Post-weaning social isolation can induce profound and long lasting effects on an animal's behaviour. The present study investigated the influence of post-weaning housing conditions on the sensitivity of rats to the behavioural effects of d-amphetamine and cocaine. The locomotor stimulant effects of both drugs were compared following acute and chronic administration. The influence of post-weaning housing conditions on the effects of d-amphetamine and cocaine on responding for food and for a conditioned reinforcer were also examined. Isolated rats showed enhanced locomotor activity on exposure to a novel environment. This difference was further exaggerated following administration of d-amphetamine (0.5 mg/kg) and cocaine (5 mg/kg). Isolated, but not enriched, rats exhibited sensitisation to the locomotor activating effects of repeated administration of a dose of 0.5 mg/kg d-amphetamine, whilst both groups sensitised equally to a dose of 1.0 mg/kg d-amphetamine. Rearing conditions did not affect sensitisation to cocaine (5, 10 mg/kg). Isolated rats exhibited a higher rate of responding for a conditioned stimulus and for food on a progressive ratio schedule of reinforcement, both of which were enhanced to a greater extent in isolates following administration of cocaine (5 mg/kg) and d-amphetamine (0.5 mg/kg). These results suggest that isolation rearing induces an enhancement in sensitivity to both the locomotor stimulant and reinforcing properties of amphetamine and cocaine.
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http://dx.doi.org/10.1007/s002130050261 | DOI Listing |
PLoS One
January 2025
Department of Animal Sciences, Washington State University, Pullman, Washington, United States of America.
The improved growth performance of calves at weaning results from an effective pre-weaning feeding strategy. The type and pasteurization process of liquid feed are among the most variable feeding practices affecting calves' growth and health. In previous studies that compared waste milk (WM) vs.
View Article and Find Full Text PDFJ Anim Sci
December 2024
Teagasc, Pig Development Department, Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork P61 C996, Ireland.
The objective was to evaluate the effect of providing dry pelleted starter diet (DPS) or a liquid mixture of milk replacer and starter diet (LMR+S) to suckling pigs housed in farrowing pens of sub-standard or optimal hygiene conditions on pig growth to slaughter, and post-weaning (PW) intestinal parameters. On day (d) 107 of gestation, 87 sows were randomly allocated to one of four treatments in a 2×2 factorial arrangement. The factors were creep feeding (DPS or LMR+S) and pre-farrowing hygiene routine (SUB-STANDARD or OPTIMAL).
View Article and Find Full Text PDFJ Dairy Sci
December 2024
Science and Technology Park, Ferdowsi University of Mashhad, Mashhad 9177948974, Iran; Department of Animal Science, Agricultural and Natural Resources Research and Education Center of Razavi Khorasan, Mashhad 91735-488, Iran. Electronic address:
Micronization, a dry-heat process, generates infrared electromagnetic short waves that can affect starch granules and gelatinization. A new method of corn processing, super-conditioned corn, a moisture-heat process, has potential to increase starch digestion and performance in calves. Therefore, incorporating super-conditioned or micronized corn in starter feed may enhance growth performance by improving total-tract starch digestion.
View Article and Find Full Text PDFJ Appl Anim Welf Sci
November 2024
Livestock Production and Management Section, ICAR-Indian Veterinary Research Institute, Bareilly, India.
This study assessed the effect of a thermo-insulated kid barrel (KB) on the behavioral, physiological, and morphometric growth performance of winter-born Black Bengal goat kids. Two groups were studied: one group was housed in a goat shed without a thermo-insulated kid barrel (control group), while the other group was housed in a shed with a thermo-insulated kid barrel (kid barrel group). Each group consisted of six kids along with their mothers.
View Article and Find Full Text PDFPorcine Health Manag
November 2024
Department Population Health Sciences, Veterinary Medicine, Farm Animal Health, Utrecht University, Yalelaan 7, 3584 CL, Utrecht, The Netherlands.
Background: Post-weaning diarrhea (PWD) is a frequently occurring health and welfare issue in weaned piglets. Behavioral changes indicating impaired health may be detectable before the onset of signs and could be useful to detect the development of PWD early, enabling targeted and timely interventions. Current algorithms enable automated behavioral classification on the group level, while PWD may not affect all piglets in one pen and individual level analysis may be required.
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