The Veterinary Record, July 14, 2007 T graeca T horsfieldii Increase in Increase in Month Carapace Carapace Carapace Carapace of study Weight (g) length (mm) width (mm) Weight (g) length (mm) width (mm) 1 4·5 2·7 2·9 2·8 2·4 2·0 2 2·8 2·3 3·3 3·7 3·0 3·9 3 11·0 a 5·7 c 5·5 5·2 b 3·0 d 3·2 4 9·9 a 4·6 c 4·5 3·1 b 2·2 d 3·0 5 21·2 a 9·7 c 3·5 0·2 b 1·2 d 0·7 6 10·9 a 4·2 c 4·1 0·4 b 0·2 d 0·3 a, b Different superscripts within a row indicate a significant difference (P<0·05) c, d Different superscripts within a row indicate a significant difference (P<0·05) TABLE 1: Mean growth performance in Testudo graeca and Testudo horsfieldii over the six months of the study Month of study T graeca T horsfieldii 1 60·79 46·93 2 19·98 27·52 3 11·67 20·30 4 16·89 29·13 5 12·11 42·58 TABLE 2: Mean feed conversion ratios of Testudo graeca and Testudo horsfieldii over five months of the study Performance, bacterial shedding and microbial drug resistance in two tortoise species E. K. Barbour, N. A. Chacra, H. Gali-Mouhtaseb, L. Jaber, P. Nehme, H. Shaib, R. Sadek, N. Usayran Testudo graeca, commonly known as the Mediterranean spur-thighed tortoise, and Testudo horsfieldii, known as the Horsfield or Steppe tortoise (Ernst and Barbour 1989), are both facing extinction (Behler 1997, Barzyk 1999, Altherr and Freyer 2000, IUCN Communications Unit 2001). The study of growth performance, bacterial shedding and microbial drug resistance during the first six months of a tortoise’s second year of life, a critical period preceding their release from breeding farms to their natural habitats, is of paramount importance for present and future programmes targeting the conservation of threatened tortoise species. Any deviation from the established baseline could indicate the presence of a disease or mismanagement affecting growth or the enteric system, resulting in a different bacterial shedding pattern, or the introduction of new drug-resistant pathogens to the tor- toises’ environment. The bacterial flora in the enteric system of animals and human beings is needed to protect against potential patho- gens such as Salmonella species; this protection is achieved by a natural competitive exclusion mechanism (Mead and Barrow 1990, Barbour and others 1999). Potential patho- gens such as Salmonella species and Pseudomonas aeruginosa could carry R-plasmids (McCombie and others 1983) that are responsible for drug resistance (Bremner 1979, Shahid and others 2003). This short communication describes a study to determine the growth performance, cloacal bacte- rial shedding and antimicrobial drug resistance of potential pathogens in the first six months of the second year of life of T graeca and T horsfieldii. Nine T graeca, native to the eastern Mediterranean countries and nine T horsfieldii, alien to this region, all of one year of age, were selected from a local breeding farm located at 33·5°N, 35·5E at sea level. Tortoises of each species were placed in separate rooms (7·5 m 2 ), with the tempera- ture and humidity monitored daily. The respective average temperature and relative humidity were 17°C and 64 per cent for the winter months (December to February), and 22·5°C and 75 per cent for the spring months (March to April). The light hours and temperature in the rooms were controlled, through the installation of automatically timed neon lamps, providing 13 hours of light in a day (05.00 to 18.00) throughout the experimental period, and infrared heat lamps that were kept on 24 hours a day throughout the winter months. The tortoises were fed daily during the first two months of the study; the frequency of feeding was decreased to three times a week later on. The initial amount of feed offered (100 g per tortoise per group) was doubled after two months, and quadrupled after four months. The feed comprised pars- ley (53·1 per cent), lettuce (21·2 per cent), cabbage (21·2 per cent), multivitamin and mineral complex (0·2 per cent), and calcium (4·2 per cent); the multivitamin and mineral complex and calcium were of the type usually used in layer chicken diets (National Research Council 1984). The feed intake of each species was calculated, and the monthly feed conversion was calculated by recording the Veterinary Record (2007) 161, 62-65 E. K. Barbour, MSc, PhD, N. A. Chacra, BSc, MSc, L. Jaber, BSc, MSc, P. Nehme, BSc, MSc, H. Shaib, BSc, MSc, Department of Animal Science, Faculty of Agricultural and Food Sciences, H. Gali-Mouhtaseb, MSc, PhD, R. Sadek, MSc, PhD, Department of Biology, Faculty of Arts and Sciences, American University of Beirut, PO Box 11-0236, Lebanon N. Usayran, MSc, PhD, Department of Animal Production, Faculty of Agricultural Sciences, Lebanese University, Sin El Fil, Lebanon amount of feed consumed each month by all the individu- als of each species divided by the total weight gain. Weekly measurements of each animal’s weight, carapace width and length were recorded. Individual cloacal samples were collected from all the tortoises using sterile, flame-sealed capillary tubes. The bacteria on each capillary were reconstituted into 200 μl of sterile saline. Serial dilutions of the suspended bacteria were spread on to plates for a total bacterial count (nutri- ent agar), counts for lactose-fermenters and non-lactose- fermenters (MacConkey’s agar), and for a count of suspected Salmonella species (brilliant green agar). In addition, part of the bacterial suspension was enriched selectively on selenite broth (1:10 v/v) for Salmonella species isolation. The agar cultures were kept at 37°C, and counts were recorded after incubation for 48 hours. The inoculated selenite broth was incubated at 37°C for 24 hours, then a subculture was made on to brilliant green agar. Salmonella and P aeruginosa sus- pect colonies were subjected to biochemical characterisation (American Association of Avian Pathologists [AAAP] 1998). The drug resistance of any Salmonella species and P aerugi- nosa isolates was tested using the Kirby-Bauer method (Bauer and others 1966). Analysis of variance of weight increments, carapace width and length increments and counts of different bacteria shed was performed using MSTAT software. Means were separated by Duncan’s multiple range test (P=0·05). The average weight increments of the T graeca group were significantly higher (P<0·05) than those of the T hors- fieldii group in four of the six months of the study (Table 1). The average monthly increments in carapace width from December to May were significantly higher (P<0·05) in T graeca than in T horsfieldii (3·954 mm v 2·185 mm). In addition, the average monthly increments in carapace length were significantly higher in T graeca during the third, fourth, fifth and sixth months of the study. On the other hand, there were no significant difference in the average feed conversion between the two species in the first five months (Table 2). However, a feed conversion observation was missed in the last month of the study. The average biweekly counts of total cloacal aerobic bac- teria were not significantly different between the two species after incubation for 48 hours (Table 3). The cumulative aver- Short Communications group.bmj.com on March 21, 2013 - Published by veterinaryrecord.bmj.com Downloaded from