PS10-24. Utilization of Deciduous Tree Leaf Meal as a Component of a Complete Diet.

Abstract

Non-traditional feeds are utilized in animal agriculture as a method of reducing feed costs. Given their relative abundance, chemical and nutritional composition, and a sound understanding of how to process and incorporate them into diets, deciduous tree leaves may be a valuable feed resource for domestic livestock. Dried, ground leaf meals of white oak (WOLM) and tulip poplar (TPLM), from the manual collection of fall dropped leaves, were evaluated as alternative feeds. This evaluation involved compositional analysis, including tannin analysis (total phenolic compounds [TPC] and protein precipitation capability [PPC] with values expressed as catechin equivalents [CE]) and by leaf meal utilization in single batch per treatment generated, complete meal and pelleted growing lamb diets. Leaf meals were moderately low in protein (5.99 and 6.81 % CP) and fiber (39.93 and 36.25% NDF) for WOLM and TPLM. Both TPC and PPC existed in WOLM (5.40 and 1.22 CE) and TPLM (0.31 and 0.33 CE), respectively. All non-lamb experimental data was analyzed utilizing the general lineal modeling procedures of SAS with lamb related data analyzed utilizing the mixed effects procedures of SAS. Total phenolic compounds of diets that utilized WOLM and those that had no leaf meal decreased (P < 0.01) as a result of diet pelleting. However, TPC of diets that utilized TPLM were not affected (P > 0.05) by pelleting. Protein precipitating capability of diets decreased (P < 0.01) as a result of pelleting, further indicating destruction or inactivation of associated protein-precipitating compounds and their functionality. Leaf meals at high and low inclusion (50 and 100% of DM supplied by soybean hulls), were incorporated into complete pelleted diets (18% CP: Control diet contained 20% soybean hulls) and used in a growing lamb metabolism study (n = 6 crossbred lambs, 2 simultaneous Latin Square experiments) investigating apparent total tract digestibility and protein metabolism. Addition of leaf meals as a replacement of soybean hulls altered pellet quality (P < 0.001), while replacement decreased total-tract digestibility of dry-matter (P < 0.01), organic-matter (P < 0.01), neutral detergent fiber (P < 0.05) and acid detergent fiber (P < 0.01) without affecting (P > 0.05) crude protein digestibility. Replacement of soybean hulls with leaf meals did not affect (P > 0.05) dry-matter intake (kg/kg BW) or plasma or urinary urea nitrogen levels. As a result, WOLM and TPLM show potential as alternative feed sources for ruminant livestock animals.