Monitoring distances travelled by horses using GPS tracking collars

Objective The aims of this work were to (1) develop a low-cost equine movement tracking collar based on readily available components, (2) conduct preliminary studies assessing the effects of both paddock size and internal fence design on the movements of domestic horses, with and without foals at foot, and (3) describe distances moved by mares and their foals. Additional monitoring of free-ranging feral horses was conducted to allow preliminary comparisons with the movement of confined domestic horses. Procedures A lightweight global positioning system (GPS) data logger modified from a personal/vehicle tracker and mounted on a collar was used to monitor the movement of domestic horses in a range of paddock sizes and internal fence designs for 6.5-day periods. Results In the paddocks used (0.8–16 ha), groups of domestic horses exhibited a logarithmic response in mean daily distance travelled as a function of increasing paddock size, tending asymptotically towards approximately 7.5 km/day. The distance moved by newborn foals was similar to their dams, with total distance travelled also dependent on paddock size. Without altering available paddock area, paddock design, with the exception of a spiral design, did not significantly affect mean daily distance travelled. Feral horses (17.9 km/day) travelled substantially greater mean daily distances than domestic horses (7.2 km/day in 16-ha paddock), even when allowing for larger paddock size. Conclusions Horses kept in stables or small yards and paddocks are quite sedentary in comparison with their feral relatives. For a given paddock area, most designs did not significantly affect mean daily distance travelled.     

Effect of active immunization against growth hormone-releasing factor on growth and onset of puberty in beef heifers.

Angus and Charolais heifers (195 +/- 7 kg) were actively immunized against growth hormone-releasing factor (GRF) to evaluate the effect on concentrations of somatotropin (ST), insulin-like growth factor I (IGF-I), insulin (INS), growth, and onset of puberty. Primary immunizations were given at 184 +/- 7 d of age (d 0 of experiment) by injecting (s.c.) 1.5 mg of GRF-(1-29)-Gly-Gly-Cys-NH2 conjugated to 1.5 mg of human serum albumin (GRFi, n = 22) or 1.5 mg of human serum albumin (HSAi, n = 21). Booster immunizations of .5 mg of antigen were given on d 62, 92, 153, and 251. Antibody binding (percentage at 1:2,000 dilution) to [125I]GRF on d 69 was greater (P less than .01) in GRFi (53.7 +/- 4.5) than in HSAi (10.1 +/- .6) heifers. Serum concentration (ng/ml) and frequency (peaks/5 h) of ST release, respectively, on d 78 were lower (P less than .01) in GRFi than in HSAi heifers (3.3 +/- .1 vs 5.6 +/- .2 and .9 +/- .3 vs 2.3 +/- .2). Serum IGF-I (ng/ml) was lower (P less than .01) in GRFi than in HSAi heifers on d 69 (41 +/- 5 vs 112 +/- 4). Serum INS (microU/ml) on d 78 was lower (P less than .05) in GRFi (2.2 +/- .1) than in HSAi (3.8 +/- .2) heifers. Feed intake, ADG, and feed efficiency were lower (P less than .05) in GRFi than in HSAi heifers. Hip height was lower (P less than .01) and fat thickness was greater (P less than .05) in GRFi than in HSAi heifers by d 132 and 167, respectively. Percentage of heifers attaining puberty (progesterone greater than 1 ng/ml for two consecutive weeks) by d 209 and 379 (12.9 and 18.5 mo of age), respectively, was lower (P less than .05) in GRFi (40.9 and 45.5) than in HSAi (81.0 and 100). In conclusion, growing heifers were successively immunized against GRF. Active immunization against GRF resulted in decreased serum concentration of ST, IGF-I, and INS. In addition, GRF immunization led to lowered feed intake, ADG, and feed efficiency, increased fat depth, and delayed onset of puberty in heifers. We propose that ST and IGF-I are important metabolic mediators involved in the initiation of puberty in heifers.     

Endocrine changes in the fowl during infection with Eimeria maxima

Plasma concentrations of thyroxine (T4), triiodothyronine (T3), prolactin, growth hormone and corticosterone were measured in immature domestic fowl which were infected with Eimeria maxima, uninfected but given the same amount of food as those infected (pair-fed) or fed ad libitum. Infection with E maxima caused a decrease in plasma T4 concentration whereas pair feeding caused an increase when food intake was minimal. Plasma T3 concentrations were decreased similarly in both infected and pair-fed birds. Infection caused an increase in plasma prolactin concentration, whereas pair-feeding did not. The plasma concentration of growth hormone was not affected by any of the treatments. Plasma corticosterone concentration was markedly increased on days 5 and 6 in pair-fed birds but was not affected by infection with E maxima.     

Use of PCR-based methodologies for the determination of DNA diversity between Saccharum varieties

Summary In this study, two PCR-based methodologies were evaluated for potential use in the determination of DNA diversity between 20 commercial sugarcane hybrids and 6 outgroup varieties of S. spontaneum, S. officinarum and hybrids from early in the genealogy. The first method involved PCR amplification of sugarcane DNA in the presence of random, decamer primers (RAPDs), while the second protocol utilized specific microsatellite and telomere sequences as primers. A total of 41 RAPD primers (356 loci) were screened across the varieties of which 15 (160 loci) were used in the calculation of DNA diversity (expressed% similarity). This varied from 61 to 95%, with most of the commercial varieties showing more than 80% similarity in their DNA. The RAPD data indicated that there had been a gradual decline in DNA diversity (84% reduction) from the early inter-specific crosses to the commercial hybrids, probably as a result of backcrossing and in-breeding strategies used in the previous 5 to 6 generations of sugarcane breeding. The microsatellite and telomere data produced a much greater range in DNA similarity values (25–91%), probably due to the fact that these primers detect highly variable regions of the genome. It is suggested that these specific primers would not be suitable for determination of DNA diversity, but could be used more effectively in the development of a methodology for routine, rapid identification of sugarcane varieties.     

Challenging the developmental state: Nature conservation in Singapore

Abstract: Nature conservation efforts are often reactive to encroaching development plans and systematic conservation planning that is integral with development is not only uncommon, but is often fraught with difficulties even where it is actually attempted. Such obstacles to conservation are especially apparent in developmental states where state legitimacy is largely derived from the state's ability to develop the country. Among other things, developmental states place a premium on physical and economic development. This paper critiques, through the standpoint of nature conservation, the inadequate conceptualisation of ‘development’ in the developmental state thesis. Specifically, this paper argues that the seemingly value‐free (but ultimately economically based) underpinnings of development goals pushed by the developmental state needs to be tempered with a broader concern for the ethics of development. To that end, I draw on two case studies of nature conservation tussles in Singapore to show how alternative extra‐economic visions of development have been articulated, notwithstanding the developmental state's monopoly on the discourse (and practice) of progress and development. The case studies, set in the heady economic growth of the early 1990s, will critique two related aspects of the developmental state: its ‘amoral’ economistic conception of development and its use of growth and materialism as legitimacy.     

Geographical ‘handicaps’ and small states: Some implications for the Pacific from a global perspective

Abstract: Research on the economic performance of small states has concentrated on the implications of small size and thin local markets. An interesting feature of many of the world's smallest states, of which the Pacific region has many, is that they face additional challenges than just small size. Many are remote from global markets for their products. In addition, a large number are also islands, many of which are also mountainous. Many of the smaller states are not just islands, but are also archipelagos. Hence in addition to small size, many of the world's small states also exhibit four other characteristics that may affect their economic performance: insularity, remoteness, being archipelagos and being highly mountainous entities. This paper examines the nature of the challenges posed by these four characteristics and seeks to produce empirical evidence of how difficult it has been to overcome these challenges. The paper draws on empirical evidence for 126 very small global states, dependent territories and highly autonomous regions. The paper then turns to the position of the Pacific small states and dependent territories.