Use of feed additives to reduce ruminal methane production and deaminase activity in steers.

Effects of feeding the methane inhibitor, amicloral, and the deaminase inhibitor (DAI), 4,4'-dimethyldiphenyliodonium chloride, at 1,500 and 25 mg/kg of diet, respectively, were investigated in finishing steers. Digestibility and ruminal VFA and ammonia concentrations were measured in six steers per treatment. Organic matter digestibility was increased significantly by amicloral, DAI and amicloral plus DAI. There were no treatment effects on molar proportions of acetic acid or propionic acid, but butyric acid was highest (P < .05) when both additives were fed. Ruminal ammonia concentrations were lower (P < .05) with all three treatment diets. Ninety-six steers were allotted to eight groups, two pens (replicates) per treatment, in a 112-day feedlot study. Neither amicloral nor DAI had any effect on intake or daily gain, although feed efficiency was increased (P > .05) by 9 and 4%, respectively. Feeding amicloral plus DAI lowered intake by 19% (P < .05) and gains by 8% (P > .05) but increased the efficiency of feed utilization by 12% (P < .05).

Composition, preservation, and use of sea clam viscera as a protein supplement for growing pigs.

Use of surf clam viscera as an animal feed was assessed by measuring nutrient content, susceptibility to spoilage, preservation with organic acid, and replacement value for soybean meal when fed to growing pigs. Viscera exiting the processing plant averaged 88% moisture and 71% CP in DM. Amino acid contents (51% in DM) and profiles were similar to those of soybean meal. Storage and feeding quality of wet viscera could be maintained up to 3 wk by adding formic or propionic acid (3.5%, wt/wt). Pigs readily ate corn-based diets containing wet viscera preserved with propionic acid. Growth rate was similar for pigs from 18 kg to market weight (92 kg) when soybean meal and(or) clam viscera were fed as protein supplements. However, cooked loin roasts from pigs fed one-half or all supplemental protein from viscera (5 or 10% viscera in diet DM) had distinctive fishy aromas. To produce acceptable pork, future studies must identify lower dietary levels or withdrawal periods for viscera.

Determination of sulfadimethoxine withdrawal time from milk. Part I: Dosing, sampling, and assay.

This study was undertaken to determine whether present regulations for discarding milk from cows treated with sulfadimethoxine (SDM) can be supported by modern analytical methodology. Two groups of milking cows (10 in first group; 11 in the second) were treated orally with SDM at the recommended dose levels for 5 days. The SDM concentration in the milk was determined with 4 methods (Charm Inhibition Assay [CIA], Charm II, enzyme linked immunosorbent assay, and liquid chromatography) during the treatment and the subsequent withdrawal periods. The results of the 4 assays were compared.

Manipulating energy metabolism in sheep exposed to cold.

The effects of dietary fats level (0 and 7% tallow) and monensin (0 and 33 mg/kg of diet) were investigated in lambs at ambient temperatures of -11.9 and 12.9 C. Twenty-four nonfistulated and 16 fistulated lambs with an average weight of 73 kg and fleece length of 8 cm were randomly assigned to each fat and monensin level (6 nonfistulated and 4 fistulated lambs per treatment) in a 2 x 2 factorial arrangement of diets. There were no main treatment effects on organic matter or crude protein digestibility, though ether extract digestibility was higher on the high-fat diets (P less than 0.001) and at 12.9 C (P less than 0.05). Fat decreased (P less than 0.05) molar proportions of ruminal acetate and increased propionate. Monensin increased (P less than 0.001) propionate and decreased (P less than 0.05) butyrate. Propionate was 26% higher at -11.9 C. Respiration rate tended to be higher on the high-fat diets and was doubled (P less than 0.001) and the warm temperature (12.9 C). There were no main treatment effects on rectal temperature. Heart rate was increased (P less than 0.05) by 12% on the high-fat diets. Cold temperature exposure significantly increased free fatty acids, thyroxine, protein-bound iodine and phosphorus, and decreased plasma urea nitrogen in jugular blood. Free fatty acid and triglyceride concentrations were higher (P less than 0.05) on the high-fat diets. There were no main treatment effects on either glucose or calcium levels. These results show that dietary fat level and monensin did not consistently influence the sensitivity of full-fleeced lambs to the effects of cold-temperature exposure.

Responses of shorn and full-fleeced lambs given two levels of feed intake and exposed to warm and cold temperatures.

Studies on the effect of fleece length (5 and 85 mm) and feed intake (1 and 2 kg/day) were conducted in 9- to 10-month-old wether lambs kept at 2 environmental temperatures (-12.3 and 17.8 C). Digestion coefficients were lower (P less than 0.05) at the high level of intake and in cold-exposed lambs. Rectal temperature was lower (P less than 0.05) in lambs kept at - 12.3 C. Respiration rate increased (P less than 0.05) with increasing environmental temperature and higher feed consumption. Blood glucose and plasma urea nitrogen concentrations were not affected by feed intake level or fleece length. Glucose was higher (P less than 0.05) and plasma was lower (P less than 0.05) in lambs at low temperatures. Serum-free fatty acids were increased (P less than 0.05) in lambs given the low feeding level and kept at the low temperature. Plasma thyroxine and protein-bound iodine concentrations were lower (P less than 0.10) in full-fleeced lambs and were higher (P less than 0.05) at the low temperature.

Lasalocid and monensin in finishing diets for early weaned lambs with naturally occurring coccidiosis.

Early weaned male crossbred lambs (n = 90) with an average weight of 14 kg were used in 6 groups to evaluate the efficacy of monensin (22 mg/g of feed) and lasalocid (12.5, 25, 50, and 100 mg/kg of feed) on naturally occurring coccidiosis. Average 24-hour oocyst output at the start of the experiment ranged from 5.7 x 10(6) to 156.7 x 10(6) for monensin-treated and 100-mg lasalocid-treated groups, respectively. Monensin and lasalocid were effective against Eimeria ninakohlyakimovae of E ahsata. To day 103, body weight gains were similar for the 4 groups fed lasalocid (336 g/day) and averaged 6% higher (P greater than 0.05) than did gains in control and monensin-treated lambs. Feed efficacy averaged 9% higher (P less than 0.05) for lambs fed 25, 50, and 100 mg of lasalocid/kg of feed and 7% higher (P greater than 0.05) for lambs fed monensin and 12.5 mg of lasalocid/kg of feed. There were no treatment effects on digestibility, although lasalocid tended to increase (P greater than 0.05) crude protein digestibility (values were higher on day 76 than on day 28). Lasalocid and monensin were potent manipulators of rumen fermentation. Increasing the amount of lasalocid in the feed was associated with successive increases (P less than 0.05) in molar proportions of propionic acid and decreases (P less than 0.05) in acetic acid. Lasalocid and monensin controlled naturally occurring coccidiosis and improved performance in early weaned lambs (45 days old) under feedlot conditions.

Oocyst discharge, rumen metabolism and performance of early weaned lambs with naturally occurring coccidiosis fed monensin.

Ninety-six 9.5 kg early-weaned lambs with naturally occurring coccidiosis were fed monensin either at 0, 11, 22, or 33 mg/kg of feed for 105 days. Fecal oocyst discharge during the first three days was highest with monensin 22 mg, lowest with monensin 33 mg and averaged 149.6 x 10(3) oocysts per gram feces for all lambs. Monensin at 22 mg/kg of feed reduced Eimeria ninakohlyakimovae and E. ahsata oocyst discharge. Organic matter and crude protein digestibilities were highest (P

Haematological changes caused by Trichostrongylus colubriformis in lambs fed a dystrophogenic diet.

The effect of Trichostrongylus colubriformis on lambs maintained on a ration containing a low level of selenium and on animals receiving vitamin E and Se supplementation was investigated. The pathological changes seen in control animals slaughtered at the start of the experiment and in the animals which died during the course of the investigation revealed a high level of nutritional muscular dystrophy (NMD) in the lambs. There were no marked haematological changes in the control or infested sheep. Infestation was characterized by slight hypoalbuminaemia and gamma-globulinaemia. Serum levels of the enzymes AAT and CPK, which are important indicators of muscle necrosis and NMD, were greatly increased in sheep infested with T. colubriformis and not receiving supplementary Vit. E + Se. Data from this study therefore indicates that trichostrongylosis may aggravate the degree of muscle necrosis in lambs prone to the development of NMD.

The effects of low-dose gamma-irradiation on the wholesomeness of mangoes (Mangifera indica) as determined by short-term feeding studies using rats.

1. A control diet and diets containing 150 g non-irradiated or 150 g irradiated mangopulp/kg were given to female rats from day 15 of the gestation period until weaning in trials 1 and 2, and from 40 d before mating until 28 d post weaning in trial 3. 2. Food intake and dry-matter digestibility were similar with all diets. 3. There were no significant differences between animals given the different dietary regimens in the daily body-weight changes of weanling males, pups, nursing females or females during the immediate postlactation period. 4. No differences in haematological or blood chemistry values were found which could be attributed to the ingestion of irradiated mangoes. There was no evidence for the presence of any toxic substances in the irradiated-mango-pulp diet. 5. Gross pathological observations revealed no aberrations which could be related to the ingestion of irradiated mangoes. 6. It may be concluded that the wholesomeness of mangoes was not affected by gamma-irradiation at a dose of 75 krd.

Haematological and blood chemistry changes in ewes and lambs following supplementation with vitamin E and selenium.

1. For methods of vitamin E and selenium supplementation were evaluated using thirty-nine pregnant ewe-lambs fed on a ration containing 0.043 mg Se/kg and 25 mg vitamin E/kg. Treatments were control, fortified mineral mix (ESe salt) (300 mg vitamin E, 3 mg Se), ruminal Se pellets (505 mg Se), drench (300 mg vitamin E, 3 mg Se) and intramuscular injection (600 mg vitamin E, 3 mg Se). Only ewes supplemented, commencing approximately 50 d before parturition. 2. Birth weights were similar for all treatments and live-weight gains of lambs to 56 d of age were improved in all supplemented groups (P less than 0.05). There were no clinical cases of nutritional muscular dystrophy. 3. Se concentrations in whole blood were more than doubled in both lambs and ewes drenched or injected; responses to ESe salt and pellets were much smaller. 4. Plasma tocopherol levels were increased in injected dams and their lambs (P less than 0.001). 5. Haemoglobin concentration and erythrocyte counts were significantly higher (P less than 0.01) in control ewes and lambs than in treated lambs. 6. Lactate dehydrogenase (EC 1.1.1.27), creatine kinase (EC 2.7.3.2) and aspartate aminotransferase (EC 2.6.1.1) activities were increased in lambs from control, ESe salt and pellet groups (P less than 0.001). Glutathione peroxidase (EC 1.11.1.9) activity responded to Se supplementation in both ewes and their lambs (P less than 0.001) and the response was highest in the injected group, followed in order, by the drench, pellet, Ese salt and control groups. 7. These studies indicated that in terms of the haematological and blood chemistry changes investigated, the intramuscular injection was most effective, followed by the oral drench. Ruminal pellets and fortified salt were less satisfactory.

Effect of microbial inoculant on quality of alfalfa hay baled at high moisture and lamb performance.

The effectiveness of a microbial hay inoculant in high moisture alfalfa hay was evaluated. Alfalfa (third cutting) was baled at 72% DM without or with inoculant and at 82% DM without inoculant during yr 1. In yr 2, alfalfa (second cutting) was baled at 75% DM without or with inoculant and at 82% DM without inoculant. Application rate of inoculant was 3.8 L/.98 tonne each year. At this application rate, 90 billion cfu were applied per .98 tonne of forage. Hays were core sampled at 0, 14, 30, and 60 d after baling to determine chemical composition. By d 30, all hays had DM content of 89%. In yr 2, 12 wether lambs were assigned to three treatments in a replicated 3 x 3 Latin square. Treatments were chopped, low moisture hay plus corn; chopped, inoculated high moisture hay plus corn; and chopped, high moisture hay plus corn. All diets contained 63% alfalfa hay, 35% ground corn, and 2% minerals and vitamins. In yr 1, inoculated and low moisture hays were not different in chemical composition but were higher in CP and lower in NDF than high moisture hay. Neither NDF nor CP were different among the three hays in yr 2. Average daily gain was not different on the three diets. The feed to gain ratio was lowest for the inoculated hay, intermediate for the low moisture hay, and highest for the high moisture hay diet. Daily gain and feed to gain ratio were not different for lambs fed the inoculated hay baled at 75% DM compared with lambs fed untreated hay baled at 82% DM.