Mannan oligosaccharide as an alternative to infeed antibiotics to improve growth performance of broilers: a meta-analysis.

1. The purpose of this meta-analysis was to evaluate the effect of mannan oligosaccharide (MOS) as an alternative to antibiotic growth promoters (AGP) on feed intake (FI), body weight gain (BWG), and feed conversion ratio (FCR) of broilers.2. Data from 75,594 broilers were extracted from 17 articles (19 trials) published between January 2010 and March 2023. The main criteria for the publication selection were as follows, at least three treatments applied (negative control group without MOS or AGP versus MOS or AGP supplementation), presence of performance results, and intra-experimental variation associated with the mean of response (such as standard error). Treatments were classified as control, MOS, or AGP, and adjusted means of treatment were compared. Additionally, the average daily gain (ADG) and average daily feed intake (ADFI) of each type of supplementation were calculated relative (Δ) to the control group (ΔADFI and ΔADG) and expressed as a percentage of the difference.3. Broilers receiving a diet supplemented with MOS had a 3.7% better BWG and 3% better FCR compared to the control diet (P < 0.001), but these variables were similar to the group receiving AGP supplementation. No significant difference was detected in FI among treatments (P > 0.050). The relationship between ΔADG and ΔADFI was linear for the MOS and AGP-supplemented group (P < 0.050). The ΔADG of broilers fed diets supplemented with MOS or AGP was 6.4% and 4.54% when ΔADFI was zero, respectively. The ΔADG of MOS increased by 0.58% for every 1% of increasing observed in ΔADFI. The corresponding value for the increased ΔADG for the AGP group was 0.69%.4. The results of this meta-analysis indicated that MOS supplementation is effective in increasing BWG and reducing FCR, similar to broilers fed a diet supplemented with AGP. Therefore, MOS is a safe and sustainable alternative for AGP-free poultry production.

Different N6: N3 Ratios on Performance, Egg Quality, and Health of 81-Week-Old Laying Hens

This study aimed to evaluate different n6:n3ratios on performance, serum biochemical variables, and egg quality in 81-week-old laying hens. A total of 224 laying hens, 81-week-old Hysex White, were utilized and distributed in a completely randomized design consisting of seven treatments and eight replications of four birds per cage, totaling 56 cages. The experimental treatments consisted of seven different n6:n3fatty acid ratios: 1.0:1.0, 2.0:1.0, 4.0:1.0, 8.0:1.0, 16.0:1.0, 32.0:1.0, and 64.0:1.0. For diet formulation, sunflower oil, rich in omega-6, and linseed oil, rich in omega-3, were used. Productive performance, egg quality and serum biochemical variables of laying hens were evaluated at the end of the cycle at 26, 27, and 28 days. Analysis of variance (ANOVA) was conducted and orthogonal contrasts were used to obtain the sum of squares of the treatment of the analysis of variance in polynomial regression effects. Egg quality variables did not vary significantly between the diets. Therefore, diet supplementation with polyunsaturated fatty acids at different ratios was possible without altering egg quality. The only exception was Haugh unit, which displayed a quadratic effect indicating that the best value was the n6:n3ratio of 32, according to data significance. It was concluded that an increase in n6:n3ratios decreases laying hens' feed intake. The n6:n3 ratio of 34.64 provides greater eggs' Haugh units, decreasing from that value on. The ratios of n6:n3 did not influence the hens' serum biochemical variables.(AU)

Agaricus subrufescens and Pleurotus ostreatus mushrooms as alternative additives to antibiotics in diets for broilers challenged with Eimeria spp.

1. The effect of A. subrufescens and P. ostreatus mushrooms as an alternative to antibiotics (avilamycin or monensin sodium) on performance, intestinal morphometry, immunity, and biochemical profile of broilers challenged with Eimeria spp. was studied from 1 to 42 d old. A total of 900 male Cobb® broiler chicks were distributed, according to a completely randomised design, into five treatments with six replicates each.2. The treatments consisted of: negative control (NC) - basal diet (BD) with no anticoccidial or antibiotic (non-challenged birds); negative control challenged (NCC) - NC fed to Eimeria spp. challenged birds; BD with 0.2% A. subrufescens inclusion for challenged birds (As), BD with 0.2% P. ostreatus inclusion for challenged birds (Po); and a positive control - BD with anticoccidial and antibiotic inclusion for challenged birds (ATB).3. At 11 d.o., the birds were each inoculated orally with 1 ml solution containing 2 × 105 sporulated oocysts/ml Eimeria acervulina and 2 × 104 sporulated oocysts/ml E. maxima and E. tenella.4. Birds subjected to Eimeria spp. challenge up to 21 d of age had greater crypt depth, indicating that the presence of undesirable microorganisms had an effect on cell proliferation.5. At 21 d old, the birds receiving ATB had higher average weight gain (AWG), feed intake (AFI), and feed conversion ratio (FCR) compared to those fed diets supplemented with mushrooms (As or Po). For the total rearing period (42 days), the birds that received ATB had higher AWG and AFI (P < 0.001) compared to those that received As or Po diets. Feeding avilamycin did not affect (P = 0.0676) FCR compared to the As or Po diet groups.6. From the morphometric and blood analyses there were no differences between broilers fed ATB, Po or As diets in either rearing periods. However, Po and As supplementation lowered blood triglyceride levels. At 21d there was a difference (P < 0.05) for MCV and haemoglobin, in which the mushrooms were similar to the antibiotic. At 42 d, there was a difference (P < 0.05) in haematocrit, erythrocyte, MCV, H: L, protein and albumin variables, in which the use of mushrooms was similar to the positive control, demonstrating that both (mushrooms and antibiotics) promoted a certain improvement in the health of the chickens.7. A. subrufescens and P. ostreatus can be used in broiler diets without compromising intestinal or haematological status, however, these ingredients did not result in improvements in performance.