Comparison of Chinese Broiler Production Systems in Economic Performance and Animal Welfare

In vitro antibacterial activity of danofloxacin against Escherichia coli in Gushi chickens and its residue depletion following multiple oral administration

This study aimed to investigate the in vitro antibacterial activity of danofloxacin against Escherichia coli isolated from Gushi chickens, as well as the tissue distribution and residue depletion of danofloxacin in Gushi chickens following multiple oral administration. A total of 42 clinical E. coli strains were isolated from the cloaca of locally farmed Gushi chickens between August and October 2023. Then the minimum inhibitory concentration (MIC) of danofloxacin against these isolates was determined by broth microdilution method. Additionally, 42 healthy Gushi chickens were randomly divided into 6 groups, and danofloxacin was orally administered at a dose of 5 mg/kg body weight (BW) for 3 consecutive days. Plasma, intestinal content, and tissue samples, including muscle, skin + fat, liver, kidney, lung, and intestine, were collected at 4, 12, 24, 48, 72, and 120 h after the last administration. Danofloxacin concentrations in all samples were determined using a high-performance liquid chromatography (HPLC) method. The average concentration vs. time data were then subjected to noncompartmental analysis using Phoenix software, and withdrawal periods for danofloxacin in Gushi chickens were further determined with WT1.4 software, setting a 95% confidence interval. Results indicated a notable inhibitory effect of danofloxacin on E. coli, with an MIC50 of 0.5 μg/mL. Additionally, danofloxacin exhibited widespread distribution in Gushi chickens, detectable in all collected samples. Among all tissues, the liver exhibited the highest concentration, followed by the intestine. Even on the fifth day postadministration, danofloxacin persisted in skin + fat, liver, and lung. The elimination half-lives (t1/2λzs) of danofloxacin varied across samples: skin + fat (47.87 h), lung (30.61 h), liver (22.07 h), plasma (16.05 h), muscle (12.53 h), intestine (9.83 h), and kidney (6.34 h). Considering residue depletion and the maximum residue limit (MRL) of danofloxacin in poultry set by Chinese regulatory authorities, withdrawal periods for the kidney, muscle, liver, and skin + fat were determined as 1.03, 1.38, 3.34, and 5.85 d, respectively, rounded to a final withdrawal time of 6 d.

Enzymolytic soybean meal improves growth performance, economic efficiency and organ development associated with cecal fermentation and microbiota in broilers offered low crude protein diets

The objective of this experiment was to determine the effect of low crude protein (CP) diets containing increasing amounts of enzymolytic soybean meal (ESBM) on growth performance, economic benefit and organ development and the role of cecal fermentation and microbiota in broilers. A total of 360 one-day-old Arbor Acres chicks were randomly allocated into 6 groups with 6 replicates and 10 chicks each. The six dietary treatments consisted of a standard high-CP diet (PC), a low-CP diet (NC), and an NC diet with 0.5, 1.0, 1.5%, or 2.0% ESBM. The experiment lasted for 42 days. Compared to PC, NC showed decreased (p < 0.05) average daily gain (ADG) in broilers from 22 to 42 days and from 1 to 42 days, while increasing levels of ESBM quadratically increased (p < 0.05) ADG from 1 to 42 days. Feed cost and total revenue in the NC were lower (p < 0.05) than that in the PC, while supplementation with ESBM in the NC linearly increased (p < 0.05) net profit and economic efficiency in broilers. There were significant differences (p < 0.05) in the liver, proventriculus and gizzard indices between the PC and NC groups, and supplementation with ESBM linearly increased (p < 0.05) the relative weights of liver, pancreas, proventriculus and gizzard in broilers at 42 days of age. The PC group had a higher cecal acetic acid concentration at 21 days and propionic acid concentration at both 21 and 42 days than the NC group (p < 0.05). Cecal acetic acid and propionic acid concentrations linearly increased (p < 0.05) with increasing levels of ESBM in broilers at 42 days of age. No significant differences in ACE, Chao1, Shannon and Simpson indices were observed among groups (p > 0.05), while the cecal abundances of Bacteroides, Faecalibacterium and Clostridium IV increased (p < 0.05) with the increasing level of ESBM in the low-CP diets. In conclusion, feeding ESBM improved economic efficiency, digestive organ development, cecal fermentation and microbial community composition, and up to 2.0% ESBM addition had no negative effect on the growth performance in broilers fed low CP diets.

Overview of Avian Sex Reversal

Sex determination and differentiation are processes by which a bipotential gonad adopts either a testicular or ovarian cell fate, and secondary sexual characteristics adopt either male or female developmental patterns. In birds, although genetic factors control the sex determination program, sex differentiation is sensitive to hormones, which can induce sex reversal when disturbed. Although these sex-reversed birds can form phenotypes opposite to their genotypes, none can experience complete sex reversal or produce offspring under natural conditions. Promising evidence indicates that the incomplete sex reversal is associated with cell autonomous sex identity (CASI) of avian cells, which is controlled by genetic factors. However, studies cannot clearly describe the regulatory mechanism of avian CASI and sex development at present, and these factors require further exploration. In spite of this, the abundant findings of avian sex research have provided theoretical bases for the progress of gender control technologies, which are being improved through interdisciplinary co-operation and will ultimately be employed in poultry production. In this review, we provide an overview of avian sex determination and differentiation and comprehensively summarize the research progress on sex reversal in birds, especially chickens. Importantly, we describe key issues faced by applying gender control systems in poultry production and chronologically summarize the development of avian sex control methods. In conclusion, this review provides unique perspectives for avian sex studies and helps scientists develop more advanced systems for sex regulation in birds.

Chicken bed reuse

Aviculture is a developed and important industry worldwide. However, it is an industry that produces solid waste such as bedding. As an attempt to reduce environmental impact and productive activity costs, beds are reused by several consecutive lots which can increase microorganism concentration and lead to unsanitary conditions. In this regard, it is essential to adopt a litter pre-treatment during the gap sanitary period between lots to avoid passing problems to the birds from the current flock to the subsequent flock and to guarantee the litter quality. Several factors must be considered to guarantee that there is minimal damage to chicken production. Therefore, this literature review aims to approach the main factors that affect the thermal comfort and chicken litter quality, as well as alternatives used as an alternative biological treatment to guarantee its reuse quality.

The Impacts of Colony Cages on the Welfare of Chickens Farmed for Meat

There is growing interest in keeping meat chickens in modern colony cages (CCs) rather than conventional litter-floor barns. Suggested welfare improvements for chickens in such systems include reduced bodily lesions due to lower contact with flooring contaminated with faeces and urine, due to slatted flooring and automated faeces removal. This systematic review sought to determine the animal welfare impacts of CCs using slatted flooring, in comparison to litter-based non-cage systems. Overall, 23 relevant studies were retrieved. From one perspective, the extant research appeared mixed. Fifteen (65%) of these 23 studies identified some form of welfare concern about slatted floors, and thus CCs. Yet, when considering actual welfare indicators assessed, the tallies generated in favour of each housing system were similar. Crucially however, there were incomplete behavioural welfare measures in 100% of the empirical studies reviewed. Accordingly, significant welfare concerns exist about CCs, centring around behavioural deprivation. Given that over 70 billion chickens are farmed then slaughtered each year globally, widespread implementation of CCs would create a major animal welfare concern. Instead of implementing such CC systems, research and development is recommended into improving welfare outcomes of conventional litter barns using different forms of commercially feasible enrichment. As a minimum, a full behavioural analysis, as detailed in the Welfare Quality Assessment protocols, should form a mandatory part of any future studies aimed at assessing the welfare impacts of housing systems on farmed chickens.

Government support, talent, coupling of innovation chain and capital chain: empirical analysis in integrated circuit enterprises

Purpose

This study aims to investigate the impact of government support on the coupling coordination degree of innovation chain and capital chain in integrated circuit (IC) enterprises and to explore the mechanism for considering talent in the influence path.

Design/methodology/approach

This paper uses coupling coordination degree model to estimate the coupling of two chains, and applies dynamic panel system generalized method of moments (system-GMM) to analyze the impact of government support on coupling of two chains and conducts dynamic panel threshold regression to explore the threshold effect of talent in the influence of government support on coupling coordination degree.

Findings

Serious imbalance in the coupling of two chains is a major obstacle in IC enterprises. Government support significantly reduces the coupling coordination degree. The talent in IC enterprises has a significant threshold effect. When the number of talent is lower than the threshold value, government support has a negative impact. Once the number of talent reaches a certain level, government support can significantly enhance the coupling of two chains. Compared with state-owned enterprises, government support has a greater negative impact on the coupling of the two chains in non-state-owned enterprises. The former needs more talent to take advantage of government support.

Originality/value

This paper applies the concept of coupling into enterprises and deeply studies the coupling coordination degree of two chains. The influence mechanism of government support and talent on the coupling of two chains is explored, which reveals that government support cannot achieve the expected incentive effect without the support of talent. We also discuss the heterogeneous effect of government support and of talent in enterprises of different ownership types.

Centennial Review: Factors affecting the chicken gastrointestinal microbial composition and their association with gut health and productive performance

Maintenance of "gut health" is considered a priority in commercial chicken farms, although a precise definition of what constitutes gut health and how to evaluate it is still lacking. In research settings, monitoring of gut microbiota has gained great attention as shifts in microbial community composition have been associated with gut health and productive performance. However, microbial signatures associated with productivity remain elusive because of the high variability of the microbiota of individual birds resulting in multiple and sometimes contradictory profiles associated with poor or high performance. The high costs associated with the testing and the need for the terminal sampling of a large number of birds for the collection of gut contents also make this tool of limited use in commercial settings. This review highlights the existing literature on the chicken digestive system and associated microbiota; factors affecting the gut microbiota and emergence of the major chicken enteric diseases coccidiosis and necrotic enteritis; methods to evaluate gut health and their association with performance; main issues in investigating chicken microbial populations; and the relationship of microbial profiles and production outcomes. Emphasis is given to emerging noninvasive and easy-to-collect sampling methods that could be used to monitor gut health and microbiological changes in commercial flocks.