Evaluation of a Low-Moisture, Molasses-Based Block Containing Organic Sources of Trace Minerals and a Saccharomyces cerevisiae Fermentation Culture during the Feedlot Receiving Phase on Growth Performance, Efficiency of Dietary Net Energy Utilization, and Liver Trace Mineral Status in Newly Weaned Steer Calves

Abstract

The objective of this study was to evaluate the growth performance responses and liver trace mineral status of newly weaned steer calves offered a low-moisture, molasses-based block “stress tub” containing organic sources of trace minerals and a Saccharomyces cerevisiae fermentation culture during the first 21-d of a 42-d feedlot receiving phase. Newly weaned, single source Charolais x Angus steer calves (n = 46; body weight [BW] = 240; SEM = 1.0 kg) were used in a 42-d randomized complete block design feedlot receiving experiment. On d -1 all steers were individually weighed in the morning for allotment purposes, and steers were then stratified by initial BW and allotted to one of ten pens (n = 4 to 5 steers per pen; 5 pens per treatment) that were randomly assigned to 1 of 2 treatments: 1) no cooked molasses “stress” tub (Con) or 2) ad libitum access to a cooked molasses “stress” tub (Stress Tub; Purina Animal Nutrition, St. Louis, MO, USA) for the first 21-d (Tub). Steers were allotted to their study pens within 36 h of weaning, and the “stress” tub was introduced approximately 24 h post arrival. During the initial 14-d on feed, intake was managed by feed calls to accommodate adaptation to the receiving diet. Following the adaptation period, bunks were managed using a slick bunk management approach. Tub disappearance was monitored daily. Liver biopsies (n = 2 steers/pen) were collected on d 7, 21, and 42 for the determination of Co, Cu, Mn, and Zn. From d 0 to 21 and d 0 to 42, steers from the Tub treatment consumed greater (p ≤ 0.01) amounts of Co, Cu, Mn, and Zn compared with those in the Con treatment. A treatment × day interaction for hepatic concentrations of Co (p = 0.09), Cu (p = 0.01), and Zn (p = 0.01) were noted. On d 7, steers from Tub had greater (p ≤ 0.01) hepatic Co, Cu, and Zn concentrations compared with Con. On d 21, steers from Tub had greater (p ≤ 0.01) hepatic concentrations of Co and Cu; hepatic Zn was similar between treatments (p = 0.83). On study d 42 steers from Tub had greater (p = 0.01) hepatic Cu; however, hepatic concentrations for Co or Zn did not differ (p ≥ 0.34). During the initial 21 d of the experiment, gain efficiency was enhanced (p = 0.03) by 25.0% in steers from Tub compared with Con. Cumulative ADG, DMI, dietary NE utilization and G:F did not differ (p ≥ 0.14) between treatments. It is concluded that the use of stress tubs does not influence the overall growth performance or NE value of the diet during a 42-d receiving period. Stress tub consumption increased hepatic mineral stores during the initial 21-d period and enhanced the Cu status of calves throughout the 42-d period.

Supplemental organic trace minerals and a yeast culture product in newly weaned steers: effects of use and delivery method on growth performance and hepatic trace mineral content

“…In addition, on day 9 steers reached DMI equivalent to 2% of BW, which is the desired DMI for receiving calves ( Pritchard, 2005 ), and this likely contributed to the reduction in voluntary intake of the stress tub. A similar response was observed by Hamilton et al (2021) where steers reduced the consumption of the stress tub on day 5.…”

“…Final BW and ADG tended ( P ≤ 0.10) to be greater for FORCE compared to TUB and CON by 5.4% and 9.4%, respectively, G:F did not differ by treatment ( P = 0.28). In the study conducted by Hamilton et al (2021) , steers were supplemented with the same stress tub used on this trial (Purina Animal Nutrition, St. Louis, MO, USA) during the first 21 day of a 42-day feedlot receiving phase and reported a tendency for 18.5% improvement on ADG for steers that received the stress tub supplementation. However, there were no significant differences observed.…”

“…The hepatic tissue was collected by using back pressure on a 10 mL syringe. Contents were emptied from surgical tub into a wire mesh screen, and blood was rinsed-off using 0.01M of phosphate buffered saline ( Hamilton et al, 2021 ). Following this procedure there is no need for wound sealing due to the manner in which the insertions were made; gravity assists in naturally closing the wound.…”

“…Supplementation of TM and YCP in combination has led to greater performance and greater hepatic TM content compared to nontreated steers ( Hamilton et al, 2021 ). However, different delivery methods of these products when combined have not been evaluated in a feedlot setting.…”

Ruminant Lick Blocks, Particularly in China: A Review

“…The results of both studies indicated that there was an adaptation period for animals to lick LB, and the LB intake was related to the quality of the basal diet. In addition, the cleanliness of the LB surface also affects intake [87]. The variation in LB intake is large, ranging from 12.3 g/d to 500.0 g/d (Table 3), and depends on body size, physiological condition, production stage and nutrient requirements of the animals.…”