Effect of a molasses-based liquid supplement on gastrointestinal tract barrier function, inflammation, and performance of newly received feedlot cattle before and after a transport stress.

The objective of this study was to determine the effect of a dry versus a molasses-based liquid supplement on ruminal butyrate concentration, gastrointestinal tract (GIT) barrier function, inflammatory status, and performance of newly received feedlot cattle. In experiment 1, 60 mixed breed steers (234 ±â€…2.1 kg) were weaned, held overnight at a sale barn, then transported 14 h to Purdue University. After arrival, steers were weighed, blocked by body weight, and allotted within block to treatments (six pens per treatment and five steers per pen). Diets consisted of 45% roughage and 55% concentrate (dry matter basis). Treatments differed in the supplement source as follows: DRY: 10% dry supplement or LIQUID: 10% liquid molasses-based supplement. Feed intake, average daily gain (ADG), and gain:feed were determined for the three 21-d periods and overall. In experiment 2, 16 crossbred heifers (246 ±â€…7.5 kg) were used (8 heifers per treatment). Diets were the same as in experiment 1 and were fed for 60 d. On d 56 ruminal fluid samples were collected at 0, 3, 6, and 9 h after feeding. To mimic a stress event, heifers were transported for 4 h on d 61, rested overnight, and transported 12 h on d 62. Blood was collected from heifers immediately prior to transport and immediately upon their return. Gut barrier function using a Cr-EDTA marker was determined after transportation. Data were analyzed using the GLIMMIX procedure of SAS. Steers fed the liquid supplement had greater (P ≤ 0.03) ADG through d 42 and overall compared to steers fed the dry supplement. Feed intake did not differ (P = 0.25) between treatments from d 0 to d 21. However, steers fed the liquid supplement showed greater (P < 0.001) dry matter intake after d 21 and overall compared to those fed the dry supplement. Steers fed the liquid supplement tended (P < 0.09) to have reduced serum haptoglobin and lipopolysaccharide-binding protein (LBP) compared to those fed the dry supplement. Heifers fed the liquid supplement had greater (P = 0.02) Cr in urine and tended (P = 0.07) to have lower serum LBP after transport compared to those fed the dry supplement. Heifers fed the liquid supplement had 72% lower serum haptoglobin before, but only a 19% lower serum haptoglobin after transport compared to animals fed the dry supplement (treatment × time; P = 0.07). Therefore, the liquid supplement altered GIT barrier function, and improved inflammatory status, resulting in increased growth of receiving cattle.

Stress from weaning, feed restriction, transportation, and gastrointestinal acidosis can cause inflammation and intestinal damage, resulting in decreased absorptive capacity and immune defense capability. Gastrointestinal inflammation has a significant catabolic cost and causes nutritional resources to be directed away from anabolic processes. Molasses-based liquid supplements have the potential to improve gastrointestinal tract (GIT) barrier function in stressed, newly received feedlot cattle through increased ruminal production of butyrate from sugar. Therefore, the objective of this study was to determine the effect of a dry versus a molasses-based liquid supplement on ruminal butyrate production, GIT barrier function, inflammatory status, and performance of newly received feedlot cattle. We demonstrate that a molasses-based liquid supplement increased ruminal butyrate concentrations, altered GIT barrier function, decreased serum haptoglobin and lipopolysaccharide-binding protein, and improved the growth of stressed receiving cattle compared to a dry supplement.

Enteric methane emissions, growth, and carcass characteristics of feedlot steers fed a garlic- and citrus-based feed additive in diets with three different forage concentrations.

One hundred and forty-four Angus × Simmental steers were allotted by body weight (BW; 363 kg), breed composition, and farm origin to a 3 × 2 factorial arrangement of six treatments (4 pens per treatment) to determine the effect of Mootral (garlic + citrus extract; 0.25% of the diet dry matter [DM] vs. 0.0%) on methane (CH4) emissions, growth, and carcass characteristics of feedlot cattle. During the first 84 d, cattle were fed three different forage concentrations in the diet (15%, 41.5%, or 68% corn silage) with or without Mootral. From day 85 to slaughter, corn silage was included at 15% of the diet DM with or without Mootral. CH4 emissions were measured on day 42 to 46 and day 203 to 207. Data were analyzed using the GLIMMIX procedure of SAS. Mootral did not affect CH4 emissions on days 42 to 46 (P ≥ 0.47), but there was a forage effect, where steers fed the 68% corn silage emitted more CH4 on a g/d (P = 0.05) and a g/kg of dry matter intake (DMI; P = 0.007) basis and tended (P = 0.07) to produce more CH4 on g/kg BW basis compared to steers fed the 15% corn silage diet. On day 203 to 207, steers fed Mootral emitted less (P ≤ 0.03) CH4 on a g/d, g/kg DMI, and g/kg BW basis compared to steers not fed Mootral. There was an interaction (P = 0.03) between forage concentration and Mootral for DMI from day 0 to 84, where Mootral decreased DMI of steers fed 15% corn silage but did not affect DMI of steers fed 41.5% or 68% corn silage. There were no effects (P ≥ 0.22) of forage concentration or Mootral on BW or average daily gain at any time, or on DMI from day 84 to slaughter and overall. However, overall calculated net energy for maintenance (NEm) and net energy for gain (NEg) tended to be greater for steers fed Mootral (P ≤ 0.10). Intake from day 0 to 84 was lower and gain:feed from day 0 to 84 and overall was greater (P = 0.04) for steers fed 68% compared to steers fed 41.5% corn silage. Calculated NEm and NEg from day 0 to 84 and overall were greater for steers fed 68% corn silage compared to steers fed 41.5% corn silage (P ≤ 0.03). Mootral tended to decrease (P ≤ 0.09) fat thickness and yield grade. In conclusion, increasing forage concentration increased CH4 emissions and Mootral decreased CH4 production in 15% corn silage diets and tended to improve carcass leanness.

Methane (CH4) production from enteric fermentation in ruminant animals is a contributor to global CH4, which is a greenhouse gas. Mootral (Mootral SA, Rolle, Switzerland) is a feed supplement that contains garlic and bitter orange extracts that are known to inhibit methanogenic bacteria. The objective of the current study was to quantify CH4 production and determine growth, intake, and carcass characteristics of feedlot steers fed Mootral in diets with a low, medium, and high forage concentration. Our findings demonstrate that increasing forage concentration increased CH4 emissions and that Mootral decreased CH4 production in 15% corn silage diets and improved carcass leanness. Mootral could be used in commercial feedlots and other grain-feeding scenarios as an effective method to decrease CH4 emissions.

Effect of aspirin to intentionally induce leaky gut on performance, inflammation, and carcass characteristics of feedlot cattle.

The negative impacts of stress on gastrointestinal tract (GIT) barrier function can result in compromised animal growth and health. Aspirin is known to cause mucosal injury leading to increased gut permeability and tight junction damage and can be used as a model to study leaky gut in cattle. The objective of this study was to determine the long-term impact of aspirin-induced chronic leaky gut on cattle growth and carcass attributes. Two treatments were evaluated in two studies: control (no aspirin) or 0.25% of the diet dry matter (DM) aspirin fed daily. Diets consisted of 50% corn, 24% dried distillers grains, 20% corn silage, and 6% supplement on a DM basis. In experiment 1, sixteen Angus × Simmental heifers, allotted by body weight (BW) and breed composition, were fed diets for 154 d. On day 155, heifers were dosed with 1 liter of a 180-mM Cr-ethylenediaminetetraacetic acid solution using an esophageal tube and had urine collected every 1.5 to 3 h for 48 h for analysis of Cr as a measure of gut leakiness. In experiment 2, ninety-six Simmental × Angus steers (355.0 ± 14.8 kg) were allotted by BW and breed composition and fed treatment diets for 159 d. Weight was recorded monthly and serum was collected on day 159 and analyzed for lipopolysaccharide-binding protein (LBP), interleukin-6 (IL-6), serum amyloid A (SAA), haptoglobin, and aspartate aminotransferase (AST). Data were analyzed using the MIXED procedure of SAS. Heifers fed 0.25% aspirin in experiment 1 excreted more Cr into urine compared with heifers not fed aspirin (overall treatment effect, P = 0.01). In experiment 2, aspirin tended to increase serum LBP (P = 0.06) but had no effect on concentrations of IL-6, haptoglobin, SAA, or AST (P ≥ 0.25). Aspirin tended to decrease average daily gain (P = 0.10), decreased hot carcass weight and rib-eye area (P ≤ 0.05), and increased fat thickness, marbling score, and yield grade (P ≤ 0.02). Aspirin tended to increase kidney, pelvic, and heart fat percentage (P = 0.10) and had no effect on liver abscesses (P ≥ 0.80). This study indicates that leaky gut induced by long-term administration of aspirin has negative impacts on feedlot performance and carcass composition. The negative impact of aspirin-induced leaky gut on animal performance suggests that chronic leaky gut caused by other factors (subacute acidosis, stress) may be a significant problem for the feedlot industry.

Oscillating and static dietary crude protein supply: II. Energy and protein requirements of young Nellore bulls.

The objective of this study was to evaluate whole body chemical composition and energy and protein nutrient requirements for maintenance and gain of Nellore bulls. Fifty young bulls, with an average age of 7 ± 1 mo and initial body weight (BW) of 260.0 ± 8.1 kg, were used in this experiment. Four bulls were used as baseline reference animals and were slaughtered at the beginning of the experiment. Four bulls were fed at maintenance (12 g dry matter [DM]/kg of BW), whereas 42 bulls were divided into six groups (n = 7/group) and were randomly assigned to the following dietary treatments 105 (low [LO]), 125 (medium [MD]), or 145 (high [HI]) g crude protein (CP)/kg DM, LO to HI (LH), LO to MD (LM), or MD to HI (MH) oscillating CP at a 48-h interval for 140 d. At the end of the experiment, bulls were slaughtered and samples of the whole body were collected. All samples were lyophilized, ground, and composed as percentage of component of empty body weight (EBW) from each bull. A power model was used to estimate carcass, non-carcass components, and gastrointestinal content of the shrunk body weight (SBW), and CP and water present in the empty body, whereas an exponential model was used to estimate adipose tissue and ether extract (EE) present in the EBW. Nonlinear regression equations were developed to predict heat production from metabolizable energy (ME) intake and retained energy (RE). The net energy requirements for maintenance and ME for maintenance were 77 and 122.75 kcal/EBW0.75/d, respectively. The efficiency of ME utilization for maintenance was 62.7%. The equation obtained for net energy for gain (NEg) was: NEg (Mcal/EBW0.75/d) = 0.0535 × EBW0.75 × EBG0.7131, where EBG is the empty body gain, and the efficiency was 24.25%. Net protein requirement for growth (NPg) was: NPg (g/d) = 227.372 × EBG - 19.479 × RE. There was a linear increase for carcass, CP, and water present in the EBW as the animal grew. The EE deposition exponentially increased as EBW increased.