• Asian-Australasian Journal of Animal Sciences
• /
• v.32 no.8
• /
• pp.1211-1218
• /
• 2019

Objective: The objective of this study was to determine the effects of age and gender (bull vs steer) on feeding behavior parameters in young beef cattle fed grass silage. Methods: The study was conducted on 180 young beef cattle at 7 to 18 mo of age. The experimental materials comprised 90 bulls produced by commercial crossing of Polish Holstein-Friesian cows with Charolais, Limousin and Hereford bulls (30 animals of each breed) and 90 steers of the same genotypes. The animals had ad libitum access to grass silage; the concentrate was fed separately, in feed stations. They received 28 g dry matter of concentrate per kg of metabolic body weight per day. Bunk visit data and silage intake for all experimental animals were recorded individually using the Roughage Intake Control system (5 feed bunks per 15 animals). Results: Age and gender (bull vs steer) exerted significant effects on the feeding behavior of young beef cattle. The frequency of bunk visits and meal frequency decreased, whereas the feeding rate of silage, and the average duration and size of a single meal increased with age (p<0.01). Bunk attendance and meal frequency were higher (p<0.01) in steers than in bulls (49.1 vs 37.4 visits/d, and 8.63 vs 7.99 meals/d, respectively). Daily feeding time was longer in steers than in bulls (102.3 vs 100.3 min/d, respectively), but the feeding rate of silage was lower in steers, and their meals were smaller in size and shorter in duration (p<0.01). Daily silage dry matter intake was higher (p<0.01) in bulls than in steers (4.62 vs 4.47 kg/d, respectively). Conclusion: The results of this study indicate that age and gender (bull vs steer) exerted significant effects on the feeding behavior of young beef cattle.

• Animal Bioscience
• /
• v.34 no.4
• /
• pp.558-566
• /
• 2021

Objective: Objectives were to estimate energy and protein requirements of dairy crossbred steers, as well as to evaluate equations previously described in the literature (HH46 and CS16) to predict the carcass and empty body chemical composition of crossbred dairy cattle. Methods: Thirty-three Holstein×Zebu steers, aged 19±1 months old, with an initial shrunk body weight (BW) of 324±7.7 kg, were randomly divided into three groups: reference group (n = 5), maintenance level (1.17% BW; n = 4), and the remaining 24 steers were randomly allocated to 1 of 4 treatments. Treatments were: intake restricted to 85% of ad libitum feed intake for either 0, 28, 42, or 84 d of an 84-d finishing period. Results: The net energy and the metabolizable protein requirements for maintenance were 0.083 Mcal/EBW0.75/d and 4.40 g/EBW0.75, respectively. The net energy (NEG) and protein (NPG) requirements for growth can be estimated with the following equations: NEG (Mcal/kg EBG) = $0.2973_{({\pm}0.1212)}{\times}EBW^{0.4336_{({\pm}0.1002)}$ and NPG (g/d) = 183.6(±22.5333)×EBG-2.0693(±4.7254)×RE, where EBW, empty BW; EBG, empty body gain; and RE, retained energy. Crude protein (CP) and ether extract (EE) chemical contents in carcass, and all the chemical components in the empty body were precisely and accurately estimated by CS16 equations. However, water content in carcass was better predicted by HH46 equation. Conclusion: The equations proposed in this study can be used for estimating the energy and protein requirements of crossbred dairy steers. The CS16 equations were the best estimator for CP and EE chemical contents in carcass, and all chemical components in the empty body of crossbred dairy steers, whereas water in carcass was better estimated using the HH46 equations.

• Asian-Australasian Journal of Animal Sciences
• /
• v.30 no.1
• /
• pp.42-50
• /
• 2017

Objective: Two trials were conducted in order to examine the effects of level of supplemental methionine on productive performance, dietary energetic, plasma amino acid concentration, and digestive function. Methods: Dietary treatments consisted of a steam-flaked corn-based diet containing urea as the only source of supplemental nitrogen supplemented with no supplemental amino acid (control), or control plus 1.01% lysine and 0.032%, 0.064%, 0.096%, or 0.128% methionine. In Trial 1, 150 Holstein steer calves ($127{\pm}4.9kg$) were utilized to evaluate the influence of treatments on growth-performance, dietary energetic, plasma amino acid concentration during the first 112 days of growing period. During the initial 56-d period calves received the 5 experimental diets. During the subsequent 56-d period all calves were fed the control diet. Results: During the initial 56-d period, methionine supplementation increased (linear effect, p<0.01) plasma methionine. In the presence of supplemental lysine, increases on level of methionine in diet did not affect average daily gain. However, increased gain efficiency (quadratic effect, p = 0.03) and estimated dietary net energy (NE; linear effect, p = 0.05). Estimated metabolizable methionine supply was closely associated ($R^2=0.95$) with efficiency NE utilization for maintenance and gain. During the subsequent 56-d period, when all calves received the control diet (no amino acid supplementation), plasma amino acid concentrations and growth performance was not different among groups. However, the effects of methionine supplementation during the initial 56-period carried over, so that following a 56-d withdrawal of supplementation, the overall 112-d effects on gain efficiency (quadratic effect, p = 0.05) dietary NE (linear effect, $p{\leq}0.05$) remained appreciable. In Trial 2, 5 cannulated Holstein steers were used to evaluate treatment effects on characteristics of digestion and amino acid supply to the small intestine. There were no treatment effects on flow of dietary and microbial N to the small intestine. Postruminal N digestion increased (p = 0.04) with increasing level of supplemental methionine. Methionine supplementation linearly increased (p<0.01) duodenal flow of methionine. Likewise, lysine supplementation increased an average of 4.6% (p = 0.04) duodenal flow of lysine. In steers that received non-supplemented diet, observed intestinal amino acid supply were in good agreement with expected. Conclusion: We conclude that addition of rumen-protected methionine and lysine to diets may enhance gain efficiency and dietary energetics of growing Holstein calves. Observed amino acid supply to the small intestine were in good agreement with expected, supportive of NRC (2000, Level 1).

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.5
• /
• pp.810-814
• /
• 1999

The influence of dietary vitamin E supplementation on meat color and ${\alpha}$-tocopherol concentrations in plasma, longissimus thoracis muscle and subcutaneous fat was investigated. Ten Japanese $Black{\times}Holstein$ crossbred steers were placed in three experimental groups receiving different supplements of vitamin E. Four steers (control) were fed no supplemental vitamin E. Two groups of three steers each, were supplemented with 500 mg dl-${\alpha}$-tocopherol acetate per animal daily for 175 days and 1,000 mg for 100 days, respectively, before slaughter. The ${\alpha}$-tocopherol concentration in plasma increased, as vitamin E were fed, and were related to the length of time and the amount of supplement. The ${\alpha}$-tocopherol concentrations in the muscle and the fat from the two supplemental groups did not differ significantly and were three or more times greater than those in the control group. Vitamin E supplementation did not affect the quantity of marbling of beef. Supplemental vitamin E stabilized the color of displayed beef around wavelengths of 500 nm and 640 nm. The two methods of vitamin E supplementation had similar effects on meat color. The effect of supplemental vitamin E on the color of beef with marbling was observed 2-3 days after slaughter and was followed for another two weeks.

• Korean Journal of Agricultural Science
• /
• v.43 no.3
• /
• pp.379-386
• /
• 2016

Four ruminally cannulated Holstein steers (BW $482.9{\pm}8.10kg$), fed low protein TMR (CP 11.7%) as a basal diet, were used to investigate changes in rumen fermentation and blood metabolism according to protein fraction, cornell net carbohydrates and protein system (CNCPS), and enriched feeds. The steers, arranged in a $4{\times}4$ Latin square design, consumed TMR only (control), TMR supplemented with rapeseed meal (AB1), soybean meal (B2), and perilla meal (B3C), respectively. The protein feeds were substituted for 23.0% of CP in TMR. Ruminal pH, ammonia-N, and volatile fatty acids (VFA) in rumen digesta, sampled through ruminal cannula at 1 h-interval after the morning feeding, were analyzed. For plasma metabolites analysis, blood was sampled via the jugular vein after the rumen digesta sampling. Different N fraction-enriched protein feeds did not affect (p > 0.05) mean ruminal pH except AB1 being numerically lower 1 - 3 h post-feeding than the other groups. Mean ammonia-N was statistically (p < 0.05) higher for AB1 than for the other groups, but VFA did not differ among the groups. Blood urea nitrogen was statistically (p < 0.05) higher for B2 than for the other groups, which was rather unclear due to relatively low ruminal ammonia-N. This indicates that additional studies on relationships between dietary N fractions and ruminant metabolism according to different levels of CP in a basal diet should be required.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.8
• /
• pp.1215-1221
• /
• 2007

Three Holstein steers fitted with ruminal and duodenal cannulae were fed grass silage-based diets supplemented with potato pulp silage as a substitute for rolled corn at levels of 0%, 50% and 100% on a DM basis in a $3{\times}3$ Latin square design to investigate the effect of potato pulp silage on nitrogen (N) utilization in ruminants. Organic matter (OM) intake, and rumen and total tract digestibilities did not differ among treatment diets. Rumen and post-rumen starch digestibilities were similar among treatments, although starch intake decreased (p<0.01) with potato pulp supplementation. There were no significant differences (p>0.05) in ruminal N utilization and non-ammonia N supply to the duodenum of steers fed grass silage supplemented with potato pulp silage as a substitute for rolled corn. There were no treatment differences (p>0.05) in rumen pH, volatile fatty acid (VFA) concentration or the molar percentages of acetate and propionate. The ammonia-N concentration in rumen fluid tended to decrease (p<0.1) when rolled corn was substituted with potato pulp silage. Ether extract intake and post-ruminal digestibility significantly (p<0.01) decreased in steers fed diets containing potato pulp silage. Concentrations of total cholesterol and phospholipids in serum markedly decreased (p<0.01) with potato pulp silage supplementation without adversely affecting liver function. These data suggested that potato pulp silage has a similar value as rolled corn as an energy source for rumen microorganisms.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.9
• /
• pp.1288-1295
• /
• 2015

In experiment 1, eighty crossbred steers ($239{\pm}15kg$) were used in a 229-d experiment to evaluate the effects of increasing levels of enzymatically hydrolyzed yeast (EHY) cell wall in diets on growth performance feedlot cattle during periods of elevated ambient temperature. Treatments consisted of steam-flaked corn-based diets supplemented to provide 0, 1, 2, or 3 g EHY/hd/d. There were no effects on growth performance during the initial 139-d period. However, from d 139 to harvest, when 24-h temperature humidity index averaged 80, EHY increased dry matter intake (DMI) (linear effect, p<0.01) and average daily gain (ADG) (linear effect, p = 0.01). There were no treatment effects (p>0.10) on carcass characteristics. In experiment 2, four Holstein steers ($292{\pm}5kg$) with cannulas in the rumen and proximal duodenum were used in a $4{\times}4$ Latin Square design experiment to evaluate treatments effects on characteristics of ruminal and total tract digestion in steers. There were no treatment effects (p>0.10) on ruminal pH, total volatile fatty acid, molar proportions of acetate, butyrate, or estimated methane production. Supplemental EHY decreased ruminal molar proportion of acetate (p = 0.08), increased molar proportion of propionate (p = 0.09), and decreased acetate:propionate molar ratio (p = 0.07) and estimated ruminal methane production (p = 0.09). It is concluded that supplemental EHY may enhance DMI and ADG of feedlot steers during periods of high ambient temperature. Supplemental EHY may also enhance ruminal fiber digestion and decrease ruminal acetate:propionate molar ratios in feedlot steers fed steam-flaked corn-based finishing diets.

• Animal Bioscience
• /
• v.34 no.1
• /
• pp.85-92
• /
• 2021

Objective: The objectives of this study were to determine the in situ degradation parameters and appropriate feeding level of pineapple cannery by-products (PCB) based on the growth performance and blood parameters of growing Hanwoo (Bos taurus coreanae) steers fed various levels of PCB. Methods: Two ruminally cannulated Holstein cows were used for in situ disappearance rate measurements. Nylon bags (5×10 cm, 45 ㎛ pore size) filled with 5 g of PCB in triplicate were inserted into the ventral sac of the two cannulated Holsteins cows and incubated for 0, 2, 4, 8, 16, 24, and 48 h. A total of 16 castrated growing Hanwoo steers (12.5±0.5 months old, 302.9±25.7 kg of initial body weight [BW]) were used for the experiment. Animals were stratified by initial BW and then randomly assigned to one of four experimental diets (0%, 1.5%, 3.0%, or 6.0% of PCB, on the dry matter [DM] basis) fed for 91-d, including 30-d of adaptation. Results: Soluble fraction a of DM and crude protein (CP) was 61.9% and 86.0%, fraction b of DM and CP was 32.7% and 11.2%, and indigestible fraction c of DM and CP was 5.4% and 2.8%. The 6.0% PCB feeding group showed lower productivity compared to animals in the other treatments. Increasing the dietary level of PCB did not alter DM intake, but it was numerically lowest in the 6.0% feeding group. The gain to feed ratio was linearly decreased by increasing of PCB. The quadratic broken-line test estimated that 2.5% (DM basis) was the maximum feeding level of PCB in growing Hanwoo steers (y = 0.103 - 0.001×[1.245-x]2, R2 = 0.18). Conclusion: Diets containing up to 2.5% PCB can be fed to growing Hanwoo steers without adverse effects on growth performance.

• Journal of Animal Science and Technology
• /
• v.63 no.1
• /
• pp.16-24
• /
• 2021

The suppressive effect of monensin as an ionophore-feed additive on enteric methane (CH4) emission and renewable methanogenesis were evaluated. To clarify the suppressive effect of monensin a respiratory trial with head cage was performed using Holstein-Friesian steers. Steers were offered high concentrate diets (80% concentrate and 20% hay) ad libitum with or without monensin, galacto-oligosaccharides (GOS) or L-cysteine. Steers that received monensin containing diet had significantly (p < 0.01) lower enteric CH4 emissions as well as those that received GOS containing diet (p < 0.05) compared to steers fed control diets. Thermophilic digesters at 55℃ that received manure from steers fed on monensin diets had a delay in the initial CH4 production. Monensin is a strong inhibitor of enteric methanogenesis, but has a negative impact on biogas energy production at short retention times. Effects of the activity of coprophagous insects on CH4 and nitrous oxide (N2O) emissions from cattle dung pats were assessed in anaerobic in vitro continuous gas quantification system modified to aerobic quantification device. The CH4 emission from dungs with adults of Caccobius jessoensis Harold (dung beetle) and the larvae of the fly Neomyia cornicina (Fabricius) were compared with that from control dung without insect. The cumulative CH4 emission rate from dung with dung insects decreased at 42.2% in dung beetles and 77.8% in fly larvae compared to that from control dung without insects. However, the cumulative N2O emission rate increased 23.4% in dung beetles even though it reduced 88.6% in fly larvae compared to dung without coprophagous insects. It was suggested that the antibacterial efficacy of ionophores supplemented as a growth promoter still continued even in the digested slurry, consequently, possible environmental contamination with the antibiotics might be active to put the negative impact to land ecosystem involved in greenhouse gas mitigation when the digested slurry was applied to the fields as liquid manure.

• Asian-Australasian Journal of Animal Sciences
• /
• v.25 no.11
• /
• pp.1568-1574
• /
• 2012

Three Holstein steers in the growing phase, each with a ruminal cannula, were used to test the hypothesis that the synchronization of the hourly rate of carbohydrate and nitrogen (N) released in the rumen would increase the amount of retained nitrogen for growth and thus improve the efficiency of microbial protein synthesis (EMPS). In Experiment 1, in situ degradability coefficients of carbohydrate and N in feeds including Korean rice wine residue (RWR) were determined. In Experiment 2, three total mixed ration (TMR) diets having different rates of carbohydrate and N release in the rumen were formulated using the in situ degradability of the feeds. All diets were made to contain similar contents of crude protein (CP) and neutral detergent fiber (NDF) but varied in their hourly pattern of nutrient release. The synchrony index of the three TMRs was 0.51 (LS), 0.77 (MS) and 0.95 (HS), respectively. The diets were fed at a restricted level (2% of the animal's body weight) in a $3{\times}3$ Latin-square design. Synchronizing the hourly supply of energy and N in the rumen did not significantly alter the digestibility of dry matter, organic matter, crude protein, NDF or acid detergent fiber (ADF) (p>0.05). The ruminal $NH_3$-N content of the LS group at three hours after feeding was significantly higher (p<0.05) than that of the other groups; however, the mean values of ruminal $NH_3$-N, pH and VFA concentration among the three groups were not significantly different (p>0.05). In addition, the purine derivative (PD) excretion in urine and microbial-N production (MN) among the three groups were not significantly different (p>0.05). In conclusion, synchronizing dietary energy and N supply to the rumen did not have a major effect on nutrient digestion or microbial protein synthesis (MPS) in Holstein steers.