72 research outputs found
Utilization of near infrared reflectance spectroscopy for prediction of the nutritional composition of beef and pork samples
Near-infrared reflectance spectroscopy
(NIRS) offers the potential for rapid, low-cost
analyses of meat samples. Beef and pork
samples were analyzed by both standard
laboratory (AOAC) methods and NIRS.
Regression equations were developed to relate
the two methods. Coefficients of determination
between NIRS and AOAC results were .929 for
dry matter, .965 for crude protein, and .996 for
ether extract. NIRS and AOAC procedures
yielded very similar results (DM, 38.82 vs
38.58; CP, 17.78 vs. 17.83; and EE, 18.83 vs.
18.00). NIRS appears to be a rapid and reliable
predictor of nutritional composition of ground
beef and pork based on regression equations we
have developed with a limited number of
samples
Whole corn rations for finishing heifers: A comparison of self-fed and mixed supplement, with and without salt.
Twenty-four Hereford x Angus heifers averaging 714 lbs. were allotted by weight to four groups of six animals each to study effects on gain, feed intake, and feed efficiency of: 1. Free-choice whole corn without roughage. 2. Protein supplement either mixed with whole corn or supplied seperately (free-choice). 3. Omitting sal
Changes in nutrient content of rye, triticale, and wheat whole-plant forages with maturity
We compared upland and bottomland cereals seeded during 1991 at the KSU Agricultural Research Center - Hays. The five crops (three varieties of triticale, a winter wheat, and a winter rye) were harvested as whole plants during the latter part of the growing season. Crude protein (CP), ac id detergent fiber (ADF), and neutral detergent fiber (NDF) were estimated using near infrared spectroscopy. Compute r models were developed to describe nutrient changes. Crude protein content decreased whereas the two fiber components increased with maturity. Rye and wheat tended to have lower CP values when day 125 was used as the arbitrary harvest date. We observed only slight differences i n nutritional components between upland and bottomland plantings
Delayed winter supplemental feeding and year-round mineral supplementation of beef cows on native range
Polled Hereford cows on native Flint Hills pasture not supplemented until February lost more weight from December to February, lost less from February to May, and were in poorer condition before calving than cows supplemented beginning in November. But calf survival, birth weight, and calf average daily gain were similar for both groups. Feeding cows a calcium, phosphorus, trace mineral mix did not improve any measure of cow or calf performance
Response of yearling steers to burning and fertilizing pasture and intensive early season stocking (bluestem pastures)
Nine pastures totaling 492 acres were summer grazed by yearling Hereford, Hereford-Angus cross, and Angus steers distributed equally by breed. Five pastures were burned April 22, 1975; four were not burned. Burned and nonburned pastures had 0, 40, or 80 lbs. of nitrogen per acre applied aerially April 29, 1975. Stocking rates were determined with herbage production data from experimental plots under similar treatments. Under equal fertilization and stocking ratios, burned and fertilized pastures produced as much or more average daily gain and more gain per acre than nonburned pastures. Fertilizing and heavier stocking tended to reduce average daily gains but increased gains per acre. Steers on the early season, intensely-stocked pasture gained the most per day (1.78 lbs.) and produced the highest gain per acre (70 lbs.)
Effect of adding fat to feedlot rations
Fat is added to commercial feedlot rations as a concentrated energy source and to reduce dustiness and wear of feed processing machinery. We added fat at varying levels ( 0 to 6% of the ration) to study effects from fat and the influence of a surface-active additive. Two hundred 700-pound steers were allotted to 40 pens of 5 each all fed 135 days on the rations show in Table 12, according to the schedule shown in Table 13
Minerals in esophageal samples from steers on native bluestem pastures
This report summarizes monthly mineral contents of burned and control native bluestem pastures determined with samples from fisulated steers. Burning decreases calcium (Ca), potassium (K), and iron (Fe), and slightly decreases zinc (Zn). All minerals we studied were adequate for grazing cattle except that magnesium (Mg) and Potassium (K) appear to be borderline during winter months
The ecology of herbivore-induced silicon defences in grasses
Silicon as a defence against herbivory in grasses has gained increasing recognition and has now been studied in a wide range of species, at scales from individual plants in pots to plant communities in the field. The impacts of these defences have been assessed on herbivores ranging from insects to rodents to ungulates. Here, we review current knowledge of silicon mediation of plant-herbivore interactions in an ecological context. The production of silicon defences by grasses is affected by both abiotic and biotic factors and by their interactions. Climate, soil type and water availability all influence levels of silicon uptake, as does plant phenology and previous herbivory. The type of defoliation matters and artificial clipping does not appear to have the same impact on silicon defence induction as herbivory which includes the presence of saliva. Induction of silicon defences has been demonstrated to require a threshold level of damage, both in the laboratory and in the field. In recent studies of vole-plant interactions, the patterns of induction were found to be quantitatively similar in glasshouse compared with field experiments, in terms of both the threshold required for induction and timing of the induction response. The impacts of silicon defences differ between different classes of herbivore, possibly reflecting differences in body size, feeding behaviour and digestive physiology. General patterns are hard to discern however, and a greater number of studies on wild mammalian herbivores are required to elucidate these, particularly with an inclusion of major groups for which there are currently no data, one such example being marsupials. We highlight new research areas to address what still remains unclear about the role of silicon as a plant defence, particularly in relation to plant-herbivore interactions in the field, where the effects of grazing on defence induction are harder to measure. We discuss the obstacles inherent in scaling up laboratory work to landscape-scale studies, the most ecologically relevant but most difficult to carry out, which is the next challenge in silicon ecology
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