VetSRev
Database of veterinary systematic reviews
Database of veterinary systematic reviews
J Dairy Sci (2021) 104: 9752–9768
Our primary objective was to perform a meta-analysis and meta-regression to evaluate the effects of diets supplemented with calcium salts of palm fatty acids (CSPF) compared with nonfat supplemented control diets (CON) on nutrient digestibility and production responses of lactating dairy cows. Our secondary objective was to perform a meta-analysis to evaluate whether experimental design affects production responses to supplemental CSPF. The data set was formed from 33 peer-reviewed publications with CSPF supplemented at ≤3% diet dry matter. We analyzed the interaction between experimental design (continuous vs. change-over) and treatments (CON vs. CSPF) to evaluate whether experimental design affects responses to CSPF (Meta.1). Regardless of experimental design, we evaluated the effects of CSPF compared with CON on nutrient digestibility and production responses of lactating dairy cows by meta-analysis (Meta.2) and meta-regression (Meta.3) approaches. In Meta.1, there was no interaction between treatments and experimental design for any variable. In Meta.2, compared with CON, CSPF reduced dry matter intake [DMI, 0.56 ± 0.21 kg/d (±SE)] and milk protein content (0.05 ± 0.02 g/100 g), increased neutral detergent fiber (NDF) digestibility (1.60 ± 0.57 percentage units), the yields of milk (1.53 ± 0.56 kg/d), milk fat (0.04 ± 0.02 kg/d), and 3.5% fat corrected milk (FCM, 1.28 ± 0.60 kg/d), and improved feed efficiency [energy corrected milk (ECM)/DMI, 0.08 kg/kg ± 0.03]. There was no effect of treatment for milk protein yield, milk fat content, body weight, body weight change, or body condition score. Compared with CON, CSPF reduced the yield of de novo milk fatty acids (FA) and increased the yields of mixed and preformed milk FA. In Meta.3, we observed that each 1-percentage-unit increase of CSPF in diet dry matter reduced DMI, increased NDF digestibility, tended to increase FA digestibility, increased the yields of milk, milk fat, and 3.5% FCM, reduced the content of milk protein, reduced the yield of de novo milk FA, and increased the yields of mixed and preformed milk FA. In conclusion, our results indicate no reason for the restrictive use of change-over designs in CSPF supplementation studies or meta-analysis. Feeding CSPF increased NDF digestibility, tended to increase FA digestibility, and increased the yields of milk, milk fat, and 3.5% FCM. Additionally, CSPF increased milk fat yield by increasing the yields of mixed and preformed milk FA.
Dos Santos Neto, J. M., de Souza, J., & Lock, A. L. (2021). Effects of calcium salts of palm fatty acids on nutrient digestibility and production responses of lactating dairy cows: A meta-analysis and meta-regression. J Dairy Sci, 104(9), 9752–9768. https://doi.org/10.3168/jds.2020-19936 Animals, Female, Diet/veterinary, Cattle, cattle, cows, dairy cattle, dairy cows, meta-analysis, Dietary Supplements, Animal Nutrition (Production Responses) [LL520], effects, Food Composition and Quality [QQ500], Animal Nutrition (Physiology) [LL510], butterfat, cattle feeding, Dairy Animals [LL110], diets, Mathematics and Statistics [ZZ100], milk fat, body weight, data analysis, research, studies, body condition, feeding, fiber, fibre, interactions, composition, feeding stuffs, feeds, milk, Milk and Dairy Produce [QQ010], milk production, yields, Calcium, dry matter, fatty acids, Digestion, Animal Feed/analysis, feed conversion efficiency, feed supplements, digestibility, milk yield, milk products, *Lactation, supplements, Feed Composition and Quality [RR300], production, fat, dairy cow, dairy products, salts, calcium, nutrient availability, Nutrients, milk components, milk composition, milk constituents, milk quality, experimental design, plot design, milk fat percentage, milk protein percentage, milk proteins, protein content, *Fatty Acids, fatty acid supplementation, Palmitic Acid, Salts, milk fat yield, milk protein yield, responses, animal fat, milk fat production