title: Effect of supplementation of lysine producing microbes vis-a-vis source and level of dietary protein on performance and egg quality characteristics of post-peak layers.
abstract: OBJECTIVE
  The aim was to study the effect of supplementation of lysine producing microbes (LPM) as an in vivo source of lysine on performance and egg quality characters of post-peak layers.
  
  
  METHODS
  BIS (1992) specified diets (except crude protein [CP] and lysine) were prepared using either soybean meal (SBM) or groundnut extractions (GNE) or sunflower extractions (SFE) with 16 and 15% CP resulting in six control diets. Further, each control diet was fortified with either synthetic lysine or LPM to meet BIS (1992) specified lysine requirement resulting in the set of 12 test diets. Each of the eighteen diets was offered to quadruplets groups of 4 post-peak (52 weeks) commercial laying hens in each. The trial lasted for 119 days.
  
  
  RESULTS
  The results revealed that the feed consumption and body weight changes and Roche yolk color and yolk index were significantly (p ≤ 0.05) different among different treatments. However, egg production, feed efficiency, egg weight, egg shape index, Haugh unit score, albumen index and shell thickness, and net returns remained non-significant (p ≤ 0.05) among different treatments. Among main factors, protein level (16% and 15% CP) made a significant (p ≤ 0.05) difference in egg production (79.6 and 75.1%) and feed efficiency (2.64 and 2.81 kg feed/kg egg mass, respectively). Among protein source GNE- and SFE-based diet fed groups showed significantly (p < 0.0%) higher feed consumption and body weight gain than SBM based diets fed birds. Yolk color (7.0, 7.3 and 7.3, respectively) and yolk index (0.40, 0.38 and 0.43, respectively) were significantly (p ≤ 0.05) different from the protein sources. CP level and Protein source interaction effects showed significant differences in albumen index and Haugh unit score.
  
  
  CONCLUSIONS
  Optimum level of protein (16% CP) and GNE as a source of protein tended to be superior in increasing the performance and egg characteristics of post-peak layers and supplementation of lysine in either synthetic or LPM form found to be beneficial in optimizing their performance.
authors.affiliation: Department of Animal Nutrition, Livestock Research and Information Center, Karnataka Veterinary and Fisheries Science University, Nagamangala, Mandya, Karnataka, India.
authors.forename: G U
authors.initials: GU
authors.lastname: Manju
authors.affiliation: Department of Animal Nutrition Veterinary College, Karnataka Veterinary and Fisheries Science University Hebbal, Bangalore, Karnataka, India.
authors.forename: B S V
authors.initials: BS
authors.lastname: Reddy
authors.affiliation: Department of Animal Nutrition, Veterinary College, Karnataka Veterinary and Fisheries Science University, Hebbal, Bangalore, India.
authors.forename: Gideon
authors.initials: G
authors.lastname: Gloridoss
authors.affiliation: Department of Animal Nutrition, Veterinary College, Karnataka Veterinary and Fisheries Science University, Hebbal, Bangalore, India.
authors.forename: T M
authors.initials: TM
authors.lastname: Prabhu
authors.affiliation: Department of Animal Nutrition, Veterinary College, Karnataka Veterinary and Fisheries Science University, Shivamogga, Karnataka, India.
authors.forename: K S
authors.initials: KS
authors.lastname: Giridhar
authors.affiliation: Department of Animal Nutrition, Veterinary College, Karnataka Veterinary and Fisheries Science University, Hassan, Karnataka, India.
authors.forename: N
authors.initials: N
authors.lastname: Suma
keywords: egg characteristics; lysine; lysine producing microbes; performance; post peak layers