Effects of Dried Distillers Grains in Supplements for Beef Cows During Late Gestation on Cow-Calf Performance and Metabolic Status

Abstract

Forty multiparous Nellore cows, with an average body weight, body condition score, and gestation days of 533 ± 32 kg, 5.7 ± 0.4 points, and 198 days, respectively, were managed under continuous grazing on a Urochloa decumbens pasture and either received or did not receive 1 kg/day of supplement varying in the levels of inclusion of dried distillers grains (DDG) (Control, 0% DDG, 42% DDG, or 84% DDG) during the last trimester of gestation. The objective was to evaluate the effects of prepartum DDG supplementation on performance, reproduction, fetal development, and calf performance. A quadratic effect of supplementation on BW variation pre- and postpartum was observed (p < 0.05), with cows treated with 42% DDG showing higher BW gain prepartum and low BW loss postpartum. Cows supplemented with 42% DDG had lower levels of non-esterified fatty acids and β-hydroxybutyrate prepartum (p < 0.05). However, body weight-related metrics, such as condition score, carcass traits, and metabolic indicators, varied only by measurement day (p < 0.05). No effect of supplementation was observed on fetal development, calf metabolic profile, milk yield, or postnatal calf performance (p > 0.05). It is recommended to include up to 42% DDG in supplements for beef cows during late gestation grazing on low-quality tropical forage conditions.

Keywords: ethanol byproduct; fetal programming; metabolizable protein; negative energy balance; rumen undegradable protein.

Figure 1

Body weight (A), body condition score (B), ribeye area (C), and rump fat thickness (D) measured throughout the peripartum period of Nellore cows supplemented or not with different levels of dried distillers grains during the last trimester of gestation. There was no treatment effect (p > 0.05) and no interaction between treatment and time (p > 0.05). ^{a, b, c, d} Repeated measures over time followed by different letters differ from each other with p < 0.05.

Figure 2

The concentrations of glucose (A), insulin-like growth factor 1 (IGF-1) (B), total proteins (C), albumin (D), and globulin (E) in Nellore cows supplemented or not during the final third of gestation with different levels of dried distillers grains. There was no treatment effect (p > 0.05) and no interaction between treatment and measurement day (p > 0.05). ^{a, b, c, d, e} Repeated measures over time followed by different letters differ from each other with p < 0.05.