A 6-yr evaluation of prescribed-fire timing on yearling cattle growth performance and plant community dynamics on native tallgrass prairie in the Kansas Flint Hills.

A 6-yr experiment was conducted to determine the effects of prescribed-fire season on stocker cattle growth performance and rangeland plant community characteristics in the Kansas Flint Hills. Eighteen pastures were grouped by watershed and each watershed was randomly assigned to 1 of 3 prescribed-fire treatments: spring (11 April ±â€…5.7 d), summer (25 August ±â€…6.2 d), or autumn (2 October ±â€…9.0 d). All burns were applied prior to grazing in years 1, 2, 3, and 5; however, no burns were applied in year 4 because of unfavorable burn conditions. Over 5 consecutive grazing seasons, 1,939 yearling stocker calves (initial BW = 281 ±â€…58.9 kg) were grazed from May to August at a targeted stocking density of 280 kg live-weight + ha-1. Beginning in June of 2018 (pretreatment), a permanent 100-m transect was established in each pasture and was used to determine plant-species composition using a modified step-point method. Forage biomass accumulation and root carbohydrate concentrations of 4 native tallgrass plant species were also measured. All data were analyzed as a completely randomized design using a mixed model. Average daily gain (ADG) was 0.05 to 0.07 kg greater (P = 0.02) for calves grazing spring-burned pastures compared with calves grazing summer- or autumn-burned pastures; however, ADG did not differ (P ≥ 0.55) between calves assigned to the summer or autumn prescribed-fire treatments. Basal cover of all graminoids and all forbs did not differ (P ≥ 0.30) among prescribed-fire treatments; however, basal cover of C3 grasses tended (P = 0.06) to be greater while basal cover of C4 grasses tended (P = 0.08) to be less in autumn-burned pastures compared with spring-burned pastures. Forage biomass accumulation did not differ (P = 0.58) among treatments. In addition, root starch or root water-soluble carbohydrate concentrations in big bluestem (Andropogon gerardii), little bluestem (Schizachyrium scoparium), Indiangrass (Sorghastrum nutans), or purple prairieclover (Dalea purpurea) did not differ (P ≥ 0.26) among prescribed-fire treatments. Overall, we interpreted these data to suggest that prescribed-fire timing had small influences on yearling stocker cattle growth performance and rangeland plant composition but did not influence forage biomass accumulation or root carbohydrate concentrations of key native tallgrass plant species in the Kansas Flint Hills.

Effects of corn processing and dietary wet corn gluten feed inclusion on performance and digestion of newly received growing cattle.

Effects of corn processing and of dietary inclusion of wet corn gluten feed (WCGF) on growth performance and digestibility were analyzed in 2 experiments. Dietary treatments were arranged as a 2 × 2 factorial. Diets contained corn as either whole-shelled corn (WSC) or as dry-rolled corn (DRC), and they contained either 47% corn with no WCGF or 29% corn with 30% WCGF. In Exp. 1, 279 crossbred calves (230 kg) were allocated to treatments in a complete block design and were used to measure performance and digestion during a 60-d receiving period. Corn processing did not affect (P ≥ 0.31) growth performance. Inclusion of WCGF in the diet increased final BW and ADG (P = 0.03) but did not affect gain efficiency (P = 0.45). Digestibility of DM was increased (P < 0.01) by dietary inclusion of WCGF, and this response was greater in diets containing DRC than in those containing WSC (interaction P = 0.02). For Exp. 2, a digestibility trial used 5 ruminally cannulated Holstein heifers (248 ± 13 kg BW) in a 4 × 4 Latin square with the additional animal administered the same treatment sequence as another heifer. A tendency (P = 0.09) was observed for heifers fed DRC to have greater DMI than those fed WSC. Dietary WCGF inclusion increased (P ≤ 0.01) DMI. Similar to observations in Exp. 1, DM digestibility was improved by addition of 30% WCGF to diets containing DRC but not diets containing WSC (interaction P = 0.02). Ruminal pH was not affected by corn processing (P = 0.90), but it tended (P = 0.09) to be increased by dietary WCGF additions. Ruminal VFA concentrations were not different between WSC and DRC, but dietary inclusion of 30% WCGF decreased (P < 0.01) acetate concentrations and increased (P = 0.05) butyrate concentrations. Liquid passage rate from the rumen and ruminal liquid volume were not affected by corn processing or dietary WCGF inclusion (P ≥ 0.66). In summary, processing corn had no effect on steer performance, but including WCGF in the diet at 30% of DM increased gains of steers over the 60-d receiving period. Diet digestibility did not follow the same pattern observed for gains and efficiencies.

Effect of oral meloxicam on health and performance of beef steers relative to bulls castrated on arrival at the feedlot.

Castration in weaned calves is stressful and affects profitability by reducing ADG and increasing susceptibility to disease. This study evaluated the effect of meloxicam, a nonsteroidal anti-inflammatory drug (NSAID), on performance and health of calves received as steers compared with bull calves surgically castrated on arrival at the feedlot. British × Continental bulls (n = 145) and steers (n = 113; BW = 193 to 285 kg) were transported for 12 h in 3 truckloads (d 0), weighed, and randomly assigned to receive either lactose placebo (CONT; 1 mg/kg) or meloxicam (MEL; 1 mg/kg) suspended in water and administered per os, 24 h before castration. On d 1, bulls were surgically castrated (CAST) and steers were processed without castration (STR). Combinations of CONT/MEL and CAST/STR were allocated to 24 pens (6 pens per treatment) of 8 to 14 calves each. Pen was the experimental unit. Plasma meloxicam concentrations at the time of castration (d 1) were determined by HPLC-mass spectroscopy. Pen-level ADG, DMI, and G:F were estimated using BW obtained on d 0, 14, and 28 and weigh-back of feed. Individual animals were classified as sick based on a depression score of ≥2 on a 5-point scale and a rectal temperature of ≥39.8°C. On d 0, 1, and 14, calf chute temperament was evaluated using a 4-point scale. Data were analyzed using generalized linear mixed models and survival curve analyses. Castration reduced pen ADG (P < 0.001) and G:F (P < 0.001) from d 1 to 14, yet no effects (P > 0.45) were apparent by d 28. For all treatment groups, DMI increased with days on feed (P < 0.0001) but was less in CAST compared with STR calves (P < 0.016) throughout the study. From d 15 to 28, ADG increased (P = 0.0011) in CAST but not STR calves, and G:F decreased (P = 0.0004) in STR but not CAST calves. In CAST calves only, MEL treatment reduced the pen-level first pull rate (P = 0.04) and reduced bovine respiratory disease morbidity rate (P = 0.03). The frequency of chute escape behavior was greater on arrival and at castration in CAST vs. STR calves (P < 0.01) but not significantly different at d 14 (P = 0.22). Mean MEL concentrations at castration were no different between treated STR and CAST calves (P = 0.70). Meloxicam administration before castration in postweaning calves reduced the incidence of respiratory disease at the feedlot. These findings have implications for developing NSAID protocols for use in calves at castration with respect to addressing animal health and welfare concerns.

Read distance performance and variation of 5 low-frequency radio frequency identification panel transceiver manufacturers.

Use of electronic animal identification technologies by livestock managers is increasing, but performance of these technologies can be variable when used in livestock production environments. This study was conducted to determine whether 1) read distance of low-frequency radio frequency identification (RFID) transceivers is affected by type of transponder being interrogated; 2) read distance variation of low-frequency RFID transceivers is affected by transceiver manufacturer; and 3) read distance of various transponder-transceiver manufacturer combinations meet the 2004 United States Animal Identification Plan (USAIP) bovine standards subcommittee minimum read distance recommendation of 60 cm. Twenty-four transceivers (n = 5 transceivers per manufacturer for Allflex, Boontech, Farnam, and Osborne; n = 4 transceivers for Destron Fearing) were tested with 60 transponders [n = 10 transponders per type for Allflex full duplex B (FDX-B), Allflex half duplex (HDX), Destron Fearing FDX-B, Farnam FDX-B, and Y-Tex FDX-B; n = 6 for Temple FDX-B (EM Microelectronic chip); and n = 4 for Temple FDX-B (HiTag chip)] presented in the parallel orientation. All transceivers and transponders met International Organization for Standardization 11784 and 11785 standards. Transponders represented both one-half duplex and full duplex low-frequency air interface technologies. Use of a mechanical trolley device enabled the transponders to be presented to the center of each transceiver at a constant rate, thereby reducing human error. Transponder and transceiver manufacturer interacted (P < 0.0001) to affect read distance, indicating that transceiver performance was greatly dependent upon the transponder type being interrogated. Twenty-eight of 30 combinations of transceivers and transponders evaluated met the minimum recommended USAIP read distance. The mean read distance across all 30 combinations was 45.1 to 129.4 cm. Transceiver manufacturer and transponder type interacted to affect read distance variance (P < 0.05). Maximum read distance performance of low-frequency RFID technologies with low variance can be achieved by selecting specific transponder-transceiver combinations.

Comparison of short-term health and performance effects related to prophylactic administration of tulathromycin versus tilmicosin in long-hauled, highly stressed beef stocker calves.

Health and feed performance parameters of 293 beef stocker calves at risk for bovine respiratory disease were compared after metaphylactic administration of one of two antimicrobials (tulathromycin or tilmicosin) with different durations of activity; the antimicrobial was administered 1 day after arrival. Calves that received metaphylactic tulathromycin displayed significant improvement in morbidity, mortality, and first-treatment success rates (P<.05) compared with tilmicosin-treated calves. Tulathromycin-treated calves also showed a significantly improved average daily gain and feed:gain ratio (P<.05) compared with tilmicosin-treated calves. Under conditions of this study, calves receiving tulathromycin were healthier through a 43-day growing phase compared with calves receiving tilmicosin. This health difference likely accounted for the differences in feed performance between the treatment groups.

Source of dietary lipid may modify the immune response in stressed feeder cattle.

Five studies were conducted to evaluate the effects of lipid source on performance and health of stressed feeder cattle. A total of 332 heifers (195 +/- 2.37 kg initial BW) in trial 1 and 336 heifers (206 +/- 1.70 kg initial BW) in trial 2 were fed diets containing ground flaxseed (FLAX), rolled full-fat soybeans (SOY), or tallow (TAL) at 13, 20, or 4%, respectively (DM basis). All diets were formulated to be isonitrogenous and isocaloric. The ADG and G:F for the first 7 d and for the entire feeding period were greater (P < 0.05) for TAL and FLAX than for SOY. Percentage of animals treated and retreated for bovine respiratory disease did not differ among dietary treatments. The FLAX treatment increased (P < 0.05) total n-3 PUFA concentrations in the plasma, whereas SOY increased (P < 0.05) plasma concentrations of total n-6 PUFA. In trial 3, 18 steers were individually fed diets containing TAL and 18 steers were fed a diet containing SOY (20% of DM). In trials 4 and 5, 18 steers were individually fed diets containing TAL and 18 steers were fed diets containing FLAX (12.9% of DM). On d 14 and 17 of study 3, 4, and 5, 16 steers from each dietary treatment were injected i.v. with Escherichia coli O55:B5 lipopolysaccharide (LPS), and 2 steers from each diet were injected with saline. Rectal temperatures after LPS challenge were lower (P < 0.05) for SOY and FLAX than for TAL, and plasma TNF was greater (P < 0.05) for SOY than for TAL. Serum haptoglobin and blood fibrinogen increased and white blood cell count decreased in response to LPS, but none of these variables was affected by treatment. Although this research failed to measure an effect of lipid source on feedlot morbidity or mortality, these studies indicate that altering the source and type of dietary fatty acids may modify the immune response in stressed feeder cattle and that performance may be hindered by feeding full-fat soybeans to receiving cattle.

Soybean hulls as a primary ingredient in forage-free diets for limit-fed growing cattle.

In Exp. 1, 300 heifers (260 kg initial BW) were used to compare growth performance of cattle fed forage-free diets containing predominantly soybean hulls with that of cattle receiving roughage- and corn-based diets and to determine whether cattle fed soybean hull-based diets would respond to supplementation with methionine hydroxy analogue (MHA), lipid-coated betaine, or concentrated separator by-product (CSB; a source of betaine). Treatments included 1) a roughage-based diet fed at 2.75% of BW, 2) a corn-based diet fed at 1.5% of BW, 3) a corn-based diet fed at 2.25% of BW, 4) a soybean hull-based diet fed at 1.5% of BW (SH1.5), 5) a soybean hull-based diet fed at 2.25% of BW (SH2.25), 6) SH1.5 top-dressed with 11.4 g/d Alimet (10 g/d MHA), 7) SH2.25 top-dressed with 11.4 g/d Alimet, 8) SH2.25 top-dressed with 7 g/d of a lipid-coated betaine product (4.2 g/d betaine), and 9) SH2.25 top-dressed with 250 g/d CSB (15.5 g/d betaine). Supplemental MHA, betaine, and CSB did not change DMI, ADG, or gain:feed ratio for cattle fed soybean hulls. Heifers fed soybean hull-based diets gained 29% slower (P < 0.05) and had 27% lower gain:feed ratios than heifers fed the corn-based diets. Cattle fed soybean hull-based diets had gains that were lower (P < 0.05) than those of cattle fed the roughage-based diets, but gain:feed ratios were similar because cattle were fed less of the soybean hull-based diets. Roughage-fed cattle had similar gains but 25% lower (P < 0.05) gain:feed ratios than cattle fed the corn-based diets. In Exp. 2, degradation by ruminal microbes of betaine in anhydrous betaine, betaine-HCl, feed-grade betaine, lipid-coated betaine, and CSB was evaluated in vitro using ruminal inocula collected from steers fed a high-grain or high-roughage diet. The roughage diet led to less betaine disappearance than the grain diet. More betaine was degraded from CSB than from other sources, perhaps because sugars provided by CSB stimulated fermentation, but no large differences occurred among the other four sources. Betaine from all sources was extensively degraded, although some betaine may escape ruminal degradation.

Escape protein for beef cows: III. Performance of lactating beef cows grazing smooth brome or big bluestem.

Grazing trials were conducted utilizing individually supplemented lactating beef cows in a 2-yr study to determine the effect of supplemental escape protein (EP) on cow/calf performance during the active growth periods of smooth brome and big bluestem. Graded levels (0, .11, .23, and .34 kg of EP/animal from an equal-protein-basis mixture of blood meal and corn gluten meal were offered daily, replacing corn starch and molasses, which was used as the energy control. All cows received 582 g of supplemental DM/d. Analyses for the smooth brome study indicated a cubic response (P less than .05) to milk production and calf daily gain. No response to EP supplementation (P greater than .10) was observed for the big bluestem study. Analysis of esophageal extrusa samples collected throughout the grazing seasons for both years demonstrated that quality of forage selected by the animal decreased as the trial progressed. Using a 16-h modified dacron bag technique that did not adjust for microbial attachment, protein escaping degradation for smooth brome and big bluestem was estimated to range from 7.0 to 14.5% and 22.2 to 30.3%, respectively. There was limited response to a moderate level of EP supplementation of lactating cows grazing smooth brome, but calf gains were depressed by both the low and the high levels of EP. Lactating cows grazing big bluestem did not respond to EP supplementation, but added energy supplement depressed calf gains.

Hydrolysis time as a factor affecting the nutritive value of feather meal and feather meal-blood meal combinations for growing calves.

The objectives of this research were to determine 1) the effects of hydrolysis time on feather meal (FTH) protein digestion and ruminal escape and 2) whether adding blood meal (BM) to FTH evoked a complementary response in animal performance. A lamb digestion trial was conducted to estimate true protein digestibility of soybean meal (SBM), BM, and FTH hydrolyzed for 10, 12, 15, or 18 min. Ruminal escape was estimated in situ. Two 94-d growth trials were conducted using 60 growing calves (226 kg) per trial to evaluate urea, FTH, BM, and 87.5:12.5, 75:25, and 50:50 combinations (CP percentage basis) of FTH:BM. There were small numerical differences in estimated escape of protein from the rumen and DM and protein digestibilities due to hydrolysis time. True protein digestibility of the 10- and 18-min samples was 5% higher (P less than .05) than for the 12- or 15-min FTH samples. In the growth trial, the slope-ratio technique showed that the most efficiently used protein supplement was 100% BM (protein efficiency = 2.45 +/- .19). No differences (P = .30) in protein efficiency were observed among supplements containing various combinations of FTH:BM. There was a quadratic (P less than .01) response to the level of BM, indicating a complementary effect. The largest complementary effect occurred at the 12.5% level of the BM addition. There were no nutritionally important effects of hydrolysis time between 10 and 18 min. Furthermore, supplements can be formulated more economically using small amounts of BM with FTH without compromising biological efficiency.