Heat and moisture production and minimum ventilation requirements of tom turkeys during brooding-growing period.

Abstract

Heat and moisture production rates of Nicholas tom turkeys raised under lab-scale commercial production settings were continually measured during a five-week brooding-growing period. Functions were established that relate age and body mass (BM) of the birds to their specific total heat production rate (THP), sensible heat production rate (SHP), moisture production rate (MP), and CO 2 production rate. MP of the current study included both latent heat loss of the birds and evaporation of moisture from the litter and drinkers. Comparison of the HP and MP data from the current study with those in the ASAE Standard (EP 270.5) for BM = 0.1 to 1.1 kg revealed a 4% (for BM = 0.1 kg) to 282% (for BM = 1.0 kg) higher MP and a 2% to 107% lower SHP for the current study. THP from the current study was generally greater (up to 49%) than that in the Standard except for younger birds (< 0.1 kg) whose THP was 36% less than that in the Standard. THP of the experimental tom turkeys peaked near two weeks of age. Compared with the literature data, HP and MP characteristics of the litter-grown young turkeys more closely resemble those of equal BM broilers raised on litter (Reece and Lott, 1982). Minimum ventilation rates (MVR) based on the new MP data for the five-week brooding-growing period were determined and tabulated for selected cold outside conditions and thermoneutral inside conditions. There were substantial discrepancies in MVR between the literature (MWPS, 1990) recommendations and the values derived from this study, with the literature MVR being 20 to 557% of the derived MVR. The age- or BM-dependent MVR obtained from the current study provide a new, convenient reference for ventilation design and operation of turkey brooder houses. Moreover, the equations of CO2 production rate from this study provide a practical tool for estimating ventilation rates in naturally ventilated brooder facilities. The results further revealed the urgent need to systematically update the literature HP and MP data for ventilation design of animal structures so that modern genetics, nutrition, housing systems, and management schemes can be more realistically reflected