Economic Analysis of Yearling-Fed and Calf-Fed Systems of Native Beef and Dairy-Beef Crossbred Steers

The contribution of dairy steers to the U.S. fed beef supply has increased over the last 2 decades. In part, due to declining beef cow numbers and increased use of sexed dairy semen to produce genetically superior replacement heifers from the best dairy cows in the herd. Raising dairy cattle for beef production offers unique opportunities and challenges when compared with feeding native beef cattle. Dairy steers offer predictable and uniform feedlot performance (ADG, DMI, G:F) as a group, and improved quality grades compared with their native beef counterparts. However, dairy steers yield less red meat compared with native beef cattle due to a greater ratio of bone to muscle, internal fat, organ size, and gastrointestinal tract weight. Dairy steers present carcass size problems in the beef packing industry, with Holstein carcasses being too long and Jersey carcasses being light weight. Beef × dairy crossbreeding strategies are being implemented on some dairy farms to increase the income generated from bull calves and to improve the feed efficiency and yield of beef produced from the U.S. dairy herd. This new model of beef production from the dairy herd is not without its challenges. Early beef × dairy crossbreeding efforts have demonstrated variable results. Successful adoption of beef × dairy crossbreeding in the cattle industry will depend on the proper selection of beef sires that excel in calving ease, growth, muscling, and marbling traits to complement the challenges realized with dairy genetics involved in beef production.

Our objective was to determine the effect of calf-fed (CF) or yearling-fed (YF) finishing systems on performance and carcass characteristics of beef × dairy (DB) crossbred steers compared to native beef (NB) steers. The NB steers (n = 160) were acquired from Capitol Land and Livestock in Schwertner, Texas. The DB steers (n = 184) were acquired from 5-Star Dairy in Hart, Texas. The CF (n = 194) steers were transported directly to a commercial feedyard (Buffalo Feeders, Buffalo, OK) from the source. Steers in the YF system (n = 150) were transported to the Marvin Klemme Research Range, near Bessie, OK, to graze mixed grass prairie for 144-d before finishing. At Buffalo Feeders, steers were sorted by finishing system and breed-type into commercial size pens, so each breed-type × system combination were in a single pen. Data were analyzed using SAS 9.4 Mixed Procedure (SAS Institute, Cary, NC) with individual steer as the experimental unit. For CF, initial finishing BW did not differ for DB and NB (P = 0.11), while the initial finishing BW of NBYF was greater (P < 0.01) than DBYF due to NBYF steers having greater ADG on pasture. At reimplant, BW of YF steers was greater (P < 0.01) than CF steers. The DBYF steers had the greatest overall ADG (P < 0.01) with NBCF having the least ADG (P < 0.01) with NBYF and DBCF being intermediate. Back-fat thickness (P = 0.03) was greatest in NBCF, and DBYF having the least BFT, while DBCF and NBYF were intermediate. Overall liver abscesses had breed-type (P < 0.01) and finishing system effects (P = 0.01) with DB and YF steers having higher incidence of liver abscesses. Total net return was greatest (P < 0.01) in NBYF followed by DBYF, DBCF, and NBCF, respectively. Grazing beef × dairy steers before feedlot finishing can improve animal performance and certain carcass characteristics, but there is still a high incidence of liver abscesses. Since DB systems had intermediate returns, these animals can be competitive to their NB counterparts, but the higher prevalence of liver abscesses needs to be further researched.

This study examined dose-response effects of supplemental dietary dl-α-tocopheryl acetate (VE) on growth performance, immune response, and carcass and meat sensory characteristics in two breeds of cattle. Seventy-five crossbred beef steers (361 ± 22 kg) were blocked by weight, randomly assigned to one of five treatment groups, and fed a ration supplemented with 0, 250, 500, 1000 or 2000 IU VE steer−1 d−1. Sixty Holstein steers (366 ± 22 kg were similarly blocked and allocated (no 250 IU treatment). Four days post-slaughter the left sirloin subprimal of each steer was removed and vacuum packaged. On day 13, small cores were cut from the gluteus medius (GM) and packaged with O2-permeable wrap; these were then displayed under 45-W natural white light for up to 10 d at 4 °C. Serum α-tocopherol increased (P &lt; 0.0001) with increasing VE in both breeds, although more so (P &lt; 0.0001) in beef steers. The GM α-tocopherol levels increased linearly (P &lt; 0.0001) with increasing VE, but more so (P &lt; 0.0002) in beef steers. The levels of α-tocopherol in semimembranosus muscle, perirenal and subcutaneous fat, and liver also increased linearly (P &lt; 0.0001) in both breeds. Growth performance of all steers and carcass characteristics of beef steers were not affected (P &gt; 0.10) by VE. Dairy steers receiving 1000 IU d−1 had darker (P &lt; 0.03) ribeyes. There were no effects (P &gt; 0.10) of VE on sensory attributes of frozen steaks. Surface metmyoglobin formation was deterred by VE supplementation in meat from beef (linear, P &lt; 0.016) but not dairy (P &gt; 0.10) steers. Lipid oxidation was suppressed (linear, P &lt; 0.0002) by VE but more so (P &lt; 0.0001) in beef than in dairy meat (72.9% vs. 40.0% suppression, respectively, at 2000 IU d−1). Immune response increased (P &lt; 0.074) at higher levels of VE. In summary, VE supplementation improved immune response and increased serum and muscle α-tocopherol levels, resulting in delayed metmyoglobin formation (beef) and lipid oxidation (beef and dairy) in a dose-dependent manner. Supplemental VE was more effective in meat from beef steers than in that from dairy steers. Key words: Vitamin E, immunity, growth, carcass

The objective of this research was to evaluate the effect of feeding fresh cassava root (CR) along with a feed block containing high was to sulfur (FBS) on feed intake, digestibility, rumen fermentation, and blood thiocyanate concentration in Thai native beef cattle. Four Thai male native beef cattle, initial body weight (BW) of 130 + 20.0kg, were used in this study. The experiments were randomly assigned according to a 2 × 2 factorial arrangement in a 4 × 4 Latin square design. The main factors were supplemented fresh CR levels (1.0 and 1.5% BW) and across to a feed block supplemented with sulfur added 2% (FBS-2) and 4% (FBS-4). Intakes of rice straw, concentrate diets, and FBS were not affected by treatments. Intakes of CR, sulfur, and total intake were significantly altered by the FBS treatment. The apparent dry matter and organic matter digestibility coefficient were significantly higher in animals fed FBS-4 than in those fed FBS-2. The ruminal ammonia nitrogen concentration was not affected by treatment and ranged from 15.6 to 17.6mg/dl. Populations of protozoa and fungal zoospores were similar across treatments, whereas the bacterial population was significantly different between sulfur levels in the feed block. Feeding CR with FBS did not change total volatile fatty acid (VFA) concentrations and VFA profiles except for the propionic acid concentration, which was higher in the group with CR supplementation at 1.5% BW. Cattle fed CR with FBS showed similar blood urea nitrogen concentration at various feeding times and overall. In contrast, CR supplementation at 1.5% BW with FBS-2 increased blood thiocyanate concentrations. Therefore, supplementation of FBS-2 was beneficial to Thai native beef cattle fed with 1.5% BW fresh CR as it improved digestibility and rumen fermentation presumed, because HCN from fresh cassava root was converted into thiocyanate, which is nontoxic to farm animals.

This study aimed to study the effect of excessive elemental sulfur addition on intake, digestibility, rumen characteristics, blood metabolitesand nitrogen balance in Thai native beef cattle fed diets containing high fresh cassava root (FCR) supplementation. Four Thai native beef cattle with an initial body weight (BW) of 100 ± 10.0 kg were used and randomly assigned to a 2 × 2 factorial in a 4 × 4 Latin square design. Two levels of FCR supplementation at 15 (FCR-1.5) and 20 g/kg of BW (FCR-2) and two levels of sulfur supplementation in concentrate at 10 (Sulfur-1) and 20 g/kg dry matter concentrate (Sulfur-2) were evaluated. This study showed that sulfur and FCR in combination (p < 0.05) increased dry matter and organic matter digestibility and bacterial population. Sulfur-2 resulted in higher (p < 0.05) sulfur intake and serum thiocyanate concentration than Sulfur-1. FCR-2 had a greater (p < 0.05) FCR intake, total volatile fatty acidsand propionate concentration than FCR-1.5. In conclusion, excessive elemental sulfur addition with high FCR supplementation showed no negative effect in Thai native beef cattle.

Simple SummaryAs a result of the recent ban on antibiotics in feed, animal probiotics are becoming increasingly popular. Yeast is extensively used as both a probiotic and prebiotic in the gastrointestinal tracts of ruminants. The purpose of this study is to determine how adding yeast (Saccharomyces cerevisiae) to the diet and changing the roughage-to-concentrate ratio (R:C ratio) affects nutrient consumption, rumen fermentation, microbial protein synthesis, and protozoal population in Thai native beef cattle. The roughage source was urea–calcium-hydroxide-treated rice straw. The findings suggest that supplementing with a R:C ratio of 40:60 and a LY of 4 g/hd/d boosted nutrient digestibility, volatile fatty acid (VFA) production, propionic acid (C3) in particular, and microbial protein synthesis while lowering protozoal population.The objective of this research is to investigate the effect of yeast (Saccharomyces cerevisiae) adding and roughage-to-concentrate ratio (R:C ratio) on nutrients utilization, rumen fermentation efficiency, microbial protein synthesis, and protozoal population in Thai native beef cattle. Four Thai native beef cattle, weighing an average of 120 ± 10 kg live weight, were randomly assigned to four dietary treatments using a 2 × 2 factorial arrangement in a 4 × 4 Latin square design. Factor A was the level of roughage-to-concentrate ratio (R:C ratio) at 60:40 and 40:60; factor B was the levels of live yeast (LY) supplementation at 0 and 4 g/hd/d; urea–calcium-hydroxide-treated rice straw were used as a roughage source. Findings revealed that total intake and digestibility of dry matter (DM), organic matter (OM), and crude protein (CP) were increased (p < 0.05) by both factors, being greater for steers fed a R:C ratio of 40:60 supplemented with 4 g LY/hd/d. Ruminal ammonia nitrogen, total volatile fatty acid (VFA), and propionate (C3) were increased (p < 0.05) at the R:C ratio of 40:60 with LY supplementation at 4 g/hd/d, whereas rumen acetate (C2) and the C2 to C3 ratio were decreased (p < 0.05). With a high level of concentrate, LY addition increased total bacterial direct counts and fungal zoospores (p < 0.05), but decreased protozoal populations (p < 0.05). High-concentrate diet and LY supplementation increased nitrogen absorption and the efficiency of microbial nitrogen protein production. In conclusion, feeding beef cattle with 4 g/hd/d LY at a R:C ratio of 40:60 increased C3 and nutritional digestibility while lowering protozoal population.

This experiment evaluated the use of Mitragyna speciosa Korth leaf pellets (MSLP) on feed intake and nutrient digestibility in Thai native beef cattle. Four Thai native beef cattle steers were randomly assigned according to a 4 × 4 Latin square design to receive four dietary treatments. The treatments were as follows: control (no supplementation), MSLP supplement at 10 g/hd/d, MSLP supplement at 20 g/hd/d and MSLP supplement at 30 g/hd/d, respectively. All animals were fed a concentrate mixture at 0.5% body weight, while urea lime-treated rice straws were fed ad libitum. Findings revealed that feed intakes were increased by MSLP, which also significantly increased the digestibility of dry matter (DM), organic matter (OM) and neutral detergent fiber (NDF). Ruminal total volatile fatty acid (TVFA) concentration and propionate (C3) proportion were increased (p < 0.05) with MSLP supplementation, whereas ruminal ammonia-N (NH3-N), plasma urea nitrogen (PUN), acetate (C2), C2:C3 ratio and estimated methane (CH4) production decreased (p < 0.05). Total bacterial, Fibrobacter succinogenes and Ruminococus flavefaciens populations increased (p < 0.05) at high levels of MSLP supplementation, while protozoal populations and methanogenic archaea reduced (p < 0.05). Supplementation of MSLP also increased the efficiency of microbial nitrogen protein synthesis. Supplementing beef cattle with MSLP 10−30 g/hd/d significantly increased rumen fermentation end products and nutrient digestibility by mitigating protozoal populations and estimated CH4 production.

This study evaluated the effects of replacing soybean meal (SBM) with black soldier fly larvae (BSFL) in powdered and pelleted forms on feed intake, rumen fermentation, and nutrient digestibility in Thai native beef cattle. Four male Thai native beef cattle (3-3.5 years old; 370±20.0 kg body weight) were assigned to a 4×4 Latin square design to evaluate the effects of replacing SBM with BSFL in the concentrate portion of the diet. The dietary treatments were: T1, control diet with SBM as the sole protein source; T2, 50% of SBM replaced with powdered BSFL; T3, 25% of SBM replaced with pelleted BSFL; and T4, 75% of SBM replaced with pelleted BSFL. Replacing SBM with BSFL had no significant effect on dry matter (DM) intake, ruminal pH, ammonia-nitrogen, or volatile fatty acid concentrations (p>0.05). Neutral detergent fiber intake was significantly higher in cattle fed the diet containing 75% pelleted BSFL compared to those fed 25% pelleted BSFL (p<0.01). Crude protein digestibility improved overall in BSFL-supplemented groups compared to the control (p<0.01). The highest DM digestibility was observed at 25% pelleted BSFL, significantly higher than at 75% inclusion (p<0.05). At 4 hours post-feeding, blood urea nitrogen concentration was significantly lower in cattle fed the 75% pelleted BSFL diet compared to those fed 25% pelleted BSFL (p<0.05). Protozoal populations, total volatile fatty acid concentrations, and the volatile fatty acid profile did not differ significantly among treatments (p>0.05). Replacing SBM with BSFL, particularly at 25% in pelleted form, improves nutrient digestibility without impairing rumen fermentation, supporting its potential as a functional protein source in ruminant diets.

The principle of the study was to assess the influence of yeast-fermented cassava pulp (YFCP) as a protein supplement on feed intake, nutrient digestibilities, rumen microbial protein synthesis, fermentation end-products, and N-balance in Thai native beef cattle. The experiment was conducted following the 4 × 4 Latin square design using 4 levels of YFCP supplementation (0, 100, 200, and 300g/head/day) in 3-year-old Thai native beef cattle crossbreds. The response of YFCP supplementation level using rice straw as a roughage source revealed promising results. The rumen ecology parameters including cellulolytic, amylolytic, and proteolytic bacterial population were significantly increased while the protozoal population were reduced, as affected by increasing level of YFCP supplementation (P <0.05). In parallel with these results, totals VFA, propionate (C3) production in the rumen, and the ratio of C2:C3 were remarkably increased (P < 0.01), while rumen methane production by prediction from VFA was decreased (P < 0.01), as YFCP supplementation increased. Regarding, the nutrient digestibilities, those of OM and CP were remarkably enhanced (P <0.01), hence increased DM intake. Furthermore, the use of YFCP at high level resulted in the highest N-balance and N retention absorption (P < 0.01). The results indicated that YFCP can be nutritionally enhanced by yeast fermentation, thus is promising to be used as a protein source in ruminant feeding.

Effect of Delonix regia seed meal supplementation in Thai native beef cattle on feed intake, rumen fermentation characteristics and methane production

This study investigated the effects of sulfur supplementation and cyanide-utilizing ruminal bacteria (CUB) on nutrient digestibility, rumen fermentation, and blood urea-nitrogen (BUN) in Thai native beef cattle fed fermented total mixed rations (FTMR) containing fresh cassava root. Two CUB strains, &lt;italic&gt;Enterococcus gallinarum&lt;/italic&gt; KKU-BC10 and &lt;italic&gt;Enterococcus faecium&lt;/italic&gt; KKU-BF7, were isolated from the rumen based on their hydrogen cyanide (HCN) degrading capacity. Four dietary treatments were prepared by formulating FTMR with 40% rice straw and 40% fresh cassava root (dry matter (DM) basis), supplemented with other concentrate ingredients, and differing by additive: (1) 1% sulfur, (2) 2% sulfur, (3) &lt;italic&gt;E. gallinarum&lt;/italic&gt; KKU-BC10, or (4) &lt;italic&gt;E. faecium&lt;/italic&gt; KKU-BF7. Each ration was fermented anaerobically for seven days before feeding. Four male Thai native beef cattle (2.5 years old; 222 ± 12.0 kg initial body weight) were allocated to the four treatments in a 4 × 4 Latin square design, with each animal receiving all four treatments across the four experimental periods. All FTMR treatments effectively reduced HCN to safe levels for ruminant feeding. Specifically, HCN content in the FTMR dropped from ~60–84 mg/kg DM before fermentation to ~41–52 mg/kg DM after 7 days, remaining well below the 100 mg/kg DM safety threshold for cattle. No significant differences were observed in dry matter intake, nutrient digestibility, or total volatile fatty acid concentrations (&lt;italic&gt;p&lt;/italic&gt; &gt; 0.05). However, fiber intake was enhanced by microbial inoculation. Cattle receiving &lt;italic&gt;E. gallinarum&lt;/italic&gt; KKU-BC10 showed the highest neutral detergent fiber intake (&lt;italic&gt;p &lt;/italic&gt;&lt; 0.05). In contrast, &lt;italic&gt;E. faecium&lt;/italic&gt; KKU-BF7 supplementation resulted in the highest acid detergent fiber intake (&lt;italic&gt;p&lt;/italic&gt; &lt; 0.01). Notably, cattle fed &lt;italic&gt;E. faecium&lt;/italic&gt; KKU-BF7 also had significantly lower blood urea-nitrogen concentrations at 4 hours post feeding (&lt;italic&gt;p&lt;/italic&gt; = 0.04), indicating improved nitrogen utilization. Rumen pH and ammonia–nitrogen levels remained within physiological ranges across all treatments. These findings confirm that sulfur and CUB supplementation in FTMR supports the safe use of fresh cassava root in ruminant diets. Moreover, &lt;italic&gt;E. faecium&lt;/italic&gt; KKU-BF7 shows potential to enhance nitrogen efficiency beyond detoxification.

Four Thai male native beef cattle, initial body weight (BW) of 100 ± 3.0 kg were randomly assigned in a 4 × 4 Latin square design to receive four dietary treatments with inclusion of urea calcium sulphate mixture (U-cas) in feed block (FB) at 0, 120, 150, and 180 g/kg dry matter (DM). Total intakes were increased with the increasing level of U-cas supplementation in FB and the result obtained the highest when supplementation of U-cas in FB at 180, followed by 150, 120, and 0 g/kg DM, respectively. Moreover, supplementation of U-cas in FB at 180 g/kg DM could reduce total N excretion (4.1 g/day), as compared to others treatments, while N retention and proportion of N retention to N intake were increased up to 6.9 g/day and 14.9 %, respectively. On the other hand, the blood biochemistry and hematological parameters were not different among treatments except concentration of plasma urea N, plasma glucose, and total blood protein were improved especially with U-cas supplementation at 180 g/kg DM in FB. In conclusion, supplementation of U-cas at 180 g/kg in FB improved feed intake, N utilization, and blood biochemistry in Thai native beef cattle fed on rice straw.

The purpose of this study was to see how substituting cassava pulp fermented yeast waste (CSYW) for soybean meal (SBM) in a concentrate affected feed intake, digestibility, and rumen fermentation in Thai native beef cattle. In this study, four male Thai native beef cattle with an average age of 15.0 ± 25.0 months and body weights of 140 ± 5.0 kg were used. The experimental design was a 4 × 4 Latin squared design, with dietary treatments of CSYW replacing SBM at 0, 33, 67, and 100% in the concentrate mixture. It was discovered that the presence of CSYW had no negative impact on feed intake, nutritional intake, or apparent digestibility (p > 0.05). CSYW had no significant effects on ruminal pH or temperature (p > 0.05). When the amount of CSYW in the diet increased, the rumen ammonia–nitrogen concentration increased (p < 0.05). Blood urea nitrogen was not affected by CSYW (p > 0.05). The total bacterial population increased when the diet's CSYW amount was increased (p < 0.05). Feeding CSYW to beef cattle had no influence on total volatile fatty acid, acetic acid (C2), or butyric acid (C4) proportions (p > 0.05). The concentration of propionic acid (C3) and the C2:C3 ratio increased when the amount of CSYW in the diet was increased (p < 0.05). In conclusion, CSYW can completely replace SBM in a concentrate diet for beef cattle with no adverse effects on feed utilization or rumen fermentation while the total bacterial population and C3 concentration increase.

Effect of feeding feed blocks containing different levels of urea calcium sulphate mixture on feed intake, digestibility and rumen fermentation in Thai native beef cattle fed on rice straw

The objective of this experiment was to study the effects of Brazilian spinach (Alternanthera sissoo) pellet (BSP) supplementation on rumen fermentation, protozoal population, and methane (CH4) estimation in beef cattle. Four male Thai native beef cattle, 3 years old, with an average bodyweight of 180 ± 5 kg, were randomly arranged in a 4 × 4 Latin square design. The cattle were supplemented (on-top) with four levels of BSP (2, 4, 6, and 8% dry matter intake (DMI), respectively). The roughage component, derived from rice straw, was fed at 40 % of DMI, while the concentrate diet was fed at 60 % of DMI. The result of the experiment demonstrated that BSP supplementation had no effect on the DMI, nutrient intake, or nutrient digestibility (p > 0.05). Rumen pH and ammonia-nitrogen concentration were not significant, while the average protozoal population linearly decreased (p = 0.002) with BSP supplementation. Mean blood urea-nitrogen concentration was linearly increased (p = 0.004) when increasing the level of BSP. Brazilian spinach pellet had no significant effect on total volatile fatty acids (TVFA), VFA profiles, and CH4 estimation (p > 0.05). Nitrogen balance was no different from the supplementation of BSP. The study indicates that Brazilian spinach pellet supplementation showed no noticeable effects on feed intake, rumen parameters, and nitrogen utilization; however, at 6–8% of DMI, there was a decrease in protozoal population, with no corresponding reduction in CH4 estimation.