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| Author | Murray, Martyn G.; Brown, David | ||||
| Title | Niche Separation of Grazing Ungulates in the Serengeti: An Experimental Test | Type | Journal Article | ||
| Year | 1993 | Publication | The Journal of Animal Ecology | Abbreviated Journal | T. J. Anim. Ecol. |
| Volume | 62 | Issue | 2 | Pages | 380-389 |
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| Abstract | 1. The niche separation of three species of alcelaphine antelope (wildebeest, topi and hartebeest) with similar body size was compared by measuring bite weight, bite rate, intake rate and selectivity of tame animals in plots containing grass at different growth stages. 2. On growing swards, hartebeest had a smaller bite weight and lower intake rate, and were also less selective of green leaf, than either topi or wildebeest. On senescent swards, hartebeest were more selective of leaf than the other two species. 3. Wildebeest had a faster bite rate than either topi or hartebeest on swards with low biomass and high protein content of green leaf (green flush). Bite weight and intake rate of wildebeest and topi were similar despite the difference in breadth of their incisor rows. 4. Topi were significantly more selective of green leaf than the other two species and were the only species to maintain a rapid bite rate on swards with high green leaf biomass. 5. The feeding experiments did not reveal significant cross-overs between species in the rate of food intake on different grass types, but each species was most proficient either in leaf selection or bite rate when feeding on grass swards in a particular growth stage. We suggest that growth stage is a primary determinant of niche separation. 6. In Serengeti, grazing ungulates which migrate are specialists of the earlier growth stages of grass which tend to be transient, while those that are residential specialize on late growth stages which are more enduring. The mobility of species, and the spatial and temporal dynamics of pastures containing different growth stages of grass, contribute to niche separation. | ||||
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| Call Number | Equine Behaviour @ team @ | Serial | 3544 | ||
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| Author | Negi,G. C. S.; Rikhari, H. C.; Ram,Jeet; Singh, S. P. | ||||
| Title | Foraging Niche Characteristics of Horses, Sheep and Goats in an Alpine Meadow of the Indian Central Himalaya | Type | Journal Article | ||
| Year | 1993 | Publication | The Journal of Applied Ecology | Abbreviated Journal | J. Appl. Ecol |
| Volume | 30 | Issue | 3 | Pages | 383-394 |
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| Abstract | 1. Data on plant species foraged, foraging hours, bite rate, bite size and species dry matter (DM) removed per species per bite were collected in tussock grass-forb (Grass-F), forb-tussock grass (Forb-G), Trachydium-forb (Forb), Rhododendron-Cassiope and early successional communities from May to September in a moderately foraged Central Himalayan alpine meadow in order to study the foraging niche characteristics of horses, sheep and goats. 2. The three animals together grazed 30 plant species, of which 20 were grazed by horses, 22 by sheep and 16 by goats. 3. The average foraging hours (5.2-13.2), bites per minute (23-51) and mg DM per bite (59-99) for horses, sheep and goats were significantly different in different communities and months. 4. The foraging search cost, reckoned as distance walked per unit DM eaten, was highest for goats (15.4 km kg$^{-1}$), followed by sheep (8.1 km kg$^{-1}$) and horses (1.2 km kg$^{-1}$). 5. Of the total intake of horses (3.25 kg DM day$^{-1}$), the Forb community alone accounted for 40%. Sheep (0.74 kg DM day$^{-1}$) resembled horses in this respect. In contrast, the contribution of this community was negligible in the diet of goats in which the Grass-F community contributed most to the intake. 6. Forbs were the largest dietary category for all animal species. The selection ratio varied from 0.7 to 11.3 for forbs, 1.0 to 7.2 for sedges and 1.1 to 2.5 for grasses. 7. Response breadth (in terms of species grazed) was similar for horses and sheep (0.46 vs. 0.43) and somewhat wider for goats (0.49). 8. Grazing pressures below the carrying capacity of the community appeared to favour botanical diversity. | ||||
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| Call Number | Equine Behaviour @ team @ | Serial | 3545 | ||
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| Author | Steelman, S.M.; Michael-Eller, E.M.; Gibbs, P.G.; Potter, G.D. | ||||
| Title | Meal size and feeding frequency influence serum leptin concentration in yearling horses | Type | Journal Article | ||
| Year | 2006 | Publication | Journal of Animal Science | Abbreviated Journal | J. Anim Sci. |
| Volume | 84 | Issue | 9 | Pages | 2391-2398 |
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| Abstract | Energy is an essential nutrient for all horses, and it is especially important in performance horses, pregnant and lactating mares, and young growing horses. A negative energy balance in horses such as these may result in unsatisfactory performance, decreased fertility, or slow growth. Therefore, ensuring adequate energy intake is an important aspect of the nutritional management of the equine. This study was undertaken to investigate the effects of feeding large, carbohydrate-rich, concentrate meals on the satiety-inducing hormone, leptin. Three groups of yearling horses were rotated through 3 feeding schedules in a replicated 3x3 Latin square design. Horses were fed 2, 3, or 4 times per day (2x, 3x, and 4xfeeding schedules, respectively), each for a period of 11 d, with the total amount of daily feed held constant. Horses were weighed and BCS was determined on the first day of each period. Blood samples were collected before the morning meal on d 1, 4, and 7 of each period. Additionally, blood was sampled for the last 24 h of the 2xand 4xdietary periods. Neither weight nor BCS changed during the study (P = 0.99 and P = 0.28, respectively). Both mean and peak plasma glucose were greatest in 2xhorses (P < 0.05), as were mean areas under the curve. Serum leptin concentration increased in 2xhorses (P < 0.05), but not in horses fed 3 or 4 times daily. Leptin was elevated in horses with greater BCS (P < 0.05) and increased steadily throughout the study (P < 0.05). Data from the 24-h collection indicated that 2xhorses had fluctuations in leptin production throughout the day (P < 0.05), whereas horses fed 4 times daily did not. Overall, this study indicates that feeding horses 2 large concentrate meals daily can increase mean serum leptin concentrations and may cause fluctuations in leptin production over a 24-h period. This departure from baseline leptin concentration has the potential to affect appetite, along with numerous other physiological processes. | ||||
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| Notes | 10.2527/jas.2005-281 | Approved | no | ||
| Call Number | Equine Behaviour @ team @ | Serial | 3561 | ||
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| Author | Williams, J.L.; Friend, T.H.; Nevill, C.H.; Archer, G. | ||||
| Title | The efficacy of a secondary reinforcer (clicker) during acquisition and extinction of an operant task in horses | Type | Journal Article | ||
| Year | 2004 | Publication | Applied Animal Behaviour Science | Abbreviated Journal | Appl. Anim. Behav. Sci. |
| Volume | 88 | Issue | 3-4 | Pages | 331-341 |
| Keywords | Equine; Horse; Clicker training; Operant conditioning; Secondary reinforcers | ||||
| Abstract | “Clicker training” is a popularly promoted training method based on operant conditioning with the use of a secondary reinforcer (the clicker). While this method draws from theories of learning and is used widely, there has been little scientific investigation of its efficacy. We used 60 horses, Equus callabus, and assigned each horse to one of six reinforcement protocols. The reinforcement protocols involved combinations of reinforcers administered (primary versus secondary plus primary), schedule of reinforcement (continuous versus variable ratio), and reinforcers applied during extinction (none or secondary). There were no differences (P>=0.11) between horses which received a secondary reinforcer (click) followed by the primary reinforcer (food) and those which received only the primary reinforcer (food) in the number of trials required to train the horses to touch their noses to a plastic cone (operant response). There also were no differences (P>=0.12) between horses which received the secondary reinforcer plus primary reinforcer and those which received only the primary reinforcer in regards to the number of trials to extinction. We conclude that there is no difference in the amount of training required to learn the operant task or in the task's resistance to extinction between horses that received a secondary reinforcer followed by a primary reinforcer versus horses which received only a primary reinforcer. | ||||
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| Call Number | Equine Behaviour @ team @ | Serial | 3581 | ||
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| Author | Langbein, J.; Siebert, K.; Nuernberg, G.; Manteuffel, G. | ||||
| Title | The impact of acoustical secondary reinforcement during shape discrimination learning of dwarf goats (Capra hircus) | Type | Journal Article | ||
| Year | 2007 | Publication | Applied Animal Behaviour Science | Abbreviated Journal | Appl. Anim. Behav. Sci. |
| Volume | 103 | Issue | 1-2 | Pages | 35-44 |
| Keywords | Dwarf goats; Operant conditioning; Visual discrimination learning; Secondary reinforcement | ||||
| Abstract | The use of secondary reinforcement is widely accepted to support operant learning in animals. In farm animals, however, the efficacy of secondary reinforcement has up to now been studied systematically only in horses (“clicker training”), and the results are controversial. We investigated the impact of acoustical secondary reinforcement on voluntary, self-controlled visual discrimination learning of two-dimensional shapes in group-housed dwarf goats (Capra hircus). Learning tests were conducted applying a computer-controlled learning device that was integrated in the animals' home pen. Shapes were presented on a TFT-screen using a four-choice design. Drinking water was used as primary reinforcement. In the control group (Gcontrol, n = 5) animals received only primary reinforcement, whereas in the sound group (Gsound, n = 6) animals got additional acoustical secondary reinforcement. Testing recall of shapes which had been successfully learned by the goats 6 weeks earlier (T1), we found a weak impact of secondary reinforcement on daily learning success (P = 0.07), but not on the number of trials the animals needed to reach the learning criterion (trials to criterion, n.s.). Results in T1 indicated that dwarf goats did not instantly recall previously learned shapes, but, re-learned within 250-450 trials. When learning a set of new shapes (T2), there was a strong influence of secondary reinforcement on daily learning success and on trials to criterion. Animals in Gsound reached the learning criterion earlier (P < 0.05) and needed fewer trials (1320 versus 3700; P < 0.01), compared to animals in Gcontrol. Results suggest that acoustical secondary reinforcement supports visual discrimination learning of dwarf goats, especially when the task is new and the salience of S+ is low. | ||||
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| Call Number | Equine Behaviour @ team @ | Serial | 3583 | ||
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| Author | Halford; G.S.; Halford, J.M . | ||||
| Title | Secondary reinforcement: signal or substitute reward? A preliminary investigation | Type | Journal Article | ||
| Year | 1969 | Publication | Abbreviated Journal | Aus. J. Psychol | |
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| Call Number | Equine Behaviour @ team @ | Serial | 3588 | ||
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| Author | Byrne, T.; Sutphin, G.; Poling, A. | ||||
| Title | Acquisition, extinction, and reacquisition of responding with delayed and immediate reinforcement | Type | Journal Article | ||
| Year | 1998 | Publication | Behavioural Processes | Abbreviated Journal | Behav. Process. |
| Volume | 43 | Issue | 1 | Pages | 97-101 |
| Keywords | Acquisition; Delayed reinforcement; Extinction; Rats | ||||
| Abstract | The present study investigated acquisition, extinction, and reacquisition of free-operant responding when rats' lever presses produced water after a resetting delay of 0, 10, 20, or 30 s. Results indicated that: (1) responding was acquired rapidly at all delays without shaping or autoshaping; (2) resistance to extinction was directly related to delay length and inversely related to intermittency of reinforcement; (3) responding acquired with delayed reinforcement recovered less rapidly from extinction, and was less efficient, than responding acquired with immediate reinforcement. Comparing these results with those of studies using discrete-trials and free-operant procedures with no reinforcement delay suggest that the specific conditions under which behavior is maintained determines, in part, the behavioral effects of delay and intermittency of reinforcement. | ||||
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| Call Number | Equine Behaviour @ team @ | Serial | 3601 | ||
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| Author | Flannigan, G.; Stookey, J.M. | ||||
| Title | Day-time time budgets of pregnant mares housed in tie stalls: a comparison of draft versus light mares | Type | Journal Article | ||
| Year | 2002 | Publication | Applied Animal Behaviour Science | Abbreviated Journal | Appl. Anim. Behav. Sci. |
| Volume | 78 | Issue | 2-4 | Pages | 125-143 |
| Keywords | Horse; Time budget; Stereotypies; Housing | ||||
| Abstract | Day-time (08.30-05.30 h) time budgets were generated from 55 light and 55 draft late pregnancy mares housed in tie stalls from ten pregnant mares' urine (PMU) farms using continuous video recording. Equal numbers of light and draft mares were filmed on each farm during the months of February and early March. The actions recorded included eating, drinking, resting (standing and recumbent), standing active, and interactions between horses (aggressive and non-aggressive). In addition, the presence and duration of stereotypic behaviours such as cribbing, head bobbing, weaving, and wood/bar chewing were recorded. Light mares spent significantly more time feeding and significantly less time standing active and standing resting (P<0.05, Rank Sum Two Sample Test). However, the time budget of both groups fell within the range of previously published activity budgets of feral horses. Therefore, the differences noted may not be clinically relevant. Three light and two draft mares performed repetitive behaviours at a level that is considered stereotypic (at >5% of their daily time budget). There was no significant difference in the number of horses performing stereotypies between light and draft mares. When the time budgets of both light and draft mares who performed stereotypies were pooled, the activities did not differ significantly from their counterparts who did not perform stereotypies. Because of the overall low prevalence of stereotypies and the fact that time budgets were similar to free-range horses, we believe that the management practice of keeping large numbers of pregnant mares in tie stalls is rational and that the welfare of mares is sound. Furthermore, we did not see a behavioural justification for a bias in the weight class of horses used within this management system. | ||||
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| Call Number | Equine Behaviour @ team @ | Serial | 3637 | ||
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| Author | Davies Morel, M.C.G.; Newcombe, J.R.; Holland, S.J. | ||||
| Title | Factors affecting gestation length in the Thoroughbred mare | Type | Journal Article | ||
| Year | 2002 | Publication | Animal Reproduction Science | Abbreviated Journal | |
| Volume | 74 | Issue | 3-4 | Pages | 175-185 |
| Keywords | Gestation length; Mare age; Foals; Month of year; Ovulation-mating interval | ||||
| Abstract | In order to assist in the accurate prediction of the timing of parturition in the mare true gestation length, along with the potential effect of a number of factors, was investigated. Data from 433 Thoroughbred foal pregnancies were used. Sequential ultrasonic scanning allowed the true gestation length (fertilisation-parturition) to be ascertained, as apposed to previous work, which used the mating-parturition interval. An average gestation length of 344.1+/-0.49 days was evident. Colt foal pregnancies were significantly (P<0.001) longer (346.2+/-0.72) than fillies (342.4+/-0.65). Month of birth had a significant effect on gestation length in all foals (P<0.001). With foals born in January having the shortest gestation lengths and those born in April the longest. Mare age, year of birth, stallion age, stud farm and the interval between ovulation and mating had no significant effect. It is concluded that (i) the gestation length range (315-388 days), all resulting in viable foals is noteworthy and of clinical importance when considering the classification of dysmaturity in foals, (ii) mares carrying colt foals due to be born in the middle of the breeding season (April) are likely to have the longer gestation lengths. | ||||
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| Call Number | Equine Behaviour @ team @ | Serial | 3638 | ||
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| Author | Geisbauer, G.; Griebel, U.; Schmid, A.; Timney, B | ||||
| Title | Brightness discrimination and neutral point | Type | Journal Article | ||
| Year | 2004 | Publication | Canadian Journal of Zoology | Abbreviated Journal | Can. J. Zool |
| Volume | 82 | Issue | 4 | Pages | 660-670 |
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| Abstract | Abstract: Equine brightness discrimination ability and color discrimination were measured using a two-choice discrimination task. Two Haflinger horses (Equus caballus L., 1758) were trained to discriminate 30 different shades of grey varying from low to high relative brightness. Their ability to distinguish shades of grey was poor, with calculated Weber fractions of 0.42 and 0.45. In addition, a “neutral point” test to determine the dimensionality of color vision was carried out. Three hues of blue-green were tested versus a range of grey targets with brightnesses similar to those of the blue-green targets. A neutral point was found at about 480 nm. Thus, we can conclude that horses possess dichromatic color vision. |
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| Call Number | Equine Behaviour @ team @ | Serial | 3649 | ||
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