Effects of long-term supplementation with amino acid-complexed manganese on performance, egg quality, blood biochemistry and organ histopathology in laying hens

The present study aimed to assess the impact of dietary valine levels on layer production performance, egg quality, immunity, and intestinal amino acid absorption of laying hens during the peak lay period. For this purpose, a total of 960 33-week-old Fengda No.1 laying hens were randomly divided into five experimental groups and fed with valine at the following different levels in a feeding trial that lasted 8 weeks: 0.59, 0.64, 0.69, 0.74, and 0.79%, respectively. Productive performances were recorded throughout the whole rearing cycle and the egg quality, serum indexes, and small intestine transporters expression were assessed at the end of the experiment after slaughter (41 weeks) on 12 hens per group. Statistical analysis was conducted by one-way ANOVA followed by LSD multiple comparison tests with SPSS 20.0 (SPSS, Chicago, IL, USA). The linear and quadratic effects were tested by SPSS 20.0. Egg mass, laying rate, broken egg rate, and feed conversion ratio were significantly improved with increasing dietary valine levels. However, the egg weight, eggshell thickness, albumen height, Haugh unit, and egg yolk color were significantly decreased with increasing dietary valine levels. Serum catalase (CAT), immunoglobulin A (IgA) and IgM levels, and malondialdehyde (MDA) levels were negative responses to valine-treated laying hens. Dietary supplemented valine enhanced the trypsin activity of duodenum chime and promoted the mRNA expression levels of ATB0,+, and LAT4 in the jejunum and corresponding serum free Ile, Lys, Phe, Val, and Tyr level. However, valine treatment significantly downregulated the mRNA expression levels of PePT1, B0AT1, LAT1, and SNAT2 in the small intestines and corresponding serum free Arg, His, Met, Thr, Ala, Asp, Glu, Gly, and Ser level. Our results suggest that 0.79% valine dietary supplementation can improve production performance by promoting amino acid nutrient uptake and utilization, and suggest a supplement of 0.79% valine to diet.

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Relationship between the level and the action period of fiber in diets to laying hens

Acta Scientiarum Animal Sciences ◽

10.4025/actascianimsci.v43i1.49033 ◽

2020 ◽

Vol 43 ◽

pp. e49033

Author(s):

João Paulo Ferreira Rufino ◽

Frank George Guimarães Cruz ◽

Ronner Joaquim Mendonça Brasil ◽

Pedro Alves de Oliveira Filho ◽

Ramon Duque Melo ◽

...

Keyword(s):

Experimental Design ◽

Specific Gravity ◽

Laying Hens ◽

Egg Quality ◽

Eggshell Thickness ◽

Egg Weight ◽

Tukey Test ◽

Negative Effect ◽

The Relationship

The aim of the present study was to evaluate the relationship between the level of fiber and its action period in diets to laying hens on performance and egg quality. 180 Hisex white hens (65 weeks-old) were randomly allocated to 3 groups of 60 birds each, comprising 10 replicates of six birds per treatment. The experimental design was factorial scheme considering three levels of fiber (2.50, 4.87 and 7.24%) in birds’ diets, and three action periods of this fiber (short - 21 days, medium - 56 days, and long - 105 days) in the feed. The estimates of treatments were firstly subjected to ANOVA and a subsequent Tukey test at 5%. Birds fed diets with moderate levels of fiber (4.87%) presented better (p < 0.05) performance. High levels of fiber caused a significant reduction in performance. Birds fed diets with low and moderate levels of fiber produced eggs with better (p < 0.05) quality. High levels of fiber caused a significant reduction in egg quality. The exposure of birds to diets with fiber for long-term caused a negative effect (p < 0.05) on performance, egg weight and percentage of its main structures, albumen height, yolk height, eggshell thickness, and the specific gravity.

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