Effects of prebiotics and precision biotics on performance, animal welfare and environmental impact. A review.

This review aims to analyze the recent studies about prebiotics and precision biotics, as alternatives to animal growth promoters. These substances improve intestinal health, growth performance and poultry environmental impact. Prebiotics are insoluble fibers, that have no nutritive value, but they promote the growth of positive bacteria, increase the nutrients absorption and modulate the immune response. Instead, precision biotics are carbohydrates with glycosidic linkages, which interact with gut bacteria metabolism, reducing the excretion of nitrogen and consequentially, the poultry environmental impact. In the last years, different studies were published in this field, and for this reason, it is necessary to organize the results found. It was shown that mannan-oligosaccharides and ß-glucans increase ileal nutrient digestibility, nitrogen retention and antibodies titers. Inulin, arabinoxylans-derived oligosaccharides, and galacto-oligosaccharides improved intestinal morphology, arranging for a larger absorption surface area. It was reported that prebiotics enhance the colonization of positive bacteria and can reduce the count of Campylobacter colonies. Furthermore, xylo-oligosaccharides are often used in animal feed, due to their ability to form organic acids, which decompose noxious substances, improving litter quality, and consequentially, reducing the environmental impact. Litter quality is a relevant aspect for ammonia emissions and for animal welfare. Whether the litter quality is poor, footpad dermatitis increase, worsening animal welfare and increasing nitrogen emissions to air. Precision biotics select metabolic pathways to modulate amino acid degradation, reintegrating the nitrogen discarded, and reducing the ammonia level in litter. It was also reported an improvement of growth performance and a better animal welfare. In conclusion, prebiotics and precision biotics can have positive effects on animal performance and welfare, and they can be a new strategy to reduce the environmental impact of chickens' farms.

Soil Organic Matter and Nutrient Levels in Outdoor Runs in Organic Laying Farms.

To evaluate the nutrient load due to the grazing of laying hens in outdoor runs, monitoring of soil characteristics was conducted in three Italian organic farms. For each farm, soil samples were taken from three increasing distances from the hen house and two depths, and different chemical parameters were evaluated. The comparison among the results from the different distances shows that N-NO3 and Olsen P are the most affected parameters by hen feces: both present high values with a statistically significant difference in the area close to the poultry house and for the most superficial layer. Even TKN and TOC show significant differences between the concentrations of the first layer (more concentrated) and those of the second layer (less concentrated). In general, the surface soil layer closest to the chicken house is the portion of the outdoor run most affected by chicken droppings and represents the most critical point in terms of potential environmental impact. Therefore, it is necessary to intensify the management of the outdoor run with tools that can facilitate the grazing of animals and with vegetation that can absorb nutrients by limiting leaching and runoff.

Prenatal and Early Postnatal Behavioural Programming in Laying Hens, With Possible Implications for the Development of Injurious Pecking.

Injurious pecking (IP) represents a serious concern for the welfare of laying hens (Gallus gallus domesticus). The risk of IP among hens with intact beaks in cage-free housing prompts a need for solutions based on an understanding of underlying mechanisms. In this review, we explore how behavioural programming via prenatal and early postnatal environmental conditions could influence the development of IP in laying hens. The possible roles of early life adversity and mismatch between early life programming and subsequent environmental conditions are considered. We review the role of maternal stress, egg conditions, incubation settings (temperature, light, sound, odour) and chick brooding conditions on behavioural programming that could be linked to IP. Brain and behavioural development can be programmed by prenatal and postnatal environmental conditions, which if suboptimal could lead to a tendency to develop IP later in life, as we illustrate with a Jenga tower that could fall over if not built solidly. If so, steps taken to optimise the environmental conditions of previous generations and incubation conditions, reduce stress around hatching, and guide the early learning of chicks will aid in prevention of IP in commercial laying hen flocks.

Effect of Different Percentage of Camelina sativa Cake in Laying Hens Diet: Performance, Welfare, and Eggshell Quality.

Although camelina [Camelina sativa (L.) Crantz] is a good source of protein, antioxidants, and polyunsaturated fatty acids, its antinutritional compounds limit its use in animal feeding. The aim of this study was to verify the effect of feeding laying hens with up to 20% of camelina cake from a breeding line containing a low level of glucosinolates on performance, welfare, and eggshell quality. Two hundred and forty Hy-Line® hens from 18 to 51 weeks of age were divided into three treatments: control (C), camelina cake 10% (CAM10), and camelina cake 20% (CAM20). Egg number was recorded daily, while egg weight, feed consumption, and mortality were recorded weekly. At 24 and 43 weeks of hen age, shell resistance to fracture was measured. Our results demonstrate no detrimental effects for CAM10 and CAM20 diets on feed intake, growth performance, and welfare. No difference in egg production was detected among the diets. The significant (p < 0.05) interaction of diet and age factors suggest that the addition of camelina cake, up to 20%, likely protects the eggshell of older hens. Our findings confirm that camelina cake might be an alternative and sustainable protein source for hens.

Effect of Feed Restriction on the Behaviour and Welfare of Broiler Chickens.

Under intensive rearing conditions, the welfare of broiler chickens may be at risk depending on genotype and sex, due to their different growth rates. The practice of quantitative feed restriction may also impact on welfare. This study aimed to evaluate behaviour and corticosterone content in plasma and faeces at different ages using 896 one-day-old chicks housed in 32 pens, allocated to 8 groups, i.e., 2 genotypes (standard vs. high breast yield) × 2 sex × 2 feeding plans (ad libitum vs. restricted, AL vs. FR). The feeding system affected the percentage of standing (9.84% vs. 11.7% in AL vs. FR; p ≤ 0.001), feeding (7.51% vs. 8.17%; p ≤ 0.01) and sitting/lying (67.0% vs. 64.1%; p ≤ 0.001), and the faeces corticosterone content (12.2 vs. 13.6 ng/g in AL vs. FR; p ≤ 0.10). Sex affected the percentage of pecking other chickens, standing and comfort behaviours. Changes in behaviour were recorded between high and standard breast yield genotypes with faeces corticosterone which tended to be higher in the former (p ≤ 0.10). Significant interactions between the main factors and age were observed. Major changes in behaviour were due to feed restriction, which stimulated activity during restriction.

Animal-Based Measures for the On-Farm Welfare Assessment of Geese.

Currently, no specific animal-based measures (ABMs) protocols are available for geese in commercial meat production systems. Following a critical review of the literature and consultation of experts, seven ABMs, potentially valid and feasible for the on-farm welfare assessment of geese, were identified and then tested in 12 farms in Poland to assess their inter-observer reliability. Two observers conducted the assessment, which was divided into two phases. First, a handling test assessed the human-animal relationship (HAR), and a 100% inter-observer reliability was achieved by the observers when evaluating the attitudes of stockpeople and the reactions of geese to humans. Next, an animal inspection was conducted, and the observers simultaneously and independently visually evaluated 100 randomly selected geese per farm and assessed whether the selected ABMs could be identified. In terms of inter-observer reliability, high correlation coefficients were found for plumage dirtiness (ρ = 0.745; p < 0.01), twisted wings (ρ = 0.890; p < 0.001), and broken/twisted wings (ρ = 0.858; p < 0.001). The results showed that plumage dirtiness, twisted wings, and broken/twisted wings are valid and reliable measures. Further research should address the reliability of ABMs of geese in other types of production systems.

A Data-Driven Prediction Method for an Early Warning of Coccidiosis in Intensive Livestock Systems: A Preliminary Study.

Coccidiosis is still one of the major parasitic infections in poultry. It is caused by protozoa of the genus Eimeria, which cause concrete economic losses due to malabsorption, bad feed conversion rate, reduced weight gain, and increased mortality. The greatest damage is registered in commercial poultry farms because birds are reared together in large numbers and high densities. Unfortunately, these enteric pathologies are not preventable, and their diagnosis is only available when the disease is full-blown. For these reasons, the preventive use of anticoccidials-some of these with antimicrobial action-is a common practice in intensive farming, and this type of management leads to the release of drugs in the environment which contributes to the phenomenon of antibiotic resistance. Due to the high relevance of this issue, the early detection of any health problem is of great importance to improve animal welfare in intensive farming. Three prototypes, previously calibrated and adjusted, were developed and tested in three different experimental poultry farms in order to evaluate whether the system was able to identify the coccidia infection in intensive poultry farms early. For this purpose, a data-driven machine learning algorithm was built, and specific critical values of volatile organic compounds (VOCs) were found to be associated with abnormal levels of oocystis count at an early stage of the disease. This result supports the feasibility of building an automatic data-driven machine learning algorithm for an early warning of coccidiosis.

Text Mining Analysis to Evaluate Stakeholders' Perception Regarding Welfare of Equines, Small Ruminants, and Turkeys.

Welfare of animals significantly depends on how stakeholders perceive their needs and behave in a way to favor production systems that promote better welfare outcomes. This study aimed at investigating stakeholders' perception of the welfare of equines, small ruminants, and turkeys using text mining analysis. A survey composed by open-ended questions referring to different aspects of animal welfare was carried out. Text mining analysis was performed. A total of 270 surveys were filled out (horses = 122, sheep = 81, goats = 36, turkeys = 18, donkeys = 13). The respondents (41% veterinarians) came from 32 different countries. To describe welfare requirements, the words "feeding" and "water" were the most frequently used in all the species, meaning that respondents considered the welfare principle "good feeding" as the most relevant. The word "environment" was considered particularly important for turkeys, as well as the word "dry", never mentioned for other species. Horses stakeholders also considered "exercise" and "proper training" important. Goat stakeholders' concerns are often expressed by the word "space", probably because goats are often intensively managed in industrialized countries. Although the sample was too small to be representative, text mining analysis seems to be a promising method to investigate stakeholders' perception of animal welfare, as it emphasizes their real perception, without the constraints deriving by close-ended questions.

Differences in prevalence of welfare indicators in male and female turkey flocks (Meleagris gallopavo).

Previous research has shown that the transect walks (TW) method provide a practical and effective approach to welfare assessment in broiler and turkey farms. This method for turkey welfare assessment is reasonable in terms of time demands within minimal costs. Furthermore, TW approach resembles the routine checks used by farmers. The overall aim of this study was to verify the feasibility of the TW method as potential practical tool for on-farm welfare assessment in turkeys during the fattening period. A total of 14 commercial turkey farms (8 male and 6 female flocks) of the same genetic strain (British United Turkeys [B.U.T.] - Big 6) with similar management standard procedures were evaluated. Bird ages at evaluation ranged from 122 to 138 D and 90 to 103 D old, for males and females, respectively. Two independent assessors walked slowly on randomized longitudinal paths (transects) within each house, while recording the prevalence of birds showing any of the 12 welfare and health indicators considered: immobility, lameness, wounds, small size, featherless, dirtiness, sick, terminally ill, dead, and behavioral indicators, such as, aggression towards mate, interaction with humans and mating. The effect of assessor, gender, and interaction assessor by gender was evaluated by using ANOVA. Reliability of the method was noted by the effect of gender (P < 0.001) for immobility, lameness, wounds, and dirtiness indicators. Male flocks showed higher prevalence of immobility (0.035±0.004% vs. 0.004±0.001%), lameness (2.269±0.108% vs. 1.253±0.051%), wounds (0.288±0.014% vs. 0.127±0.009%), and dirtiness (0.050±0.004% vs. 0.022±0.004%) as compared to female flocks. Differences among assessors were relatively minor, with differences detected only for back and tail wounds, dirtiness, aggression towards mate, and interaction with humans. This study reports advantages and limitations of this method for welfare assessment on-commercial turkey flocks and it is the first description of the Italian welfare profile of turkey's commercial flocks.

Environmental impact assessment of alfalfa (Medicago sativa L.) hay production.

On-farm production of hay and high-protein-content feed has several advantages such as diversification of on-farm cultivated crops, reduction of off-farm feed concentrates transported over long distances and a reduction in runoff during the winter season if grown crops are perennial. Among those crops cultivated for high-protein-content feed, alfalfa (Medicago sativa L.) is one of the most important in the Italian context. Nevertheless, up to now, only a few studies have assessed the environmental performance of alfalfa hay production. In this study, using the Life Cycle Assessment approach, the environmental impact of alfalfa hay production in Northern Italy was analyzed. More in detail, two production practices (without and with irrigation) were compared. The results show that alfalfa hay production in irrigated fields has a better environmental performance compared to non-irrigated production, mainly because of the yield increase achieved with irrigation. In particular, for the Climate Change impact category, the impact is equal to 84.54 and 80.21kgCO2/t of hay for the scenario without and with irrigation, respectively. However, for two impact categories (Ozone Depletion and Human Toxicity-No Cancer Effect), the impact of irrigation completely offsets the yield increase, and the cultivation practice without irrigation shows the best environmental performance. For both scenarios, the mechanization of harvest is the main environmental hotspot, mostly due to fuel consumption and related combustion emissions. Wide differences were highlighted by comparing the two scenarios with the Ecoinvent process of alfalfa hay production; these differences are mostly due to the cultivation practice and, in particular, to the more intensive fertilization in Swiss production.

The transect method: a novel approach to on-farm welfare assessment of commercial turkeys.

Currently, no animal-based protocol for on-farm welfare assessment of commercial turkeys is available. The birds' size and flighty nature make obtaining a representative sample using traditional methods difficult. The transect walks (TW) approach provides a potential alternative for on-farm assessments of turkey welfare. We compared the TW approach with a traditional method, and data collected as the birds were moved out of the house during the load out process (L). Ten commercial 19- to 20-week-old Hybrid turkey flocks were evaluated (1 flock/house/farm). Half of the flocks were housed on farms deemed as "faring well" by the company, the other half were on "suboptimal" farms. Each house was subdivided longitudinally into 4 transects. Two observers walked the transects in random order, recording the total number of birds per transect that were immobile; lame; aggressive towards a mate; interacting with humans; with visible head, vent, or back wounds; engaging in mounting behaviors; small; featherless; dirty; sick; terminal; or dead. Flocks were re-evaluated on the same day using the individual sampling method (S), where randomly selected birds were scored as they took 10 steps. Flocks were re-assessed within 48 h of the transect evaluation, as birds were funneled out of the house during load out. Using ANOVAs we determined the effects of observers, method, management, and their interactions on proportions of turkeys per house within each category. Outcome parameters were not affected by management (P>0.05 for all) or observer (P>0.05 for most), but an assessment method effect was detected (P<0.05). S differed from the 2 other methods (P<0.05) for most parameters except aggression towards a mate, back wounds, dirty, sick, and vent wounds. Differences were not detected between data collected using TW and during L, except for dead (P=0.0007) and immobile (P=0.007). Results suggest that the TW method is a promising tool for on-farm turkey welfare assessment as it produced results similar to those obtained at L when all birds could be scored individually.

Mantle thermal pulses below the Mid-Atlantic Ridge and temporal variations in the formation of oceanic lithosphere.

A 20-Myr record of creation of oceanic lithosphere is exposed along a segment of the central Mid-Atlantic Ridge on an uplifted sliver of lithosphere. The degree of melting of the mantle that is upwelling below the ridge, estimated from the chemistry of the exposed mantle rocks, as well as crustal thickness inferred from gravity measurements, show oscillations of approximately 3-4 Myr superimposed on a longer-term steady increase with time. The time lag between oscillations of mantle melting and crustal thickness indicates that the mantle is upwelling at an average rate of approximately 25 mm x yr(-1), but this appears to vary through time. Slow-spreading lithosphere seems to form through dynamic pulses of mantle upwelling and melting, leading not only to along-axis segmentation but also to across-axis structural variability. Also, the central Mid-Atlantic Ridge appears to have become steadily hotter over the past 20 Myr, possibly owing to north-south mantle flow.