Tropical pasture hay utilization with slaframine and cottonseed meal: ruminal characteristics and digesta passage in wethers.
Sixteen mature, ruminally cannulated wethers (average BW = 41 +/- 1 kg) were fed a low-quality hay diet with or without a cottonseed meal (CSM) supplement and the parasympathomimetic agonist slaframine (SF). Treatments were basal diet (Mitchell grass hay, 4.8% CP, 46.8% ADF) available on an ad libitum basis, basal diet plus SF (8 micrograms/kg BW, 2 x daily i.m. injection), basal diet plus CSM (41.0% CP; 100 g/d), or basal diet plus SF and CSM. Treatments were arranged as a 2 x 2 factorial within a replicated 4 x 4 Latin square with 20-d periods followed by a 10-d adjustment during which only the basal diet was fed. All measurements were performed within the final 10 d of each period. Slaframine increased salivary flow by 10 to 35% (P < .07), ruminal fluid dilution rate by 8 to 11% (P < .10), and pH by 3 to 4% (P < .001). A twofold increase (P < .05) in ruminal cellulolytic bacteria numbers occurred in SF-treated wethers. Despite these SF-induced changes in the ruminal environment, whole-tract apparent nutrient digestibility, N and mineral balance, and ruminal VFA concentrations were not changed. Cottonseed meal increased forage intake by 34 to 54% (P < .001) and DM digestibility by 30% (P < .001). Cottonseed meal supplementation of a Mitchell grass hay diet improved nutritional status and attenuated live weight loss.
Bird
A R
AR
Sheep and Wool Branch, Queensland Department of Primary Industries, Brisbane, Australia.
Croom
W J
WJ
Bailey
J V
JV
O'Sullivan
B M
BM
Hagler
W M
WM
Gordon
G L
GL
Martin
P R
PR
D000470:Alkaloids / Q000008:administration & dosage / Q000494:pharmacology*; D000641:Ammonia / Q000032:analysis; D000821:Animal Feed; D000818:Animals; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development; D003369:Cottonseed Oil / Q000008:administration & dosage; D004043:Dietary Fiber / Q000378:metabolism; D004063:Digestion / Q000187:drug effects; D004435:Eating; D005232:Fatty Acids, Volatile / Q000032:analysis; D005527:Food, Fortified; D005772:Gastrointestinal Transit / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D007273:Injections, Intramuscular / Q000662:veterinary; D008297:Male; D009183:Mycotoxins / Q000008:administration & dosage / Q000494:pharmacology; D010277:Parasympathomimetics / Q000008:administration & dosage / Q000494:pharmacology*; D006109:Poaceae; D012417:Rumen / Q000737:chemistry / Q000187:drug effects* / Q000382:microbiology; D012472:Salivation / Q000187:drug effects; D012756:Sheep / Q000502:physiology*
D000470:Alkaloids; D003369:Cottonseed Oil; D004043:Dietary Fiber; D005232:Fatty Acids, Volatile; D009183:Mycotoxins; D010277:Parasympathomimetics; C009275:slaframine; D000641:Ammonia