Abstract
Four experiments were conducted to evaluate: (1) effects of calcium salts of soybean oil (CSSO) supplementation to Bos taurus beef cows post-AI on conception rates and (2) on pregnancy ...establishment factors; (3) effects of CSSO supplementation to late gestating beef cows on the performance of the offspring; (4) the viability of utilizing low-moisture molasses-based blocks (LMB) as a delivery method for CSSO. In Exp. 1, 1,771 cows were divided into groups, and inseminated on d 0. After AI, groups received CSSO (n = 11), or prilled saturated fat (CON; n = 11) from d 0 to 21. Cows receiving CSSO had greater (P = 0.01) pregnancy rates. In Exp. 2, 90 cows housed in 18 pens were assigned to the same treatments and timed AI program from Exp. 1. On d 15, selected cows were assigned to conceptus collection. On d 20 blood was sampled for RNA extraction. CSSO supplementation increased (P = 0.05) mRNA expression of IFNT by the conceptus, and blood mRNA expression of ISGs. In Exp. 3, cows were assigned to receive: CSSO (n = 52) or CON (n = 52) during late gestation. CSSO cattle had greater (P ≤ 0.02) colostrum and plasma IgG; greater (P ≤ 0.05) expression of adipogenic and myogenic genes; required fewer microbial treatments for BRD (P = 0.05) and had greater longissimus muscle area compared to CON cohorts. In Exp. 4, 36 cows (n = 9 pens) were assigned to receive: 1) NOSUPP; 2) LMB, 24.7% CSSO; 3) CONC, hand-fed, 24.7% CSSO. Plasma FA were modified (P < 0.01) in CONC and LMB vs. NOSUPP cows. Collectively, these results present CSSO supplementation as a strategy to improve reproductive success in Bos taurus beef cows and productive performance of offspring born from supplemented dams. These results are associated to effects of linoleic acid and its ω-6 derivates. Additionally, the use of LMB seems to be a valid delivery method for CSSO supplementation, and consequently ω-6 FA, to beef cows.
Abstract
The objective of this study was to rank beef heifers for residual feed intake and greenhouse gas emissions using an unprocessed, grass hay diet. Fifty yearling Angus heifers were monitored ...for 62 days using the SmartFeed individual intake measuring technology (C-Lock Inc., Rapid City, SD) in drylot pens at the Oklahoma State University Range Cow Research Center located in Stillwater, OK. Means ± SD for dry matter intake (DMI; 6.76 ± 1.20 kg), average daily gain (ADG; 0.51 ± 0.21 kg), body weight (BW; 338.67 ± 55.24 kg), and residual feed intake (RFI; -0.04 ± 0.80 kg) were recorded while the heifers were fed unprocessed long-stem grass hay (10.3% CP, 2.0 Mcal ME, and 56% TDN). Additionally, a subset of 29 heifers were subjected to the collection of gas flux data using an open-circuit, portable, gas-quantification system (GreenFeed, C-Lock Inc., Rapid City, SD) to measure (means ± SD) oxygen consumption (O2; 3979.51 ± 510.32 g), carbon dioxide production (CO2; 5299.65 ± 610.89 g), and methane production (CH4; 202.656 ± 28.30 g). Using R, RFI was calculated using a multiple regression equation to predict DMI using BW0.75 and ADG (P > 0.05; R2 = 0.37). To analyze forage utilization efficiency, heifers were classified into three RFI categories consisting of efficient (n = 16), average (n = 16), and inefficient (n =18). The ADG was low for all RFI classifications and similar for all three categories (P < 0.05). Heifers classified in the top third of RFI rank consumed 22% less forage per day compared to the inefficient heifers. The phenotypic correlation between DMI with CO2, CH4, and O2 was 0.66, 0.18, and 0.49, respectively. These data suggest that progress in feed efficiency can be achieved when cattle are tested using a moderate-quality, unprocessed forage diet.
Abstract
Metaphylactic treatments are used in cattle enterprises to mitigate bovine respiratory disease (BRD). Crossbred beef calves (n = 78; BW = 272 ± 25.8 kg) were randomly assigned 1 of 2 ...metaphylactic treatments. Upon arrival, calves were processed (ear tagged, vaccinated, dewormed, ear notched) and administered either 1.2 mL/50 kg BW of tulathromycin with a 7-d post-metaphylactic interval (PMI) or 2 mL/50 kg BW of gamithromycin with a 5-d PMI. Cattle were observed daily for signs of morbidity and a Clinical Attitude Score (0 normal to 5 morbid) was recorded. Calves that scored a 1 or greater and PMI eligible were pulled and rectal temperatures were recorded; if temperature exceeded 40°C, calves were given enrofloxacin. If calves were pulled a second time and criteria met, ceftiofur was the final antibiotic administered. Performance data and cost analysis were analyzed using the MIXED procedure of SAS 9.4, with repeated measure of day used for performance data. Morbidity and treatment with second antibiotic data were analyzed using the GLIMMIX procedure of SAS 9.4. There were no differences in morbidity (P = 0.17) or treatment with second antibiotic (P = 0.32). There was no treatment × day interaction or main effect for treatment for BW or ADG, but there was a main effect of day as BW increased (P < 0.001) through the sampling period and gain from days 0 to14 was greater than gain from days 14 to 28 (P = 0.001) and 28 to 42 (P < 0.001). Initial antibiotic costs ($32.73 vs. $21.74) and overall costs ($32.74 vs. $24.16) were greater (P < 0.001) in cattle administered tulathromycin compared to gamithromycin treated calves. While there were no differences between antibiotic treatments for health or performance, these data indicate that gamithromycin was a more cost-effective metaphylactic treatment for newly received, high-risk calves.
Abstract
A 2-year trial was conducted at the Marvin Klemme Range Research Station in Bessie, OK, to analyze the effects of supplementing steers on native range with extruded 100% DDGS cubes ...(MasterHand Milling, Lexington, NE). Two main plot treatments were: Positive Control (PC, 249 ± 3.5 kg) supplemented with DDGS cubes at 1.8 kg/steer on alternate days only in late summer stocked at 2.5 ha/steer and High Supplement (HS, 247 ± 3.5 kg),1/3 increase in stocking rate with 0.75% of BW supplement rate with DDGS cubes 5 days per week for the entire duration of the season. For both years all steers were implanted with 200 mg progesterone and 20 mg estradiol benzoate (Synovex S, Zoetis Animal Health) upon arrival. Three reimplant treatments were applied in mid-summer: 1) no reimplant; 2) Synovex S; or 3) 40 mg trenbolone acetate and 8 mg estradiol (Revalor G, Merck Animal Health). In each pasture, 1/3 of the steers received each reimplant treatment. Steers grazed from mid to late May to late September in both 2019 and 2020. Data recorded for both years were combined and were analyzed using the PROC MIXED in SAS as a split-plot experimental design, with supplement treatment in the main plot and mid-season reimplant in the split plot. Early season ADG for HS was 0.36 kg greater (P < 0.01) than PC. However, late season ADG did not differ (P ≥ 0.81). Gain per hectare was 43.3 kg greater (P < 0.01) for HS as compared to PC. Results from this 2-year trial show that the use of an extruded 100% DDGS cube is a viable option to successfully increase stocking while not only minimizing the potential lack of performance on an individual animal basis, but instead increased the performance of these animals in western Oklahoma. More research needs to be done to determine the effect on range condition.
Abstract
Cotton byproducts, such as whole cottonseed (WCS) and cotton gin byproduct (CGB) can be utilized as cattle feed. Our objective was to evaluate the feeding value of WCS and CGB when included ...in a growing ration. Fifty-six yearling steers with a starting body weight of 288±3.8 kg were used in an 84-day trial. Steers were blocked by weight for pen assignments, and treatments were randomly assigned within pen. The nutritionally balanced diets were fed to appetite as total mixed rations through Calan gates. Treatment 1 (TRT 1), was composed of corn silage, ground corn, and soybean meal. Treatment 2 (TRT 2) replaced some of the corn and soybean meal with WCS (15% of the diet DM). Treatment 3 (TRT 3) replaced some of the silage with CGB (25% of the diet DM). Treatment 4 (TRT 4) replaced some of the corn and soybean meal with WCS (15% of the diet DM) and some of the silage with CGB (25% of the diet DM). Dry matter intake (DMI) was similar for TRT 1 and 2, which were lower (P >0.5) compared to TRT 3 and 4 (8.8, 8.5, 11.3, and 10.3±0.24 kg/d for TRT 1, 2, 3, and 4, respectively). Average daily gain did not differ between TRT 1, 2, and 4, but was higher (P >0.5) for TRT 3 (1.27, 1.18, 1.32, and 1.54 ± 0.05 kg/d for TRT 1, 2, 3, and 4, respectively). Gain to feed ratios were highest (P >0.5) for TRT 1 and 2 compared with TRT 3 and 4 (0.16, 0.15, 0.12, and 0.13±0.009, respectively). This study demonstrates that cotton byproducts can be utilized in growing cattle diets to replace a portion of corn, soybean meal, and corn silage while resulting in similar or enhanced performance.
Abstract
The objective of this study was to compare high and low residual feed intake (RFI) beef cows when consuming an unprocessed, grass hay diet (93% DM, 8.73% CP, 2.11 Mcal ME, and 59.25% TDN). ...Relationships of hay intake to carbon dioxide (CO2) and methane (CH4) production were also evaluated. Thirty-six mature Angus and Angus x Hereford cows were assigned randomly to five pens (n = 6 or 9) and individual feed intakes were collected for 52-d using SmartFeed intake units (C-Lock Inc., Rapid City, SD) at a stocking rate of 3 cows per feeder. An open-circuit, gas-quantification system (GreenFeed, C-Lock Inc., Rapid City, SD) was used to collect CO2 (7611.63±714.09 g) and CH4 (283.64±37.10 g) production for 9 days of collection per pen for a minimum of 20 visits per cow (n = 22 cows, 36.18±14.24 visits). Data collection on cows included (means ± SD) dry matter intake (DMI; 13.86±2.16 kg), metabolic body weight (MBW, 111.65±9.28 kg), average daily gain (ADG, 0.77±0.29 kg), and rib eye area by ultrasound (REA, 46.62±6.34 cm).To calculate RFI (0.03±1.71), a multiple regression model was used to predict DMI (PDMI = ADG + REA + MBW; R2=0.50, P = 0.001). Cows were categorized into three RFI classes: low (n = 7), moderate (n = 6), and high (n = 9). Differences between RFI and RFI class and DMI and RFI class were analyzed using PROC MIXED in SAS (SAS, Cary, NC). Low RFI cows (-1.81 kg) consumed 12.08 kg hay DM daily and high RFI cows (1.59 kg) consumed 15.27 kg hay DM daily (P < 0.001). Correlations between DMI and daily gas exchange were estimated using PROC CORR in SAS (SAS, Cary, NC). Pearson Correlation Coefficients were significant between DMI and CO2 (r=0.58, P = 0.004), and CH4 (r=0.70, P < 0.001) production. Differences in feed intake for high and low RFI rankings were similar to previously reported literature when growing cattle consumed energy-dense diets.
Abstract
The objective of this experiment was to further investigate effects of feeding dried citrus pulp (DCP) to cattle. Crossbred beef heifers (n = 167, initial body weight = 266 ± 1.8 kg) ...arriving on 2 delivery dates were used in a 42-day receiving trial. Heifers were processed after arrival and placed randomly into 8 pens on each delivery date (10 or 11 heifers/pen; total of 16 pens). Each pen was assigned randomly to 1 of the 2 supplements. Dietary treatments were: 1) a corn and distillers’ grains based receiving supplement (control), or 2) an identical receiving supplement except it contained 20% dried citrus pulp (replacing a portion of the corn). Heifers had access to bermudagrass hay and water for ad libitum intake, but were only offered up to 1.8 kg/day of their appropriate receiving supplement. Cattle were observed daily for clinical bovine respiratory disease (BRD), if presenting symptoms of BRD and if rectal temperature was ≥ 40° C; cattle were treated according to a standard preplanned protocol with antibiotic and deemed morbid. Weights were recorded on day 0, 14, 28, 41, and 42. Statistical analyses were performed by using the Mixed and GenMod procedures of SAS 9.4 with treatment as the fixed effect and delivery date as a random effect. Dietary treatment had no effect on body weight on any day, or on the overall average daily gain (ADG; P > 0.54). Heifers fed the control supplement had a greater ADG from day 28 to 42 (P = 0.07) compared to those fed DCP. Incidence of morbidity was not affected by DCP supplementation (P = 0.53). In conclusion, feeding dried citrus pulp in receiving supplements resulted in similar overall average daily gain and did not affect the incidence of bovine respiratory disease within the 42-day receiving period.
Abstract
The objective was to determine if restricting drinking water affects animal performance and hematological responses in cattle grazing high-moisture-content, fresh wheat pasture. Angus-cross ...steers (n = 10, 411 kg ± 24.5 kg) were randomly assigned to either 100% or 50% of baseline (d -7 to 0) water intake. The design of this experiment was a completely randomized design with 5 replications, with steer as experimental unit. Steers were individually hand-watered 1X per d for the entire experiment (d -7 to 28). Body weight, packed-cell volume (PCV), plasma total solids (PTS), fecal DM (F_DM), eyeball recession score (ERS) and skin turgor score (STS) were recorded from each steer weekly. Forage mass and forage DM were calculated weekly by hand-clipping ten, randomly-located samples using a 0.96-m forage hoop. Data were analyzed using ANOVA methods in SAS v9.4, and pairwise comparisons of means were completed using Fisher’s LSD methods at the nominal 0.05 level of significance. Restricted steers gained less than unrestricted steers (P < 0.01, 1.04 vs. 1.35 kg / d, respectively). Fecal DM percentage did not differ (P = 0.26). There was no difference in PCV (P = 0.15) or PTS (P = 0.27); however PCV and PTS linearly decreased (P < 0.001) from d -7 to 28 for both treatment groups. Eyeball recession score and STS did not differ between treatment groups (P = 0.34). The mean forage mass and forage DM (d -7 to 28) were 2,229 kg per hectare and 24%, respectively. In conclusion, restricting water intake to cattle grazing wheat pasture resulted in lower ADG; however differences in hematological measures of dehydration were not observed in this study.
Abstract
Bovine respiratory disease (BRD) is the leading cause of morbidity and mortality in beef cattle. Common management practices in addition to BRD have been shown previously to cause ...inflammation. The objectives of this study were: (1) characterize the inflammatory profiles as indicated by haptoglobin concentrations, over a receiving period in high-risk cattle; (2) evaluate the impact of on-arrival metaphylactic antimicrobial therapy on inflammatory profiles in high risk cattle; and (3) examine the relationship between inflammatory profile and BRD morbidity and mortality in high risk cattle. This 70 d trial was repeated over two years. A total of 160 black/black white face crossbred heifers were acquired from local auction markets and randomly assigned at arrival to treatment groups. Heifers were purchased by an order buyer from auction barns. At arrival, heifers were randomly assigned to either receive tulathromycin (Draxxin, META, n = 40) or not (NO META, n = 40) upon arrival. Each group was housed on a 10-acre pasture planted in annual ryegrass where they were offered complete commercial supplemental feed (14% CP) and free choice (both Purina Animal Nutrition, Nashville, TN) mineral and were observed daily for clinical signs of BRD. Cattle were weighed and blood was collected every seven days from d0 to d20, and again on d70. Haptoglobin concentrations were determined using ELISA. Effects of treatment and morbidity on haptoglobin concentration were tested using the MIXED procedure of SAS. Overall morbidity was 28.5%. Initial body weight (227 kg META, 229 kg NO META, P > 0.10) did not differ between the two treatment groups. However, final body weight differed between treatment groups (294 kg META, 289kg NO META). Haptoglobin concentrations remained elevated over time for all groups (P = 0.03). Metaphylaxis did not affect haptoglobin concentration (P > 0.10). There was a significant increase in BRD cases from day 0 to 20 (P = 0.00). Morbidity (BRD vs no BRD) did not impact haptoglobin concentrations. Overall, metaphylaxis did not affect haptoglobin levels or BRD incidence.
Abstract
The white-tailed deer breeding industry has developed into a $1.6 billion-dollar annual sector. However, even with this rapidly growing industry, little is known concerning certain mineral ...requirements for deer raised in confinement and their conception success. Previous research has suggested that white-tailed does are more apt to conceive with elevated circulating levels of zinc, vitamin E, and selenium. This research project consisted of ninety-three does on standard confinement diets, supplemented with only a single dose of Zn, Se, Mn, and Cu via MultiMin at the time of CIDR input. Supplementation of MultiMin was fixed across all animals in the study. These does were assessed by drawing blood at the time of artificial insemination (AI). Whole blood and serum samples were analyzed for micromineral levels (Co, Cu, Fe, Mn, Mo, Se, and Zn) and fat-soluble metabolites (vitamin A, vitamin E, and cholesterol) at Texas Veterinary Diagnostic Laboratory and analyzed using PROC REG in SAS. Conception success was determined by the does conceiving a fawn from from artificial insemination procedure which was verified via genetic testing of the fawn. It was found that the model containing the main effects vitamin E, zinc, and selenium along with their interactions of vitamin E by Zn and Se by Zinc was significant (P < 0.05; R2=0.15) on positively affecting conception success from artificial insemination. In particular, a tendency was detected in the relationship of vitamin E and selenium (P < 0.1). In post hoc analysis, parameter estimates from the regression were used, and selenium fixed at a level of 144 ng/mL is the point at which supplemental vitamin E has positive effects on conception from AI. This model shows that both vitamin E and selenium are required at higher levels than previously thought in confinement-reared white-tailed deer with intensive breeding programs. With further research using vitamin E and selenium, the mineral requirements of white-tailed deer in confinement can be better understood and aide producers in reproductive efficiency in their captive deer herds.
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