The effect of feeder space allocation on productivity and physiology of Hy-Line W-36 hens housed in conventional cages

The Relationship between Animal Welfare and Farm Profitability in Cage and Free-Range Housing Systems for Laying Hens in China

Several countries and regions have regulations in place to provide standards for the welfare of production animals, which have implications for breeding, management and trade. In the chicken egg production industry, the welfare impacts of this are not well understood. In the past decades, free-range systems were widely used for local chicken breeds in poultry industry in China, but their use has gradually declined due to the lower competitiveness compared to commercial cage systems. However, the practices of free-range systems for hens raising have gradually increased again over the past decade, as consumer individualized demand for higher food quality and animal welfare has increased. We recruited 14 free-range farms and 45 cage farms from Beijing, Shandong, Hebei, Anhui, Yunnan, Gansu and Jiangsu provinces in China, for an evaluation of hen welfare, production and economic outcomes from farm operations. This study provides data for the welfare outcomes of laying hens in China and preliminarily explored the relationship between welfare level and economic income within farming system types. The researchers visited the farms and used Welfare Quality measures to investigate the welfare, and farm self-reported profits. Nonparametric Mann−Whitney U tests were used to compare the welfare scores between cage and free-range rearing farms. Correlation and regression are used for the analysis of the animal welfare scores, economic data, and production metrics. The general income from free-range farms was linearly correlated with red mite score and stocking density (p < 0.001 and p < 0.05, respectively). The results showed less centimeters of feeder and drinker space per animal in the free-range system than in cage systems (p < 0.05 and p < 0.01, respectively). Welfare scores for both the stocking density and beak condition were significantly better in the free-range systems than the cage systems (p < 0.001), as were qualitative behavior assessment scores (p < 0.05). The total egg production and peak egg production in cage farms were much higher than in free-range farms (p < 0.001), and egg loss rate was significantly lower (p < 0.001). While the production efficiency of free-range farms was lower than that of cage farms, general income per 10,000 hens was actually higher. Our results provide some evidence that some welfare indicators and general income (per 10,000 hens) in free-range farms in China were better than those of cage farms. The results indicate that better parasite control and lower stocking densities may result in improved hen welfare on free-range farms and potentially improve profitability. The level of welfare and economic benefits of free-range farms vary widely, and there was potential room for improvement in feeding space, drinking water space and human−animal relationship.

Effect of light intensity and stocking density on the performance, egg quality, and feather condition of laying hens reared in a battery cage system over the first laying period

The present study aimed to determine the effects of varying light intensity (high 121.8, medium 57.4 and low 11.9 lux) and stocking density (high 552.3, medium 736.3, and low 1104.5 cm² cage floor area per hen) treatments on the performance, egg quality, and certain feather condition traits of Lohmann-Brown hens reared in a battery cage system between 20 and 40 weeks of age. Body weight was determined individually at 19 weeks and at 50% yield age (sexual maturity). Feed intake, egg yield, egg weight, and feed conversion ratio were determined weekly. Feather condition was also evaluated individually at 40 weeks of age. Hens reared under high light intensity and low stocking density reached sexual maturity and peak yield earlier than others. The highest body weight was determined for hens reared under high light intensity (1536.6 g), while the lowest in the medium light intensity group (1461.2 g). Hens reared under high and medium light intensity showed higher egg yield than those reared in low intensity (120.5, 120.0 and 112.8 eggs, respectively). In addition, hens reared at low and medium stocking density had higher egg yield than high density (119.7, 120.7, and 112.9 eggs, respectively). Hens reared under low (61.6 g) and medium (61.0 g) light intensity produced heavier eggs than hens in high light intensity (59.6 g). While feed intake was not affected in any treatment, hens reared at low and medium stocking density had a better feed conversion ratio than hens at high density (2.19, 2.20, and 2.40, respectively). Our study results showed that a sustainable production is possible by maintaining the welfare-performance balance when 50-60 lux light intensity and 700-800 cm² cage floor area per hen are provided.

The effect of an enriched laying environment on welfare, performance, and egg quality parameters of laying hens kept in a cage system

The aim of this study was to evaluate the welfare and performance of laying hens kept in a furnished cage system equipped with additional feeders. A total of 72 Lohmann Brown hens were randomly assigned to 4 experimental groups. Each group consisted of 6 cages housing 3 birds per cage (18 birds per group). Group I was a control group without an extra feeder in the cages. Experimental groups GII, GIII, and GIV contained one, 2, and 3 additional feeders in the cages, respectively. The assessment of bird welfare was based on production, physiological and behavioral parameters, as well as on the basis of external appearance. The experiment lasted 12 wk. The obtained results suggest that enriching laying hens' cages with additional feeders improved the welfare of the hens. Enrichment of cages significantly reduced the number of feather pecking and aggressive behaviors in the GII and GIV groups (P < 0.01) and the GIII group (P < 0.05). Breast plumage was significantly (P < 0.05) better in the GII group compared with that in the control group. The control group also had the worst general plumage (P < 0.01). The GII and GIV groups were also characterized by significantly (P < 0.05) lower blood corticosterone concentrations compared with the control group. No negative changes in egg production and quality parameters were observed in the experimental groups. Only eggs from the GIV group had significantly (P < 0.05) lower breaking strength than those from the control and GII group. The results suggest that the best solution is to place 1 additional feeder in furnished laying hens' cages.

Bacillus subtilis Strain DSM 29784 Modulates the Cecal Microbiome, Concentration of Short-Chain Fatty Acids, and Apparent Retention of Dietary Components in Shaver White Chickens during Grower, Developer, and Laying Phases

This study investigated the efficacy of a single strain of Bacillus subtilis (SSB) in modulating the composition of cecal microbiota and its link to the concentration of short-chain fatty acids (SCFA) and apparent retention (AR) of components. A total of 720, 4-week-old Shaver White chicks were allotted to control (CON), 1.1E+08 (low, LSSB), 2.2E+08 (medium, MSSB), or 1.1E+09 (high, HSSB) CFU/kg of diet groups. At grower (10-week), developer (16-week), and laying (28-week) phases, excreta and cecal digesta samples were taken for AR, microbial, and SCFA analyses. Microbial analysis involved high-throughput sequencing of the V3-V4 hypervariable regions of 16S rRNA gene. Bacterial diversity decreased (P < 0.05) at the developer phase as the SSB dose increased; however, a distinct clustering pattern (P < 0.05) of bacterial community was noted. Bacteroides and Faecalibacterium were differentially enriched in the developer for SSB-fed compared to CON-fed birds. Although no differences in microbial diversity were detected in grower and layer phases, different species of Clostridium (XVIII, XIVa, IV, and XIVb)-major butyrate producers-were identified in all phases, with stronger effect sizes for SSB-fed compared to CON-fed birds. Isobutyric acid was elevated in dose response (P = 0.034) in layer phase. In addition, the relative abundances of Alistipes, Lactobacillus, and Bifidobacterium were positively correlated (P < 0.05), with AR of most components for SSB-fed birds in the pullet phase. The results suggested that supplementing chickens' diet with B. subtilis DSM 29784 may selectively enrich beneficial bacterial communities, which in turn are critical in promoting the growth and performance of hens.IMPORTANCE In egg-laying chickens, the trend in the move away from the cage to alternative housing systems and restriction in antimicrobial use requires alternative approaches to maintain health and prevent diseases. There is increased research and commercial interest toward alternative gut health solutions while improving the performance and product safety in poultry production systems. One such approach, in recognition of the importance of the gut microbial community, is the use of microbes as feed supplements (such as probiotics). Unlike meat-type chickens, studies assessing the efficacy of such microbial supplements are limited for egg-laying chickens. Thus, by conducting a comprehensive assessment of the hen microbiota in response to various levels of B. subtilis DSM 29784 during the pullet phase (grower and developer) and the layer phase, the present study demonstrates the importance of direct-fed microbes in modulating gut microbiome, which may relate to improved performance efficiency in the pullet and layer phases.

The effect of space allowance and cage size on laying hens housed in furnished cages, Part II: Behavior at the feeder

Standards for feeder (a.k.a. feed trough) space allowance (SA) are based primarily on studies in conventional cages where laying hens tend to eat simultaneously, limiting feeder space. Large furnished cages (FC) offer more total space and opportunities to perform a greater variety of behaviors, which may affect feeding behavior and feeder space requirements. Our objective was to determine the effects of floor/feeder SA on behavior at the feeder. LSL-Lite hens were housed in FC equipped with a nest, perches, and a scratch mat. Hens with SA of either 520 cm2 (Low; 8.9 cm feeder space/hen) or 748 cm2 (High; 12.8 cm feeder space/hen) per bird resulted in groups of 40 vs. 28 birds in small FC (SFC) and 80 vs. 55 in large FC (LFC). Chain feeders ran at 0500, 0800, 1100, 1400, and 1700 with lights on at 0500 and off at 1900 hours. Digital recordings of FC were scanned at chain feeder onset and every 15 min for one h after (5 scans × 5 feeding times × 2 d) to count the number of birds with their head in the feeder. All occurrences of aggressive pecks and displacements during 2 continuous 30-minute observations at 0800 h and 1700 h also were counted. Mixed model repeated analyses tested the effects of SA, cage size, and time on the percent of hens feeding, and the frequency of aggressive pecks and displacements. Surprisingly, the percent of birds feeding simultaneously was similar regardless of cage size (LFC: 23.0 ± 0.9%; SFC: 24.0 ± 1.0%; P = 0.44) or SA (Low: 23.8 ± 0.9%; High: 23.3 ± 1.0%; P = 0.62). More birds were observed feeding at 1700 h (35.3 ± 0.1%) than any at other time (P < 0.001). Feeder use differed by cage area (nest, middle, or scratch) over the d (P < 0.001). The frequency of aggressive pecks was low overall and not affected by SA or cage size. Frequency of displacements was also low but greater at Low SA (P = 0.001). There was little evidence of feeder competition at the Low SA in this study.

Providing laying hens in group-housed enriched cages with access to barley silage reduces aggressive and feather-pecking behaviour

Two trials were conducted to study the effect of feeding barley silage on the behaviour and performance of beak-trimmed laying hens. In each trial, 20 hens and 2 roosters were housed in each of eight group-housed enriched cages, with four cages provided a laying hen diet and four cages additionally given free access to barley silage. Egg production and quality, and hen behaviour were assessed throughout the trials (Trial One 20–30 weeks; Trial Two 19–28 weeks). Data were analysed using Proc Mixed of SAS 9.4 and differences were significant when P ≤ 0.05. Silage-fed hens consumed 41 (13.9 g DM) and 50 (13.5 g DM) grams of silage per hen per day in Trials One and Two, respectively, while consuming less layer diet. Birds fed silage spent less time expressing aggressive and feather-pecking behaviours and in nest boxes, and more time feeding than control birds. Egg production, egg quality, and bird weight were not affected by treatment; yolk colour was darker for the silage treatment. Feathering quality was improved in silage-fed birds compared to control birds. It was concluded that providing hens with access to barley silage can improve welfare indicators without negatively affecting the egg production and egg quality.

The effect of cage and house design on egg production and egg weight of White Leghorn hens: an epidemiological study

Hen performance can be affected by many interacting variables related to cage design, such as floor area, height, tier arrangement, and feeder and drinker type and placement within the cage. Likewise, features of house design such as waste management and lighting can also affect hen productivity. The influence of these design aspects on hen performance has not been fully assessed. Determining the effects of numerous, interacting variables is impractical in a traditional experiment; therefore, an epidemiological approach, using variability in cage and house design among and within commercial producers, was employed to identify features that affect egg production and egg weight. A universal cage measurement system was created to calculate cage design variables. A database for recording information on cage design, resource location, waste management, environmental conditions, and hen productivity was developed. Production outcomes were assessed from placement to 60 wk of age in White Leghorns (n = 165-168 houses). Using GLM, a statistical model was identified that best described the variance in egg traits. Eggs/hen-housed increased with greater feeder space allocation (P = 0.031); taller cages (P = 0.029); rear (vs. front) drinker location in vertical cages (P = 0.026); and regular removal of manure from the house (P = 0.005). Case weight of eggs was greater in A-frame houses where manure was removed regularly instead of being left in the house (P < 0.001); with increasing cage floor slope (P = 0.001); in cages where drinkers were placed more toward the front or back of the cage as compared with the middle of the cage (P < 0.001); with more space/hen (P = 0.024); and with higher caloric intake (P < 0.001). Perhaps because of its negative correlation with egg production, case weight of eggs increased with less feeder space allocation (P = 0.004) and shorter cage heights (P < 0.001). These results reveal important effects of feeder space, floor space, cage height, drinker position, and waste management on hen productivity.

Effect of floor density on growth performance of Pearl Grey guinea fowl replacement pullets

Little is known of the optimal floor density for the Pearl Grey (PG) guinea fowl pullet. Hence, the objective of this study was to determine the effect of varying floor density on the growth performance of PG guinea fowl pullets. In 3 replicates, 1-d-old guinea keets (n = 786) were weighed individually and randomly assigned to floor pens covered with pine wood shavings at 80, 69, 60, and 53 birds/pen, equivalent to densities of 18, 15.6, 13.6, and 12 birds/m(2), respectively. The birds were allowed feeder space of 2.3, 2.7, 3.1, and 3.5 cm/bird, respectively, and water space of 1.2, 1.4, 1.6, and 1.8 cm/bird, respectively. The photoperiod was 23 h at 0 to 11 wk of age (WOA) and 8 h at 12 to 16 WOA. Birds were fed diets comprising 3,000 and 3,100 kcal of ME/kg of diet at 0 to 4 and 5 to 8 WOA, respectively, and 24% CP. At 9 to 16 WOA, the diets comprised 3,100 kcal of ME/kg and 18% CP. Feed and water were provided for ad libitum consumption. Body weight and feed consumption were measured weekly. Overall, BW gains were higher (P < 0.05) and feed conversion ratios (FCR) were significantly lower in birds reared at a floor density of 18 birds/m(2) than in birds reared on other treatments at 0 to 8 WOA. However, at 9 to 16 WOA, birds at floor densities of 12 birds/m(2)exhibited higher BW gain and feed consumption and lower FCR (P < 0.05) than those at floor densities of 13.6, 15.6, and 18 birds/m(2). Therefore, this study suggests an optimum floor density of 18 and 12 birds/m(2) at 0 to 8 and 9 to 16 WOA, respectively, to achieve the highest possible FCR for the PG guinea fowl replacement pullets.

Hen welfare in different housing systems

Egg production systems have become subject to heightened levels of scrutiny. Multiple factors such as disease, skeletal and foot health, pest and parasite load, behavior, stress, affective states, nutrition, and genetics influence the level of welfare hens experience. Although the need to evaluate the influence of these factors on welfare is recognized, research is still in the early stages. We compared conventional cages, furnished cages, noncage systems, and outdoor systems. Specific attributes of each system are shown to affect welfare, and systems that have similar attributes are affected similarly. For instance, environments in which hens are exposed to litter and soil, such as noncage and outdoor systems, provide a greater opportunity for disease and parasites. The more complex the environment, the more difficult it is to clean, and the larger the group size, the more easily disease and parasites are able to spread. Environments such as conventional cages, which limit movement, can lead to osteoporosis, but environments that have increased complexity, such as noncage systems, expose hens to an increased incidence of bone fractures. More space allows for hens to perform a greater repertoire of behaviors, although some deleterious behaviors such as cannibalism and piling, which results in smothering, can occur in large groups. Less is understood about the stress that each system imposes on the hen, but it appears that each system has its unique challenges. Selective breeding for desired traits such as improved bone strength and decreased feather pecking and cannibalism may help to improve welfare. It appears that no single housing system is ideal from a hen welfare perspective. Although environmental complexity increases behavioral opportunities, it also introduces difficulties in terms of disease and pest control. In addition, environmental complexity can create opportunities for the hens to express behaviors that may be detrimental to their welfare. As a result, any attempt to evaluate the sustainability of a switch to an alternative housing system requires careful consideration of the merits and shortcomings of each housing system.