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Two experiments were conducted to evaluate the effects of virtual fencing on stress in beef cattle. In both experiments, cattle were contained by either physical, 2-strand electric fencing or by use of a proprietary, GPS-based virtual fencing collar, with no physical interior fencing. In both studies, hair from the tail switch was collected at the end of the experiment, and analyzed for cortisol concentration to measure the accumulated stress experienced by the cattle. Additionally, a subset of cattle were fitted with pedometers to measure behavior responses. In the initial pilot experiment, 55 heifers were grazed for 28 d in either 1 physically-fenced pasture or 1 virtually-fenced pasture. In the second experiment, 59 mature cows and heifers were grazed for 56 d in 1 of 2 physically-fenced or 1 of 2 virtually-fenced pastures (4 pastures total). In the second experiment, blood samples were also collected and NEFA and lactate were quantified in plasma. Only descriptive statistics were summarized for the pilot experiment, which indicated that hair cortisol concentrations were within published ranges for both fence types (0.39 ± 0.32 and 0.37 ± 0.15 pg/mg for physically- or virtually-fenced animals, respectively), and step count and motion index appeared elevated in the first few days of adaptation to virtual fence. The second experiment was analyzed with analysis of variance as a completely random design with pasture as the experimental unit. No effect of fence type was found for behavior (number of steps, standing time, lying bouts, or motion index; P > 0.16). Further, no difference was observed in cortisol, lactate nor NEFA (P > 0.14) concentrations due to fence type. None of this data suggests that virtual fencing is different from physical fencing in the effects on cattle stress and behavior, indicating further research and development of virtual fencing technology are warranted. [ABSTRACT FROM AUTHOR]

Automatic feeding systems are being used more frequently to understand individual cattle behavior and intake variation when cattle are group housed. The objective of this experiment was to evaluate if bunk preference exists, and if so, how bunk preference affects performance, intake, or efficiency of feedlot steers. Angus steers (n = 123; initial BW = 293 ± 33.8 kg) were blocked by BW and sire and assigned to 1 of 4 pens, each containing 6 automated feed bunks (Insentec RIC; Hokofarm Group, Marknesse, Netherlands), in a randomized complete block design. Steers were fed a common diet and free to consume feed from any bunk within the pen without restriction. A steer's preferred bunk was defined as the bunk from which the most feed was consumed. In any week, 80% of steers consumed less than 29% of that week's total feed intake from the preferred bunk, indicating no strong preference for a specific bunk. The maximum weekly feed intake consumed from a preferred bunk was 57%. Further, the percentage of intake from the preferred bunk did not affect overall ADG, feed intake, or G:F (P > 0.64). These results suggest that a few steers may have a relatively strong preference for a specific feed bunk; however, this preference was not associated with performance, intake, or efficiency. Researchers can design experiments (at a stocking density of 5 steers per bunk) that restrict or alter an individual animal's access to any specific bunk, because such access, or lack of access, does not alter the animal's performance or feed intake. [ABSTRACT FROM AUTHOR]

Automatic feeding systems are being used more frequently to understand individual cattle behavior and intake variation when cattle are group housed. The objective of this experiment was to evaluate if bunk preference exists, and if so, how bunk preference affects performance, intake, or efficiency of feedlot steers. Angus steers (n = 123; initial BW = 293 ± 33.8 kg) were blocked by BW and sire and assigned to 1 of 4 pens, each containing 6 automated feed bunks (Insentec RIC; Hokofarm Group, Marknesse, Netherlands), in a randomized complete block design. Steers were fed a common diet and free to consume feed from any bunk within the pen without restriction. A steer's preferred bunk was defined as the bunk from which the most feed was consumed. In any week, 80% of steers consumed less than 29% of that week's total feed intake from the preferred bunk, indicating no strong preference for a specific bunk. The maximum weekly feed intake consumed from a preferred bunk was 57%. Further, the percentage of intake from the preferred bunk did not affect overall ADG, feed intake, or G:F (P > 0.64). These results suggest that a few steers may have a relatively strong preference for a specific feed bunk, however this preference was not associated with performance, intake, or efficiency. Researchers can design experiments (at a stocking density of 5 steers per bunk) that restrict or alter an individual animal's access to any specific bunk, because such access, or lack of access, does not alter the animal's performance or feed intake. [ABSTRACT FROM AUTHOR]

Interest in automated, precision feeding equipment is increasing, and users need information about how to effectively use this new approach. Our objective was to determine the effect of competition for a feeding space at an automated supplement feeder on supplement intake behavior. Mixed breed beef steers (n = 128, initial BW = 257 ± 29.2 kg) were randomly assigned to 8 paddocks. One paddock (16 steers) was selected to have continuous access to the feeder for the duration of the 16-wk trial; this paddock was designated the "tester" paddock. The automated feeder consisted of a large bin that dispensed supplement into 4 feeding stations. Supplement dispense was triggered by the presence of an eligible animal's RFID tag; each steer was limited to 0.50 kg supplement/d by the electronics of the feeder. Weekly, additional paddocks were commingled with the tester paddock to increase competition for the feeder, resulting in a stocking density from 4 to 32 steers per feeding station in various weeks. Approximately 30% of the steers did not voluntarily use the feeder; therefore effective competition was less than the study design. Supplement intake and GPS location were recorded for steers in the tester paddock, and averaged for each wk; week was the experimental unit (n = 16). Weekly mean supplement intake and time spent near the feeder were regressed on feeder stocking density. Tester steers consumed an average of 0.36 kg supplement/d. Competition for a feeder space numerically reduced (P = 0.15) supplement intake by 0.002 kg/d per steer of competition. Steers spent 6% of the time within 15 m of the feeder regardless of competition (P = 0.82). This data illustrates that in scenarios similar to these experimental conditions, the feeder can be stocked with at least 80 animals with minimal effects on supplement intake. [ABSTRACT FROM AUTHOR]

Interest in automated, precision feeding equipment is increasing, and users need information about how to effectively use this new approach. Our objective was to determine the effect of competition for a feeding space at an automated supplement feeder on supplement intake behavior. Mixed breed beef steers (n = 128, initial BW = 257 ± 29.2 kg) were randomly assigned to 8 paddocks. One paddock (16 steers) was selected to have continuous access to the feeder for the duration of the 16-wk trial; this paddock was designated the "tester" paddock. The automated feeder consisted of a large bin that dispensed supplement into 4 feeding stations. Supplement dispense was triggered by the presence of an eligible animal's RFID tag; each steer was limited to 0.50 kg supplement/d by the electronics of the feeder. Weekly, additional paddocks were commingled with the tester paddock to increase competition for the feeder, resulting in a stocking density from 4 to 32 steers per feeding station in various weeks. Approximately 30% of the steers did not voluntarily use the feeder; therefore, effective competition was less than the study design. Supplement intake and GPS location were recorded for steers in the tester paddock, and averaged for each wk; week was the experimental unit (n = 16). Weekly mean supplement intake and time spent near the feeder were regressed on feeder stocking density. Tester steers consumed an average of 0.36 kg supplement/d. Competition for a feeder space numerically reduced (P = 0.15) supplement intake by 0.002 kg/d per steer of competition. Steers spent 6% of the time within 15 m of the feeder regardless of competition (P = 0.82). These data illustrate that in scenarios similar to these experimental conditions, the feeder can be stocked with at least 80 animals with minimal effects on supplement intake. [ABSTRACT FROM AUTHOR]

Four years of feedlot performance and carcass characteristics were pooled on spring-(SPRING) and fall-(FALL) born steers (n=460) into a mixed model to evaluate the effects of calving season, sire breed (Angus [AN], Charolais [CHAR] or Hereford [HER]) and their interaction on feedlot performance and carcass traits. Initial and final BW, DOF, ADG, DMI, and G:F were evaluated as performance measures and HCW, YG, FT, REA, and MS were collected at harvest. There was no season by breed interaction for entry or final BW (P >0.05). SPRING steers (400.2 kg, 686.4 kg) weighed more than FALL (350.9 kg, 668.3 kg) upon entering and leaving the feedyard (P< 0.001). CHAR weighed 14.3 kg less than AN upon feedlot entry (P=0.01) although final BW did not differ by breed (P >0.05). SPRING steers (21.8 kg/d) consumed more feed than FALL steers (18.8 kg/d; P=0.002), but there was no difference in gain:feed due to calving season nor sire breed (P=0.575). A calving season by sire breed interaction was present for ADG and DOF (P=0.014). FALL AN (1.70 kg/d) and FALL HER (1.80 kg/d) gained more than FALL CHAR (1.55 kg/d;P< 0.001) and FALL AN were fed over a shorter period than FALL CHAR and FALL HER (P=0.006). However, average daily gain of SPRING calves did not differ by breed (P >0.05). There was a tendency for FALL (400.9 kg) steers to have lighter carcasses than SPRING steers (407.9 kg; P=0.068). HER carcasses were 18.0 kg heavier than AN carcasses (P< 0.001), but did not differ from CHAR (P=0.13). CHAR had larger REA (93.5 cm2) than both AN (87.7 cm2) and HER steers (88.5 cm2;P=0.001). Fall-born steers had less YG than spring-born steers (P< 0.042). Feedlot performance was generally less for fall-born steers finished during the winter months. Under these conditions, numerous performance and carcass traits were influenced by the interaction of breed and season. [ABSTRACT FROM AUTHOR]