ObjectivesThe objective of this study was to evaluate the effectiveness of the SDSU Beef 2020 program on increasing participant knowledge and impacting production practices. Unlike the pork or poultry industries, the US beef industry is not vertically integrated and as a result the beef supply is managed by producers in a variety of roles. While these producers are knowledgeable about their specific sector, some may not be as familiar with the other aspects of beef production. South Dakota State University hosts an Extension program entitled Beef 2020 with the goal of bridging this knowledge gap.Materials and MethodsBeef 2020 was a 3-d Extension program that was targeted to cattle producers, beef purveyors and allied industry representatives and addressed the management factors that influence beef carcass traits. Topics included live market cattle evaluation, health and disposition in relation to carcass quality, genetics, feeding and management, and a presentation on new value-added beef cuts. Beef 2020 also provided the opportunity for participants to view market animals live and participate in a mock auction to determine the purchase price. They observed the harvest process and then participated in a hands-on fabrication of their beef carcass. Information gathered from fabrication was used to calculate the value of the carcass they purchased. We hypothesized that the program improved participant knowledge of the beef industry and resulted in changes in participants’ operations to improve carcass quality. Participants (n = 113) were asked to complete a survey at the conclusion of the program where they rated each topic session, indicated their knowledge of the industry before and after the program, and answered other open-ended questions intended to improve the program year after year. Session ratings were scored on a scale of 1 (not valuable) to 10 (highly valuable). Prior and post program knowledge was evaluated on a Likert scale of 1 (none) to 10 (highly knowledgeable). Data were compiled from survey responses from 2013 to 2018. Statistical analysis was conducted on participant previous and post industry knowledge using a one tailed t test and significance was indicated at ɑ < 0.05. Mean ratings and standard deviations were reported for all other data.ResultsParticipation in Beef 2020 improved participant knowledge by 2.3 points (5.4 vs. 7.7, P < 0.0001). Participants also indicated that sessions were valuable with average scores ranging from 7.2 ± 2.1 (Natural and Organic Production) to 8.9 ± 1.2 (Pre and Post Weaning Strategies to Improve Carcass Traits). Additionally, 84% of the respondents indicated they will implement strategies presented during the program in their own operations, while another 11% indicated they may implement new strategies. Participants also indicated the program was beneficial (9.5 ± 1.1) and it should be conducted again (9.6 ± 1.2).ConclusionBeef 2020 effectively improved participant knowledge of the management factors that influence value differences in beef cattle, which resulted in improved marketing opportunities and carcass value for their operations.

We conducted 2 experiments to determine lysine loss from 2 lipid-coated lysine products after mixing with silage. In our first experiment, we mixed 2 lipid-coated lysine products, crystalline lysine or crystalline lysine and amounts of lipid identical to amounts included in lipid-coated lysine products, with alfalfa or corn silage that had 2 different amounts of acidity. Lysine appeared to disassociate from lipid-coated lysine products in a nonlinear manner after mixing with either alfalfa or corn silage at different amounts of acidity. Additionally, silage source and acidity affected amounts of lysine released from lipid-coated lysine products after mixing. In a corresponding experiment, in vitro estimates of lysine available to ruminal microbiota after mixing with alfalfa or corn silage at different amounts of acidity were measured by ammonia release. In vitro measures were conducted with or without monensin to allow estimates of effects of monensin on amounts of lysine released from the 2 lipid-coated lysine products. It is unclear whether in vitro estimates of lysine fermentation from lipid-coated lysine are truly reflective of ruminal degradation of lysine from lipid-coated lysine because amounts of time needed to measure differences between different lysine sources were greater than typical estimates of mean ruminal particulate retention time. Nonetheless, monensin apparently reduced ammonia release from lysine, but ammonia release from lipid-coated lysine did not differ from crystalline lysine. Clearly, methods of manufacture together with physical and chemical characteristics of diet can affect amounts of lysine provided from lipid-coated lysine products to ruminants.

Estimates of diet quality from samples of mechanically harvested corn residues likely under-predict nutrient density in diets selected by grazing cattle. Our objective was to determine if measures of chemical composition or near-infrared reflectance spectroscopy (NIRS) of diet samples collected from ruminally cannulated cows could allow accurate estimates of diet selection among cows fed binary mixtures of cornstalk and noncornstalk (i.e., husk and leaf) residues. Six ruminally cannulated cows were placed in a 6 × 6 Latin square to evaluate predictions of diet intake. After complete ruminal evacuation, cows were fed 1-kg meals (DM-basis) containing different combinations of cornstalk and noncornstalk residues in ratios of 0:100, 20:80, 40:60, 60:40, 80:20, 100:0. Diet samples from each meal were collected by removal of ruminal contents after 1-h and were either machine-rinsed, hand-rinsed or unrinsed to evaluate effects of endogenous compounds on predictions of diet composition. Diet samples were analyzed for NDF, ADF, acid detergent insoluble ash (ADIA), ADL, CP and NIRS to calculate diet composition. Greater amounts of rinsing increased NDF and ADF content and decreased ADIA and CP content of diet samples (P < 0.01). Rinsing tended to increase (P < 0.06) ADL content of diet samples. Differences in concentration between cornstalk and noncornstalk residues within each chemical component were standardized by calculating a coefficient of variation (CV). Accuracy and precision of estimates of diet composition were analyzed by regressing predicted diet composition and known diet composition. Predictions of diet composition were improved by increasing differences in concentration of chemical components between cornstalk and noncornstalk residues up to a CV of 22.6 ± 5.4%. Predictions of diet composition from unrinsed ADIA and machine-rinsed NIRS had the greatest accuracy (slope = 0.98 and 0.95, respectively) and large coefficients of determination (r2 = 0.86 and 0.74 respectively). Subsequently, a field trial was performed to evaluate predictions of diet composition in cattle grazing corn residue. Five cows were placed in 1 of 10 paddocks (6.1 AUM/ha) and allowed to continuously graze or to strip-graze (4.7% of BW/12 h) corn residues. Predictions of diet composition from ADIA, ADL and NIRS did not differ (P = 0.99), and estimates of cornstalk intake tended to be greater (P = 0.09) in strip-grazed compared to continuously grazed cows. These data suggest that diet composition can be predicted by chemical components or NIRS by ruminal collection of diet samples among cattle grazing binary mixtures of forage.

Grazing cattle often select diets with greater digestibility and presumably greater energy concentration in comparison to the average of the overall biomass available for grazing. Thus, estimates of diet energy based on measures of concentrations of chemical components in samples of mechanically harvested corn residues are unlikely to be strongly correlated to diets selected by grazing cattle. We used 6 ruminally cannulated cows in a replicated 3 x 3 Latin square experiment to determine energy balance, apparent nutrient digestibility and N retention using indirect respiration calorimetry in cattle fed diets of individual components of corn residues. Gross energy intake was greater (P < 0.01) when cows were fed leaf (18.0 Mcal/d) compared to husk and stalk (13.0 and 12.8 Mcal/d, respectively). Digestible energy (% of GE) was least (P < 0.01) and fecal energy was greatest (P < 0.01) when cows were fed stalk compared to husk or leaf. Metabolizable energy (% of DE) was greatest (P < 0.01) for leaf, intermediate for husk and least for stalk. Interestingly, energy lost as methane (% of DE) was nearly 68% greater when cattle were fed husk or stalk compared to leaf. Heat production (Mcal/d) during feeding or fasting was not different (P ≥ 0.81) when cows were fed leaf, husk or stalk. Subsequently, NEm (Mcal/kg DMI) was greatest (P < 0.01) for leaf (1.46) than husk (0.90) or stalk (0.68). Retained N was greatest (P < 0.01) for cows fed leaf compared to husk and stalk. Despite differences in measures of NEm and N retention, total-tract digestion of NDF and ADF were greatest (P < 0.01) for husks, least for stalks and intermediate for leaf. Overall, these data indicate that differences in total-tract digestion and ruminal methane production impact energy available to grazing cattle from different components of corn residue.

Grazing annual cool-season forages after oat grain harvest in South Dakota may allow an opportunity to increase efficient use of tillable land. However, data are limited regarding effects of stocking density on diet selection, nutrient digestion, performance, and N retention by cattle grazing annual cool-season forage. Heifers were blocked by initial BW (261 ± 11.7 kg) and randomly assigned to 1 of 12 paddocks (1.1 ha) to graze a mixture of grass and brassica for 48 d. Each paddock contained 3, 4, or 5 heifers to achieve 4 replicates of each stocking density treatment. Ruminally cannulated heifers were used to measure diet and nutrient intake. Effects of stocking density on diet and nutrient selection were measured after 2, 24, and 46 d of grazing, and BW was measured at the beginning, middle, and end of the experiment as the average of d 1 and 2, d 22 and 23, and d 47 and 48 BW, respectively. Measures of DMI and DM, OM, NDF, and ADF digestion were collected from d 18 to 23. Increased stocking density increased intake of brassica relative to grass on d 24 (quadratic, = 0.02), but increased stocking density decreased (linear, ≤ 0.01) intake of brassica compared with grass on d 48 (stocking density × time, < 0.01). Increased stocking density increased DM (quadratic, < 0.01), OM (quadratic, = 0.01), and NDF (quadratic, = 0.05) digestion, and stocking density tended to increase DMI (quadratic, = 0.07). Additionally, increased stocking density quadratically increased ( = 0.05) N retention but did not affect overall BW gains. Increased stocking density did, however, contribute to linearly decreased ( = 0.05) BW gains from d 1 to 22 of grazing, but BW gains during the latter half of the experiment were greater than BW gains from d 1 to 22. Ruminal concentration of acetate:propionate was least on d 24 of grazing, and ruminal nitrate concentration tended to linearly decrease ( = 0.06) with greater amounts of time on pasture. Ruminal liquid and particulate fill and amounts of VFA were less (quadratic, ≤ 0.01) with greater amounts of time on pasture. Apparently, binary mixtures of brassica and grass planted after oat grain harvest can provide an opportunity to increase efficient use of land by providing forage resources. Increased stocking density may facilitate a more rapid adaptation to and intake of brassica among cattle grazing brassica-grass-based pastures.

Abstract We conducted 2 experiments to determine lysine bioavailability from 2 lipid-coated lysine products. In an in vitro experiment we mixed each lipid-coated lysine product with either alfalfa- or corn-silage at different amounts of acidity. Scanning electron micrographs indicated that surface structure of each lipid-coated lysine particle was eroded after mixing with silage. Additionally, visual evaluation of scanning electron micrographs suggested that peripheral surface abrasion of lipid-coated lysine may be greater when lipid-coated lysine was mixed with alfalfa silage in comparison to corn silage. In a corresponding experiment, in vivo measures of lysine bioavailability to sheep from 2 lipid-coated lysine products and lysine-HCl were determined after mixing in corn silage. Plasma lysine concentrations increased linearly (P < 0.01) in response to abomasal lysine infusion indicating that our model was sensitive to increases in metabolizable lysine flow. Bioavailability of each lipid-coated lysine source and dietary lysine-HCl were calculated to be 23, 15, and 18%, respectively. Even though each dietary source of lysine increased plasma lysine, rates of increases in plasma lysine from one lipid-coated lysine source (linear; P = 0.20) and lysine-HCl (linear; P = 0.11) were not different from plasma lysine levels supported by diet alone. However, the rate of plasma lysine increase in response to lysine from the other lipid-coated lysine source was greater (P = 0.04) than plasma lysine from feed alone. Nonetheless, the rate of plasma lysine increase in response to lipid-coated lysine did not differ (P ≥ 0.70) from the rate of plasma lysine increase from lysine-HCl. Clearly, methods of manufacture, together with physical and chemical characteristics of diet, can impact amounts of metabolizable lysine provided from lipid-coated lysine products. Direct measures of lysine bioavailability from lipid-coated lysine products after mixing with diets should be based on measurements with the products treated similarly to the method of feeding.

Phytochemical plant tannins (condensed and hydrolysable tannins) are one of the most abundantly available plant secondary metabolites. These plant tannins have potential to significantly impact rumen fermentation, rumen microbiota population changes, nutrient digestibility and animal production. The objective of this study was to determine whether the phytochemical tannin-containing sericea lespedeza leaf pellet, ground pine bark, or its combination would have effects on rumen fermentation and microbial diversity in meat goats. Twenty four Kiko-crossbreed intact male goats (Capra hircus; BW= 38.6 ± 2.7 kg) were randomly assigned to four treatments (n = 6): 1) 30% bermudagrass hay and 70% grain mix, 2) 30% pine bark (PB) and 70% grain mix, 3) 30% sericea lespedeza (SLP) and 70% grain mix, and 4) 15% PB, 15% SL pellet, and 70% grain mix. Goats supplemented with mixed diets had decreased (P < 0.05) concentrations of acetate, while goats received PB diet exhibited reduced concentrations of isobutyrate (P < 0.001), isovalerate (P < 0.01), and valerate (P < 0.01) acids compared to those in the control and SLP diets. In this study, Bacteroides (30 to 55%) and Firmicutes (30 to 47%) were the major bacterial phyla, while Prevotella spp. was the most predominant rumen bacterial species in the percentage of 22.1, 42.2, 28.9, and 23.9 for control, PB, SLP, and mixed diets, respectively. The community of rumen bacterial species in PB-supplemented group was greater for Marinifilum spp. (P < 0.04), Bacteroides spp. (P < 0.02), and Oribacterium spp. (P < 0.03) compared with other treatment groups. Supplementing tannins in goat diets such as PB and SLP diets has a potential to positively modify rumen bacterial community, but there were no synergistic effects on rumen fermentation.

Haemonchus contortus one of the most pathogenic widely distributed blood sucking nematode of sheep and goats [20, 22]. Adult H. contortus can suck about 0.05 mL of blood/ worm/day [27]. Several highly effective anthelmintic drugs were used for controlling of such worms, however these drugs were no longer be used due to rapid developing of the parasite drug resistance [26]. Developing of new control programs to H. contortusis critical for goat enterprise expansion. One of these control programs is using of the phytochemical bioactive compounds to overcome H. contortus problems. Phytochemical condensed tannins (CT) used efficiently as natural alternative anthelmintics to control gastrointestinal nematodes (GIN), as it safe, eco-friendly and easily applicable feed additives [31].

We evaluated effects of enzymatically hydrolyzed yeast (EHY) and supplementation frequency on nitrogen balance and digestibility parameters in periparturient beef cows. Eighty multiparous cows fed a common brome hay-based diet (CP = 8.0 ± 0.17%) were blocked by expected calving date and stratified by BCS before random assignment of treatment. Beginning 88 ± 5 d before parturition, cows were provided 1-kg daily or 3-kg every 3-d of a soybean hull-based supplement that contained 0 or 3 g/kg EHY. The daily supplement was designed to meet ruminal N requirements. Cows were provided a bolus of TiO2 (10 g/d) at the time of supplement feeding for 10-d beginning 64-d before calving and again 34-d before calving. Fecal and urine samples were collected each 12-h for 6-d beginning 4-d after cattle first received TiO2. Initiation of sample collection was delayed between each d so that composite samples of urine and feces were representative of every 2-h in a 24-h period. Samples of hay, supplement, feces and urine were analyzed for DM, OM, N, NDF, ADF and ADIA. Fecal TiO2 allowed calculation of fecal output and ADIA was used to calculate hay intake. Urine creatinine acted as a urine output marker. Data were analyzed as a 2 × 2 factorial design. There were no interactions of EHY, supplementation frequency or sampling time. Neither EHY (P = 0.31) or supplementation frequency (P = 0.57) affected estimates of DMI, but DMI estimates tended to increase (P = 0.08) from 10.8 to 11.1 ± 0.2 kg/d as cattle neared parturition. Apparent total-tract digestibility of DM (54.4 ± 0.6%), OM (58.2 ± 0.6%), NDF (51.7 ± 0.8%) and ADF (46.0 ± 0.9%) was not different (P > 0.10) between EHY and control; however, daily supplementation increased (P ≤ 0.06) apparent total-tract digestibility of DM (55.6 vs. 54.1 ± 0.8%), OM (58.9 vs. 57.5 ± 0.6%), NDF (52.6 vs. 50.8 ± 0.8%) and ADF (46.8 vs. 45.2 ± 0.9%) compared to supplementation every 3 d. We observed no effects of EHY (P = 0.55) or supplementation frequency (P = 0.60) on N retention (15.1 ± 4.6 g/d); however, N retention decreased (P = 0.03) from 21.3 to 8.8 ± 4.4 g/d as cattle neared parturition. These data suggest that daily supplementation can provide benefit to diet digestion, but increases in diet digestibility in response to more frequent supplementation were not related to changes in N retention.

Procedures: Two grazing experiments were performed to 1) investigate the effects of supplementing condensed tanninscontaining pine bark powder on average daily gain, ruminal fermentation, and rumen microbial diversity dynamics (Experiment 1), and 2) to quantify the influence of different sources of extracted tannins supplementations on ruminal fermentation and rumen microbial diversity changes of goats grazing fresh forages (Experiment 2). In experiment 1, 20 Kiko-Boer cross male goats (Capra hircus; initial body weight= 39.7 ± 2.55 kg) were randomly assigned to 2 experimental diets (alfalfa pellet vs. pine bark powder). Alfalfa pellet (no tannin as a control) or pine bark powder (11% condensed tannins) was supplemented at 0.5% body weight for targeted total dry matter intake of 1.2% body weight. The remaining dry matter intake of each diet was obtained from grazing for 55 days. In experiment 2, 12 Kiko-Boer cross goats were used to measure average daily gain, ruminal fermentation, and gut microbial population in the rumen of goats grazing bermudagrass. The animals were randomly assigned to 3 experimental diets: 1) no tannins (control), 2) chestnut extract at 100 g/d, and 3) quebracho tannin extract at 100 g/day.

An important part of any production system is the reproductive performance associated with replacement heifers. In the majority of beef operations, heifers are moved to a drylot for a period of time to be weaned and then must again be moved to a forage grazing situation. Therefore, experiments were conducted to determine whether previous grazing experience affected performance and conception rates. In Exp. 1, beef heifers were moved to a forage grazing situation after a 44-d weaning period in the drylot [EXPER (experienced); n=33] or were moved to a forage grazing situation 27 d before the start of the breeding season [NIV (naïve); n=32]. In Exp. 2, beef heifers were moved to a forage grazing situation before the breeding season (EXPER; n=207) or were moved to a forage grazing situation immediately following AI (NIV; n=214). In Exp. 1, after being moved, NIV heifers lost 1.6±0.08kg/d for the first week they were turned to grass compared with EXPER heifers that gained 0.88±0.08kg/d (P<0.0001). This resulted in a linear (P<0.01) BW gain among EXPER heifers and a quadratic (P=0.04) BW gain among NIV heifers. In Exp. 2, EXPER heifers had increased ADG (P<0.01; 0.58±0.03kg/d) from AI to pregnancy diagnosis and more (P=0.04) became pregnant to AI (59.4%) compared with NIV heifers (0.21±0.03kg/d and 49.1%). In summary, transitioning naive heifers to pasture resulted in BW loss during the first week after movement, and if this transition occurred immediately following AI, pregnancy success to AI was reduced.

Th e objective of this study was to investigate the eff ects of feeding strategy on cow feedlot performance, carcass traits and economics. Despite cows consuming less feed and lower labor costs, cows on self-fed diets had the highest feed cost of gain. Although self-fed diets can improve market cow quality, other low-cost alternatives require further investigation. Summary Forty-eight cull (market) cows were blocked by weight and body condition to investigate the eff ects of feeding strategy on feedlot performance, carcass traits and economics. Diets evaluated were (1) corn-mixed hay (HAY), (2) barley-barley silage (SILAGE) and (3) a self-fed ground diet using a controlled intake system (LIMIT). All diets were formulated to provide 60 megacalories per pound (Mcals/lb) of net energy for gain (NEg) and 11.5 percent crude protein (CP) using mixed hay, barley silage and a commercial supplement containing soy hulls as roughage sources for HAY, SILAGE and LIMIT, respectively.

Sulphur-induced polioencephalomalacia (sPEM), a neurological disorder affecting ruminants, is frequently associated with the consumption of high-sulphur (S) water and subsequent poor performance. Currently, there is no economical method for S removal from surface water sources, and alternative water sources are typically neither readily available nor cost-effective. Determination of genes differentially expressed in response to high-S water consumption may provide a better understanding of the physiology corresponding to high dietary S and ultimately lead to the development of treatment and prevention strategies. The objective of this study was to determine changes in gene expression in the liver, an organ important for S metabolism, of fibre-fed steers consuming high-S water. For this study, liver tissues were collected on the final day of a trial from yearling steers randomly assigned to low-S water control (566 mg/kg SO4 ; n = 24), high-S water (3651 mg/kg SO4 ; n = 24) or high-S water plus clinoptilolite supplemented at either 2.5% (n = 24) or 5.0% (n = 24) of diet dry matter (DM). Microarray analyses on randomly selected healthy low-S control (n = 4) and high-S (n = 4; no clinoptilolite) steers using the Affymetrix GeneChip Bovine Genome Array revealed 488 genes upregulated (p < 0.05) and 154 genes downregulated (p < 0.05) in response to the high- vs. low-S water consumption. Real-time RT-PCR confirmed the upregulation (p < 0.10) of seven genes involved in inflammatory response and immune functions. Changes in such genes suggest that ruminant animals administered high-S water may be undergoing an inflammation or immune response, even if signs of sPEM or compromised health are not readily observed. Further study of these, and other affected genes, may deliver new insights into the physiology underlying the response to high dietary S, ultimately leading to the development of treatments for high S-affected ruminant livestock.

Requirements have been published for 13 different minerals in beef cattle diets. Other minerals such as chlorine, chromium, molybdenum, and nickel are known to be essential for beef cattle; however, there is currently not enough data available to accurately determine requirements. For some of the required minerals, requirements vary depending on cow size and stage of production. This variability results from increased mineral demand for the products of conception and for milk production. For these minerals, requirements are always greatest during peak lactation and lowest for non-lactating cows in mid-gestation.

Poor performance and S-induced polioencephalomalacia (sPEM) have been observed in ruminant livestock in high-S drinking water regions. No gainful method of removing S from drinking water is available and therefore a feed supplement that negates the effects of high-S water is needed. Our objective was to determine if supplementing Mo improves health and performance of steers administered a high-fiber diet and high-S drinking water. We hypothesized that if the supplemental Mo adequately bound excess S in the rumen, it would not be available at toxic concentrations. Yearling steers (n = 96; 260.0 ± 1.3 kg BW) were stratified by pretrial BW into 12 feedlot pens (n = 8 steers per pen). One of 3 treatments, low-S water (LS; 375 mg SO(4)/L), high-S water (HS; 2,218 mg SO(4)/L), or high-S water plus Mo (HSMO; 2,218 mg SO(4)/L; 187.5 mg Mo/kg DM), were randomly assigned to pens within 4 blocks for a 56-d trial. Body weights were recorded on d -2, -1, 29, 56, and 57, ruminal H(2)S concentrations were measured by rumenocentesis on d -1, 29, and 57, and liver biopsies were performed on d -1 and 57. Performance data were analyzed over the 56-d trial period (overall) as well as over 2 periods: Period 1 (d 0 to d 28) and Period 2 (d 29 to d 56). One case of sPEM was confirmed by the presence of cortical lesions in the HS treatment group. Daily DMI and ADG were affected by treatment and period (P < 0.001) main effects. The LS steers had the greatest (P < 0.05) DMI followed by HS and HSMO steers, respectively. Similar results were observed for ADG. Daily water intake was affected (P < 0.001) by period only, with greater daily water intake in Period 2 than Period 1. Change in hepatic concentrations of Cu, Fe, and Mo over the course of the trial were all affected (P < 0.001) by treatment. Hepatic Cu increased from d 1 to 57 in LS and HS steers but was depleted in HSMO steers. Hepatic Fe and Mo increased in HSMO steers only. Ruminal H(2)S concentrations were affected by treatment (P < 0.021), with greater H(2)S concentrations in HSMO compared with LS and HS steers. Signs of Mo toxicity such as severe diarrhea, loss of body condition, anorexia, changes in hair color, and stiffness in joints were observed in the Mo supplemented steers. These results indicate that added dietary Mo does not adequately bind excess S in the rumen, causing aggravated toxic effects from potentially both the high dietary S and Mo.

Previous research has reported that diets high in protein and sulfur decreased uterine pH in cattle. The objective of this study was to determine the effect of high N and high S intake on uterine pH. Holstein (n = 15) and Angus-cross (n = 5) heifers (337.5 ± 8.4 kg of BW) were randomly assigned to 1 of 4 diets: control (CON; 13.4% CP and 0.17% S); high nitrogen (HN; CON plus urea supplement); high sulfur (HS; CON plus calcium sulfate); or both high nitrogen and sulfur (HNS). Diets were individually fed at 2.6% of BW on a DM basis using Calan gates and estrus was synchronized to occur on d 13 (d 0 = start of dietary treatment). Blood samples were collected on d -2 and daily (d 1 to 28) at 1400 h to determine concentrations of plasma urea nitrogen (PUN), sulfate (d 1, 4, 8, 12, 16, 20, 24, and 28), and progesterone. Uterine pH was measured on d 16, 20, 24, and 28 (d 3, 7, 11, and 15 of the estrous cycle). There was a treatment, time, and treatment by time interaction (P < 0.01) on concentrations of PUN. There was an effect of treatment (P < 0.01) on concentrations of sulfate, with concentrations being increased in HS compared with CON, HN, and HNS (P < 0.01), and HNS increased compared with CON (P < 0.01) and HN (P < 0.01). Uterine pH was increased in HN and HNS compared with CON (P < 0.02), whereas HS was not different from any treatment (P > 0.11). There was no effect of time (P = 0.26) or treatment by time interaction (P = 0.71) on uterine pH. In summary, uterine pH was increased in HN and HNS compared with CON, whereas HS was intermediate and was associated with increased concentrations of PUN.

Beef cows that exhibit estrus before fixed-time AI have been reported to have increased pregnancy success and increased concentrations of progesterone during the subsequent estrous cycle. Therefore, these experiments were conducted to evaluate if initiation of standing estrus before an injection of GnRH during a fixed-time AI protocol affected LH pulses, subsequent concentrations of progesterone, and luteal steroidogenic enzyme expression. In Experiments 1 and 2, cows were treated with the CO-Synch protocol (100 μg GnRH day -9, 25 mg PGF(2α) day -2, and 100 μg GnRH day 0) and allotted to one of two treatments: 1) cows that initiated estrus before GnRH on day 0 (estrus; n = 5) or 2) cows that did not initiate estrus and were induced to ovulate by the GnRH on day 0 (no estrus; n = 5). In Experiment 1, blood samples were collected at 15-min intervals from 0 to 6 (bleed 1), 12 to 20 (bleed 2), 26 to 34 (bleed 3), and 40 to 48 (bleed 4) h after GnRH. Daily blood samples were collected for 17 d. Initiation of estrus before the GnRH injection had no effect on LH release or the pattern of progesterone increase; however, cows detected in estrus had overall increased (P = 0.002) concentrations of progesterone compared with cows not in estrus. In Experiment 2, estrus was detected with the HeatWatch system. Location and size of the ovulatory follicle was determined on day 0 by transrectal ultrasonography at time of injection with GnRH. Blood samples were collected on days 3, 4, 5, 7, and 9; luteal tissue was collected on day 10 (n = 4 estrus and n = 9 no estrus) from corpus luteum (CL) originating from similar-sized follicles (13.0 to 16.0 mm). Total cellular RNA was extracted, and relative mRNA levels were determined by real-time reverse transcription PCR and corrected for GAPDH. There was no effect of estrus on CL weight or concentrations of progesterone. In addition, there was no effect of estrus, follicle size, or CL weight on luteal expression of LH receptor, StAR, CYP11A1, or 3βHSD. However, there was a correlation between follicle size and CL weight (P = 0.01; R(2) = 0.43); for every increase of 1 mm in follicle size, CL weight increased by 1.5 g. In summary, estrus did not influence release of LH, CL weight, progesterone concentrations, or expression of steriodogenic enzymes. However, as follicle size increased, CL weight increased; therefore, both follicle size and CL weight were associated with progesterone concentrations.

To report the signalment, history, clinical signs, diagnostic and surgical findings and outcome in dogs and cats with retained swabs, medical records of dogs and cats that were referred to four referral centres were reviewed. Cases in which a retained surgical swab was identified during surgery at the referral hospital were selected for further study. The signalment, history, clinical signs, diagnostic and surgical findings and outcome in these cases were reviewed. Thirteen dogs with retained surgical swabs were included in the study. Bodyweight ranged from 9 to 45 kg. The initial surgery was a ‘non‐routine’ abdominal procedure in seven dogs, ovariohysterectomy in five dogs and perineal hernia repair in one dog. Time from initial surgery to presentation at the referral centre ranged from four days to seven years. Treatment involved major surgery in eight of the 13 dogs. Outcome was excellent in 12 of 13 cases, one dog was euthanased.

Two hundred forty Angus crossbred steers were used to determine the influence of feeding various quantities of wet and dry distillers grains to finishing steers on carcass characteristics, meat quality, retail-case life of ground beef, and fatty acid profile of LM. Three replications of 5 dietary treatments were randomly applied to 15 pens in each of 2 yr. A finishing diet containing dry-rolled corn, soybean meal, and alfalfa hay was fed as the control diet. Wet distillers grains with solubles (DGS) or dry DGS was added to the finishing diets at either 20.0 or 40.0% of the dietary DM to replace all soybean meal and part of the cracked corn in treatment diets. Carcasses of steers fed DGS had greater (P < 0.05) fat thickness (1.47 vs. 1.28 cm), greater (P < 0.05) USDA yield grades (3.23 vs. 2.94), and smaller (P < 0.05) percentage of yield grades 1 and 2 (41.1 vs. 60.4%) than carcasses of steers fed the control diet. Longissimus muscle from steers fed dry DGS had greater (P < 0.05) ultimate pH values (5.52 vs. 5.49) than LM from steers fed wet DGS. Ground beef from steers fed DGS had greater (P < 0.05) concentrations of α-tocopherol (1.77 vs. 1.43 μg/g) than ground beef from steers fed the control diet. Ground beef from steers fed 40% DGS had greater (P < 0.05) thiobarbituric acid-reactive substances (2.84 vs. 2.13 mg/kg) on d 2 of retail display than ground beef from steers fed 20% DGS. Longissimus muscle of steers fed DGS had less (P < 0.05) C17:0 and more (P < 0.05) C18:0, C18:1t, C16:1c9, C18:2c9c12 (where t is trans and c is cis), and total PUFA than LM of steers fed the control diet. Feedlot steers fed DGS may need to be marketed earlier than normal to avoid excess external fat and carcasses with a greater numerical yield grade. These data suggest feeding DGS to finishing steers will have no adverse or beneficial effects on glycolytic variables (dark cutters), retail display life of ground beef, or meat tenderness. However, beef from cattle finished on diets containing DGS will likely have a greater proportion of PUFA and therefore may be more susceptible to oxidative rancidity.