene substitution (g.1007A>G) on abnormal midpiece (AM) was 0.71%, the genotypic values-as expressed by LSmeans-were 0.1 (AA) and 0.81 (AG).

The aim of this study was the determination of genetical and environmental factors that affect the occurrence of aberrant spermatozoa. The evaluation comprised 1,543 ejaculates collected from 57 boars representing BHZP 77 (Pietrain line db.77 (R)), German Large White, German Landrace and Pietrain. The morphological investigation was done using standard protocols. Ejaculates were analysed with an optical microscope and abnormal sperm cells were differentiated into varying morphological abnormalities such as abnormal heads, apical ridge defects of the acrosome, abnormal tails and cytoplasmic droplets. The statistical evaluation using the SAS-procedure Glimmix considered the fixed effects breed, age and season besides the random animal effect. A significant effect (p < 0.05) of breed on the elevated occurrence of cytoplasmic droplets was found in German Large White boars. Although there were significant effects (p < 0.05) of the season on each anomality - except for the cytoplasmic droplets - a significant increase of the anomalities during summer did not exist. There was an age dependent effect on all investigated anomalities (p < 0.05). Additionally, the breeding value was calculated for the incidence of individual anomalities. In this context there were clear differences between populations considering the different kinds of anomalities. In total, the data suggest that selection on a reduced number of sperm cell anomalities might lead to an improvement of sperm quality parameters and will therefore enhance boar fertility.