Document Type
Thesis - Open Access
Award Date
2024
Degree Name
Master of Science (MS)
Department / School
Dairy and Food Science
First Advisor
Prafulla Salunke
Abstract
Our objective was to determine the effects of isoacids (ISO; IsoFerm, Zinpro Inc.) on the lactation performances, feed efficiency, and milk fatty acids (FA) profile of Holstein cows under 2 forage neutral detergent fiber (NDF) levels (FL). The study was designed for a 10-wk long (including 2-wk for covariate) randomized complete block design. Sixty-four mid-lactating Holstein cows [662± 71 kg body weight, 119 ± 51d in milk (DIM), 2 ± 0.9 parity] were blocked by parity, DIM, and prior milk yield (MY) for multiparous cows or genetic merit for primiparous cows. Cows were randomly assigned to 1 of the 4 diets (n = 16 per treatment), which were arranged as 2 × 2 factorial, with 2 FL containing 16.6%(LF) and 20.7% forage NDF (HF) without (WIA) or with ISO (IA, Isobutyrate- 40 g/d per cow). Diets were formulated to meet NASEM (2021) requirements containing similar crude protein (16.5%), NDF (26.4% LF, 28% HF), and net energy for lactation (1.72 Mcal/kg DM). Dry matter intake (DMI) and MY were recorded daily, and milk composition were analyzed weekly. Data were analyzed in R using lme4, where the final model included wk., FL, ISO, and FL × ISO as fixed effects and block as a random effect. The ISO did not affect DMI, a greater DMI was observed in LF than HF (27.8 vs. 25.95 ±0.81 kg/d, P
Publisher
South Dakota State University
Recommended Citation
Ahmed, Sumon, "Effects Of Isoacids Supplementation in Lactating Cows’ Diet Varying in Forage Fiber Level on Performances, Feed Efficiency, and Milk Fatty Acids Profile" (2024). Electronic Theses and Dissertations. 964.
https://openprairie.sdstate.edu/etd2/964
Rights Statement
