Floor eggs in goose breeders: patterns, genetic and environmental influences, and physiological indexes

A floor egg is an egg that is not laid in the nest, which is a prevalent issue in many fowl breeder farms, lowering egg collection efficiency, hatching performance, and economic benefits. Although the pattern and influencing factors of floor laying have been extensively reported in chickens and ducks, it is not clear in geese. Herein, the Yangzhou goose breeders were selected, and the time and location preferences, genetic and environmental influences, and physiological indexes in floor laying were investigated. The results revealed distinct time and location preferences existed. More floor eggs were laid from 2:00 to 5:00 and 8:00 to 12:00 am, with a concentration observed in the feed trough. Moreover, the proportion of floor eggs was higher at the early stage than at other stages of the laying cycle, and the fast-growing line laid more floor eggs than dual-purpose and high-yielding lines (P < 0.05). In addition to genetic factors, the effect of environmental influences on floor eggs was also surveyed. More floor eggs were observed in the family housing system than in large-group and small-population housing systems, and geese who reared in north-facing houses laid more floor eggs than in south-facing houses (P < 0.05). Physiological indexes were compared between floor-laying and nest-laying geese. Significantly decreased serum progesterone and prolactin levels were detected, alongside down-regulated gene expressions of progesterone receptor in ovaries, oxytocin receptor in both pituitary and ovaries, corticotropin-releasing hormone in ovaries, and dopamine receptor D2 in hypothalamus and ovaries in floor-laying geese compared to nest-laying geese (P < 0.05). In addition, a practical and inexpensive approach of adding a single decoy egg to the nest box effectively reduced the proportion of floor eggs (P < 0.05). Taken together, these data provide scientific information for patterns, genetic and environmental influences, and physiological indexes of floor eggs, thereby contributing to effective control of floor laying in goose breeders' production.

Variation in litter occupancy and dust bathing patterns among layer strains following periods of litter restriction

Producers are moving toward cage-free systems to house laying hens. These include aviary styles with multilevel wire enclosures and litter areas on the floor. In aviaries with doors hens can be confined within the tiered enclosure, which can be done to promote oviposition in nests and prevent hens from laying eggs in litter. However, there are multiple genetic strains of laying hen used in the egg industry, and some show different temporal patterns for key behaviors that could affect when they want to be on litter. For example, though dust bathing by laying hens is typically considered to peak in early afternoon, there may be variation in timing of motivation to dust bathe among strains. Differences in hens' temporal patterns, coupled with aviary configurations or management practices, may restricts birds' ability to perform important behaviors, such as dust bathing (DB), when they would most prefer to do them. Our objective was to determine if there were strain differences in the temporal pattern of DB. We examined the timing of DB in 4 strains of laying hen (Hy-Line Brown [HB], Bovans Brown [BB], DeKalb White [DW], and Hy-Line W36 [W36]) housed in aviaries using 144 hens of each strain per aviary unit (4 units/strain). We recorded the number of hens DB and on litter using instantaneous scan sampling every 5 min using video collected at 26 and 28 wk of age beginning at 11:35 (when litter access began each day) to 20:00 (lights off). Brown strains acclimated to litter access more slowly than white strains. Hens of all strains DB most often soon after gaining access to litter, and more white hens (DW and W36) DB simultaneously and in the presence of more conspecifics. Further examination of diurnal rhythm of behaviors, such as dust bathing, under unconstrained conditions by a range of genetic strains of laying hens is needed to design management practices and aviary styles that best meet hens' needs.

Commercial hatchery practices have long-lasting effects on laying hens' spatial behaviour and health

The commercial hatchery process is globally standardized and exposes billions of day-old layer chicks to stress every year. By alleviating this early stress, on-farm hatching is thought to improve animal welfare, yet little is known about its effects throughout production. This study compared welfare indicators and spatial behaviours during the laying period of hens hatched in an on-farm environment (OFH) to those hatched in a commercial hatchery and transferred at one day-old to a rearing barn (STAN). In particular, we assessed how OFH and TRAN hens differed in space-use and movement behaviours following the transfer to the laying barn at 17 weeks of age, a similar stressor encountered by STAN hens early in life, and determined whether effects aligned more with the 'silver-spoon' or 'environmental matching' hypothesis. We found that for the first three months post-transfer into the laying barn, OFH hens, on average, transitioned less between the aviary's tiers and spent less time on the littered floor. Because OFH hens became behaviourally more similar to STAN hens over time, these results suggest that OFH hens required a prolonged period to establish their daily behavioural patterns. Furthermore, OFH hens had more severe keel bone fractures throughout the laying period but similar feather damage and body mass to STAN hens. No differences were found in hen mortality or the number of eggs per live hen. These findings support the environmental matching hypothesis and suggest that early-life stressors may have prepared hens for later-life stressors, underscoring the importance of both early-life and adult environments in enhancing animal welfare throughout production.

Space use and navigation ability of hens at housing in the aviary for the laying phase: effect of enrichment with additional perches and genotype

The present study tested the hypothesis that increased availability of perches could favor the adaptation and navigation ability of pullets of different genotypes at housing in a new aviary system for the laying phase. To this purpose, 900 Lohmann White-LSL and 900 Hy-line Brown were randomly allocated at 17 wk of age in 8 pens of an experimental aviary, according to a bifactorial arrangement with 2 genotypes (Brown vs. White) × 2 types of pens (enriched or not enriched with additional perches besides those of the aviary). Data collected between 17 and 20 wk of age showed that the enrichment with additional perches decreased the use of the aviary perches while the rate of successful landings/take-offs was unaffected. As for the effect of genotype, during the night a lower rate of hens on the floor (0.15 vs. 6.63%) and a higher rate of hens on the additional perches (2.47 vs. 0.98%) was found in White compared to Brown hens (P < 0.001); the former hens also used the third tiers for sleeping on the aviary uppermost perches (P < 0.001). During the day, White hens used more the third tier (32.8 vs. 15.6%; P < 0.001) and the additional perches (3.88 vs. 0.91%; P < 0.01) compared to Brown hens, while they stood less on the floor (18.3 vs. 22.6%; P < 0.05). White hens performed a significantly higher number of landings (80.7 vs. 21.9; P < 0.001) and of take-offs (74.3 vs. 10.0; P < 0.001) per pen compared to Brown hens. The risk of unsuccessful landings was higher in Brown compared to White hens (odd ratio: 6.65; 95% confidence interval: 4.36-10.1; P < 0.001). In conclusion, the enrichment with additional perches played a major role in hen distribution and space use than in their navigation ability. At the same time, the significant differences between the 2 genotypes call for a careful evaluation of the aviary design and animal management to optimize welfare at housing and possibly productive results of laying hens.

Impacts of Rearing Enrichments on Pullets and Free-Range Hens’ Positive Behaviors across the Flock Cycle

Simple Summary

Enrichment during the indoor rearing of young laying hens (pullets) destined for free-range systems may improve pullet development and increase motivated natural behaviors (termed ‘positive behaviors’) such as foraging, dust bathing and chick play. Hy-Line Brown® chicks (n = 1700) were floor-reared indoors across 16 weeks with three enrichment treatments (n = 3 pens/treatment): (1) standard control, (2) weekly novel objects—‘novelty’, (3) perching/navigation structures—‘structural’. Pullets (16 weeks old: n = 1386) were then transferred to nine identical pens within rearing treatments, with outdoor range access from 25 to 65 weeks. Video cameras recorded the pullet pens, adult indoor pens, and outside range. During rearing, observations of play behavior in chicks at 2, 4 and 6 weeks showed no overall effect of rearing treatment. At 11 and 14 weeks only the novelty hens were observed to increase their foraging across age with no differences between treatments in dust bathing. Observations of adult hens at 26, 31, 41, 50, 60 and 64 weeks showed that the structural hens exhibited more dust bathing and foraging overall than the control hens, but that both novelty and/or structural hens showed small increases relative to control hens depending on the behavior and location. Across age, adult hens differed in the degree of dust bathing performed inside or outside and foraging outside but not inside. For litter-reared pullets, additional enrichments may result in some long-term increases in positive behaviors.

Abstract

Enrichment during the indoor rearing of pullets destined for free-range systems may optimize pullet development including increasing motivated natural behaviors (termed ‘positive behaviors’) including foraging, dust bathing and chick play. Hy-Line Brown® chicks (n = 1700) were floor-reared indoors across 16 weeks with three enrichment treatments (n = 3 pens/treatment): (1) standard control, (2) weekly novel objects—‘novelty’, (3) perching/navigation structures—‘structural’. At 16 weeks, pullets (n = 1386) were transferred to nine identical pens within rearing treatments with outdoor range access from 25 to 65 weeks. Video cameras recorded the pullet pens, adult indoor pens, and outside range. During rearing, observations of play behavior (running, frolicking, wing-flapping, sparring) in chicks at 2, 4 and 6 weeks (total of 432 thirty-second scans: 16 observations × 3 days × 9 pens) showed no overall effect of rearing treatment (p = 0.16). At 11 and 14 weeks only the ‘novelty’ hens were observed to increase their foraging across age (p = 0.009; dust bathing: p = 0.40) (total of 612 thirty-second scans per behavior: 17 observations × 2 days × 2 age points × 9 pens). Observations of adult hens at 26, 31, 41, 50, 60 and 64 weeks showed that the structural hens exhibited overall more dust bathing and foraging than the control hens (both p < 0.04) but both novelty and/or structural hens showed small increases depending on the behavior and location (total of 4104 scans per behavior: 17 observations × 2 days × 6 age points × 9 pens × 2 locations = 3672 + an additional 432 observations following daylight saving). Across age, adult hens differed in the degree of dust bathing performed inside or outside (both p ≤ 0.001) and foraging outside (p < 0.001) but not inside (p = 0.15). For litter-reared pullets, additional enrichments may result in some long-term increases in positive behaviors.

Effects of Captivity on the Morphology of the Insertion Sites of the Palmar Radiocarpal Ligaments in Hominoid Primates

Simple Summary

In this manuscript, we report the results of our 3D geometric morphometric analyses of the distal radial epiphysis in wild and captive gorillas, chimpanzees, and orangutans. We have identified significant differences in the insertion sites of the palmar radiocarpal ligaments between the wild and captive specimens of each species that are likely related to the locomotor behaviors developed in captivity. We believe that our study deals with a subject of great social impact in today’s world: the well-being of animals living in captivity, especially hominoid primates. Our findings provide novel information on the effect of captivity on the anatomy and locomotor behavior of hominoid primates. We trust that this information can be a basis for improving the artificial spaces where these captive primates live by increasing their available space and providing structures that more closely simulate their natural environment.

Abstract

The environmental conditions of captive hominoid primates can lead to modifications in several aspects of their behavior, including locomotion, which can then alter the morphological characteristics of certain anatomical regions, such as the knee or wrist. We have performed tridimensional geometric morphometrics (3D GM) analyses of the distal radial epiphysis in wild and captive gorillas, chimpanzees, and orangutans. Our objective was to study the morphology of the insertion sites of the palmar radiocarpal ligaments, since the anatomical characteristics of these insertion sites are closely related to the different types of locomotion of these hominoid primates. We have identified significant differences between the wild and captive specimens that are likely related to their different types of locomotion. Our results indicate that the habitat conditions of captive hominoid primates may cause them to modify their locomotor behavior, leading to a greater use of certain movements in captivity than in the wild and resulting in the anatomical changes we have observed. We suggest that creating more natural environments in zoological facilities could reduce the impact of these differences and also increase the well-being of primates raised in captive environments.