Supplementation of molasses-based liquid feed for cattle fed on limpograss hay

Authors: ABREU, DACIELE - University Of Florida; DUBEUX, JOSE - University Of Florida; DANTAS, LUANA - University Of Florida; Jaramillo, David; SANTOS, ERICK - University Of Alberta; VAN CLEEF, FLAVIA - University Of Florida; GARCIA, CARLOS - University Of Florida; DILORENZO, NICOLAS - University Of Florida; RUIZ-MORENO, MARTIN - University Of Florida

Submitted to: Animals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/25/2022
Publication Date: 8/29/2022
Citation: Abreu, D., Dubeux, J., Dantas, L., Jaramillo, D.M., Santos, E., Van Cleef, F., Garcia, C., Dilorenzo, N., Ruiz-Moreno, M. 2022. Supplementation of molasses-based liquid feed for cattle fed on limpograss hay. Animals. 12(2227). https://doi.org/10.3390/ani12172227.
DOI: https://doi.org/10.3390/ani12172227

Interpretive Summary: Seasonality in forage production limits the quantity and quality of forage on pasture. Even when forage is available in the period of scarcity, protein might still be a limiting nutrient in animal performance. Feed supplementation is a powerful tool to adjust nitrogen (N) levels in the diet of ruminants during critical periods. Urea is commonly used as a source of non-protein nitrogen in molasses supplements. This dietary protein provides amino acids as well as nitrogen for microbial protein synthesis. Moreover, molasses has sensorial characteristics, such as pleasant taste, which help to increase overall dry matter intake and promote growth of fiber-digesting bacteria. The objective of this work was to evaluate the effects of different levels of liquid supplementation based on molasses enriched with 32% crude protein on ingestion, digestibility, and rumen fermentation. The results of this study indicated that addition of a molasses-based liquid feed to a Hemarthria altissima hay-based diet can improve the nutrient supply to animals, notably volatile fatty acids (VFA) and microbial N. Liquid supplementation had an additive effect on intake of animals fed Hemarthria altissima hay but did not increase hay intake. Results from this study are relevant for addressing management strategies for reducing feed costs in beef cattle operations in the southeastern US Gulf Coast region, through the use of stockpiled pasture forages.

Technical Abstract: Two experiments were performed to evaluate the effects of 1) different levels of liquid supplementation (LS) based on molasses enriched with 32% crude protein (CP) on intake of Hemarthria altissima hay (LH), digestibility, and rumen fermentation and; 2) different levels of LS based on molasses enriched with 32% CP in the in vitro gas production in LH diets. In Exp. 1, 12 heifers and 12 adult male castrated and cannulated cattle were used. Treatments were allocated in a randomized block design, in four treatments: CTL, access ad libitum to the LH; SUP2, ad libitum access to LH and supplementation with 0.9 kg/d; SUP4, ad libitum access to LH and supplementation with 1.8 kg/d and; SUP6, ad libitum access to LH with 2.7 kg/d. In Exp. 2, treatments were carried out in a randomized block design with four different proportions of LH diet: CTL, 100% LH; SUP2, 85% LH and 15% LS; SUP4, 70% LH and 30% LS; SUP6, 55% LH and 45% LS. In Exp. 1 liquid molasses-based supplementation did not affect LH intake (P>0.05). Molasses intake improved as the supply increased, not reducing the intake of LH. In Exp.2, the addition of LS to the LH caused a change in the VFA profile, with an increase in propionate production in vitro. Results of this study indicated that addition of a molasses-based liquid feed to a Hemarthria altissima hay-based diet can improve the nutrient supply to animals, notably volatile fatty acids (VFA) and microbial N, and should be considered when utilizing LH.