Effect of perches on liver health of hens

Balancing act: Studying the effect of perch space allowance on welfare in Canadian laying strain pullets raised in floor pens with access to a single-tier perch system to 18 wk of age

The rearing environment for pullets should mirror their later production environment as closely as possible. However, existing perch space recommendations are based on data for laying hens rather than pullets. This study explores the impact of perch space allowances on the welfare of Canadian laying strain pullets raised to 18 wk. Two trials were conducted with 1,032 Lohmann Brown-Lite (LB) and LSL-Lite (LW) pullets each. A randomized complete block (trial) design was used with a 4 (perch space) × 2 (strain) factorial arrangement. Birds were raised in 16 floor pens (3 × 3 m each; 897.67 cm2 per bird). Wooden perches were provided from d 1, allowing 6, 9, 12, or 15 cm perch space per pullet. Data were tested for normality, and log+1 transformed if necessary. Significance was declared at P≤0.05. Data were collected for basic health and functioning (body weight, mortality, pullet width, keel bone damage, and tibia bone parameters), affective states (comb damage, heterophil-to-lymphocyte (H/L) ratios, and behavior), and natural living (perch usage and jumping success). Perch space did not affect mortality, keel bone damage, tibia breaking strength, comb damage, or H/L ratios. At 16 and 18 wk, LB body weight slightly increased while the LW body weight decreased with increasing perch space (P=0.05 and 0.02). At 3 wk, pullets spent a higher percentage of time wing flapping on the perch when provided 15 cm compared to 6 cm (P=0.04). During the scotoperiod at 18 wk, a higher percentage of birds perched with 12 and 15 cm perch space than 6 cm (P<0.01). Pullet width at 18 wk was 12.52 cm (sitting) and 11.66 cm (standing) for the LB and 13.85 cm (sitting) and 12.94 cm (standing) for the LW. Overall, perch space allowance had minor effects on the measured welfare indicators. Based on pullet width, a minimum of 12.5 cm for LW and 13.9 cm for LB pullets should be provided to allow all pullets to sit on the perch simultaneously.

Evaluating the Effects of Replacing Alfalfa with Broussonetia papyrifera Branch/Leaf Powder on Growth and Serum Indicators in Dezhou Donkeys

The purpose of this experiment was to study the apparent digestibility and the effects of Broussonetia papyrifera (BP) branch/leaf powder supplementation on growth performance and serum indicators in donkeys. The results showed that the apparent digestibility of dry matter (DM), crude protein (CP), crude fiber (CF), neutral detergent fiber (NDF), acidic detergent fiber (ADF), and digestible energy content (DE) of BP branch/leaf powder were 51.88%, 67.27%, 64.86%, 49.59%, 54.73%, 40.87%, and 6.37 MJ/kg, respectively. The average daily gain (ADG) in the 20% group was significantly higher than in the 0% and 30% groups. The serum albumin (ALB) levels in the 0% and 10% groups were significantly higher than those in the 20% and 30% groups, while the serum globulin (GLB) content in the 10% group was significantly lower than in the other groups. The 20% group showed decreased serum triglyceride (TG) levels compared to the other groups. Both the 20% and 30% groups exhibited lower total cholesterol (TC) levels and increased alanine aminotransferase (ALT) compared to the 0% and 10% groups and higher serum lactate dehydrogenase (LDH) levels than the 10% group. The 30% group had higher serum immunoglobulin A (IgA) levels than the other groups, while all three BP branch/leaf powder groups had lower serum tumor necrosis factor (TNF-α) levels than the 0% group. There was a gradual increase in serum total antioxidant capacity (T-AOC) with the increasing amount of BP branch/leaf powder added. In conclusion, the optimal supplemental proportion of BP branch/leaf powder in the diet is 20%. Furthermore, BP branch/leaf powder can improve growth performance, serum immune indices, and antioxidant capacity in Dezhou donkeys.

Effects of fermented herbal tea residue on meat quality, rumen fermentation parameters and microbes of black goats

Herbal tea residue (HTR) is generally considered to be a reusable resource which has still retains considerable proportion of nutrients and active substances. This study aimed to investigate the effects of substitution of whole corn silage with fermented herbal tea residue (FHTR) on meat quality, serum indices, rumen fermentation, and microbes in Chuanzhong black goats. Twenty-two female Chuanzhong black goats (4 months old) with similar weight (9.55 ± 0.95 kg) were selected and randomly divided into two groups. FHTR was used to replace 0% (CON group) and 30% (FHTR group) of whole corn silage in the diets and fed as a total mixed ration (TMR) for Chuanzhong black goats. The adaptation feeding period was 7 days, and the experimental period was 35 days. Results illustrated that the FHTR group had higher value of a* and concentrations of DM and CP and lower rate of water loss (P < 0.05) than the CON group. For the serum indices, goats fed with 30% FHTR had higher (P < 0.05) concentration of CR on day 35. For rumen fermentation, the pH and ratio of acetic acid/propionic acid (AA/PA) in the FHTR group were significantly lower than those in the CON group (P < 0.05). In addition, we studied the goats's rumen microbial community composition and found that the dominant phyla were Firmicutes, Bacteroidetes,and Tenericutes; and the dominant genera were Quinella, Candidatus_Saccharimonas, and Saccharofermentans. There was a significant difference in the beta diversity of the rumen microbiota between groups (P < 0.05). To sum up, the addition of FHTR can affect the meat quality, serum indices, improved rumen fermentation by adjusted the diversity and function of the rumen microbiota.

Effects of supplemented multicomponent mycotoxin detoxifying agent in laying hens fed aflatoxin B1 and T2-toxin contaminated feeds

The present study was conducted to determine the ability of multicomponent mycotoxin detoxifying agent (MMDA) in feed to prevent the gastrointestinal absorption of aflatoxin B1 (AFB1) and T2-toxin supplemented via spiked maize. For comparisons, hens were fed with uncontaminated basal diet without or with addition of MMDA at 2 g/kg feed. The trial consisted of 105 laying hens (Lohmann Brown) without obvious signs of disease allocated to 7 treatment groups in 35 pens. Responses were demonstrated on laying performance and health status throughout the 42 d experimental period. The results of laying performance indicated significantly decreased egg mass with increasing mycotoxin (AFB1 and T2-toxin) levels up to the maximum tolerated dosage, however simultaneous presence of MMDA laying performance was slightly modified linearly to increasing application. Dose-dependent pathological changes in liver and kidneys and their relative weights, changes in blood parameters and reduced eggshell weights were observed in the hens fed AFB1 and T2-toxin. The pathological changes in the hens fed with diets containing AFB1 and T2-toxin without MMDA were significantly higher as compared with the control group, but eggshell stability was not affected. The contents of AFB1, T2-toxin and their metabolites in liver and kidney tissues were significantly decreased in the hens supplemented with MMDA at 2 and 3 g/kg in feed. MMDA supplementation significantly reduced the deposition of AFB1, T2-toxin and their metabolites in liver and kidneys at the maximum tolerated dosage (2 and 3 g/kg) indicating specific binding to AFB1 and T2-toxin in the digestive tract as compared to the corresponding diets without MMDA. Exposure of AFB1 and T2-toxin indicated significantly decreased egg mass with increasing mycotoxin levels up to the maximum tolerated dosage because of the significantly reduced egg production. Therefore, in this study, MMDA could reduce negative effects of feeding AFB1 and T-2 to laying hens.

An assessment of responses to egg production and liver health of Japanese quails subjected to different levels of metabolizable energy

OBJECTIVE

Current quail production is configured as an economic activity in scale. Advancements in quail nutrition have been limited to areas such as breeding and, automation of facilities and ambience. The objective of this study was to evaluate the performance responses, liver and oviduct morphometry, and liver histology of Japanese laying quails subjected to different levels of nitrogen-corrected apparent metabolizable energy (MEn).

METHODS

A completely random design was used that consisted of nine levels of MEn, six replicates, and five hens per cage with a total of 270 quails. The experimental period lasted for 10 weeks. The variables of performance were subjected to analysis of variance and then regression analysis using the broken-line model. The morphometric and histological variables were subjected to multivariate exploratory techniques.

RESULTS

The MEn levels influenced the responses to zootechnical performance. The brokenline model estimated the maximum responses for feed intake, egg production, egg weight, and egg mass as 3,040, 2,820, 1,802, and 2,960 kcal of MEn per kg of diet, respectively. Multivariate analysis revealed that the occurrence of hepatic steatosis and increased levels of Kupffer cells were not related to MEn levels.

CONCLUSION

The level of 2,960 kcal/kg of MEn meets performance variable requirements without compromising hepatic physiology.

Consumer attitudes towards egg production systems and hen welfare across the world

Concurrent with the growth of the human population, global egg production has experienced exponential increase in the last 50 years. This exponential growth has been made possible through the refinement of intensive egg production systems, predominately, conventional cages. The significant amount of liberties conventional cages withhold from hens has also formed the basis of growing challenge to the industry in many countries, with some major regions such as the European Union making sweeping regulatory reform. These reforms were driven by well-organised animal advocacy groups, fuelled by aligning consumer attitudes and behaviours. In the absence of concerted hen welfare advocacy and cage-free movement in much of the rest of the world, it is difficult to know what consumer attitudes and knowledge may exist outside the European Union. This study aimed to contribute to this knowledge by surveying 4,292 members of the public at random across 14 geographically and culturally diverse countries (Australia, Bangladesh, Brazil, Chile, China, India, Malaysia, Nigeria, Pakistan, Philippines, Sudan, Thailand, UK and USA). The findings show that most participants across all countries eat eggs, most state that it matters to them that hens do not suffer in the process of producing the eggs they eat, and importantly, a majority of participants in most countries (except Nigeria) would prefer (to varying degrees) to purchase eggs from hens not kept in cages. Participant knowledge of the dominant system of egg production in their country varied greatly, with frequent uncertainty. This suggests a need for clarity and consistency in communication to consumers during campaigns, in order to mitigate confusion. Most importantly, although these similarities existed across the countries, important regional differences were also present. This underscores the importance of understanding animal and agricultural issues by geopolitical region, and of locally tailoring strategy. The findings of this research will be of strategic use to egg producers and animal welfare advocates alike in understanding and appropriately catering to consumers in the future.

Farm Environmental Enrichments Improve the Welfare of Layer Chicks and Pullets: A Comprehensive Review

Currently, cage housing is regarded as a global mainstream production system for laying hens. However, limited living space and confinement of birds in cages cause welfare and health problems, such as feather pecking, osteoporosis, obesity, and premature aging. Many studies have been conducted to alleviate layer welfare problems by providing farm environmental enrichments such as litter, sand, alfalfa bales, chick papers, pecking stones, pecking strings, perches, slopes, elevated platforms, aviaries and outdoor access with a trend towards complex enrichments. The provision of appropriate enrichments continuously attracts layers towards pecking, foraging, dust bathing, and locomotion, thereby giving lifelong benefits to laying hens. Hence, raising chicks and pullets under such conditions may reduce feather and skin damage, as well as accumulation of abdominal fat, and improve several biological features such as health, productivity, quality products, and docility of laying hens. Therefore, providing enrichment during the first few days of the layer’s life without any interruption is crucial. In addition, due to different farm conditions, environmental enrichment should be managed by well-trained farm staff. For example, in preventing feather pecking among the birds, litter materials for foraging are superior to dust bath materials or new items. However, a limited supply of litter creates competition and challenges among birds. Therefore, providing farm environmental enrichment for layers requires proper handling, especially in commercial layer farms. Hence, improving the welfare of chicks and pullets through optimizing on-farm environmental enrichments is essential for production systems practicing cage housing.

Mentha piperita as a promising feed additive used to protect liver, bone, and meat of Japanese quail against aflatoxin B1

The present study was conducted to evaluate aflatoxin B₁ (AFB₁) detoxification effects of some medicinal plants under both in vitro and in vivo. The in vitro experiment was performed with 25 treatments in 5 replications. The samples of medicinal plants were incubated with AFB₁ for 72 h, and the toxin residual in the supernatant was determined. The highest aflatoxin elimination was found to be related to peppermint (81%). Thereafter, in vivo experiment was conducted to investigate the effects of peppermint dried leaves, essential oil, and menthol on liver, bone, and meat, as well as the performance of growing Japanese quail fed diet contaminated with AFB₁. A total of 640 7-day-old Japanese quails were assigned using a completely randomized design as 2 × 4 factorial arrangement with two levels of AFB₁ (including 0 and 2.5 mg/kg diet) and four treatments (including no additive; peppermint powder, 20 g/kg; peppermint essential oil, 800 mg/kg; and menthol powder, 400 mg/kg). Those birds fed AFB₁-contaminated diet with no additives showed the worst liver health status by considering super oxide dismutase (P = 0.0399), glutathione peroxidase (P = 0.0139), alanine aminotransferase (P < 0.0001), and aspartate aminotransferase levels (P = 0.0512). However, the supplementation of AFB₁ contaminated diet with additives improved their liver health status. Menthol receiving birds showed the highest tibia strength, while the birds fed with AFB₁-contaminated diet with no additives had the weakest bone strength (P < 0.0001). A significant increase was also observed in malondialdehyde level of meat by dietary inclusion of AFB₁, which was well-repressed by the dietary supplementation of peppermint essential oil and menthol (P = 0.0075). Body weight gain dramatically decreased by adding AFB₁ to the diet, which was recovered with the dietary supplementation of additives (P = 0.0585). According to the results of the current study, peppermint and its derivatives can be used to suppress aflatoxin effects on the liver, bone, and meat quality and to improve the performance of Japanese quails.

Effects of Broussonetia papyrifera silage on rumen fermentation parameters and microbes of Holstein heifers

The structure and types of rumen microbes are closely related to host health. This study aimed to evaluate the effect of Broussonetia papyrifera silage (BPS) gradually replacing the whole crop maize silage (WCMS) on total tract digestibility, rumen fermentation parameters, serum biochemical indicators, and rumen microbes of Holstein heifers. The diet treatment consisted of four proportions of BPS (0%, 25%, 50% and 75%) as substitute for WCMS (designated as T0, T25, T50 and T75, respectively). Twenty heifers (body weight = 245 ± 24 kg) were randomly divided into four groups of five heifers, and randomly received one diet. The feeding adaption period was 7 days, and the experiment period was 30 days. Our findings suggested that the digestibility of neutral detergent fiber and crude protein increased linearly with the increased in BPS (P < 0.05). The concentrations of total protein and albumin increased quadratically with the increased in BPS (P < 0.05). The 16s high-throughput sequencing showed that feeding BPS did not change the diversity and structure of the rumen microbes of heifers. However, the relative abundances of Tenericutes and SR1-Absconditabacteria increased linearly with the increased in BPS (P < 0.05). The Weighted Correlation Network Analysis results suggested that ALT concentration was positively correlated with the abundance of Prevotella-1 (r = 0.73; P = 0.007). In general, Holstein heifers fed with BPS did not change the diversity and uniformity of rumen microbes, and enhanced the body protein metabolism.

Investigation of the Morphology of Adrenal Glands in Hens Kept in Two Different Housing Systems-A Pilot Study

It is difficult to objectively assess the chronic effects of housing systems on livestock and particularly on laying hens. However, this seems to be important in the context of animal welfare. Therefore, we conducted the present study in order to compare the effect of two different housing conditions, single cage (SC) and floor pen (FP), on the morphology of the adrenal gland. A higher amount of interrenal cells, which secrete stress hormones, can lead to a difference in the relation of adrenal and interrenal cells, which could be interpreted as an indication of chronic stress. For this purpose, adrenal glands were extracted, prepared, stained and examined by microscopy, and total area of the cut, total area of interrenal cells and total area of adrenal cells were measured. As a result, all laying hens had a higher percentage of interrenal cells than adrenal cells (FP: interrenal cells/adrenal cells = 78.37%/21.63%; SC: 80.00%/20.00%). The median of adrenal-interrenal ratio did not differ significantly (FP = 0.2503, SC = 0.2499), while the variation of the ratio between laying hens in FP and SC showed a slight tendency of a higher ratio in adrenal glands of FP (p < 0.0870). Body weight and adrenal-interrenal ratio were significantly negatively correlated in laying hens in FP (rS = -0.943, p < 0.0048) but not in SC (rS = -0.162, p = 0.7283). There was no significant correlation between body weight and total cell area for interrenal cells or adrenal cells. Body weight was significantly lower for laying hens kept in SC than for laying hens kept in FP (p < 0.0001). Due to the present results, it can be concluded that keeping laying hens in single cages can have a negative effect on body weight.

Comparison of the frequency of patho-anatomic findings in laying hens with findings in broiler chickens and turkeys detected during post-mortem veterinary inspection

We have investigated the health condition of laying hens on the basis of patho-anatomic findings obtained during the veterinary inspection after slaughter. To assess the severity of the health condition of laying hens, we compared the incidence of findings with the findings in broiler chickens and turkeys. In the period from 2010 to 2017, 17,346,183 laying hens, 887,994,167 broiler chickens, and 919,843 turkeys were transported from Czech farms to slaughterhouses in the Czech Republic. The competent veterinary authority in the Czech Republic (the State Veterinary Administration) carried out a veterinary inspection of these birds slaughtered in the slaughterhouse and recorded the patho-anatomic findings. From the recorded data, the number of patho-anatomic findings (intravital origin) of the organs and parts of the bodies (liver, intestines, lungs, heart, spleen, genital tract, urinary system, CNS, skin, head, body, limbs, and whole animal) were analysed. We found increased patho-anatomic findings in the liver (26.76%) and limbs (6.03%) in hens, and also high numbers of findings in the category of total findings (1.57%) were detected. In liver findings, chronic findings (22.09%) were prevailing over the acute findings (4.67%), compared to broiler chickens (chronic 0.04%, acute 0.03%) and turkeys (chronic 1.90%, acute 0.00%). The differences between hens, broilers, and turkeys were significant (P < 0.001). The incidence of traumatic, chronic, and acute findings in hens (3.88%, 1.71%, and 0.44%, respectively) was higher (P < 0.001) in the case of the legs, compared with broiler chickens (0.02%, 0.08%, and 0.02%, respectively) and turkeys (0.27%, 0.23%, and 0.05%, respectively). The results show that the health condition of laying hens is significantly worse than in case of broiler chickens and turkeys, especially in the impact on the liver due to the likely effect of nutrition not corresponding to the intensity of the production of laying hens, and the impact on the limbs due in particular to traumatic changes caused by inappropriate transport handling and inadequate conditions (especially cage housing) of laying hens.

Harmful Effects and Control Strategies of Aflatoxin B₁ Produced by Aspergillus flavus and Aspergillus parasiticus Strains on Poultry: Review

The presence of aflatoxin B₁ (AFB₁) in poultry diets decreases the hatchability, hatchling weight, growth rate, meat and egg production, meat and egg quality, vaccination efficiency, as well as impairing the feed conversion ratio and increasing the susceptibility of birds to disease and mortality. AFB₁ is transferred from poultry feed to eggs, meat, and other edible parts, representing a threat to the health of consumers because AFB₁ is carcinogenic and implicated in human liver cancer. This review considers how AFB₁ produced by Aspergillus flavus and Aspergillus parasiticus strains can affect the immune system, antioxidant defense system, digestive system, and reproductive system in poultry, as well as its effects on productivity and reproductive performance. Nutritional factors can offset the effects of AFB₁ in poultry and, thus, it is necessary to identify and select suitable additives to address the problems caused by AFB₁ in poultry.

Equations of prediction for abdominal fat in brown egg-laying hens fed different diets

The objective was to use noninvasive measurements to formulate equations for predicting the abdominal fat weight of laying hens in a noninvasive manner. Hens were fed with different diets; the external body measurements of birds were used as regressors. We used 288 Hy-Line Brown laying hens, distributed in a completely randomized design in a factorial arrangement, submitted for 16 wk to 2 metabolizable energy levels (2,550 and 2,800 kcal/kg) and 3 levels of crude protein in the diet (150, 160, and 170 g/kg), totaling 6 treatments, with 48 hens each. Sixteen hens per treatment of 92 wk age were utilized to evaluate body weight, bird length, tarsus and sternum, greater and lesser diameter of the tarsus, and abdominal fat weight, after slaughter. The equations were obtained by using measures evaluated with regressors through simple and multiple linear regression with the stepwise method of indirect elimination (backward), with P < 0.10 for all variables remaining in the model. The weight of abdominal fat as predicted by the equations and observed values for each bird were subjected to Pearson's correlation analysis. The equations generated by energy levels showed coefficients of determination of 0.50 and 0.74 for 2,800 and 2,550 kcal/kg of metabolizable energy, respectively, with correlation coefficients of 0.71 and 0.84, with a highly significant correlation between the calculated and observed values of abdominal fat. For protein levels of 150, 160, and 170 g/kg in the diet, it was possible to obtain coefficients of determination of 0.75, 0.57, and 0.61, with correlation coefficients of 0.86, 0.75, and 0.78, respectively. Regarding the general equation for predicting abdominal fat weight, the coefficient of determination was 0.62; the correlation coefficient was 0.79. The equations for predicting abdominal fat weight in laying hens, based on external measurements of the birds, showed positive coefficients of determination and correlation coefficients, thus allowing researchers to determine abdominal fat weight in vivo.

The effect of perch availability during pullet rearing and egg laying on the behavior of caged White Leghorn hens

Enriched cages, compared with conventional cages, allow egg laying strains of chickens to meet some behavioral needs, including a high motivation to perch. The objective of this study was to determine if perch availability during rearing affected perch use as adults and if perch presence affected eating and drinking in caged White Leghorn hens. Chickens were assigned to 14 cages each with and without 2 round metal perches from hatch to 16.9 wk of age. At 17 wk of age, pullets were assigned to laying cages consisting of 1 of 4 treatments. Treatment 1 chickens never had access to perches (controls). Treatment 2 chickens only had access to 2 round metal perches during the laying phase (17 to 71 wk of age). Treatment 3 chickens only had access to 2 round perches during the pullet phase (0 to 16.9 wk of age). Treatment 4 chickens had access to the perches during both the pullet and laying phase. Each treatment during the adult phase consisted of 9 cages with 9 birds/cage for a total of 36 cages. Automatic infrared cameras were used to monitor behavior of hens in each cage for a 24-h period at 19, 24, 29, 34, 39, 44, 49, 54, 59, 64, and 69 wk of age. Behavior was also recorded twice weekly by an observer in the room where the hens were housed during photophase from 25 to 68 wk of age. Behavioral data were analyzed using ANOVA with repeated measures and the MIXED model procedure. A greater proportion of hens without perches as pullets used the rear perch more during both photophase and scotophase than hens with prior pullet perching experience. Eating and drinking activities of caged adult Leghorns were not impaired by their prior experience to perches as pullets or by the presence of perches in laying cages. It is concluded that providing perches in cages to White Leghorns during pullet rearing did not facilitate use of perches as adults.