Nano and natural zeolite feed supplements for dairy goats: Feed intake, ruminal fermentation, blood metabolites, and milk yield and fatty acids profile

Zeolite particle size can affect its characteristics as a rumen modifier, thus its form may not only affects the goats' health during the transition period but also their milk quantity and quality. Our objectives of this study were to evaluate the effects of zeolite supplementation either in its natural or nano form on ruminal fermentation characteristics, blood biochemical parameters, and milk production and chemical composition of dairy goats. Thirty-nine late pregnant Damascus goats (initial body waight: 26.1 ± 0.93 kg, mean ± SD) were randomly assigned to three experimental dietary treatments (n = 13/ treatment) for 90 days of an experimental period: The control treatment was fed a basal diet without feed additives, natural zeolite [supplemented at 20 g/kg of dry matter (DM) to the basal diet], and nano zeolite (supplemented at 0.4 g/kg DM to the basal diet). Both zeolite forms increased (P < 0.05) ruminal pH, total protozoal count, Diplodinium spp ciliates, and reduced (P < 0.01) ammonia, while nano zeolite enhanced the total short-chain fatty acids concentration compared to the control. Supplementation of nano zeolite increased (P = 0.01) the blood calcium and reduced (P < 0.05) total cholesterol, total lipids, aspartate aminotransferase, alanine aminotransferase activities compared to other diets. Goats fed nano zeolite produced higher (P < 0.01) milk yield without affecting the feed intake, while both zeolite forms resulted in similar reductions (P < 0.05) in milk fat, protein, lactose, solid not fat, and somatic cell count. No differences were detected in milk total saturated fatty acids and total odd and branched-chain fatty acids among treatments while, nano zeolite reduced (P = 0.03) milk concentration of eicosanoic acid (C20:0). Natural zeolite tended to reduce (P = 0.08) the concentrations of total mono-unsaturated fatty acids in milk, while nano zeolite resulted in higher (P = 0.04) miristoleic (C14:1-Cis9; omega 5) than the control. No differences were detected in the total and individual polyunsaturated fatty acids compared to the control. In conclusion, nano zeolite was more pronounced as a feed additive than its natural form to support goats through late pregnancy to early lactation and to enhance milk quality.