Increasing hay inclusion in silage-based receiving diets and its effects on performance and energy utilization in newly weaned beef steers

Effects of Supplemental Calcium Propionate and Concentrate Level: Growth Performance, Body Fat Reserves, and Health of High-Risk Beef Calves

The aim of this study was to examine the impact of daily calcium propionate (CaPr) supplementation (0 or 20 g/calf) on growth performance, dietary energetics, body fat reserves, serum metabolites, and hematological responses in high-risk beef calves fed diets with varying (50, 60, or 70%) concentrate (CON) levels. In addition, a cost/income analysis of CaPr supplementation was carried out. Forty-eight crossbred bull calves (152.8 ± 1.56 kg body weight and 5.5 months of age) were involved in a fully randomized experimental design employing a 2 × 3 factorial arrangement of treatments. Calves were allocated (n = 8 per treatment) to individual pens (3.14 × 5.25 m) and were subjected to one of the following treatments during 42 d: No CaPr supplementation in diets containing 50, 60, or 70% CON (NoCaPr + 50, NoCaPr + 60, NoCaPr + 70, respectively) or daily CaPr supplementation dosed at 20 g/calf in diets containing 50, 60, or 70% CON (20CaPr + 50, 20CaPr + 60, 20CaPr + 70, respectively). Non-supplemented calves exhibited decreased dry matter intake (DMI) with increasing CON levels in their diets, while CaPr-supplemented calves displayed the opposite effect (interaction, p = 0.04). In calves fed a lower-CON diet (50%), those supplemented with CaPr showed greater average daily gain (ADG, 20.2%, p = 0.05) and lower DMI (2.2%, p = 0.03), resulting in improved ADG/DMI ratio, dietary energy, and energy retention (24.6, 14.4, and 18%, p < 0.05). These effects diminished when calves received diets with 60 or 70% CON but led to a 14.2% increase in rump fat thickness (p = 0.04). Only in non-supplemented CaPr calves, increasing the level of CON from 50 to 70% in the diet increased ADG (21.2%), decreased DMI (2.2%), and improved the ADG/DMI ratio (22.7%), with no impact on dietary net energy utilization. Non-supplemented calves exhibited an increase in lymphocytes as CON levels rose in their diets, whereas CaPr-supplemented calves showed the opposite effect (interaction, p = 0.05). Supplementation of CaPr decreased total protein (TP, p = 0.03) and albumin (ALB, p < 0.01) serum concentrations, with lower concentrations observed in 20CaPr + 50. CaPr supplementation reduced (p = 0.01) total cholesterol (TCHO) levels. An interaction between CaPr and CON level (p = 0.02) was observed since TCHO levels remained consistently low at higher CON levels. Glucose was decreased with increasing levels of CON (p = 0.02) but not (p = 0.85) for CaPr-supplemented calves. NoCaPr + 50 and NoCaPr + 70 increased (p = 0.05) ALB concentration. Gamma glutamyltransferase levels increased (p = 0.05) with increasing CON levels irrespective of CaPr supplementation. Comparing the profit within the same CON level in the diet, CaPr treatments yielded higher income, with the largest difference in profit observed when CaPr was supplemented at 50% CON level (USD 29 more/calf). In conclusion, CaPr supplementation proves to be an effective strategy for enhancing growth performance and dietary energy among high-risk beef calves, resulting in greater economic returns. The groups that received CaPr demonstrated superior profitability, particularly in calves fed diets with lower CON levels. Under the conditions in which this experiment was carried out, the optimal response occurred when the low-CON diet (50%) was supplemented with CaPr.

Dietary Guanidine Acetic Acid Addition Improved Carcass Quality with Less Back-Fat Thickness and Remarkably Increased Meat Protein Deposition in Rapid-Growing Lambs Fed Different Forage Types

The aim of this study was to investigate whether guanidine acetic acid (GAA) yields a response in rapid-growing lambs depending on forage type. In this study, seventy-two small-tailed Han lambs (initial body weights = 12 ± 1.6 kg) were used in a 120-d feeding experiment after a 7-d adaptation period. A 2 × 3 factorial experimental feeding design was applied to the lambs, which were fed a total mixed ration with two forage types (OH: oaten hay; OHWS: oaten hay plus wheat silage) and three forms of additional GAA (GAA: 0 g/kg; UGAA: Uncoated GAA, 1 g/kg; CGAA: Coated GAA, 1 g/kg). The OH diet had a greater dry matter intake, average daily gain, and hot carcass weight than the OHWS diet. The GAA supplementation increased the final body weight, hot carcass weight, dressing percentage, and ribeye area in the longissimus lumborum. Meanwhile, it decreased backfat thickness and serum triglycerides. Dietary GAA decreased the acidity of the meat and elevated the water-holding capacity in mutton. In addition, the crude protein content in mutton increased with GAA addition. Dietary GAA (UGAA or CGAA) might be an effective additive in lamb fed by different forage types, as it has potential to improve growth performance and meat quality.

Galyean Appreciation Club Review: Revisiting nutrition and health of newly received cattle - What have we learned in the last 15 years?

Our objective was to review the literature related to the health and management of newly received cattle published since a previous review by Duff and Galyean (2007). Bovine respiratory disease (BRD) continues to be a major challenge for the beef industry. Depending on disease severity, animals treated for BRD have decreased performance and lowered carcass value. Diagnosis of BRD is less effective than desired, and progress on developing real-time, chute-side methods to diagnose BRD has been limited. Systems that combine lung auscultation with temperature and BW data show promise. Assessment of blood metabolites and behavior monitoring offer potential for early identification of morbid animals. Vaccination and metaphylaxis continue to be important tools for prevention and control of BRD, but antimicrobial resistance is a concern with antibiotic use. Dietary energy concentration and roughage source/level continue to be important topics. Mineral supplementation has received considerable attention, particularly the use of organic vs. inorganic sources and injectable minerals or drenches given on arrival. Use of probiotics and prebiotics for newly received cattle has shown variable results, but further research is warranted. Health and nutrition of newly received cattle will continue to be an important research area in the years to come.

Meta-analysis of the effects of chemical and microbial preservatives on hay spoilage during storage

A meta-analysis was performed to evaluate the effects of chemical (50 articles) and microbial (21 articles) additives on hay preservation during storage. Multilevel linear mixed-effects models were fit with response variables calculated as predicted differences (Δ) between treated and untreated samples. Chemical preservatives were classified into five groups such as propionic acid (PropA), buffered organic acids (BOA), other organic acids (OOA), urea, and anhydrous ammonia (AA). Moderators of the models included preservative class (PC), forage type (FT; grass, legumes, and mixed hay), moisture concentration (MC), and application rate (AR). Dry matter (DM) loss during storage was affected by PC × FT (P = 0.045), PC × AR (P < 0.001), and PC × MC (P = 0.009), relative to the overall effect of preservatives (-0.37%). DM loss in PropA-treated hay was numerically reduced to a greater extent in grasses (-16.2), followed by mixed hay (-1.76), but it increased (+2.2%) in legume hay. Increasing AR of PropA resulted in decrease in DM loss (slope = -1.34). Application of BOA, OOA, PropA, and AA decreased visual relative moldiness by -22.1, -29.4, -45.5, and -12.2 percentage points, respectively (PC; P < 0.001). Sugars were higher in treated grass hay (+1.9) and lower in treated legume hay (-0.8% of DM) relative to their untreated counterparts (P < 0.001). The application of all preservatives resulted in higher crude protein (CP) than untreated hay, particularly urea (+7.92) and AA (+5.66% of DM), but PropA, OOA, and BOA also increased CP by 2.37, 2.04, and 0.73 percentage points, respectively. Additionally, preservative application overall resulted in higher in vitro DM digestibility (+1.9% of DM) relative to the untreated hay (x¯=58.3%), which increased with higher AR (slope = 1.64) and decreased with higher MC (slope = -0.27). Microbial inoculants had small effects on hay spoilage because the overall DM loss effect size was -0.21%. Relative to untreated (x¯=4.63% DM), grass hay preserved more sugars (+1.47) than legumes (+0.33) when an inoculant was applied. In conclusion, organic acid-based preservatives prevent spoilage of hay during storage, but their effectiveness is affected by FT, MC, and AR. Microbial inoculants had minor effects on preservation that were impaired by increased MC. Moreover, legume hay was less responsive to the effects of preservatives than grass hay.

Evaluation of batch fraction, corn silage inclusion level, and mixing duration on long particle distribution of finishing diets for beef cattle

Background:  Differing fractions of a batch of feed, differing ingredient characteristics, and inadequate mix time can lead to non-uniformity within a mix of feed.  Methods: The experiment was designed as a 5 x 2 x 2 factorial arrangement with seven replications per simple treatment mean. Factors included: 1) batch fraction (BF; n = 5); 2) corn silage inclusion level (CSLVL; n = 2) 15% or 30% inclusion (dry matter basis); and 3) mixing duration (DR; n = 2) of 20 or 25 mixer revolutions. Data were analyzed as a completely randomized design using a binomial approach. The Penn State Particle Separator was used to separate fractions of the total mixed ration (TMR). Results: No interactions between BF, CSLVL, and DR were detected ( P ≥ 0.31) for any dependent variables. There was an increase ( P = 0.01) in retention on the 19 mm sieve from the first BF compared to the last BF. CSLVL altered ( P = 0.01) retention on the 19 mm sieve. Increasing DR from 20 to 25 revolutions had no appreciable influence ( P = 0.23) on particles greater than 19 mm.  CSLVL ( P = 0.01) and DR ( P = 0.01) altered particle retention on the 8 mm sieve. BF ( P = 0.01), CSLVL ( P = 0.01), and DR ( P = 0.02), influenced particle retention on the 4 mm sieve. CSLVL impacted ( P ≤ 0.01) particles remaining in the bottom pan and particles greater than 4 mm. BF ( P = 0.01) and CSLVL ( P = 0.01) altered particles greater than 8 mm. Conclusions: These data indicate that BF and CSLVL fed alters particle size distribution that in turn could alter dry matter intake, dietary net energy content, and influence daily gain. Mixing DR had no appreciable influence on particle size distribution of the TMR.