Feeding a persistent laying hen from day 0 until 110 weeks of age: Performance impact

The amount and ratio of protein and energy fed during rearing and laying might influence the growth curve, body composition and laying persistency of hens. We studied the influence of a low or high apparent fecal digestible (AFD) Lys level in all rearing diets and constant or reduced ME level and source during laying (reducing energy over time high oil = REHO; constant energy high oil = CE; reducing energy over time low oil = RELO) on growth and laying persistency in a 2 × 3 factorial arrangements. Per treatment, 240 one-day-old Dekalb White pullets were divided over 8 pens and housed until 110 wk of age. Body weight was measured every 4 wk, feed intake and egg weight weekly, eggs were collected daily. Data were subjected to mixed model analyses. The egg production curve was modelled using a non-linear regression function. In general, there were no interaction effects (P > 0.05). Feeding a low AFD Lys diet during rearing reduced feed intake and therefore AFD Lys and ME intake (P < 0.001), resulting in lower BW long-term (wk 5 to 24, 48, 56 to 72, 96 and 110; P < 0.05). Egg mass production of pullets fed low AFD Lys was slightly higher in wk 44 to 72 (P = 0.038) and 72 to 100 (P = 0.056), while laying persistency was reduced, indicated by a longer peak production phase but a higher slope of decline (modelled data; P < 0.001). During laying, hens fed CE diets had the lowest feed and AFD Lys intake from wk 20 onwards (P < 0.05), but a similar ME intake. Egg weights of hens fed RELO diets were lighter from wk 20 onwards (P < 0.001). The peak production phase was 3 wk shorter for hens fed CE diets (P < 0.001), while the slope of decline after wk 85 was steeper for hens fed RELO diet (P < 0.001). Feeding higher AFD lysine during rearing and optimizing energy source during laying can improve BW, feed efficiency, and laying persistency, emphasizing the long-term impact of early nutrition.