The E¡ects of Breed, Neonatal Age and Pregnancy on the Plasma Copper Status of Goats in Oman N.I.E.D. Osman 1 *, E.H. Johnson 2 , R.M. Al-Busaidi 2 and N.F. Suttle 3 1 Department of Animal Science, College of Agriculture, Al Zaim Al Azhary University, Khartoum North, Sudan; 2 Department of Animal and Veterinary Sciences, College of Agriculture, Sultan Qaboos University, Alkhod, Sultanate of Oman; 3 Honorary Research Fellow, Moredun Research Institute, Penicuik, UK *Correspondence: c/o Dr O.M. Gaafar, Department of Animal Science, College of Agriculture, Sultan Qaboos University, POBox 34, Alkhod 123, Sultanate of Oman Osman, N.I.E.D., Johnson, E.H., Al-Busaidi, R.M. and Suttle, N.F., 2003. The e¡ects of breed, neonatal age and pregnancy on the plasma copper status of goats in Oman. Veterinary Research Communications, 27(3), 219^229 ABSTRACT There is a history of copper de¢ciency in grazing Omani livestock and the copper status of three economically important goat breeds, Jabal Akhdar (JA), Batina (B) and Dhofari (D) were therefore compared in October/November (cool season) and June (dry season) in a penned £ock given a plentiful dietary supply of copper. In the cool season, 62 lactating does (5 JA, 12 B and 33 D), their 0^5-day-old kids (17 JA, 19 B and 22 D) and 25 dry does (17 JA, 5 B and 3 D) were blood sampled. In the dry season, the does sampled were either barren (15 JA, 16 B and 13 D) or pregnant (9 JA, 13 B and 33 D). The samples were analysed for total copper (TCu) and trichloroacetic acid (TCA)-soluble copper (TCA-sol Cu). There were no e¡ects of breed on TCu or TCA-sol Cu in the cool season, the overall means being 0.75 (SE 0.049) and 0.59 (SE 0.052) mg/L. The mean TCu was low in kids at birth (0.59 mg/L) but had increased to 0.86 mg/L by 4 days of age ( p50.001); breed di¡erences were found ( p50.002), the pooled values for JA, B and D being 0.77, 0.59 and 0.68 (SE 0.033^0.044) mg/L, respectively. By the dry season, the mean TCu had risen in barren does to 0.96 (0.045) mg/L but not in pregnant does (0.76 (0.047) mg/L; p50.002) and breed di¡erences had emerged, the mean for D being 20% lower than those for JA and B ( p50.05). The highest TCu values were found in the 7-month-old kids in June (1.17 (0.039) mg/L) but the breeds did not then di¡er. Some e¡ects on TCA solubility were found but were considered unreliable. Breed e¡ects may have been diminished by the generous supply of copper and early stage of lactation studied. Keywords: age, breed, goats, lactation, neonate, plasma copper, pregnancy, season Abbreviations: AAS, atomic absorption spectrometry; AES, Agricultural Experimental Station; B, Batina; D, Dhofari; JA, Jabal Akhdar; TCu, total copper; TCA, trichloroacetic acid; TCA-sol Cu, TCA-soluble copper; TM, thiomolybdates INTRODUCTION Copper de¢ciency in Oman has been associated with shalal (ataxia) in grazing goats (Ivan et al., 1990) and in calves at a research station in Oman (El-Hag, 1990) but its causes have not been elucidated. Total plasma copper concentrations (TCu) are commonly used to assess copper status (Maas and Smith, 1996) but are in£uenced by VeterinaryResearchCommunications,27(2003)219^229 # 2003 Kluwer Academic Publishers. Printed inthe Netherlands 219