title: Effect of rotational vs continuous intensive stocking of bahiagrass on performance of Angus cows and calves and interaction with sire type on gastrointestinal nematode burden.
abstract: Performance of Angus cows and calves was compared between two methods of bahiagrass (Paspalum notatum Flügge) grazing management, rotational stocking (ROT) and continuous intensive stocking (CIS), where stocking rate was varied by adjusting available pasture area as forage growth rate changed during the growing season. Effects of sire type (low [LO] vs high [HI] EPD for nematode egg shedding rate [EPG]) also were studied. Data were analyzed for two complete cycles of calf production from breeding through weaning. There was no effect of pasture grazing management method on cow BW, cow body condition score, adjusted 205-d calf weaning weight, and preweaning calf ADG. Five genera of nematodes (Ostertagia, Haemonchus, Trichostrongylus, Cooperia, and Oesophagostomum) were recovered from calves removed and killed at times throughout the grazing season. Mean nematode numbers recovered increased (P < .05) for all species as the grazing season progressed from spring to fall, consistent with results on EPG (P < .001). Effect of sire type on EPG was not significant; however, sire type did affect mean EPG (P < .05) from a subset of calves placed in drylot after weaning and sampled for three consecutive days. Sire type affected IgG1 titer to H. placei (LO = .50 +/- .012, HI = .45 +/- .011) and IgA titer to O. radiatum (LO = .28 +/- .006, HI = .26 +/- .005), and there was a sire type x pasture grazing method interaction on IgG1 titer to H. placei (LO-ROT = .49 +/- .016, HI-ROT = .49 +/- .017, LO-CIS = .50 +/- .017, HI-CIS = .41 +/- .014). Increased anti-parasite antibody titers in progeny of sires with EPD for low nematode egg shedding rates may reflect increased host resistance to these parasites.
authors.affiliation: Subtropical Agricultural Research Station, ARS, USDA, Brooksville, FL 34601, USA.
authors.forename: A C
authors.initials: AC
authors.lastname: Hammond
authors.forename: M J
authors.initials: MJ
authors.lastname: Williams
authors.forename: T A
authors.initials: TA
authors.lastname: Olson
authors.forename: L C
authors.initials: LC
authors.lastname: Gasbarre
authors.forename: E A
authors.initials: EA
authors.lastname: Leighton
authors.forename: M A
authors.initials: MA
authors.lastname: Menchaca
mesh_terms: D000704:Analysis of Variance; D000821:Animal Feed / Q000592:standards*; D000822:Animal Husbandry / Q000379:methods; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood / Q000276:immunology; D001823:Body Composition / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D001947:Breeding; D002417:Cattle; D002418:Cattle Diseases / Q000235:genetics / Q000276:immunology / Q000635:transmission*; D004064:Digestive System / Q000469:parasitology*; D004435:Eating / Q000502:physiology*; D005260:Female; D006189:Haemonchus / Q000254:growth & development / Q000276:immunology / Q000302:isolation & purification; D008297:Male; D009348:Nematoda / Q000254:growth & development / Q000276:immunology / Q000302:isolation & purification; D009349:Nematode Infections / Q000235:genetics / Q000635:transmission / Q000662:veterinary*; D009815:Oesophagostomum / Q000254:growth & development / Q000276:immunology / Q000302:isolation & purification; D010028:Ostertagia / Q000254:growth & development / Q000276:immunology / Q000302:isolation & purification; D010270:Parasite Egg Count / Q000662:veterinary; D006109:Poaceae; D011897:Random Allocation; D012621:Seasons; D014254:Trichostrongylus / Q000254:growth & development / Q000276:immunology / Q000302:isolation & purification
chemical_list: D000909:Antibodies, Helminth