Feeding phytogenic ingredients combined or not with Lithothamnium calcareum and a mycotoxin binder to lactating cows: Effects on performance, nutrient digestibility, physiological parameters, and nitrogen excretion

Abstract

A study was conducted to evaluate the effects of phytogenic feed additives combined or not with buffer compounds and a mycotoxin binder on performance, nutrient digestibility, N utilization, and purine derivatives excretion in lactating cows. Thirty-six Holstein (162 ± 76 days in milk and 32.6 ± 5.57 kg/d milk yield) cows were blocked (n = 12) according to parity, days in milk, and milk yield and were randomly assigned to the following treatments: control (CON), no feed additive; phytogenic feed additive at 5 g/d (PA); and PA + 140 g of buffer compounds (Lithothamnium calcareum, NaHCO3, and MgO) + 25 g/d of a mycotoxin binder (PABB). The PFA mixture contained pepper oleoresin and extracts of cinnamon, pepper, onion, grape seed, Curcuma sp., and Quillaja sp. Treatments were provided mixed into minerals. Cows were allowed a 2 wk-covariate period, and treatments were applied for the following 9 wks. Tukey’s test was used to determine differences between treatment groups. Dry matter (DM) intake was greater (P < 0.001) when feeding phytogenic additives, either PA or PABB, in comparison with CON. Similar nutrient intake was observed between PA and PABB groups. Digestibility of DM was greater (P = 0.047) in cows fed PA than CON but did not differ from those fed PABB. Milk yield was greater (P = 0.041) in cows fed PA than CON group, whereas PA and PABB had similar production values (32.1, 33.6, and 32.8 kg/d for CON, PA, and PABB, respectively). Fat production was increased (P = 0.002) when feeding feed additives. Milk protein concentration was greater (P = 0.043) in PABB-cows than both PA and CON groups. There was no evidence for treatment effects on milk urea nitrogen concentration, feed efficiency, or serum concentrations of glucose and urea-N. The heart rate was lower (P = 0.026) in CON group than PA or PABB during the morning period evaluation. Skin temperature of the face region was elevated (P = 0.040) in cows fed PABB than CON during the morning period. Milk N secretion tended to be greater (P = 0.096) in cows fed treatments with phytogenic additives (PA and PABB) than CON. Relative N excretion (g/kg of N intake) in urine, feces, and milk were not affected by treatments. Urinary purine derivatives daily excretion was similar among treatments. Phytogenic feed additives improve performance of cows, whereas providing a blend of buffer components and mycotoxin binder may increase milk protein concentration.