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چکیده
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There are evidences that at least for the first 3 weeks of age, newborn calves have limitations in intestinal nutrient digestion. According to studies with monogastric animals, lysophospholipids can improve gut permeability to macromolecules, modifying membranous proteins channels, upregulating various genes in the intestinal epithelium, and immunomodulatory actions. Therefore, in the present study, 48 new- born female Holstein calves [37.5 ± 2.9 (SD) kg of body weight (BW)] were used in a completely randomized design to investigate the effects of a mixture of lysophospholipids (Lipidol, LPL, Easy Bio System Inc.) incorporated into calf starter on growth performance and nutri- ent digestibility (CP, EE, OM, and DM) of pre-weaning dairy calves. We hypothesized that the LPL might improve nutrient digestion, and gastrointestinal tract health and consequently, enhanced ADG in dairy calves. Calves had free access to calf starter and clean water from d 3 to weaning time. The treatments were the control (CON, without additive) and a commercial blend of LPL at 0.5, 1, and 1.5 g/kg of starter feed. The CONTRAST statement of SAS was used to test the linear, quadratic, and orthogonal contrasts (CON × LPL) of LPL supplementation. The threshold of significance was set at P ≤ 0.05, and trends were declared at 0.05 < P ≤ 0.10. The results of the present study showed that overall ADG (1–63 d) was significantly affected by LPL supplementation compared with the CON group (0.520 vs. 0.468 g/d, respectively; P = 0.027). The LPL supplementation did not affect the apparent digestibility of DM and OM. However, the CP digestibility linearly improved (P = 0.046) by increasing the LPL levels in the calf starter. Our observa- tion showed a 7% increase in total-tract CP apparent digestibility with LPL supplementation, relative to the CON group (P = 0.059). In this study, a trend for increased EE digestibility was observed with LPL supplementation compared with the CON (86.7 vs. 83.4, P = 0.1). In conclusion, supplementation of LPL in starter feed improved ADG and CP digestibility in pre-weaning dairy calves.
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