Effects of isoenergetic supplementation as water use mitigation strategy on water footprint and health of nursing bull calves

• Published in: Translational animal science 2023-01, Vol.7 (1), p.txad127-txad127
• Main Authors: Macias Franco, Arturo, da Silva, Aghata Elins Moreira, de Moura, Felipe Henrique, Norris, Aaron B, Roloson, Serena Breanne, Gerrard, David E, de Mello, Amilton, Fonseca, Mozart A
• Format: Article
• Language: English
• ISSN: 2573-2102; 2573-2102
• DOI: 10.1093/tas/txad127

Abstract Sustainable livestock systems focus on mitigating natural resource use such as water. Dietary management strategies can significantly reduce the water footprint of livestock animals; however, animal health is of concern when animals reduce water intake due to subacute dehydration. To evaluate potential consequences of this nutritional management intervention, a total of 23, 60 ± 3 days old nursing Holstein bull calves, weighing 94.7 ± 12.07 kg, were distributed in a completely randomized design and received one of three diets. Control was a basal diet composed of a non-medicated milk replacer (milk replacer; n = 7), and the additional two diets, were composed of the same non-medicated milk replacer in addition to either lipid [n = 8; milk replacer + menhaden fish oil (3 %)] or soluble carbohydrate [n = 8; milk replacer + corn starch (7%) isoenergetic to fat group] supplements. Animals were offered ad libitum mineral mix and water, as well as 120 g/day of a composite mix of dried microbrewery’s spent grains. Data were analyzed as linear and generalized linear mixed models with diet as a fixed effect and animal as random utilizing R studio (R Core Team, 2021, Vienna, Austria; SAS Inst., Cary, NC). Within supplementation groups, lipid supplemented calves had the highest lymphocyte (63.24 vs 57.69 counts/100 lymphocytes; P