Watcharawit Meenongyai

Objective: This study aimed to evaluate the effects of different levels of coated cysteamine HCl (CSH) supplementation on growth performance, carcass traits, and meat quality in Charolais crossbred cattle.Methods: Twenty-four Charolais crossbred steers, aged 24–30 months with an initial body weight of 418±31 kg, were assigned to three dietary treatments: 0% (control), 0.5%, or 1.0% CSH in concentrate. The steers were fed the experimental diets for 200 days.Results: Increased CSH levels in concentrate diets led to significant increases (p<0.05) in body weight, hot carcass weight, cold carcass weight, and dressing percentage. CSH supplementation decreased shear force values and cooking loss (p<0.05). Meat lightness was significantly greater in the 1.0% CSH-supplemented group (p<0.05). With increasing CSH levels, the proportion of high-value cuts, such as rib set and T-bone, increased (p<0.05), while the proportion of lower-value cuts, including macreuse, shank, and tendons, decreased (p<0.05). Non-carcass weights, including the feet, head, digestive tract, and scraps, were significantly higher in the 1.0% CSH-supplemented diet (p0.05). Muscle fiber diameter was significantly larger in the 1.0% CSH-supplemented group (p<0.05). Monounsaturated fatty acids increased (p<0.05) with higher CSH levels, whereas polyunsaturated and saturated fatty acids exhibited a significant decrease (p<0.05).Conclusion: Dietary supplementation with CSH enhances growth rate, carcass traits, and meat quality in steers. An inclusion level of 1.0% CSH in concentrate is the optimum feeding dosage, demonstrating its potential as an effective feed additive for enhancing beef production efficiency.

Objective: This study aims to assess the impact of aging time on the quality of meat, fatty acid profiles, and volatile compounds in cooked Thai native beef. Materials and Methods: The experiment utilized a randomized complete block design, where the aging time (0, 7, 14, 21, and 28 days) served as the treatment and the longissimus thoracis et lumborum muscle from Thai native cattle (n = 4) was considered a block. Results: Meat color and Warner-Bratzler shear force values decreased as the aging time increased. Furthermore, the moisture content decreased while the protein and ash content increased with a longer aging time. The proportions of fatty acids showed significant differences with varying aging times. These fatty acids exhibited the highest proportions in the 14-day dry-aged beef samples. The levels of short-chain aldehydes (pentanal, heptanal, octanal, nonanal, decanal, and 2-non¬enal) and alcohols (1-hexanol and 1-octanol) decreased as the aging time increased. However, there was an increase in long-chain aldehydes (tetradecanal, hexadecanal, heptadecanal, and octadecanal) with longer aging time. In addition, the levels of toluene, dodecane, tridecane, methyl-pyrazine, 2,5-dimethyl-pyrazine, trimethyl-pyrazine, and dimethyl trisulfide were higher in 14-day dry-aged beef compared to beef that had not been aged. Furthermore, a correlation was found between the number of the 6 significant fatty acids in the dry-aged beef samples and the 12 volatile compounds in cooked beef. Conclusion: Our results suggest that aging times significantly influence the fatty acid profiles of Thai native beef, which in turn are correlated with the characteristic volatile compounds.

This study investigated the impact of different levels of coated cysteamine hydrochloride (CSH) supplementation on ruminal fermentation, nutrient digestibility, and blood metabolites in Charolais cross bulls. Twelve bulls were allotted to three feeding treatments in a replicated 3 × 3 Latin square design: 0% CSH (control), 0.5% CSH, and 1.0% CSH in concentrate. Animals were fed concentrate at 1.5% of body weight. Dry matter intake (DMI) and DMI as a percentage of body weight showed no significant differences among treatments (p > 0.10). Nutrient digestibility was consistent across treatments, except for a slight decrease in NDF digestibility with 1% CSH (p = 0.07). Ruminal pH, ammonia nitrogen, volatile fatty acid (VFA) proportions, and total VFA concentration were similar among treatments (p > 0.05). Total bacteria, fungal zoospores, and protozoa populations in the rumen did not vary significantly (p > 0.05). Blood glucose and triglyceride concentrations remained stable (p > 0.05), while blood urea nitrogen (BUN) levels were higher in CSH‐supplemented groups (p < 0.05). In conclusion, incorporating CSH levels ranging from 0.5% to 1.0% into the diet did not adversely affect feed intake, ruminal fermentation, or microbial populations. Additionally, 1.0% CSH improved BUN concentration in growing Charolais cross bulls.

This study aimed to determine the effects of coated cysteamine hydrochloride (CSH) and probiotics (PB) supplemented alone or in combination on feed intake, digestibility, ruminal fermentation, and blood metabolites of heifer beef cattle. Sixteen heifers (body weight = 210 ± 41 kg; age = 9 ± 2 months) were assigned according to a randomized complete block design in a 2 × 2 factorial arrangement. All animals were fed the basal diet, which contained an 82:17 concentrate-to-forage ratio, and the forage source was rice straw. The treatments were as follows: (1) 0% PB + 0 g/d CSH, (2) 0.1% PB + 0 g/d CSH, (3) 0% PB + 20 g/d CSH, and (4) 0.1% PB + 20 g/d CSH. The main effect of CSH supplementation has been found to improve feed intake (P < 0.05). There were no treatment interactions with nutrient digestibility or rumen fermentation parameters. Supplementation of CSH did not affect any of the variables evaluated, while probiotics supplementation increased DM digestibility due to the increases in CP and fiber fraction digestibility. Compared to controls and CSH, at 16 h post-feeding, heifers receiving probiotics tended (P = 0.07) to show 17% greater ruminal NH3-N concentration, but this effect was not evident at 2 h post-feeding. However, the main effects of probiotic supplementation showed a tendency to increase the number of total bacteria and fungal zoospores in the rumen at 2 h post-feeding. The blood triglyceride (BTG) concentration of heifers fed a diet supplemented with 20 g/d CSH and 0.1% probiotics was found to be greater than those fed CSH alone (P < 0.1) at 16 h post-feeding, and then, there were greater BTG concentrations than other treatments (P < 0.05) at 2 h post-feeding. In conclusion, the combination of CSH and PB did not potentiate the effects of probiotics on digestibility and rumen fermentation and had minimal effects on blood parameters.