Effects of dietary substitution of peanut meal for soybean meal on egg production, egg quality, oxidative status, and yolk fatty acid profile in laying ducks.

There is an urgent need to evaluate and introduce alternatives for the unsustainable and traditional feed stuffs in poultry. This study evaluated the effects of graded replacement of soybean meal (SBM) by peanut meal (PNM) on egg production, egg quality, oxidative status, and yolk fatty acid profile in laying ducks. In total, 360 Longyan ducks aged 21 weeks were allocated to five treatments, each containing six replicates of 12 birds. Birds were fed the diets containing PNM replacing 0 (control), 25, 50, 75 or 100% of SBM for 16 weeks. With the increase of PNM level, egg production was improved (quadratic, P < 0.05), egg weight and feed consumption were decreased, feed conversion ratio and egg mass were impaired at 100% PNM, and yolk colour was enhanced (quadratic, P < 0.05). Plasma malondialdehyde concentration was increased at 100% PNM, while plasma glutathione concentration was decreased (quadratic, P < 0.01) as PNM substitution increased. Total cholesterol content in yolk decreased (P < 0.01) in response to increased PNM substitution. The contents of saturated fatty acids C20:0 and C22:0 in yolk increased (linear or quadratic, P < 0.05) with increased PNM substitution, but the contents of saturated fatty acid C18:0, monounsaturated fatty acid C22:1, and polyunsaturated fatty acids C18:3n-3 and C22:6n-3 in yolk were decreased (linear, P < 0.05) as PNM replacement increased. The contents in yolk of polyunsaturated fatty acid C18:2n-6, C20:2n-6, C20:3n-6, C20:4n-6, and total amount of polyunsaturated fatty acids increased with the highest contents obtained at 75% PNM substitution. The ratio between n-6 and n-3 increased (linear, P < 0.05) as PNM substitution increased. The transcript abundance in liver of peroxisome proliferators-activated receptors γ and fatty acid synthase showed quadratic (P < 0.05) responses with PNM replacement, with the highest expression of both genes being obtained with 75% substitution with PNM. Replacement of dietary SBM with 100% PNM decreased egg production and antioxidant capacity and increased the ratio of omega fatty acid in yolk between n-6 and n-3 in laying ducks. The obtained results indicate that PNM can be used to replace up to 75% of SBM in the diet of laying ducks without negative effects on the egg-laying production or egg quality. The regression model indicated that the maximal egg mass was obtained at no more than 67.6% replacement of SBM with PNM in the diet of laying ducks.

Purinoceptors, renal microvascular function and hypertension.

Proper renal blood flow (RBF) and glomerular filtration rate (GFR) are critical for maintaining normal blood pressure, kidney function and water and electrolyte homeostasis. The renal microvasculature expresses a multitude of receptors mediating vasodilation and vasoconstriction, which can influence glomerular blood flow and capillary pressure. Despite this, RBF and GFR remain quite stable when arterial pressure fluctuates because of the autoregulatory mechanism. ATP and adenosine participate in autoregulatory control of RBF and GFR via activation of two different purinoceptor families (P1 and P2). Purinoceptors are widely expressed in renal microvasculature and tubules. Emerging data show altered purinoceptor signaling in hypertension-associated kidney injury, diabetic nephropathy, sepsis, ischemia-reperfusion induced acute kidney injury and polycystic kidney disease. In this brief review, we highlight recent studies and new insights on purinoceptors regulating renal microvascular function and renal hemodynamics. We also address the mechanisms underlying renal microvascular injury and impaired renal autoregulation, focusing on purinoceptor signaling and hypertension-induced renal microvascular dysfunction. Interested readers are directed to several excellent and comprehensive reviews that recently covered the topics of renal autoregulation, and nucleotides in kidney function under physiological and pathophysiological conditions (Inscho 2009, Navar et al. 2008, Carlstrom et al. 2015, Vallon et al. 2020).

Comparative influence of dietary probiotic, yoghurt, and sodium butyrate on growth performance, intestinal microbiota, blood hematology, and immune response of meat-type chickens.

This study was conducted to assess the effects of early dietary supplementation with probiotic, yoghurt, and sodium butyrate (SB) on the growth performance, intestinal microbiota, blood hematology, and immune response of broiler chickens. A total of 180 1-day-old SASSO broiler chicks, housed in 12 equal floor pen replicates each of 15 chicks, were assigned randomly to four feeding treatments (three replicates/treatment, n = 45): T1. Basal diet (BD) (control), T2. BD incorporated 1 g of a commercial probiotic per kilogram, T3. BD mixed with 5 g of fresh yoghurt per kilogram, and T4. BD incorporated 0.6 g SB/kg. The experimental birds received the dietary treatments from 1 to 21 days of age. The dietary supplementation (g/kg) with commercial probiotic, yoghurt, and SB during the first 21 days of age did not affect broiler's growth performance variables at day 42, relative weight of immunity organs, blood hematological indices, or the ileal and cecal bacterial counts at day 42, but increased the serum IgG levels and reduced the cecal aerobes at day 21. The probiotic and yoghurt treatments increased the serum content of antibody titer against Newcastle disease virus and decreased the counts of ileal aerobes and E. coli at day 21, whereas the SB treatment increased the ileal lactobacilli count at day 21. In conclusion, the tested feed additives displayed beneficial impacts on broilers' gut microbiota at day 21 and serum IgG at day 42, but did not affect the growth performance or blood hematological indices at 42 days of age.

Eggshell quality as influenced by sodium bicarbonate, calcium source, and photoperiod.

The effects of Ca source (limestone or a mixture of one-third limestone and two-thirds oyster shell), NaHCO3 (0 or .5%) and feeding photoperiod (16 or 24 hr) were studied in a 16-week experiment involving 240 Hy-Line W-36 Leghorn hens, 25 weeks of age. Neither egg production (percent hen-day and egg mass, kg egg/bird per 16 weeks) nor feed conversion ratio (kg feed per kg egg) were significantly (P greater than .05) affected by dietary treatment or photoperiod. However, extending the photoperiod to 24 hr significantly (P less than .05) increased feed consumption with a consequent increase in egg weight (P less than .01). Feeding oyster shell in combination with limestone significantly (P less than .05) improved specific gravity of eggs, whereas dietary NaHCO3 significantly (P less than .01) improved elasticity of the egg shell as measured by deformation. Eggshell quality was improved by increasing the photoperiod to 24 hr and was most pronounced when hens were fed diets supplemented with .5% NaHCO3 and limestone as the only source of Ca.

Feed consumption and efficiency of feed utilization in chickens as affected by restriction of feed intake under subtropical conditions.

The influence of restricted feeding was investigated in 1145 Dandarawi (D) and 1092 Rhode Island Red (RIR) chickens and in 294 D and 211 RIR hens in their first laying year. The feed utilization during the rearing period (8 to 22 weeks of age) and the feed utilization for the egg production were not significantly affected by a reduction to 85 or 70% of the ad-libitum feeding ration during rearing and/or in the first laying year of both breeds. A feed restriction to 70% is recommended for D and to 85% for RIR chickens during the rearing period followed by ad-libitum feeding.

Incorporation of sodium bicarbonate into laying rations. I. Effect on egg production and hatchability.

Two experiments were carried out on Fayoumi (I) and Rhode Island Red (II) pullets to study the effect of substituting NaCl (0.67% of the ration) by NaHCO3 (1% of the ration) and the concentration of NaHCO3 (1% and 2% of the ration). Both breeds showed different reactions to the NaHCO3 additions: the laying increased in (I) by 5-6%, whereas it decreased in (II) by 7-14%. Fertility and hatchability increased significantly. The Ca content of the shells showed an increasing trend. The incorporation of 1% sodium bicarbonate into the laying rations is recommended under the conditions of the AR Egypt.

Incorporation of sodium bicarbonate into laying rations. II. Effects on egg quality.

The replacement of 0.67% NaCl in the ration by 1% NaHCO3 leads to improvements of several parameters of the shell quality and some other egg quality characteristics in the Rhode Island Red breed. In the Fayoumi breed this influence was not clearly discernible. This also holds for an increase of the NaHCO3 content in the ration to 2%. Under the conditions in the AR Egypt the addition of 1-2% NaHCO3 for the Rhode Island Red is recommended in order to improve the shell quality and the internal quality of the eggs.