Influence of hempseed cake inclusion on growth performance, carcass characteristics, feeding behavior, and blood parameters in finishing heifers

Abstract

As the hemp industry continues to develop in the US, there is interest in feeding byproducts of industrial hemp production to livestock. A completely randomized design experiment using crossbred finishing heifers [initial body weight (BW) ± SE = 494 ± 10 kg] was conducted to determine the effects of feeding hempseed cake in a corn-based finishing diet (10% forage) formulated to meet or exceed ruminally degradable and metabolizable protein requirements on growth performance, carcass characteristics, feeding behavior, and plasma parameters. Dietary treatments were inclusion of 20% [dry matter (DM) basis] of: dried corn distillers grains plus solubles (DDGS, n = 16), or hempseed cake (HEMP, n = 15). Cattle were housed in two pens, had ad-libitum access to feed and water, and individual intakes and feeding behavior were monitored using the Insentec feeding system. Cattle were fed treatment diets for 111 days, and every 14 days BW were measured, and blood samples collected. Blood plasma was analyzed for glucose, urea nitrogen, and individual amino acids and results analyzed using repeated measures analysis in SAS. Final BW, average daily gain, gain:feed, and hot carcass weight decreased (P ≤ 0.05) by 2.3%, 7.7%, 7.7%, and 2.6% respectively in heifers fed the HEMP diet than in heifers fed the DDGS diet. Net energy for maintenance and gain (Mcal/kg of feed, DM basis), estimated based on heifer intake and performance, were greater (P = 0.02) for the DDGS diet than the HEMP diet. All other performance and carcass characteristics were not different (P ≥ 0.20) between treatments. Heifers fed the HEMP diet had greater (P < 0.05) plasma urea nitrogen concentration in samples from each collection day compared to heifers fed the DDGS diet, although there was a treatment by day interaction (P < 0.01) because of variability in the magnitude of treatment differences over time. Plasma glucose concentration was not influenced (P = 0.17) by dietary treatment. Plasma concentrations of total amino acids, non-essential amino acids, and essential amino acids were not different between treatments (P ≥ 0.09), although there were several interactions between treatment and day (P ≤ 0.04) for individual amino acids. These data suggest that hempseed cake has a lower NEm and NEg relative to dried corn distillers grains plus solubles when adequate metabolizable protein is supplied, while still providing adequate nutrition to support acceptable performance of finishing cattle.

346 Feeding Hempseed Cake Alters the Bovine gut, Respiratory and Reproductive Microbiota

“…Several factors may be contributing to the reduced ADG observed in the hemp group. As stated in our previous publication, this may include the greater acid detergent ber concentration that was present in the hempseed cake compared to DDGS (16 vs. 11% on DM basis) (Winders et al, 2022).…”

“…We identi ed changes in the ruminal, nasopharyngeal, vaginal, and uterine microbiota in beef heifers fed a nishing diet containing 20% hempseed cake relative to changes in heifers fed 20% DDGS over the course of a 16-week feeding trial. All heifers appeared healthy throughout feeding trial and heifers fed hempseed cake consumed a similar amount of feed and exhibited similar feeding behaviours as heifers fed a DDGS (Winders et al, 2022). However, hempseed cake inclusion led to a decrease in average daily gain (ADG), ultimately resulting in a lighter nal body weight in hempseed cake-fed heifers than control heifers.…”

“…A longitudinal (16-week long) study was conducted to evaluate the effect of hempseed cake inclusion in nishing diets on growth performance, carcass quality characteristics, plasma, urine, and tissue cannabinoid residues, feeding behaviour, and the gut, respiratory and reproductive tract microbiota of beef cattle. The live phase of the feeding study has been described in detail by Winders et al (2022) Brie y, a total of 32 crossbred nishing heifers (initial body weight = 494 ± 10 kg [SE], average age = 19 months) were randomly assigned into either hemp (n = 16) or control (n = 16) groups (Fig. 1).…”

“…Uterine and vaginal swabs were collected immediately after euthanasia upon the completion of the 111-day hempseed cake feeding trial for carcass data collection. Heifers were slaughtered on study days 112-120 (withdrawal days 0, 1, 4, and 8 as described by (Winders et al, 2022). Pre-slaughter withdrawal periods were established to examine the depletion of cannabinoid residues from cattle tissues.…”

Feeding hempseed cake alters the bovine gut, respiratory and reproductive microbiota

“…Uterine and vaginal swabs were collected immediately after euthanasia upon the completion of the 111day hempseed cake feeding trial for carcass data collection. Heifers were slaughtered on study days 112-120 (withdrawal days 0, 1, 4, and 8 as described by [29]. Pre-slaughter withdrawal periods were established to examine the depletion of cannabinoid residues from cattle tissues.…”