As part of the United States Beef Sustainability Program, a nationwide characterization of regional beef production practices was conducted. Data on cattle production practices were gathered through voluntary surveys and on-site visits in the Northeast and Southeast, the last of 7 cattle-producing regions studied. Participating farms and ranches (n = 817) represented 1.2 and 1.0% of beef cows in the Northeast and Southeast, respectively. Responses from finishing operations (n = 55) represented 4 and 23% of cattle fed in the Northeast and Southeast, respectively. Herd sizes reported were larger in the South-east than in the Northeast; however, stocking rates were similar. Cow-to-bull ratios were slightly greater in the Southeast, and the proportions of replacement heifers were comparable in both regions. Supplemental feed production and indoor housing were more prevalent in the Northeast compared with the warmer Southeast, where longer grazing periods were possible. Fewer feedlots were reported in the Southeast, with most being backgrounding facilities. Finishing on grass was more common in the east than in other regions. Feed intake estimated by survey respondents was comparable across regions, but relatively more silage was fed in the Northeast, whereas hay was dominant in the Southeast. Cropland producing cattle feed received most of the manure in both regions, although 25% was composted and sold in the Northeast. Labor, equipment, and energy use information was also gathered from the various operation types. The data collected help guide the development of representative production systems used in the life cycle assessment of beef.
ABSTRACT Reproduction and development are fascinating processes that exhibit significant differences among mammals. Successful propagation of species depends on male fertility and the ability of the sperm to fertilize and activate the egg and support early development. Remarkably, the specifics of how sperm structure and function have evolved and their crucial roles in fertility remain largely unknown. This synthesis provides a concise review of comparative anatomy and physiology of mammalian sperm structure and how inevitable changes regulate fertility.
Field peas (Pisum sativum) are increasingly available with limited data on the effects on forage digestibility. Two experiments were conducted to determine the effects of field pea supplementation in forage-based diets on total-tract digestibility and RUP digestibility in growing beef cattle. In Exp. 1, 5 ruminally fistulated steers (202 kg) were used in a 2 × 3 factorial. The first factor was high quality forage (50% alfalfa, 50% sorghum silage) or low quality forage (50% bromegrass hay, 50% wheat straw). The second factor was supplement type: a nonsupplemented control (CON), dry-rolled corn (DRC), or ground field peas (FP), supplemented at 0.43% of BW. Each diet was fed for 14 d. There were no interactions between forage quality and supplement type for digestibility estimates (P ≥ 0.25). Intake and digestibility of OM were greater with high quality forage (4.96 kg/d and 64.2%, respectively) than with low quality forage (3.60 kg/d and 50.1%, respectively; P < 0.01). The FP supplement increased DMI and OM digestibility (6.14±0.512 kg/d and 61.6 ± 1.94%, respectively) over DRC (5.33 kg/d and 56.1%, respectively) or CON (4.80 kg/d and 53.8%, respectively; P ≤ 0.03); DRC and CON did not differ in intake or OM digestibility. In Exp. 2, the RUP digestibility of field peas was evaluated using a mobile bag technique. The RUP content of FP was 32.6 ± 4.39% and 35.2 ± 4.39% with a postruminal digestibility of 97.4 and 98.9 ± 1.17% for yr 1 and 2, respectively, for FP grown in 2 growing seasons. Field peas are an acceptable supplement in forage diets.
Wet brewers grains (WBG) are an increasingly available by-product of the growing craft beer industry that may be useful in finishing cattle rations. Therefore, the objective of this pilot study was to determine the effects of including WBG sourced from craft brewing on the growth performance, carcass characteristics, and meat quality of finishing steers and heifers. Twenty-four [n = 24; 12 heifers (303 kg), 12 steers (346 kg)] crossbred calves were blocked by BW within sex to 12 pens (2 calves of the same sex per pen) in a 2 × 2 factorial arrangement with 3 replications per treatment and fed for 140 d. Model factors included calf sex and finishing diet [corn silage and whole shelled corn finishing diet (control) and control + 7.2% WBG]. Primal ribs (Institutional Meat Purchase Specification #103) were obtained and rib eye steaks (Institutional Meat Purchase Specification #1112) were fabricated from the 9th to 11th rib portion for additional analyses. No differences were observed in total gain, ADG, or G:F between diets (P > 0.05). However, there was a diet × sex interaction (P < 0.001) for DMI in which inclusion of WBG increased DMI in heifers compared with steers. There were no differences (P > 0.05) in HCW, YG, or marbling score, but rib fat thickness was less (P = 0.020) in WBG calves than in control calves. Diet did not alter Warner-Bratzler shear force, package purge, or cook loss measurements (P > 0.05). These data indicate low-level inclusion of WBG can maintain performance and quality of finishing cattle similar to conventional finishing diets.
The objective of this study was to determine whether Megasphaera elsdenii orally administered to transition Jersey cows would improve milk yield and reduce the risk for metabolic disease. Thirty primi- and multiparous Jersey cows, blocked according to parity and date of calving, were used in a randomized complete block design until 90 DIM and fed diets with 51% forage and 17.9 to 28.5% starch. Within each block, cows were assigned to 1 of 2 treatments: (1) control (no dose) or (2) 200 mL of Lactipro by oral drenching at 1 to 2 d postpartum (M. elsdenii, 1 × 108 cfu/mL; MSBiotec, Littleton, CO). Cows were housed in tie stalls for 4 wk after calving, in which DMI was measured, and then cows were housed in free stalls for 9 wk. Dry matter intake, BCS, and BW change were similar between treatments, and no treatment by time interactions occurred. There was no difference in milk yield between the treatments. For cows with ≥3 lactations, those dosed with M. elsdenii had greater milk and fat yields than the control cows. No treatment effect or treatment by time interactions were detected for milk fat and protein percentages and feed efficiency. Serum and urine ketones were similar between treatments. Although pre- and postpartum diets fed and management strategies for transition cows may affect whether cows respond to oral administration of M. elsdenii, mature, higher producing cows with ≥3 lactations may respond with increased milk yield when dosed with M. elsdenii.
Storage of wet brewers grain (WBG) for longer periods is challenging, and alternative techniques are required. The objective of this experiment was to evaluate the fermentation profile, dry matter loss, and aerobic stability of WBG ensiled alone or with various concentrations of dry ground corn (DGC). Samples of DGC and WBG were weighed separately and mixed forming 3 treatments: WBG alone (23% DM), a mixture of 25% DGC and 75% WBG (as-fed basis) to achieve a DM concentration of 35%, and a mixture of 46% DGC and 54% WBG (as-fed basis) to achieve 50% of DM. Samples were allowed to ferment for 0, 14, or 28 d in triplicate laboratory silos (3.78 L per bucket). Concentration (DM basis) of CP decreased (P = 0.001) with both the inclusion and the level of inclusion of DGC in the mixture. Concentration (DM basis) of water-soluble carbohydrates decreased (P = 0.001) with the inclusion of DGC in the mixture. A treatment × storage length interaction was observed (P = 0.001) for pH, but the change in patterns differed among treatments. Both, the inclusion (P = 0.01) and greater amounts of inclusion of DGC to the mixture (P = 0.001) decreased lactic acid concentration. Mixing WBG with DGC increased (P = 0.02) acetic acid concentration. Aerobic stability tended (P = 0.08) to be 12 h longer for both mixtures of WBG and DGC. Under the conditions of the present study, averaged across storage lengths, mixing WBG with DGC did not significantly speed acidification, decrease the final pH, or prolong aerobic stability of WBG.
An increased emphasis on decreasing generation intervals due to genomic selection has greatly influenced the management of bulls at AI organizations. Before genomics, the genetic value of an AI sire was determined by examining the phenotype and production traits of his daughters (i.e., proofs), and the minimum age at which sires were debuted to the industry (proven) was approximately 4 to 4.5 yr of age. Currently, one decade after the introduction of genomics to the industry, unproven, genomically tested sires between 1.5 and 4 yr of age account for half or more of AI unit sales for most major AI organizations. Accordingly, bulls destined for AI use receive optimum care and nutrition from birth, and there is a renewed interest in examining endocrine modulation’s role in puberty attainment and testicular development in bulls. In practice, hastening puberty in bulls can be used concurrently with modern techniques of oocyte collection in prepubertal heifers to minimize generation intervals in cattle, thus increasing the rate of genetic advancement. The use of young genomic bulls will likely increase or remain stable in the future, and accordingly, AI organizations will continue to focus on optimizing bull management to ensure top tier genetics are available to the industry.
In trial 1, phase 1, 48 male Holstein calves initially 2 to 4 d of age were transported 3.5 h to the research facility. Calves were randomly selected to either receive a s.c. injection of Zuprevo (Merck Animal Health, Summit, NJ; 4 mg of tildipirosin/kg of BW; TIL) the day after arrival (d 0) and again at weaning (d 42) or receive no injections (CON). Calves were fed 0.66 kg of milk replacer DM daily for 39 d and then 0.33 kg daily for 3 d. A starter was fed free choice for the 56 d of phase 1. In trial 1, phase 2, the same calves from phase 1 grouped by CON and TIL were moved to group pens (4 pens per treatment, 4 calves per pen) for the next 56 d. The starter was blended with 5% chopped grass hay and fed free choice. Trial 2 was similar to trial 1, phase 2 and used 48 two-month-old male Holstein calves. Calves were randomly selected to receive either a s.c. injection of Zuprevo (4 mg of tildipirosin/kg of BW; TIL) on d 0 or no injections (CON). In trial 1, phase 1, preweaning ADG and BCS change; postweaning starter intake and hip width change; overall starter intake, ADG, and hip width change; final hip width; and final BCS were greater for TIL than CON. During phase 2 of trial 1 and trial 2, calf ADG and hip width change were greater for TIL than CON. Overall, in transported Holstein calves, TIL improved ADG and structural growth by approximately 13%.
The objective was to evaluate the effects of an injectable trace mineral (ITM) supplement containing Zn, Mn, Se, and Cu on the humoral and cell mediated immune responses to vaccine antigens in dairy calves receiving an attenuated-live bacterin vaccine containing Mannheimia haemolytica and Pasteurella multocida. Thirty 3-mo-old dairy calves received 2 doses (21 d apart) of an attenuated-live M. haemolytica and P. multocida bacterin vaccine (Once PMH, Merck Animal Health, Summit, NJ), and a 5-way modified-live-virus vaccine (Express 5, Boehringer Ingelheim, Vetmedica, St. Joseph, MO). On the day of primary vaccination, animals were randomly assigned to 1 of the 2 treatment groups (n = 15 per group): ITM (ITM administration) or control (sterile saline injection). Treatments were administered concurrently with vaccinations. Blood samples were collected for determination of antibody titers against M. haemolytica and P. multocida and of antigen-induced proliferation and interferon-γ secretion by peripheral blood mononuclear cells. Serum Se and Mn concentrations were greater (P < 0.05) in the ITM group than the control group after ITM use. Serum end-point antibody titers against both bacteria and interferon-γ secretion by peripheral blood mononuclear cells were not different (P > 0.05) between groups. The use of ITM with bovine respiratory disease vaccines enhanced (P < 0.01) antibody titer fold-change to M. haemolytica. Proliferation of peripheral blood mononuclear cells after P. multocida stimulation was increased (P = 0.03) in the ITM group on d 21 relative to baseline value. In conclusion, ITM administration concurrently with bacterin vaccination improved the immune response to M. haemolytica and P. multocida and might be a valuable tool to enhance dairy calves’ response to bovine respiratory disease vaccination.
The objective of this experiment was to determine the effect of level of whole cottonseed (WCS) supplementation on ADG and enteric CH4 emissions of steers grazing tallgrass prairie in the summer. Steers (n = 18; initial BW = 316 ± 23 kg) were trained for 3 wk to use a portable, automated head-chamber system (GreenFeed; C-Lock Inc., Rapid City, SD). Steers were then offered from 0 to 2.9 kg/d (as fed) WCS in individual feeders for 43 d. Body weight was measured weekly before feeding. Total fat concentration of the diet (supplement + forage) at the greatest supplement intake was estimated to be 8.3% of DM. Body weight gain increased linearly as supplement intake increased (P = 0.01). Because of inadequate use of the automated head-chamber system by steers at the 0-kg WCS level, this level was excluded from further analysis. In supplemented steers, there was a tendency (P = 0.1) for a quadratic relationship between CH4 emissions (g/animal per d) and supplement intake, with minimum CH4 at 2.0 kg of supplement (WCS + bait) per day. Emission intensity (g of CH4/kg of BW gain) also responded quadratically (P < 0.004) and was minimized at approximately 2.2 kg of supplement intake per day. The results of this experiment suggest that if WCS supplementation is used to mitigate CH4 emission intensity in stocker cattle grazing tallgrass prairie in the early summer, a dose near 2 kg/d is suggested.
The purpose of this experiment was to evaluate the effects of betaine and superdosed phytase on boar reproduction during mild heat stress. Twenty-seven mature (36 wk old), crossbred boars [Duroc × (Landrace × Yorkshire)] were randomly allocated to treatment and were fed 2.6 kg/d of 1 of 3 corn, soybean meal diets: control (CNT; 250 phytase units/kg Escherichia coli phytase; n = 9), betaine (BET; 250 phytase units/kg E. coli phytase and 0.6% betaine; n = 9), and betaine and superdosed phytase (BP; 2,500 phytase units/kg E. coli phytase and 0.6% betaine; n = 9). The experiment was split into 4 environmental phases (4 wk/phase) consisting of pre-heat stress (26°C), heat stress (30.2°C), post-heat stress 1 (16.7°C), and post-heat stress 2 (17.5°C). Semen was collected weekly from each boar and was evaluated for semen quantity and quality parameters. Total motility, progressive motility and percentage of morphologically normal sperm were reduced in the heat stress period (P < 0.01) with no effects from the dietary treatments (P ≥ 0.27). Total sperm did not differ among treatments (P = 0.99). Percent distal droplets increased from the pre-heat stress to heat stress period for CNT (P < 0.01), but the increase was not statistically different for BET (P = 0.97) or BP (P = 1.00). This suggests that supplementation with betaine alone or with phytase may potentially reduce the effects of heat stress on specific morphological abnormalities, though total normal morphology did not differ.
To determine the effects of n-3 PUFA supplementation on markers of inflammation in young horses in training, 16 Quarter Horses (2 to 4 yr) were used in a randomized complete block design for a 140-d trial. Treatments consisted of a control diet (n = 8) fed at 1% BW or a treatment diet (n = 8) of concentrate fed at 0.75% BW and 700 g of a marine n-3 supplement formulated to provide 15 g of eicosapentaenoic acid and 20 g of docosahexaenoic acid. Exercise protocol was divided into 2 phases: phase 1 (d 0 to 110) consisted of early training and phase 2 (d 111 to 140) consisted of advance maneuvers. Synovial fluid was obtained from the carpal joint every 28 d and analyzed for white blood cell count, total protein, and specific gravity. Blood samples were also collected at 28-d intervals for fatty acid analysis by gas chromatography, and concentrations of carboxypeptide type II collagen (CPII) and chondroitin sulfate-846 (CS-846) were determined by ELISA. Data were analyzed using the MIXED procedure of SAS. Plasma eicosapentaenoic acid and docosahexaenoic acid increased (P ≤ 0.01) in response to supplementation. However, diet did not affect serum CPII or CS-846 nor synovial white blood cell count, total protein, and specific gravity. Levels of CS-846 tended to increase over time (P = 0.09) and CPII concentration increased (P < 0.01) in response to changes in exercise. These results indicate further studies are needed to determine the efficacy of n-3 supplementation as a preventative measure against development of osteoarthritis.
Calcium, P, Mg, K, and S retention in carcass, offal, and viscera were measured in 2 beef cattle experiments. Experiment 1 used 30 steers (245 kg of BW; SE = 4 kg) wintered at 3 levels of gain: grazing wheat pasture at a (1) high or (2) low rate of gain or (3) grazing dormant native range, and all were finished on a common diet (71% corn, 9% cottonseed hulls, 5.35% soybean meal). Experiment 2 used 46 steers (240 kg of BW; SE = 4 kg) fed 3 growing diets with similar rate of gain: (1) sorghum silage, (2) program-fed high-concentrate diet, or (3) wheat-pasture grazing, or placed directly into the feedlot. In Exp. 1, retention of Mg, K, and S (g/100 g of protein gain) during the finishing period was greater for treatments wintered at a low rate of gain during the growing period (P ≤ 0.02). There were no treatment differences for P or Ca retention during the finishing period (P ≥ 0.39). In Exp. 2, no differences were noted due to treatment (P ≥ 0.25) or feeding period (P ≥ 0.37) for Ca, P, Mg, K, and S retention (g/100 g of protein gain). Concentrations of Cu, Fe, Mn, and Na were greater in offal than carcass tissues in both experiments (P < 0.01). In both experiments, expressing mineral retention on a protein gain basis minimized effects due to BW or rate of gain, allowing for a better comparison of mineral retention across a variety of animals and diets.
The objective of this study was to evaluate the effect of processor type on fermentation profile, corn silage processing score, and physically effective NDF of whole-plant corn silage samples. A data set composed of 3,900 whole-plant corn silage samples was obtained from Rock River Laboratory (Watertown, WI). All samples were collected from 2013 to 2016 by the Chr. Hansen team under specific protocols to label samples as shredlage (SHRD) only if confirmed by farmers or custom harvesters. A total of 309 and 3,591 samples were labeled as SHRD and nonshredlage (CONV), respectively. Samples had been previously analyzed for corn silage processing score, physically effective NDF, and predicted ruminal in vitro NDF digestibility at 30 h (using near-infrared spectroscopy). In addition, 2,394 samples (272 SHRD and 2,394 CONV) had previously been analyzed via wet chemistry for fermentation profile. Loss of DM during fermentation was calculated with a predictive equation. Data were analyzed using Proc Glimmix in SAS with type of processor (SHRD vs. CONV) as a fixed effect. Statistical significance and trends were declared at P ≤ 0.05 and 0.05 < P < 0.10, respectively. The pH was less (P = 0.01; 3.90 vs. 3.97) for SHRD than CONV, which was related to greater (P = 0.001; 4.89 vs. 4.34% of DM) lactic acid concentrations. Concentrations of acetate, propionate, butyrate, and ethanol did not differ (P > 0.10) and averaged 2.27, 0.35, 0.36, and 0.57%, respectively. Recovery of DM was improved (P = 0.05; 2.42 vs. 2.73%) for SHRD, but the difference is of minor importance. Corn silage processing score was 4.6 percentage units greater for SHRD than for CONV silages (P = 0.001; 68.1 vs. 63.53% starch passing through a 4.75-mm sieve). In contrast, physically effective NDF and predicted ruminal in vitro NDF digestibility were (P = 0.001) 1.8 and 1.6 percentage units greater for CONV. Our results suggest that harvesting whole-plant corn silage as SHRD improved kernel breakage while maintaining adequate fermentation patterns compared with CONV.
Gastrointestinal parasites cost the US beef industry $3 billion annually. Therefore, the objective of this study was to assess performance parameters and reproductive success of fall-calving beef herds treated with extended-release eprinomectin compared with a conventional anthelmintic product. In Exp. 1, 119 fall-calving cows were treated with short-duration injectable ivermectin (n = 53; CONV) or injectable extended-release eprinomectin (n = 66; EPR). Cow and calf performance, pregnancy rates, calving interval, and calving distribution were analyzed. Average daily gain and change in BW were greater in EPR cows (P ≤ 0.01) than CONV. Pregnancy rates tended to be greater for EPR than CONV cows (P = 0.15). Calves from EPR dams were younger at weaning but had greater weaning weights than calves from CONV dams (P < 0.01). In Exp. 2, 74 yearling fall replacement heifers were treated with short-duration injectable ivermectin (n = 33; CONV) or injectable extended-release eprinomectin (n = 44; EPR). Performance, conception to AI, overall pregnancy rates, and calving distribution the subsequent year were analyzed. Heifers treated with EPR had heavier BW (P ≤ 0.10), greater weight gain (P ≤ 0.01), and greater ADG (P < 0.01) than CONV heifers. Conception to AI (P = 0.03) and overall pregnancy rates (P = 0.02) were greater for EPR heifers than CONV. Also, a greater proportion of EPR heifers calved in the first 21 d of the subsequent calving season (P = 0.04) than CONV. Results indicate improved performance and reproductive success for fall-calving beef herds treated with extended-release eprinomectin compared with short-duration ivermectin.
The effectiveness of sow cooling pads during lactation was evaluated under mild and moderate heat stress conditions. The moderate heat stress room was targeted to achieve 32°C from 0800 to 1600 h and 27°C for the rest of the day. The mild heat stress room was targeted to achieve 27 and 22°C for the same periods, respectively. Sows received a constant cool water flow of 0.00 (CON, n = 9), 0.25 (LWF, n = 12), or 0.50 (HWF, n = 10) L/min. Respiration rates, rectal temperatures, and skin temperatures were recorded every day (0700 and 1500 h) from the second day in the farrowing room to weaning. The respiration rates of CON sows were 23, 56, 41, and 89 breaths/min, of LWF sows were 21, 24, 29, and 41 breaths/min, and of HWF sows were 18, 20, 24, and 27 breaths/min, and respiration rate increased (P < 0.001) as heat stress increased from mild at 0700 h (22°C), to moderate at 0700 h (27°C), to mild at 1500 h (27°C), and to moderate at 1500 h (32°C). The skin temperatures of LWF sows were 1.1, 0.6, 0.8, and 0.4°C less and of HWF sows were 1.7, 0.7, 1.1, and 1.0°C less (P < 0.01) than CON sows for the same heat stress conditions. The rectal temperatures of LWF sows were 0.02, 0.20, 0.11, and 0.58°C less and of HWF sows were 0.04, 0.22, 0.02, and 0.57°C less (P < 0.05) for the same 4 treatments. The sow cooling pads reduced the effect of heat stress.
Consumer interest regarding cattle welfare has increased. This experiment evaluated exercise and roughage source on calf performance and health during a 56-d receiving period. Steers (n = 94; BW = 250 ± 12 kg) were assigned in a randomized complete block design with a 2 × 2 factorial arrangement of treatments. Factors included (1) roughage source [30% (DM basis) hay (HY) or 15% cottonseed hulls and 15% soybean hulls (HLS)] and (2) exercise [529 m of exercise (EX) 3 d/wk or no exercise (NEX)]. No differences in BW or ADG existed among treatments (P ≥ 0.24). However, HLS calves had reduced DMI from d 29 to 42, 43 to 56, and 0 to 56 (P ≤ 0.04) compared with HY calves. Overall, HLS and EX calves were more efficient than HY and NEX calves (P < 0.001 and P = 0.02, respectively). On d 56, there was an interaction for both fecal score (P < 0.01) and fecal pH (P = 0.05) with HY + NEX having reduced fecal score and fecal pH compared with all other treatments. The number of calves that required a second antimicrobial treatment for bovine respiratory disease tended (P = 0.08) to be reduced for HY and NEX calves compared with HLS and EX calves. Calves that were fed HLS or exercised had greater feed conversion efficiency than calves that were fed HY or not exercised. Further investigation is needed to determine the effects of exercise on fecal characteristics and clinical bovine respiratory disease incidence.
This experiment evaluated effects of supplemental s.c. trace-mineral injections on growth and breeding soundness of bull calves. Weaned bulls (n = 488; initial BW = 308 ± 45 kg, initial age = 203 ± 17 d) of 2 breeds (Angus and Charolais) and originating from 13 ranches in the Great Plains were transported to a common confinement facility and assigned randomly to 2 treatments: (1) s.c. injections of trace mineral (TM) containing 15 mg/mL Cu, 5 mg/mL Se, 10 mg/mL Mn, and 60 mg/mL Zn or (2) s.c. injections of physiological saline (control). Treatments were administered at arrival (d −2 or −1; 1 mL per 45 kg of BW) and on d 90 ± 1 (1 mL per 68 kg of BW). On d 0, bulls were stratified by treatment, breed, and ranch of origin and assigned randomly to 8 pens in which they were fed a growing diet for 225 d. The diet was formulated to promote a 1.5-kg ADG at a DMI of 2.6% of BW and to meet or exceed NRC (2000) requirements for Ca, Co, Cu, I, Mg, Mn, Na, P, K, Se, and Zn. Initial BW were measured and pretreatment blood plasma samples were collected on d −2 or −1. Breeding soundness examinations (BSE) were conducted and BW were measured at 10 and 12 mo of age (d 90 ± 1 and d 150 ± 1, respectively). Scrotal circumference was measured and semen samples were collected via electro-ejaculation. Motility and morphology of sperm were evaluated via light microscopy. Scrotal circumference, BW, and ADG did not differ (P ≥ 0.16) between treatments at any time. Proportions of control- and TM-treated bulls achieving minimal satisfactory BSE classifications did not differ at 10 mo of age (P = 0.98; 50 ± 3.8% for both TM and control) or at 12 mo of age (P = 0.43; 89 and 86 ± 2.2% for TM and control, respectively). Conversely, improved (P = 0.05) sperm motility was detected in TM-treated bulls compared with control-treated bulls at 12 mo of age; moreover, TM-treated bulls had greater (P ≤ 0.05) improvements in sperm morphology and motility between 10 and 12 mo of age than control-treated bulls. Among bulls that failed BSE at 10 mo of age, more TM-treated bulls tended (P = 0.10) to pass BSE at 12 mo of age than control-treated bulls (98 and 94 ± 1.6% for TM and control, respectively). Under the conditions of this experiment, sperm motility and morphology at 12 mo of age were improved in bulls treated with injectable TM at 7 and 10 mo of age compared with bulls treated with saline.
To determine the effects of photoperiod management on behavior of dairy cows, 30 lactating cows were subjected to a long-day (16 h/d light) or short-day photoperiod (8 h/d light). Feeding behavior was observed and feed refusals were collected before and after a 21-d adaptation to photoperiod treatment. Feeding behavior data were summarized for 4 daily time periods based on light schedule, and no effect of light treatment was observed for DMI, lying time, or overall feeding behavior. However, in time period 4 (1600 to 1900 h), the long-day treatment decreased lying time (28.3 vs. 37.7 min/h) and tended to increase eating time (17.5 vs. 9.03 min/h). There was also a tendency for the long-day treatment to reduce daily feed sorting. Providing supplementary light may reduce sorting and increase distribution of eating activities throughout the day, and the change in feeding pattern may be affected by the time of day the supplementary light is provided.
The purpose of this project was to evaluate the effects of superdosing phytase fed to boars on sperm production, semen quality, and serum mineral concentrations. Thirty boars (9 to 12 mo of age, PIC 280) were enrolled in the study and were fed 2.5 kg/d of a commercial corn–soybean meal diet containing 500 phytase units/kg modified Escherichia coli phytase to release 0.15% available phosphorus and 0.16% Ca. The boars were blocked by age and randomly assigned to receive 1 of 2 top-dresses at 0.5 kg/d: (1) control (corn only) or (2) superdosed (corn plus 5,000 phytase units/kg E. coli phytase to equate to 3,000 phytase units/kg in the overall diet). Semen was collected weekly from all 30 boars for 12 wk and motility, mobility, and morphology evaluated at the time of collection. Monthly semen samples were shipped to Purdue University for additional assessment of motility, morphology, viability, and DNA denaturation. Serum mineral concentrations were determined on wk 1, 6, and 12. The concentration of sperm in the ejaculate was greater in the superdosed boars (P = 0.03), resulting in a tendency for an additional 3 doses (2.8 billion cells/dose) extended per ejaculate (P = 0.10) from a 13% increase in semen output. Some significant variations in motility, mobility, and morphology were found, but all semen samples fresh and stored were considered acceptable at industry standards for use in breeding doses. Serum minerals were reduced in boars fed superdosed levels of phytase, possibly due to a shift of minerals being used for reproduction.
