Background: The digestive development of suckling calves poses significant challenges, primarily due to their limited ability to produce specific digestive enzymes, which hampers nutrient digestion and lipid absorption. Although fat digestion begins in the mouth, most fat hydrolysis occurs in the small intestine, where the action of pancreatic lipases and bile salts is crucial. Incorporating dietary emulsifiers, particularly lysophospholipids, can enhance fat digestion and absorption by promoting micelle formation and improving nutrient uptake.
Objectives: The aim of the present study was to investigate the effects of lysophospholipids on growth performance and blood parameters in Holstein calves with a diet containing saturated fatty acids.
Methods: A total of 48 calves (24 males and 24 females) with an age range of 3±1 days and an average birth weight of 39.4±4 kg were selected in a completely randomized design with 4 treatments and 12 replications for 80 days. The experimental treatments were: 1) Basic diet without additives, 2) Basic diet with 3% saturated fatty acid-rich fat, 3) Basic diet with 2 g of lysophospholipid daily, and 4) Basic diet with 2 g of lysophospholipid daily + 3% saturated fatty acid-rich fat. Lysophospholipids were added to the milk from days 6 to 40 and to the starter from days 41–80.
Results: The experimental treatments had no effect on metabolizable energy (ME) intake of the calves, nor did they significantly influence the final body weight. However, the ME/gain ratio was significantly affected by the treatments (P<0.05), with the groups receiving 3% fat showing the lowest ratio compared to the other experimental groups. Blood parameters, including glucose, cholesterol, triglycerides, blood urea, albumin, total protein, and beta-hydroxybutyrate, showed no significant alterations on days 5, 40, and 80. Furthermore, the levels of total antioxidant capacity (TAC), and malondialdehyde (MDA) were unaffected by the dietary treatments. Although fecal consistency was not impacted from 1 to 5 days, from 6 to 40 days, and 41 to 80 days, significant differences were found over the entire rearing period, with calves receiving lysophospholipid demonstrating better fecal consistency compared to the control group.
Conclusion: In conclusion, energy intake, final body weight, and blood parameters were not affected by experimental treatments. However, calves on the 3% fat diet had the lowest ME/gain ratio. Future research should explore the long-term impacts of lysophospholipids on gut health, enzyme activity, and microbiota composition, and also evaluate different dosages and application periods to optimize their efficacy in calf nutrition.