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Two hundred twenty-five lactation and litter performance records from 82 does representing four genetic groups and two diets were analyzed to quantify breed, heterosis, reciprocal F1 cross and diet effects for milk production and associative traits. Doe genetic groups were New Zealand White (NN) and Californian (CC) straightbred and Californian X New Zealand White (CN) and New Zealand White X Californian (NC) reciprocal crossbreds. Pelleted diets fed to does and litters were either a commercial control or a 74% alfalfa diet. Three sire breeds of litters included NN, CC and Flemish Giant (FG) straightbreds. Doe genetic group and diet were important sources of variation (P less than .05) for all traits examined except for litter milk efficiency (litter gain/milk intake) and doe feed efficiency (milk yield/feed intake). The sire breed of litter effect did not influence (P greater than .05) lactational performance of does nor associative preweaning traits. Straightbred NN does were heavier at kindling, yielded more milk, reared a heavier litter by 21 d and were more efficient in converting feed into milk than were straightbred CC does (P less than .01). Significant heterosis was detected for milk production and for litter size and weight at 21 d. Reciprocal differences between crossbred doe groups were observed (P less than .05) for litter milk efficiency and doe feed intake. The 74% alfalfa diet was superior to the commercial control diet for effects on milk production and litter size and weight at 21 d, although doe feed intake was increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Summary Relationships among hemoglobin (Hb) types and production traits were examined in 294 crossbred ewes from North Country Cheviot, Dorset, Finnsheep and Romney rams, and Suffolk and Columbia-type ewes. Hb BB ewe lambs were youngest at first estrus, while Hb AA ewe lambs were oldest. Ewe lamb fertility was similar for Hb AB and Hb BB ewes, and both were superior to Hb AA ewes. When Finnsheep crossbreds were excluded, frown which Hb BB was absent, Hb BB ewes had higher ewe lamb fertility than did Hb AB ewes. There was a minor advantage of the A over the B allele in ewe lamb prolificacy. Hb BB ewes were highest, Hb AB ewes were intermediate and Hb AA ewes were lowest for average fertility, prolificacy per ewe lambing, lambs born per ewe exposed to mating, total number of lambs weaned and total kilograms of lamb weaned. Grease wool production, staple length, fiber diameter grade, incidence of medullated fibers and incidence of cotted fleeces all were similar across Hb types. Likewise, Hb type did not affect milk production or composition. Ewes with Hb AB had the lowest incidence of footrot; Hb AA and Hb BB ewes were similar. Ewes with Hb AA had the lowest fecal parasite egg counts, while ewes with Hb AB or Hb BB were similar. Ewes with Hb AA also had the lowest incidence of mastitis, Hb BB ewes were intermediate and Hb AB ewes were highest. The combination of overdominance (as for footrot resistance), beneficial effects of the A allele on health-related traits (as for mastitis and parasite resistance) and the beneficial effect of the B allele on reproductive traits, if real, could partly explain the genetic polymorphism commonly reported at the Hb locus in sheep.

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.

Twenty-eight cows were assigned randomly to a daily photoperiod of 18 h light and 6 h darkness or to continuous light and were observed 1 day each month from December 1981 to February 1982. Lighting regimen did not affect eating behavior or milk production. Overall means of total eating time, number of eating bouts, and average time eating per bout on the 3 observation days were 270 to 280 min, 10 to 12 times, and 24 to 27 min. Eating behavior and milk production were not significantly correlated. Eating patterns were similar in both groups and across observation days. Peaks of eating activity occurred before sunset, bracketing the evening milking and after the offering of fresh feed in the morning. Approximately 80% of total eating activity occurred between 0900 and 2100 h in both groups. Cows had a clear preference for entry into the right or left side of the milking parlor, and entry order was repeatable. Milking order and milk production were not correlated. In one group, location of free stalls did not influence utilization; but in the other group, centrally located stalls were utilized more than stalls at either end of the alley. About 40% of cows had individual free stall preferences.

Each of 9 beef × dairy crossbred cows was presented with 2 alien calves within 5 minutes of parturition. Each cow's 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.

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.

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.