William Hohenboken

An attempt to assess traits of emotionality in crossbred ewes

Abstract Behavior of sheep isolated in a 6 m diameter enclosure, then exposed to a tethered dog in the same setting, was examined. Subjects were 2 and 3 year old crossbred ewes (North Country Cheviot, Dorset, Finnsheep, and Romney sire × Suffolk and Columbia-type dam matings). Each of 164 ewes was tested three times with 3 weeks between tests. Ewes were scored for ambulation (number of steps taken) when isolated for a 90 s period and when exposed to the dog for an additional 90 s period. Subjective investigation score, subjective emotional behavior score, number of vocalizations, number of foot-stampings, and number of eliminations (urinations plus defecations) were also examined. These traits were chosen because published research with farm mammals and rodents has indicated they are related to emotional behavior or nervousness. Ewes typically responded to isolation by initial high levels of ambulation which decreased to immobility by the end of the first 90 s. Vocalization occurred in 73% of the observations but foot-stamping occurred very rarely in the first 90 s of observations. Upon exposure of the dog, ewes commonly took several steps, then became and remained immobile for the duration of that 90 s observation. Vocalization was rarer but foot-stamping was much more common than during the period in which ewes were isolated. Eliminative behavior occurred in 53% of the observation periods and was not affected by exposure to the dog. In this experiment, high ambulation during isolation was related to greater emotional behavior, while immobility during exposure of the dog was related to greater nervousness. Vocalization and foot-stamping were predictable responses to isolation and dog exposure, respectively, but both occurred with too low a frequency to be useful measures of variation in emotional behavior. Differences between ewes with Suffolk vs. Columbia-type inheritance were small and not consistent. Ewes with Romney sires had higher scores for ambulation, investigation score, emotion score and vocalization, and ewes with Finnsheep sires scored above average for vocalization and eliminative behavior. Dorset and North Country Cheviot sired ewes were average or below for most of the traits assessing emotional behavior.

The effects of sire-breed, forage availability and weather on the grazing behavior of crossbred ewes

Abstract For 17 days, 30 non-pregnant, non-lactating crossbred ewes, six per sire-breed (Suffolk, Clun Forest, Dorset, Polypay and Border Leicester), were grazed together during daylight hours (approximately 06.00–21.00 h Pacific daylight time) in a 0.87-ha grass—clover pasture. For the remainder of each day, the ewes were penned indoors without access to feed and water. On 6 days they were observed throughout the grazing period, with individual locations and activities being recorded every 10 min. The daily grazing pattern consisted of intensive a.m. grazing until about 10.00 h and intensive p.m. grazing after about 16.00 h. Cool, cloudy days had less distinct grazing periods than warm, sunny days. Average time spent grazing was 9.23 h (4.11 h a.m. and 5.12 h p.m.), and the average times of a.m. stop and p.m. start were 10.23 and 14.59 h, respectively. Average distance traveled was 1.39 km (0.76 km a.m. and 0.63 km p.m.). Sire-breed had no effect on either grazing time or distance traveled. Weather had a greater apparent effect than forage availability on grazing time, but forage availability had a greater apparent effect than weather on distance traveled. Sire-breed groups (averaged over observation days) differed in their grazing-site preference. A ewes a.m. and p.m. grazing times were not correlated, but time of a.m. stop and p.m. start were negatively correlated. Grazing time and distance traveled were only moderately correlated.

Suckling activity and calf growth in a group of crossbred cows each rearing two foster calves

Abstract Each of 9 beef × dairy crossbred cows was presented with 2 alien calves within 5 minutes of parturition. Each cows own calf was removed and later fostered to another cow. Foster trios were observed periodically until introduction to the foster herd. The foster herd was observed continuously on Days 71, 77 and 175 after the average fostering date. Calf growth rates were recorded from birth to Day 77 and from Day 77 to Day 175. All cows were observed to allow their foster calves to nurse at the time the trio was introduced to the herd, suggesting that successful maternal-offspring bonding between calves and dam had occurred. Behavioral data taken on Days 71 and 77 were similar and were summed. Percent cross-suckling was high on Days 71 and 77 but was less on Day 175. Calf growth rates were highly variable to Day 77, and were less variable between Days 77 and 175. A high negative correlation existed between percent cross-suckling and calf growth rate to Day 77. The decrease in percent cross-suckling from Day 77 to Day 175 was directly proportional to an observed decrease in suckling frequency. Percent cross-suckling was highly variable among calves during all observation periods. The negative relationship between percent cross-suckling and calf growth rate was less evident at Day 175, possibly due to increased consumption of forage and creep feed by calves at that time. Variation among foster pairs for growth rate was not significant. In many cases, the fostering methods employed apparently did not result in the formation of a specific maternal bond between the cow and her foster calves.

Circadian behaviour, including thermoregulatory activities, in feedlot lambs

Abstract Fifty-six feeder lambs were observed each half-hour for one day per week for 7 consecutive weeks between July and September, 1973. At each observation period, the number of lambs eating, drinking, standing in an alert state, lying down and standing inactive was counted. The average number of lambs engaged in each activity over the 7 days of observation was plotted against time. Two peaks of eating, drinking and standing active occurred near sunrise and sunset. During the eating peaks, there was frequently competition for space at the self-feeder. At mid-day, lambs were inactive, standing about in groups, shading their heads under the flanks or between the hind legs of adjacent lambs. Later in the afternoon, lambs utilized the shade that became available from the perimeter fence. In both cooling strategies, lambs were particularly keen to shade their heads. All activity declined after sunset, and throughout the hours of darkness the majority of the lambs were lying down.

Simulation of beef cattle production systems in the Llanos of Colombia—part I. Methodology: An alternative technology for the tropics

Abstract A simulation model was developed to study voluntary forage intake, energy requirements for maintenance, liveweight change and calving rate of grade Zebu cows in the Llanos of Colombia. Multiplicative correction factors were fitted to intake and maintenance requirement prediction equations researched from the literature to account for reduced intake due to sparse regrowth of recently burned native savanna and to conditions of mineral deficiency, increased intake and decreased maintenance requirement during periods of high compensatory gain during the rainy season, and increased intake and maintenance requirement due to the effects of lactation and gestation. A frequency distribution was constructed relating liveweight at time of mating to subsequent calving rate, and this was used to simulate the calving rates of cow herds in the Llanos. Use of the model would allow prediction of the amount of improved pasture or supplemental feed that would be necessary to raise calving rates in a particular herd to an acceptable level, defined as at least three calves per cow every four years. The model was fitted by computer and was then run on programmable calculators. This type of simulation is suited to regions of the world in which computer time is expensive or unavailable. Verifications, validations and experimentation with the model are presented in a companion paper.

ASAS Centennial Paper: Animal breeding research and the Journal of Animal Science: A century of co-evolution

Animal breeding reports in the Journal of Animal Science (JAS) and in its predecessor, Proceedings of the American Society of Animal Production, were counted and categorized. In 22 volumes of the Proceedings of the American Society of Animal Production, 155 articles had animal breeding content, of which 54% were research reports, 17% extension communications, and 28% syntheses or reviews. Several of the latter featured advice from the livestock industry to the scientific community. Thirty-one percent of articles concerned swine, whereas beef cattle, dairy cattle, and sheep each accounted for an additional 20%. In the 67 yr of JAS publication, 3,045 research papers were identified with animal breeding content, nearly half of them published since 1990. Growth in publication output was modest during the 1950s, robust in the 1960s through 1980s, moderate in the 1990s, and static in the 2000s. Important topics included genetic resource evaluation (a subject in 55% of all manuscripts), genetic parameter estimation, selection programs, and nonrandom mating systems. Maternal effects and genotype x environment interactions were featured in 17 and 15% of all manuscripts, respectively, whereas 6% dealt with a simply inherited trait. Only 4% of manuscripts included economic analysis of a breeding program or intervention. Interest in molecular biology and biometry has surged in the 1990s and 2000s. Approximately 50% of all papers involved cattle, a fifth of which concerned dairy cattle or beef x dairy crossbreds. A quarter of papers concerned swine, 15% concerned sheep, and 3% considered laboratory rodents, with the proportional contribution of sheep research decreasing across time. Authors from the Midwestern and Southern sections of the American Society of Animal Science had greater proportional contributions than Western and Northeastern section authors, and contributions of university and state experiment station authors outnumbered those of USDA-ARS authors. The proportional contribution of international authors increased across time, reaching 45% for the 2000s, as that of university and experiment station authors decreased and that of USDA-ARS authors remained fairly constant. Subjective analysis suggested substantial levels of creativity, innovation, and cooperation in JAS animal breeding research, a strong international perspective, but also a marked degree of imitation and repetition in subject matter content.

Recorded sounds associated with feeding did not affect feeding behavior of lambs

Abstract This study was designed to determine whether periodic exposure to pre-recorded sound associated with feed delivery and consumption would alter feed intake or feeding pattern of lambs provided with fresh feed once daily. Thirty cross-bred lambs were randomly assigned to 6 pens. The trial lasted 44 days (30 July to 11 September 1982) and consisted of a 4-day acclimation to test facilities, and then cycles of 4 days without sound stimulation followed by 4 days with sound stimulation. Sound stimulation consisted of 6-min broadcasts, every 3 h, of sounds associated with feed delivery and eating. Lambs were observed continuously for 24 h on 3 days when lambs were subjected to sound stimulation and 3 days when they were not. The recorded sound stimulation affected neither feed intake nor feeding behavior. Lambs largely ignored the recorded sounds, and total feed intakes during 20 sound-stimulated vs. 20 non-sound-stimulated days were 1234 vs. 1240 kg, respectively. There was a rhythmic feeding pattern at 1–2-h intervals, synchronously throughout the barn, and this was not affected by the 6 min of sound stimulation at 3-h intervals. There were no major peaks in feeding activity except after the offering of fresh feed in the morning. Feeding activity did not change with sunrise or sunset, and peaks of eating activity were distributed at even time-intervals throughout the 24 h. The overall means per lamb for the total time spent eating, the number of eating bouts (separate eating incidents), the average time eating per bout and the number of drinking episodes across the 6 observation days were 118.8 min, 22.6 times, 5.5 min and 9.6 times, respectively.

Nutritional characteristics of Angus cows differing in lifetime calf production

Cows with better versus poorer lifetime calf production did not differ significantly in intake or passage rate of digesta under ad libitum concentrate or roughage feeding. On the concentrate diet, better cows tended towards greater fat accretion than poorer cows. On roughage they maintained, while poorer cows lost fat thickness. Key words: Cows, intake, passage rate, fat thickness

Simulation of beef cattle production systems in the Llanos of Colombia: Part 2—Results of the modelling

Abstract Verifications and validations were conducted of a simulation model of beef cattle production on tropical ranges of the Colombian Llanos. Liveweight changes were simulated for individual cows sampled at random, for cow herds alternately grazing native savanna and molasses grass (Melinis minutiflora) and for steers grazing native savanna. Correlation coefficients between observed and simulated liveweight change were high. Simulations of the calving rates of cow herds from two experiments at Carimagua Research Station were also conducted and there was reasonably good agreement between observed and simulated data. Shortcomings of the model included an inability to simulate the heavy weight losses of grazing animals on molasses grass during the dry season and under-estimates of calving rates for the most productive herds. An experiment was conducted with the validated model from which it was concluded that grazing molasses grass and weaning of calves at 84 days of age would do little to increase calving rate.