Hydrolyzed feather meal (HFM) is a feedstuff high in rumen undegraded protein (RUP) that can be used as an effective source of metabolizable protein for dairy cattle. Because the production process may vary, the rumen degradability and intestinal digestibility of HFM may also vary. Additionally, some processes may incorporate additional blood into the final product to result in feather meal with poultry blood. To determine the rumen degradability and intestinal digestibility of these products, several laboratory assays can be used; the common assays are the mobile bag (MOB), modified three-step (MTS), and Ross (ROS) assays. Although all 3 assays determine RUP digestibility, they vary in whether they are performed in situ, in vitro, or both. The objective of this study was to evaluate the ruminal degradability and intestinal digestibility of HFM originating from processes that differ in their inclusion of blood, and to compare the MOB, MTS, and ROS assays. Ten samples of HFM, which were identified by the suppliers as HFM with little blood (n = 5) and with more blood (n = 5), were spot-sampled, collected from 10 production plants across the United States, and subjected to all 3 assays. Assay type had an effect on RUP, total-tract crude protein (CP) digestibility, and the amount of RUP digested. A significant effect was observed on RDP and RUP concentrations for blood inclusion; no effect was detected for total-tract CP digestibility. We found no difference in RUP digestibility for assay or blood inclusion. There was also no interaction of the effect of assay or blood inclusion. Results suggest that even though there are differences in chemical composition in HFM associated with the inclusion of blood, such as ash and crude fat, few if any differences are observed in intestinal digestion of protein. Although the assays varied in their estimates of rumen undegraded protein, MOB and MTS yielded the most similar values. However, all 3 assays resulted in similar estimates of RUP digestibility.
Graphical Abstract Summary: In recent years, the dairy industry has been shifting toward the utilization of automated milking systems. As such, pelleted feeds are often used to incentivize cows to enter the milking box; however, data comparing different pelleting strategies are currently limited. The current experiment examined different pelleting formulation on feed preference of lactating Jersey cattle. Four pelleting formulations were compared in the taste preference experiment, including a pellet containing ingredients commonly found in dairy concentrate mixes (CMIX), a dry corn gluten feed (CGF) pellet, a pellet containing ingredients previously described to be palatable with oregano leaf (FLVR), and a high-energy pellet (ENG). Cow preference ranking from greatest to least preferred were CGF, FLVR, CMIX, and ENG pellet. Based upon Placket-Luce analysis, we conclude cows choose CGF pellets 78% of the time. These results suggest that animals prefer CGF pellets relative to those pellets containing what are often considered highly palatable ingredients, and exhibited lowered preference for pellets containing higher concentrations of starch.
Last year, over 110 million metric tons of corn silage and 2.7 million metric tons of alfalfa were harvested (USDA, 2018). Despite these amounts and because forage is costly to transport, individual dairy producers who experience troubling seeding, growing, and/or harvest may be faced with the challenge of maintaining normal milk production by feeding less forage. Fortunately, non-forage fiber sources (NFFS) may be used to supply nutrients that would otherwise come from forages. Furthermore, many of these feeds, such are corn gluten feed, beet pulp, brewers grains, canola meal, distillers grains and solubles, and soyhulls are plentifully in the Midwestern United States. Although each NFFS is unique and the chemical composition may vary due to source, when making ration balancing decisions to include them, nutritionists may be faced with similar challenges. These challenges include that these feeds are low in effective fiber, many contain less fiber than forages, are higher in rumen undegradable protein, may vary in chemical composition, and may include toxins or antinutritional factors. Although the modern dairy cow is adaptable and can utilize use NFFS as sources of nutrients to produce milk, there are still limitations to how they can be included in diets.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.