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Francis-Smith, K., & Wood-Gush, D. G. M. (1977). Copropgagia as seen in thoroughbred foals. Equine Vet J, 9(3), 155–157.
Abstract: Four Thoroughbred foals were seen to quickly eat part of the faeces deposited by their own dams on some 40 per cent of the mare-defaecating occasions observed between the second and fifth week after birth. They did not do it before or after this period. This behaviour was thought to be a feeding pattern which formed a normal part of the foal's development.
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Green Nf, G. H. (1977). The wild horse population.... Proc National Wild Horse Forum, 1, 59–65.
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Parker, G. A., & MacNair, M. R. (1978). Models of parent-offspring conflict. I. Monogamy. Anim. Behav., 26, 97–110.
Abstract: Theoretical models for Trivers (1974) concept of parent-offspring conflict are examined for species in which the effects of the conflict are felt by full sibs. A rare conflictor gene will spread if Image , whereÆ’(m) is the fitness gained by a conflictor relative to a non-conflictor offspring (Æ’(m) >1), and m is the amount of parental investment taken by a conflictor relative to m = 1 for a non-conflictor. The range of m alleles which can spread against the parent optimum decreases as the cost to the parent increases until a point is reached where there is no conflict of evolutionary interests. There would be no polymorphism for conflictor: non-conflictor alleles unless special conditions prevail. The conflictor allele which spreads most rapidly as a rare mutant against the parental optimum is not an evolutionarily stable strategy (ESS). The ESS for parent-offspring conflict in monogamous species has m0 = Æ’(m0)/2[dÆ’(m0)/dm0]. The analytical solutions are confirmed throughout by simulations.
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Nallan, G. B., Pace, G. M., McCoy, D. F., & Zentall, T. R. (1979). Temporal parameters of the feature positive effect. Am J Psychol, 92(4), 703–710.
Abstract: Trial duration and intertrial interval duration were parametrically varied between groups of pigeons exposed to a discrimination involving the presence vs. the absence of a dot. Half the groups received the dot as the positive stimulus (feature positive groups) and half the groups received the dot as the negative stimulus (feature negative groups). Faster learning by the feature positive birds (feature positive effect) was found when the trial duration was short (5 sec) regardless of whether the intertrial interval was short (5 sec) or long (30 sec). No evidence for a feature positive effect was found when the trial duration was long (30 sec) regardless of the length of the intertrial interval (30 sec or 180 sec). The results suggest that short trial duration is a necessary condition for the occurrence of the feature positive effect, and neither intertrial interval nor trial duration/intertrial interval ratio are important for its occurrence. The suggestion that mechanisms underlying the feature positive effect and autoshaping might be similar was not supported by the present experiment since the trial duration/intertrial interval ration parameter appears to play an important role in autoshaping but not the feature positive effect.
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Wells Sm, G. - R. (1979). Social behaviour and relationship in a herd of Carmargue horses. Z. Tierpsychol., 49, 363–380.
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Czerlinski, G. H., Erickson, J. O., & Theorell, H. (1979). Chemical relaxation studies on the horse liver alcohol dehydrogenase system. Physiol Chem Phys, 11(6), 537–569.
Abstract: Chemical relaxation studies on the system horse liver alcohol dehydrogenase, nicotinamide adenine dinucleotide, and ethanol were conducted observing fluorescence changes between 400 and 500 nm. Temperature-jump experiments were performed at pH 6.5, 7.0, 8.0, and 9.0; concentration-jump experiments at pH 9.0. The reciprocal of the slowest relaxation time was found to be linearly dependent upon the enzyme concentration for relatively low enzyme concentrations, as predicted earlier. Use of the wide pH-range necessitated expression of the four apparent dissociation constants of the catalytic reaction cycle in terms of pH-independent constants. The system was described in terms of only one (or two) catalysis-linked protons not associated with the electron transfer. Protonic steps in a buffered system are in rapid equilibrium, too fast to be measured with the equipment available. Assuming only two of the four bimolecular reaction steps in the four-step cycle are fast compared to the remaining two, six cases may be considered with six expressions for the reciprocal of the slowest relaxation time. Comparison with the experimental data revealed that the bimolecular reaction steps governing the slowest relaxation time change with pH. Above the effective time resolution of the temperature-lump instrument with fluorescence detection (0.1 msec) only one other relaxation time was detectable and only at pH 9. This relaxation time, found to be independent of the concentration of all reactants within experimental error (r = 10 +/- 5 msec), is most likely due to an interconversion among ternary complexes.
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Fiske, J. C., & Potter, G. D. (1979). Discrimination reversal learning in yearling horses. J. Anim. Sci., 49(2), 583–588.
Abstract: Twenty-six yearling horses were tested on a serial reversal learning discrimination combining spatial and brightness cues. An original discrimination of rewarded or nonrewarded stimuli was made followed by 20 daily reversals for position/brightness discrimination. Learning criteria were defined as 11 out of 12 correct, with the last eight responses all correct. Each horse was allowed 30 trials per discrimination to achieve criteria. Mean errors (ME) and mean trials (MT) required to achieve criteria were computed for each horse. A relative learning ability index (LAI) was calculated by the formula 1000/MT/ME. A daily emotionality score, based on a scale of one (tranquil) to six (very excitable) was assigned each horse each day after testing and a mean computed for each horse. A single subjective trainability score, based on a scale of one (difficult to train) to six (easy to train) was obtained for each horse from an independent trainer. Linear regression analyses for all 26 horses revealed a reduction in MT and ME (P<.01) over the 21-day test period indicating evidence of learning to learn. Differences (P<.05) were evident between sexes for MT and ME. Significant correlations between trainability scores and learning ability indices MT, ME, and LAI were evident for colts and geldings but not for fillies. Pooled data showed significant correlations between ME and trainability. There was a negative correlation (P<.05) between emotionality and trainability scores for all 26 horses, although the filly group did not exhibit significant correlation between these parameters.
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Rappolt, G. A., John, J., & Thompson, N. S. (1979). Canine responses to familiar and unfamiliar humans. Aggressive Behavior, 5(2), 155–161.
Abstract: Dogs were observed during controlled approaches by their owners and by strangers. Significant differences between the dogs' responses to their owners and their responses to strangers were found. These results supported the popular belief that dogs respond differently to different persons, and not merely to different situations in which persons are usually encountered.
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Jeffcott, L. B., & Dalin, G. (1980). Natural rigaidity of the horse's backbone. Equine Vet J, 12(3), 101–108.
Abstract: The functional anatomy of the thoracolumbar (TL) spine is considered in relation to the horse's ability to perform at speed and to jump. The morphological features quite clearly show the relative inflexibility of the equine back and this was confirmed by some experimental studies. Fresh post mortem specimens from 5 Thoroughbreds were used to estimate the limits of dorsoventral movement of the TL spine from mid-thoracic to the cranial lumbar (T10-L2). The individual spinous processes could be moved a mean 1.1-6.0 mm on maximum ventroflexion and 0.8-3.8 mm on dorsiflexion. The overall flexibility of the back was found to be 53.1 mm. Caudal to the mid-point of the back (T13) there was virtually no lateral or rotatory movement of the spine possible. The pathogenesis of some of the common causes of back trouble are discussed including the so-called vertebral subluxation and its treatment by chiropractic manipulation. From an anatomical viewpoint, this condition appears to be a misnomer and may simply be attributable to muscular imbalance leading to aspastic scoliosis.
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Harvey, P. H., Clutton-Brock, T. H., & Mace, G. M. (1980). Brain size and ecology in small mammals and primates. PNAS, 77(7), 4387–4389.
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