title: Effect of simulated ambient particulate matter exposure on performance, rectal temperature, and leukocytosis of young Spanish goats with or without tilmicosin phosphate.
abstract: Dust is an environmental stressor and can become extensive in agricultural production systems. Thirty-six female, Spanish goats (average BW 21.1 kg, SEM = 1.31; age = 4 mo) were randomly assigned to simulated dust events or no dust, with or without tilmicosin phosphate treatment in a 2 x 2 factorial arrangement of treatments to determine effects on performance, rectal temperature, and leukocyte changes. All goats were fed a standard growing diet (13.6% CP) consisting of 37% roughage and 63% concentrate (DM basis). Feed intake was measured daily, and BW (unshrunk) measured individually every 7 d. The tilmicosin-treated group received tilmicosin phosphate (10 mg/kg BW s.c.) before starting the study. Goats exposed to dust were enclosed as a group inside a canvass tent for 4 h each day and ground feed yard manure dust (mean particle size 100 microm) was aerosolized inside the tent to simulate a dust event. There was one single dust event (Phase I) followed by rectal temperature measurement, and heparinized blood collection for complete cell counts at 0 (pretrial), 4, 12, 20, 44, 68, and 210 h after dust exposure. This was followed by 21 d of chronic dust events (Phase II). The sampling procedures for Phase II were exactly the same as in Phase I, except that samples were obtained daily at 0 (before dust application), 4, 8, and 12 h after each dust event. Dust treatment had no effect (P > 0.05) on feed intake or ADG, but the gain:feed (G:F) ratio was lower (P < 0.05) in the control goats than the dust exposed group. Tilmicosin phosphate-treated goats had a higher (P < 0.05) G:F ratio than untreated goats. Dust exposure increased (P < 0.002), but tilmicosin treatment decreased (P < 0.05) rectal temperature at 4 and 8 h. Dust exposure increased (P < 0.02) blood lymphocyte counts compared with controls. These results suggest that simulated dust events altered rectal temperature and leukocyte counts of goats.
authors.affiliation: Texas Agricultural Experiment Station, Amarillo 79106, USA. nabateng@juno.com
authors.forename: N K
authors.initials: NK
authors.lastname: Chirase
authors.forename: C W
authors.initials: CW
authors.lastname: Purdy
authors.forename: J M
authors.initials: JM
authors.lastname: Avampato
mesh_terms: D000818:Animals; D001831:Body Temperature / Q000502:physiology*; D004391:Dust / Q000276:immunology*; D005260:Female; D015511:Goat Diseases / Q000276:immunology* / Q000517:prevention & control; D006041:Goats / Q000254:growth & development*; D007958:Leukocyte Count / Q000662:veterinary; D007964:Leukocytosis / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D018942:Macrolides / Q000008:administration & dosage*; D010316:Particle Size; D011897:Random Allocation; D013997:Time Factors; D015645:Tylosin / Q000008:administration & dosage* / Q000031:analogs & derivatives*
chemical_list: D004391:Dust; D018942:Macrolides; C052319:tilmicosin; D015645:Tylosin