Effect of stocking density on crop fill progression in broilers grown to 14 d

Authors: LINHOSS, J - Mississippi State University; Purswell, Joseph - Jody; Magee, Christopher; CHESSER, G - Mississippi State University

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/23/2020
Publication Date: 3/12/2021
Citation: Linhoss, J.E., Purswell, J.L., Magee, C.L., Chesser, G.D. 2021. Effect of stocking density on crop fill progression in broilers grown to 14 d. Poultry Science. 100:100929. https://doi.org/10.1016/j.psj.2020.11.080.
DOI: https://doi.org/10.1016/j.psj.2020.11.080

Interpretive Summary: Primary breeder guidelines indicate that 95% of chicks should have successfully located feed and water at 24h post placement. Crop fill is commonly used to assess feed and water intake for this purpose. However, crop fill is primarily discussed in trade literature and there is little scientific data to support its use as a brooding quality metric. This study examined crop fill progression at 2, 4, 8, 12, 24, and 48 h after placement and tracked body weight (BW) of birds that presented empty crops at 24 h. In this study, 86% of birds in this study had full, soft, and rounded crops at 24 h, while only 3% of birds had crops that were devoid of food or water at 24 h. BW for birds with empty crops was significantly lower at 7 d (P = 0.0063), but not at 14 d (P = 0.5350). The data indicate that crop fill rates of 95% or higher at 24 h may be difficult to achieve in typical commercial broiler settings. In addition, assessing crop fill may be a useful tool to diagnose conspicuous management problems during brooding, but it does not appear to be a direct predictor of early performance.

Technical Abstract: Crop fill rates are measured as an indirect means of assessing management during the brooding phase. Primary breeder guidelines indicate that 95% of the chicks assessed should present a crop that full, soft, and rounded after 24 h, which indicates chicks have successfully located feed and water. Crop fill progression has received little attention in the scientific literature and is primarily discussed in trade literature, and thus the dynamic nature of crop fill progression has not been previously characterized. This study examined crop fill progression at 2, 4, 8, 12, 24, and 48 h after placement and tracked body weight (BW) of birds that presented empty crops at 24 h; chicks with empty crops were identified to track post-placement BW. 86% of birds in this study had full, soft, and rounded crops at 24 h, while only 3% of birds had crops that were devoid of food or water at 24 h. BW for birds with empty crops was significantly lower at 7 d (P = 0.0063), but not at 14 d (P = 0.5350). The data herein indicate that crop fill rates of 95% or higher at 24 h may be difficult to achieve in typical commercial broiler settings. In addition, assessing crop fill may be a useful tool to diagnose conspicuous management problems during brooding, but it does not appear to be a direct predictor of early performance.