A study was conducted to determine if reduced crude protein (CP), amino acid (AA) balanced laying hen diets could maintain egg production and quality with concomitant reduction of production cost. Isoleucine (Ile) was previously reported to be a limiting AA in corn-SBM based layer rations that were reduced by 2 percentage units of CP from the commercial standard (16% CP). A total of 90 White Shaver hens (3 treatments, 5 hens/cage, n=6) were observed for the current analysis from 28 to 48 wks of age (woa) to determine the economic implications associated with CP reduction without (LCP) or with (LCP+Ile) supplemental Ile, which corresponded to digestible Ile to Lys ratios (dIle:dLys) of 68 and 82%, respectively. Hen day egg production, egg weight, feed conversion, and egg quality (shell strength, Haugh unit) were reported, and excreta samples were analyzed for nitrogen content. Cecal digesta was additionally analyzed for short chain and branched chain fatty acid concentrations. Nitrogen excretion was significantly (P<0.001) lower in hens fed the LCP diets, and production performance was optimized in the LCP+Ile group. Cecal concentrations of propionic (P<0.01) and lactic (P=0.02) acid were higher in the LCP+Ile, and BCFA levels were numerically lower (P>0.1) compared to the other treatments. Based on current (2019 Q1) commodity pricing in the Ontario market, the LCP diet was the least costly and the LCP+Ile diet yielded the greatest revenue, driven by increased egg production. Implementing a LCP, AA fortified diet may also save on additional production costs through improving flock health and reducing costs associated with ventilation and excreta removal.
Keywords: Low CP, isoleucine, laying hen, amino acids, economics.
Abstract presented at the 2019 Animal Nutrition Conference of Canada. Check out all the lectures and speakers for the upcoming 2021 edition here.
More information in https://animalnutritionconference.ca/.