Nutrition Practice to Alleviate the Adverse Effects of Stress on Laying Performance, Metabolic Profile and Egg Quality in Peak Producing Hens: II. The Probiotic Supplementation

Dietary Effects of Some Plant Extracts on Laying Performance, Egg Quality, and Some Blood Parameters in Laying Hens at Different Cage Densities

This study was carried out to determine the effects of cage density and anise extract (AE), thyme extract (TE), and black cumin extract (BCE) supplementation in the diet of laying hens on laying performance, egg quality, and some blood parameters. A total of 288 Lohman White commercial hens were blocked according to the location of their cages. The four dietary treatments included a control, basal diet + 250 mg/kg of AE, basal diet + 250 mg/kg of BCE, and basal diet + 250 mg/kg of TE for 12 weeks. The cage density affected egg production (p < 0.05), feed consumption (p < 0.01), and cracked eggs (p < 0.05). Increasing the cage density caused a linear decrease in egg production and feed consumption. Compared to the control, there was a decrease in feed consumption (p < 0.01) in the plant extract groups, and in parallel, egg production decreased. An increased cage density did not affect the egg quality traits except the shell strength. The shell strength, yolk color, yolk index, albumen index, and Haught unit were significantly affected by the plant extracts. The cage density and plant extracts had a significant effect on the serum corticosterone and glucose (p < 0.01). The highest values of corticosterone and glucose were recorded for dietary TE with a cage density of 4 birds/cm2. On the other hand, the lowest values of these parameters were recorded for AE addition with a cage density of 3 birds/cm2. As a result, an increased cage density was associated with stress and depression in the feed consumption and metabolic profiles. Supplemental AE, BCE, and TE improved the laying performance and metabolic profiles.

Humic Substances as a Versatile Intermediary

Humic substances are organic ubiquitous components arising in the process of chemical and microbiological oxidation, generally called humification, the second largest process of the carbon cycle. The beneficial properties of these various substances can be observed in many fields of life and health, whether it is the impact on the human organism, as prophylactic as well as the therapeutic effects; animal physiology and welfare, which is widely used in livestock farming; or the impact of humic substances on the environment and ecosystem in the context of renewal, fertilization and detoxification. Since animal health, human health and environmental health are interconnected and mutually influencing, this work brings insight into the excellence of the use of humic substances as a versatile mediator contributing to the promotion of One Health.

The importance of nutrition in alleviating high stocking density stress in poultry

In recent decades, the number of birds reared per unit area has dramatically spiked to increase profitability in egg and meat production. However, nowadays, the increase in sensitivity to animal welfare and consumer demands brings along with it a raised interest in stocking density. Stocking density is defined either as the number of animals or body weight per unit area or as the area per animal. High stocking density, which is a stress factor, can be defined as an increase in the number of animals per unit area or a decrease in the area per animal. Stress caused by high stocking density negatively affects the bird’s physiology and performance as well as the quality of the product obtained. The ideal stocking density should be 9 laying hens, 35 kilogrammes for broilers, and 45 quails per square metre. Otherwise, one will observe stress indicators in birds reared in more than the recommended stocking density per unit area and, consequently, a decrease in bird growth, egg production, feed efficiency, and egg or meat quality. Apart from increasing the concentrations of amino acids such as lysine, methionine, tryptophan and arginine, minerals such as selenium and chromium, and vitamins such as C and E in the diet, the addition of additives such as probiotics, humates, phytophenol compounds, and propolis is also effective in reducing or eliminating these negative effects caused by high stocking density. As a result, regulations in the nutrition of animals are effective in reducing/preventing such negative effects, thus improving animal welfare and ensuring the maintenance of optimum yield.

Effects of Stocking Density in Group Cages on Egg Production, Profitability, and Aggressive Pecking of Hens

There is an increasing concern about welfare issues related to battery cages, which are commonly used in Vietnam, and requires a modified cage that improves hen welfare while retaining its economic and management advantages. We combined adjacent conventional cages to form group cages to examine the effects of stocking density on egg production, economic returns, and aggressive pecking of hens. The control group included triplicate conventional cages with four birds/single cage (12 hens per three cages) or 450 cm² area per hen. Three group cage treatments were set up with 10, 12, and 14 birds per group cage or 540, 450, and 386 cm² of floor area per hen, respectively. Compared to 14 birds per cage, hens housed at 10 birds per group cage had a higher hen-day production, consumed less feed, and thus had a better feed conversion ratio/dozen eggs. Reducing the stocking density to 10 birds per group cage resulted in additional production cost, but it was compensated for by a high egg income, and significantly decreased aggressive pecks. Group cages benefit hen performance, profitability, and welfare when decreasing the stocking density to 10 birds per cage with 540 cm²/hen.

Effects of supplementation of dietary humate, probiotic, and their combination on performance, egg quality, and yolk fatty acid composition of laying hens

This study was carried out to determine the effects of addition of humate, probiotic, and their combination into diets on performance, egg quality, and yolk fatty acid composition of hens during the second laying period. Lohmann LSL white layers (n = 192), 46 weeks of age, were randomly divided into 4 groups and fed with basal diet (control, C), 0.3% humate (H), 0.3% probiotic (P), 0.15% humate + 0.15% probiotic (HP) for 18 weeks. Feed consumption and egg production were determined daily, egg weight was measured biweekly, and body weights were recorded at the beginning and the end of the experiment. Also, 12 egg samples from each group were randomly collected to determine the egg quality every 30 days. Laying performance, yolk color, and fatty acid composition were significantly (P < 0.05 and P < 0.01) affected by addition of humate, probiotic, and their combination into diets of layers. The HP group had higher cracked egg yield and feed conversion ratio values than control and H and P groups. Except for egg yolk color, the other egg quality parameters such as shape index, shell strength, shell thickness, albumen index, yolk index, and Haught unit were not affected by treatment (P < 0.05 and P < 0.01). The egg yolks of treatment groups had less stearic acid than those of control group. In conclusion, supplementation of humate and probiotic into the diets of laying hens increased monounsaturated fatty acids in yolk and improved feed conversion ratio and egg yolk color.

Production, nitrogenous compounds in manure and serum chemistry of laying hens provided multi-species (Lactobacillus spp.) probiotics

Context A practical, low-cost suggestion for industry to reduce ammonia (NH3) in layer houses is use of Lactobacillus species (L. rhamnosus, L. paracasei and L. plantarum) in drinking water or feed. Thus, we investigated their short-term (8 weeks) use in young layers. Aim A combination of species of Lactobacillus (L. rhamnosus, L. paracasei and L. plantarum at 1.0 × 1012 CFU/kg feed) was provided for laying hens in order to investigate effects on production, nitrogenous compounds in manure, serum chemistry and uric acid in the liver. Method Ninety-six White Leghorns (32 weeks old) were randomly assigned to a control diet (commercial feed) or a diet containing commercial feed + probiotics (g/kg feed: L. rhamnosus 1.667, L. paracasei 0.667 and L. plantarum 0.740) and fed for an additional 8 weeks. Key results No significant major effects were observed among diets on bodyweight, feed intake, egg production or feed conversion ratio. Numerical reductions were noted for feed intake (10%) and feed conversion ratio (9%) at Week 2 for layers receiving probiotics as compared to the control. Ammonia, ammonium-nitrogen (N), total Kjeldahl N and total N in manure were not changed significantly by probiotics, nor did probiotics significantly affect the serum profile (ammonia, uric acid, total protein, albumin and creatine kinase) or uric acid in the liver. There was a numerical but non-significant increase in creatine kinase (11%) after 8 weeks in serum of hens receiving probiotics; likewise, there was a non-significant 8% increase in uric acid concentration in the liver of hens receiving probiotics at the end of the experimental period. Conclusion The probiotics (L. rhamnosus, L. paracasei and L. plantarum at 1.0 × 1012 CFU/kg feed) used in this study did not significantly reduce N-containing compounds in manure of 32–40-week-old layers. Implications Age, different types of layers (and broilers) and mode of administration or concentration of probiotics play important roles in outcomes. Extensive collaborative studies are needed to provide definitive answers for use of probiotics in layer (as well as broiler) feed for reduction of N-containing compounds in poultry houses.

Response of broiler chickens reared at high density to dietary supplementation with licorice extract and probiotic

This study evaluated the effects of licorice extract and probiotic on performance, excreta characteristics and welfare-related parameters of broiler chickens reared in high stocking density. Three hundred and thirty-six 1-day old broiler chicks (Ross 308) were used in a completely randomized design with five treatments and four replicates for 42 days. Treatments were as follows: (a) positive control (PC, 12 chicks/m² ); (b) negative control (NC, 18 chicks/m² ); (c) NC + 500 ppm licorice extract (LE); (d) NC + 200 ppm probiotic (P); (e) NC + ppm LE + ppm P. Body weight gain (BWG) was affected negatively by increased density in the growing period (p < 0.05). At high density, BWG was increased in the growing and whole period by adding LE and P separately and in combination (p < 0.01). Feed conversion ratio (FCR) was not affected by stocking density. Excreta weight (g/bird) and dry matter (DM, %) were reduced by increasing density (p < 0.01). Use of feed additives at high stocking density had no significant effect on excreta weight, but DM content of excreta was higher in NC + LE + P than NC. Gait problems and footpad and hock burns were increased by increased stocking density, but were not altered by feed additives. In conclusion, licorice extract and probiotic improved BWG of broilers reared at high stocking density; however, these birds had some disorders in footpad, hock and walking ability.