•The multiple factors that can affect the intestinal health of poultry are reviewed.•Improving digestibility has a key role on intestinal health.•Grain drying and feed processing and quality effects ...on digestibility are highlighted.•Breeder gut health and incubation conditions effects on progeny are explained.•Water quality and housing conditions also affect gut health.
The intestinal health of poultry has broad implications for the systemic health of birds, animal welfare, the production efficiency of flocks, food safety, and environmental impact. The importance of this topic has grown over the past two decades and this was the focus of this workshop arranged to provide a forum for discussion and mutual learning by sharing experiences, scientific information and demonstrations of comparative effects of multiple factors that affect intestinal health under controlled conditions. This special issue is the product of that workshop.
This first paper reviews the multiple aspects that can affect the intestinal health of poultry, and individual factors are then addressed in more detail in subsequent papers. However, some factors, like breeder intestinal health, incubation conditions, early feeding, water quality, housing conditions, feedstuff quality, mycotoxin and rancidity, and grain drying will be discussed herein since will not be covered in detail elsewhere in the issue. The objective of this paper is to offer a great overview of intestinal health in poultry production and emphasize that a holistic approach is necessary when trying to minimize these dysbiosis and enteric diseases.
This study was conducted to understand the impact of including full fat high-oleic soybean meal in layer hen diets on nutrient digestibility and added nutritional value in eggs. Forty-eight layers ...(∼36 wk old) were randomly assigned to one of 4 isonitrogenous (18.5% crude protein) treatment diets with 12 replicate birds per treatment in a 3-wk study. Treatments were 1) solvent extracted defatted soybean meal + corn diet, 2) dry extruded defatted soybean meal + corn, 3) full-fat soybean meal + corn, 4) high-oleic full-fat soybean meal + corn diet. Apparent ileal digestibility of crude fat (CF) and crude protein (CP) were determined using celite (∼2%) as an indigestible marker. Tibia strength and egg quality parameters (egg weight, shell strength, Haugh unit, shell color, and yolk color) were recorded during the study. Fatty acid profiles, including the monounsaturated fatty acid, oleic acid (C18:1, cis), in eggs and adipogenic tissue (liver, muscle, and fat pad) were measured using gas chromatography (GC-FID). Digestibility values of CF ranged from 71 to 84% and CP varied from 67 to 72% for treatment diets, with treatment mean values being no different (P > 0.05) between treatment diets. No differences between treatment diets in tibia strength or egg quality parameters (egg weight, shell strength, and Haugh unit) were observed (P > 0.05) except for yolk color. Similarly, there were no differences in the total lipids in egg yolk (P > 0.05) between treatment diets. However, oleic acid percentage of total lipid in egg and tissue was significantly higher (P < 0.001) in hens given the high-oleic full-fat soybean meal diet than in other treatment groups. No difference was observed in oleic acid percentage of total lipid in egg between the other 3 treatment diets (P > 0.05). Overall, the results exhibited that the eggs and tissue of layer hens fed the full-fat high-oleic acid soybean meal diet were higher in oleic acid while the CF and CP digestibility remained similar to the digestibility of the other diets.
Localized uniform conditioning is a technique developed to spatially locate selective mining unit grades that have been derived using uniform conditioning for the assessment of recoverable resources. ...The technique has the advantage of producing selective mining unit estimates conforming to the uniform conditioning panel-specific grade-tonnage curve while introducing spatial information at the scale of the selective mining units. This paper describes an alternative technique to localized uniform conditioning which does not explicitly require the uniform conditioning panel-specific grade-tonnage curve to localize the selective mining unit estimates. The technique can therefore be implemented in mining software where uniform conditioning is not available.
Although temperature, relative humidity, and farm-associated factors are known to affect broiler live performance, data about the impact of these variables under commercial operations are still ...scarce. This study aimed to evaluate the effect of temperature, relative humidity, a thermal humidity index, management, and farm-associated factors on BW, BW gain, feed conversion ratio (FCR), and mortality of broilers raised to 35 d under commercial tropical conditions. The data analyzed included performance records of Ross 308 AP broiler flocks placed between 2018 and 2020. Environmental monitoring information was obtained from electronic sensors that captured data hourly from 80 flocks in 29 farms. Farm-associated factors were gathered using a survey of 86 farms. Three data analyses were conducted in parallel. Correlation analyses, one-way ANOVA, and machine learning techniques were employed. Results indicated that BW and BW gain were reduced, and FCR worsened (p < 0.001) up to 21 d when chickens were mainly exposed to temperatures 2.5 °C lower than the recommended optimums for each age period. At the same time, mortality at 28 and 35 d increased. In conclusion, all farm-associated factors affected chicken live performance. Variable importance analysis indicated that performance results at 14 and 21 d were significant to predict BW at 35. At the same time, sex, distance between the hatchery and farm, and farm altitude accounted for the most significant contributions from the farm-associated factors.
•A monitor for measuring ammonia in poultry houses was developed using a metal oxide semiconductor sensor.•Relative humidity and temperature compensation equations improved the MOS sensor’s ability ...to measure ammonia.•The monitor’s relative error and coefficient of variation were both <10%, comparable to those required of research instruments.•Material cost of the monitor was <$430 and its mass was <1.4kg.
To ensure poultry performance and welfare, ammonia (NH3) concentrations inside poultry houses have to be within acceptable limits; this requires regular NH3 monitoring. While there are low-cost, portable NH3 measuring devices have drawbacks. Due to its low cost, long lifetime, and short response time, a metal oxide semiconductor (MOS) sensor was used to develop a handheld NH3 monitor for use in poultry houses. Since the MOS sensor is affected by humidity and temperature, collocating relative humidity (RH) and temperature sensors with the MOS NH3 sensor and applying temperature and RH compensations greatly improved its performance. Compared to the boric acid scrubber, using broiler litter exhaust gas as the NH3 source, the relative error (RE) and coefficient of variation (CV) of the monitor averaged 7%, comparable to research-grade instruments. The monitor was more accurate than the electrochemical sensor and required less frequent purging. The response time of the unit was ∼1.5min, the total mass was <1.4kg while material cost was <$430. Hence, in addition to being convenient, the monitor provided accurate and precise measurements. With further refinements, the monitor has the potential to be used in poultry houses to control ventilation rates as a component of precision livestock farming to improve poultry performance and welfare.
Data collection is standard in commercial broiler production; however, growth modeling is still a challenge since this data often lacks an inflection point. This study evaluated body weight (BW) ...dynamics, feed intake, BW gain, feed conversion ratio (FCR), and mortality of broiler flocks reared under commercial tropical conditions with controlled feeding to optimize FCR. The data analyzed included performance records of 1347 male and 1353 female Ross 308 AP broiler flocks with a total of 95.4 million chickens housed from 2018 to 2020. Decision trees determined high- and low-feed-efficiency groups using FCR at 35 d. Logistic, Gompertz-Laird, and von Bertalanffy growth models were fitted with weekly BW data for each flock within performance groups. The logistic model indicated more accurate estimates with biological meaning. The high-efficiency males and females (
< 0.001) were offered less feed than the low-efficiency group and were consistently more efficient. In conclusion, greater feeding control between the second and the fourth week of age, followed by higher feed allowance during the last week, was associated with better feed efficiency at 35 d in males and females. Additionally, models demonstrated that a reduced growth rate resulted in heavier chickens at 35 d with better feed efficiency and greater BW gain.
Due to its potential environmental and public health impacts, emissions of ammonia (NH3) as well as several other gases from US livestock farms may be regulated. Broiler houses are important sources ...of NH3 emissions. However, there are no emissions data from roaster (8–12 wk old broilers, ∼4 kg ea.) houses. Producers treat the litter in broiler houses with acidifiers, such as sodium bisulfate (SBS, NaHSO4) to reduce ammonia production and protect bird health. However, there is very little data on the effect of acidifiers, particularly at high application rates on ammonia emissions. The impact of different SBS application rates High (0.95–1.46 kg m−2, whole house), Medium (0.73 kg m−2, whole house), Low (0.37–0.49 kg m−2, whole house), and Control (0.37–0.49 kg m−2, brood chamber) on ammonia emissions was evaluated in commercial roaster houses over 22 months spanning eight flocks. Ammonia emission from each fan was measured with an acid scrubber that operated only when the fan operated. Emissions were calculated using >95% measured data with the rest being estimated using robust methods. Exhaust ammonia–N concentrations were inversely correlated with the SBS application rates. Emission rates on animal unit (AU, where 1 AU = 500 kg live-mass) basis (ER, g d−1 AU−1) were reduced by 27, 13, and 5%, respectively, in the High, Medium, and Low treatments vs. the Control treatment (mean: 100 g d−1 AU−1, range: 86–114 g d−1 AU−1). Emission rates for the Control treatment measured in this study on roasters were mostly higher than ERs in the literature. Differences in ERs are not only due to diet, environmental and management conditions, but also due to measurement methods.
► Ammonia emission rates from four roaster houses were measured over eight flocks. ► Each house received a different acidifier (sodium bisulfate) application rate. ► The control treatment daily ammonia–N emission rate was 100 g per 500-kg live-mass. ► Emission rates were inversely correlated with the acidifier application rate. ► The acidifier is limited in its ability to reduce ammonia emissions.
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