An application of multi-objective linear programming for the achievement of breeding goals in herd health programs.
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Animals↗
Biomedical subjects
W Chalupa
Publications and source records attributed to W Chalupa.
Milk lipoprotein lipase activity during long-term administration of recombinant bovine somatotropin.
The effect of long-term administration of recombinant bovine somatotropin to dairy cows on milk lipoprotein lipase activity was investigated. Recombinant bovine somatotropin was administered daily to 32 cows (8/treatment). Treatments were 0 (control), 12.5, 25.0, and 50.0 mg/d or recombinant bovine somatotropin administered in once daily intramuscular injections. Treatments began at 28 to 35 d of lactation and continued until 294 d of lactation. Recombinant bovine somatotropin treatments had no significant effect on milk lipoprotein lipase activity; enzyme activity for each treatment was 97.87, 108.96, 99.96, and 92.43 units/ml of milk, respectively. A significant effect of the stage of lactation was unrelated to recombinant bovine somatotropin administration. Enzyme activity peaked at approximately 20 wk of the treatment or 25 wk postpartum. These results indicate that long-term administration of recombinant bovine somatotropin does not alter the processes that lead to lipoprotein lipase activity in milk.
Animals↗
Acid-base and electrolyte balance in dairy heifers fed forage and concentrate rations: effects of sodium bicarbonate.
Eight Holstein heifers were fed diets of alfalfa hay, corn silage, or finely ground corn grain with or without NaHCO3 in a rotating experimental design. Acid-base status and renal excretion of electrolytes were evaluated during short-term (1 and 5 day) and long-term (24 day) feeding trials. Heifers fed alfalfa hay had a greater metabolic buffering capacity than did heifers fed corn silage. Heifers fed grain had lower blood pH and bicarbonate values than did those fed the forage diets. The most pronounced effects of grain-feeding were aciduria and phosphaturia. Aciduria did not occur when NaHCO3 was added to the grain at 2% of the ration on a dry matter basis. Grain-fed heifers had significantly (P less than 0.05) lower blood and urine pH and bicarbonate values, and excreted significantly more calcium, phosphorus, and magnesium in the urine than did those fed grain plus NaHCO3. Sodium bicarbonate, as a 2% dietary supplement, counteracted many effects of high-grain diets.
Acid-Base Equilibrium↗
Sulfur influences on rumen microorganisms in vitro and in sheep and calves.
When continuously cultured ruminal microbes were given orchardgrass hay and sufficient sulfuric acid or hydrochloric acid to maintain a pH of 5.5, fermentation and numbers of protozoa were reduced compared with cultures whose pH was controlled with phosphoric acid. Likewise, when sulfur-deficient, purified diets were supplied to cultures, less methane (mmol X liter-1 X d-1), 3.2 vs 32.6, was produced and fewer cellulolytic bacteria (log10/ml), 5.8 vs 7.2 were present than when cultures were given the same diet supplemented with .3% elemental sulfur. The rumen of sheep fed the .04% sulfur diet had reduced digesta weights (1.69 vs 3.2 kg) compared with sheep fed the diet with .34% sulfur at the same intake. There also was reduced methanogenesis 12.3 vs 25.8 mmol X liter-1 X d-1) and reduced numbers of cellulolytic bacteria (7.4 vs 8.4 log10/ml) in sulfur-deficient sheep in comparison to sulfur-supplemented sheep. In growing calves, the same types of bacteria predominated in the rumen, but more facultative anaerobic bacteria were isolated from calves fed .04% sulfur than from calves fed diets with .34 to 1.72% sulfur. None of the dietary levels of sulfur appeared toxic. Regardless of treatment, volatile fatty acids were more predominant than lactic acid as end-products of fermentation of ruminal microbes in fermenters, sheep and calves. The greater methanogenesis and the greater cellulolytic bacterial numbers of sulfur-supplemented sheep compared with sulfur-deficient in vitro cultures, is interpreted to be the result of recycling of sulfur to the rumen in sheep where it is efficiently scavengered by ruminal bacteria.
Animal Feed↗
Ruminal fermentation in vivo as influenced by long-chain fatty acids.
Responses of ruminal microbes to long-chain fatty acids in forms of free acids, calcium salts, or triglycerides were measured in trials with rumen cannulated heifers. Addition of fatty acids at 10% to a basal diet of 50% corn silage and 50% grain increased fat content 3 to 10 to 12%. Long-chain fatty acids with a high melting point (stearic acid) and calcium salts of long-chain fatty acids (vegetable fat and tallow) decreased acetate:propionate by about 20%. Long-chain fatty acids with a low melting point (oleic acid) and the triglyceride form of long-chain fatty acid (tallow) decreased acetate to propionate ratio by 50 to 60%. Even though they were not completely inert in the rumen, responses with the hard long-chain fatty acids (stearic acid) and with calcium salts of long-chain fatty acids confirm that these are efficacious for protecting ruminal microbes from adverse effects of fat. With calcium salts of long-chain fatty acids, dietary buffers may be needed to maintain ruminal pH so that dissociation of salts does not occur. Long-chain fatty acid supplementation at 10% of the diet is probably more than the amount needed to optimize productivity and health. With most diets, 6 to 8% supplemental long-chain fatty acid is probably sufficient.
Animals↗
Response of dairy cows to sodium bicarbonate and limestone in early lactation.
A total of 108 dairy cows at three locations were fed a diet supplemented with sodium bicarbonate and limestone during the first 16 wk of lactation. Complete mixed diets were fed for ad libitum intake and consisted of concentrate and corn silage (60:40, dry matter). The four treatments were: 1) basal diet, 2) basal plus 1.2% sodium bicarbonate, 3) basal plus 1.4% limestone, and 4) basal plus 1.2% sodium bicarbonate plus 1.4% limestone. Dry matter intake was increased for 8 wk by sodium bicarbonate, then decreased from wk 9 to 16. Intake was decreased by limestone alone or in combination with sodium bicarbonate. Sodium bicarbonate increased milk production for 8 wk and 4% fat-corrected milk for 16 wk. Average dry matter intake, milk production, and 4% fat-corrected milk (kg/day) for the 16 wk were: 1) 20.2, 31.1, 27.3; 2) 19.8, 32.0, 28.7; 3) 18.9, 31.4, 27.9, and 4) 18.4, 29.7, 27.2 for diets 1 to 4. Ruminal pH was decreased, and volatile fatty acid concentration was increased by added sodium bicarbonate and appeared to result from increased feed intake. Digestibility of nutrients was unaffected by supplements. Sodium bicarbonate affected regulation of blood and urine pH and concentration of electrolytes more than limestone. Serum magnesium was reduced with sodium bicarbonate, although not beyond normal physiological reference range.
Animals↗
Digestion and absorption of lipids and bile acids in sheep fed stearic acid, oleic acid, or tristearin.
Sheep were fed diets containing 7.5% added stearic acid, oleic acid, or tristearin for 21 days. In addition, 50 microCi/kg cerium-141 was included for the last 10 days on experimental diets as an unabsorbed reference substance. In the rumen dietary triglycerides were approximately 50% hydrolyzed, and hydrogenation resulted in saturation of the free fatty acid fraction. Some net synthesis of phospholipids, presumably microbial phospholipids, occurred in the rumen. In the intestine immediately distal to the pylorus, extensive secretion of bile acids, cholesterol, phospholipids, triglycerides, free fatty acids, and lipase occurred. This resulted in doubling of fatty acid fluxes through the duodenum. These endogenous secretions were reabsorbed rapidly however, with the major site of lipid and bile acid absorption in the region .6 to 4 m distal to the pylorus. Additional but less absorption occurred in the more distal segments of the small intestine. Overall absorption of stearic acid, oleic acid, and tristearin supplements was in the range 60 to 70%, and no differences were apparent between fats. Unsaturated fatty acids were over 90% absorbed as compared with 55 to 65% for saturated fatty acids. No significant effect of any of the supplements was observed on ruminal total volatile fatty acids, ratios of volatile fatty acids, or on overall cellulose or caloric digestion.
Abomasum↗
Rumen fermentation in vitro as influenced by long chain fatty acids.
Responses of rumen microbes to fatty acids were evaluated by production of total volatile fatty acid and ratio of acetate to propionate. Fermentations were under carbon dioxide for 20 h in 50-ml Erlenmeyer flasks in a Dubnoff metabolic shaking incubator. Flasks contained 20 ml medium, 1 ml reducing solution, 750 mg substrate (450 mg hay plus 300 mg grain), and varying amounts of long-chain fatty acids supplied as free acids, as calcium salts, or as triglycerides. They were inoculated with 5 ml rumen fluid obtained from a cow fed 3.6 kg grass hay, 2.3 kg grain, and .2 kg tallow daily. Volatile fatty acid production was decreased by long-chain fatty acids that contained less than 18 carbon atoms and by unsaturated long-chain fatty acids with 18 carbon atoms. Lauric acid decreased volatile fatty acid production by 69% and induced unusual acetate/propionate ratio (40:1). Stearic acid, however, did not affect volatile fatty acid production or acetate/propionate ratio. Within two series of long chain fatty acids (myristic, palmitic, stearic, arachidic; stearic, oleic, linolenic), melting point accounted for 93 to 95% of the variation of volatile fatty acid production and acetate/propionate. As calcium salts, long chain fatty acids caused small changes of fermentation. Our data support the proposition that hard fats and calcium salts of long-chain fatty acids do not interfere with ruminal fermentation.
Acetates↗
Effects of diaryliodonium chemicals on rumen fermentation in vitro and in vivo.
In vitro fermentation studies demonstrated that diaryliodonium chemicals were inhibitors of amino acid utilization. Only small differences were found in comparative effectiveness of different analogs and salt forms of chemicals tested. Protection against degradation and(or) uptake was greatest for valine, methionine, isoleucine, leucine and phenylalanine. Although changes were not as large, animals fed 4,4'-dimethyldiphenyliodonium chloride for 112 d had higher ruminal concentrations of amino acids and lower concentrations of ammonia. Decreased production of acetate in conjunction with increased production of propionate and butyrate resulted in improved fermentation efficiencies. Fermentative shifts in vivo were not as large as those observed in vitro and additional investigations are needed to determine whether feeding diaryliodonium chemicals increases the transfer of energy in digested carbohydrates to volatile fatty acids.
Amino Acids↗
Effects of diaryliodonium chemicals on nitrogen utilization in growing steers.
Diaryliodonium chemicals increased nitrogen (N) absorption, utilization of absorbed N and N retention in growing steers. Fifty parts per million of the chemicals (diphenyliodonium chloride, diphenyliodonium bromide, 4,4'-difluorodiphenyliodonium chloride or 4,4'-dimethyldiphenyliodonium chloride) in the diet appeared sufficient to promote significant (P less than .05 or .10) improvements in N utilization. Diet digestibility was either not affected or improved slightly. We suggest that diaryliodonium chemicals improve N utilization by adjusting the ruminal degradation of dietary protein to yield more amino-N and less ammonia-N.
Animals↗
Effects of 4,4'-dimethyldiphenyliodonium chloride on performance of growing cattle.
Two 112-d studies were conducted to evaluate effects of the deaminase inhibitor, 4,4'-dimethyldiphenyliodonium chloride, on performance of growing cattle. With diets containing low levels of crude protein (i.e., 11%), 25 ppm of chemical in the diet increased (P less than .05) gain and improved (P less than .05) feed efficiency. Feed intake was not affected. Higher levels of chemical (50 and 100 ppm) produced equivalent responses. With a higher level of dietary crude protein (i.e., 14%) gain and feed efficiency were not improved and some decreases in feed intake were observed. Performance responses resulting from adjustments in ruminal nitrogen transactions to provide more alpha-amino-N depend upon whether the animal needs additional amino acids for maintenance and production. Our data demonstrated that the supply of amino acids can be increased either by adjustment of ruminal nitrogen transactions with a chemical agent or by increasing concentration of dietary protein.
Animals↗
Effects of monensin and amicloral on rumen fermentation.
Fermentative adjustments produced by monensin and amicloral and by combinations of monensin plus amicloral were investigated in vitro. Monensin increased (P < .05) production of propionate, usually decreased production of acetate and butyrate and partially reduced methanogenesis, but no accumulation of gaseous hydrogen was observed. Amicloral not only increased production of propionate (P < .05), but also usually increased butyrate production, decreased (P < .05) acetate production and almost completely inhibited (P < .05) methanogenesis, and substantial quantities (P < .05) of hydrogen accumulated in the gas phase. Both chemical agents were effective (P < .05) in decreasing utilization of an exogenous amino acid load. Monensin plus amicloral produced fermentative adjustments comparable to those predicted from cultures medicated with monensin or amicloral alone; thus, effects mediated by the combined agents were additive and no consistent positive or negative synergestic activities were noted. Characteristic adjustments in rumen fermentation caused by monensin, by amicloral and by additivity of these adjustments are reflections of the two chemical agents manipulating ruminal reactions by different mechanisms.
Animals↗
In vitro fermentation of feces from normal and chronically diarrheal horses.
Feces from 13 healthy horses and 8 horses with chronic diarrhea were subjected to an in vetro fermentation procedure that had been developed for rumen fluid. Fermentations were conducted over 6 hours in a closed system, with and without an essential amino acid (EAA) mixture being added to the basic starch-buffer medium. The addition of EAA caused no significant difference in results of fermentation of feces from healthy horses. For diarrheic animals, there was a significant (P less than 0.01) increase in gas and total volatile fatty acids production whether EAA were present or not, and alpha-amino nitrogen was utilized in significantly (P less than 0.01) greater amounts only if EAA was present. Fermentations were repeated on feces from five of the eight diarrheal horses after they had been treated with oral iodochlorhydroxyquin for 1 week, and had shown desirable clinical response. A significant difference was not shown between pre- and posttreatment fermentations, except for decreased butyrate production. The results are consistent with the hypothesis that chronic equine diarrhea is primarily a colonic disease and indicates that colonic maldigestion may, in part, be responsible for excess fecal water.
Amino Acids, Essential↗
Feeding behavior changes of cattle during introduction of monensin with roughage or concentrate diets.
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Animal Feed↗
Production of animal protein from nonprotein nitrogen chemicals.
Ruminants obtain amino acids (AA) from microbial protein synthesized in the rumen and from feed proteins that escape ruminal degradation. Synthesis of microbial protein provides a mechanism for obtaining AA from NPN. Effectiveness of NPN utilization depends upon production and utilization of ammonia by rumen microbes. Because ammonia is produced from protein and NPN, feeding proteins resistant to microbial degradation forces utilization of ammonia derived from NPN. The quantity of microbial cells formed in the anaerobic rumen fermentation system is primarily dependnt upon energy supply but can be modulated by types and supplies of other nutrients (i.e. amino-N, minerals growth factors) and by growth rate of rumen bacteria. Potential quantities of NPN that can be utilized with different feed ingredients can be estimated from amounts of feed protein degraded in the rumen, and requiring transformation into protein via growth of rumen microbes, and from amounts of energy provided by feed ingredients. High energy feed ingredients with low amounts of degradable protein are most favorable for NPN utilization, but NPN has also been used successfully with high-fibrous, low energy feed materials. Growth, lactation and reproduction have been obtained on diets containing more than 97% of the nitrogen from NPN, but microbial protein alone cannot provide quantities of AA needed for high levels of productivity. Regulating ruminal degradation of dietary protein and utilizing NPN for rumen protein production is a highly desirable strategy for producing human foods with ruminants.
Amino Acids↗
Degradation of amino acids by pure cultures of rumen bacteria.
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Amino Acids↗
Degradation of amino acids by the mixed rumen microbial population.
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Amino Acids↗
Rumen bypass and protection of proteins and amino acids.
Potent rumen microbial proteases and deaminases rapidly degrade protein and amino acids which are soluble in the rumen liquid phase. Because protein sources vary in their solubility, the degree of degradation in the rumen is variable. Methods of decreasing protein and amino acid degradation in the rumen include heat treatment, chemical treatment, encapsulation, use of amino acid analogs, selective manipulation of balances of rumen metabolic pathways, and esophageal groove closure. It is important that procedures do not interfere with ruminal metabolism or post-ruminal digestion. Bypassing the rumen changes sites in the digestive tract of nutrient digestion and absorption and provides a mechanism for supplementing outflow of nutrients from the rumen. A feasible approach to production of animal protein from ruminants would be utilization of nonprotein nitrogen for rumen protein production, maximization of rumen bypass of dietary protein, and supplementation with rumen nondegradable amino acids.
Amino Acids↗