Higher Levels Of Crude Protein Research Articles

Effect of feeding system on performance and carcass characteristics of yearling steers, steer calves and heifer calves.

Three types of cattle (Angus x Hereford yearling steers, Charolais x British breed steer calves and Hereford heifer calves) were evaluated for their response to different feeding systems utilizing high moisture corn, corn silage and soybean meal as major feed ingredients. Feeding ing systems for steers included: A = 85% concentrate; B = 40% concentrate; C = two phase, with switch from all corn silage to 85% concentrate in the middle of the feeding period; D = same as C except switch occurred late in the feeding period; E = all corn silage continuously. Heifer diets consisted of the following ratios of corn silage to concentrate: low energy = 89:11; medium energy = 67:33; and high energy = 100 fed at a moderate (10.9% for low energy and medium energy, and 11.7% for high energy) and high (13.8%) crude protein level. Treatments within each experiment were terminated at approximately the same final weight. Increasing percentage corn added to the total diet increased ADG in most comparisons. Adjusted to a constant carcass weight, increasing dietary energy increased fat thickness and reduced percentage retail product with no effect on quality grade in yearling steers and heifer calves. In Charolais cross-steer calves, increasing energy level increased quality grade with no effect on yield grade or percentage retail product. Energetic efficiency slightly favored system C in yearling steers while steer calves maximized efficiency on A. Hereford heifers were the most energetically efficient on medium energy diets.

Variation in Winter Levels of Crude Protein among Artemisia tridentata Subspecies Grown in a Uniform Garden

We discovered that the midwinter crude protein content of Artemisiu trident&u is under genetic control. Our study demonstrated that some accessions ofA. tridentutu, grown under uniform conditions, contained significantly higher levels of crude protein than others. Subspecies tridentutu contained significantly higher levels of crude protein than subspecies vuseyunu and wyomingensis. However, the accessions that contained the highest levels of crude protein have been reported to be the least palatable to mule deer. A superior strain of A. triiientutu can be developed by combining the high protein-yielding accessions with accessions that are higher in palatability. The new strain could supply more protein for mule deer on winter ranges.

Growth response of Tilapia zillii fingerlings fed isocaloric diets with variable protein levels

Six purified casein diets within a range of 21–53% crude protein were fed for 3 weeks to young tilapia ( Tilapia zillii) to determine the optimum protein requirement and protein: energy ratio for growth. Growth rate increased proportionally to protein level of the diet to an incorporation rate of about 35%. Beyond this a gradual retardation in growth rate was observed. The diet containing about 30% crude protein with a protein: energy ( P E ) ratio of 81, however, appeared to be more efficiently utilized by the fish in terms of protein deposition and energy retention than diets with higher levels of crude protein. These results indicate that Tilapia zillii requires about 35% protein in the diet for optimum growth while 30% for the maximum bodily protein deposition when casein is used as the sole source of protein. All six diets, however, showed an excellent feed conversion. Protein efficiency ratio (PER) decreased with the increase in protein in the diet.

STRAW QUALITY OF CEREAL CULTIVARS BEFORE AND AFTER TREATMENT WITH ANHYDROUS AMMONIA

Straw components of 14 wheat, oat and barley cultivars grown at four locations, 1975–1976, were compared for feed quality attributes before and after ammoniation. Based on a combined statistical analysis, significant differences (P < 0.05) among cultivars occurred among and within crops for crude protein (CP), in vitro digestible organic matter (DOM) and crude fibre (CF) for untreated straw residues. Average CP and DOM levels were lowest for wheat (3.6 and 36.7%, respectively). Barley had the highest average CP (4.9%) and oats the highest average DOM (39.8%). Wheat straw had substantially higher average CF than either oats or barley. Straw from Pitic 62 wheat, Random oats and Fergus barley showed superior quality attributes (high DOM and CP, low CF) for their respective crops. Neepawa wheat straw appeared to have the poorest quality overall. The straws were treated with anhydrous ammonia (5% on a wt/DM basis) and left in a sealed container at 20° and 15% moisture for 6 days. Following ammoniation: all wheat cultivars had higher CP levels than the oat and barley cultivars; average improvements in CP for wheat, oats and barley were 8.1, 4.7 and 5.3 percentage units, respectively; average DOM levels were similar for wheat, oats and barley; average improvements in DOM were 8.6, 6.1 and 6.6 percentage units, respectively. Neepawa had significantly higher CP following ammoniation than the oat or barley cultivars and showed the highest improvement in DOM (10.1 percentage units). Based on DOM values of the wheat, oat and barley straws, the cultivars Pitic 62, Random and Fergus would still be preferred after ammoniation. There was little to choose between several cultivars within crops for CP content after treatment with ammonia.

Nutrition and Population Dynamics of the Prairie Vole, Microtus ochrogaster, in Central Illinois

SUMMARY (1) Nutrition and demographic characteristics of three populations of prairie voles were compared in adjacent, but distinctly different, habitats in central Illinois. (2) Live trappings from 1972 to 1976 provided data for two cyclic fluctuations in density. Densities reached higher levels in all habitats during the first cycle (prairie-38/ha, bluegrass-128/ha and alfalfa-244/ha) than during the second cycle (10/ha, 60/ha and 102/ha, respectively). (3) Voles had greater reproduction and survival and higher body weights in the alfalfa than in the bluegrass or prairie habitats. Data obtained by snap-trapping indicated that litter sizes and fat reserves were also greater in the alfalfa habitat. (4) Examination of stomach contents showed that dicotyledons comprised a major portion of the vole diet in all habitats even though grasses dominated the vegetation in the bluegrass and prairie habitats. Voles in the latter habitats supplemented their diet with seeds and insects. (5) Analysis of nutrients in three common food items (alfalfa, clover and bluegrass) revealed that legumes not only contained more digestible energy than bluegrass but also higher levels of crude protein, calcium, phosphorus and sodium. Moreover, voles grew more rapidly, bred earlier and produced more young when fed alfalfa than when fed dandelions and bluegrass. (6) When released in enclosures, voles grew faster and reproduced sooner in the alfalfa than in the bluegrass or prairie habitats. (7) We conclude that the quality of available food can exert a strong influence on the density of herbivores. Higher forage quality accounted for greater peak densities of vole populations, but it did not prevent population declines.

Optimum Dietary Protein to Energy Ratio for Channel Catfish Fingerlings, Ictalurus punctatus

Twenty-one semipurified diets were formulated to determine the optimum protein:energy ratio (P/E) for channel catfish fingerlings. Seven crude protein levels and three energy levels at each protein level were utilized. The protein, lipid, and digestible carbohydrate sources were hexane-extracted whole egg powder, salmon-corn oil mixture, and white dextrin, respectively. After an initial 2 week conditioning period, the experimental diets were fed in triplicate to groups of 30 +/- 3 channel catfish fingerlings weighing 205 +/- 10 g and kept in 110 liter flow-through aquaria at 26.7 +/- 1.1 degrees. The diets were fed at a rate equalling 3% of the total wet body weight/day divided into three equal feedings and adjusted weekly for 9 weeks. An approximate fivefold increase in body weight was observed. These data indicate that the concept of P/E ratios must be restricted to diets containing adequate levels of protein and total energy. Based on average daily gain, diets containing energy levels between 275 and 341 kcal/100 g had an optimum P/E ratio of approximately 88 (24-36% crude protein). Diets containing 24% crude protein and 275 kcal/100 g diet appeared to be utilized more efficiently in terms of percent protein deposited than diets containing higher crude protein levels.

Nutritive value of white clover and perennial ryegrass

Thirty Romney wether hoggets were individually fed for 94 days at maintenance or ad lib.levels of nutrition on pure or 50 : 50 mixed diets of white clover and perennial ryegrass. Comparative slaughter and balance techniques were used to study the utilisation of dietary energy. The white clover contained higher levels of crude protein than the ryegrass, but lower levels of soluble and structural carbohydrates. Animals fed white clover grew faster than those fed ryegrass, but the growth rates of those on the mixed diet were not significantly different from the average of those on the two pure diets. The average apparent digestibility of the gross energy of all rations was 75%. Of the digestible energy (DE) 82% and 84% was metabolised by the maintenance and ad lib. animals, respectively. There were no significant differences between diets either in percentage digestibility or percentage metabolisability, but the metabolisable energy (ME) content of the dry matter (DM) consun;ed at the maintenance le...

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Los resultados obtenidos en este estudio y aquí informados, con aves de líneas ponedoras y para asar en diferentes etapas de crecimiento, demuestran que: 1, Aunque la harina de coco contiene un alto porcentaje de proteína bruta, la misma es, sin embargo, deficiente en algunos de los aminoácidos esenciales requeridos por las aves, particularmente la lisina y la metionina-cistina; 2, la sustitución de unidad por unidad de harina de maíz por harina de coco resultó en una deficiencia en calorías en las dietas prácticas; 3, la harina de coco (elaborada por el proceso "expeller") fue consumida satisfactoriamente por aves para asar, en dietas prácticas para el engorde, a un nivel de hasta 50 por ciento; y 4, las consideraciones económicas tales como el precio y la disponibilidad de los ingredientes determinarán el nivel de harina de coco que deberá usarse en dietas prácticas, hasta un nivel máximo de 50 por ciento.

Response of Two Alfalfas (Medicago sativa L. and M. falcata L.) to Time and Rate of Potassium Application in the Subarctic1

AbstractAnnual topdressings of K at 0, 42, and 166 pounds per acre, applied either in spring or mid‐summer, were compared with 2 alfalfas—Medicago sativa (var. ‘Vernal’) and M. falcata—for 3 seasons in Alaska's Tanana Valley.Stands of both alfalfas thinned rapidly during the study but stands and stand losses showed virtually no relationship to K treatments. Winterkill accounted for most of the reduction of stands and Vernal winterkilled more than M. falcata.K treatments resulted in large differences in yield. Both rates of K topdressing resulted in higher alfalfa yields than no topdressing; and 166 pounds of K per acre were superior to 42 pounds per acre.Crude protein content of forage was seldom influenced to a significant extent by K applications. Where differences existed, crude protein content was lowest with the highest rate of K application. M. falcata contained higher levels of crude protein than Vernal.K content of forage, virtually always lowest where no K was topdressed, was usually higher in alfalfa topdressed with 166 pounds of K per acre than at the lower rate. K content was lower in Vernal than in M. falcata.Highest percentage recovery in forage of applied K occurred with no topdressing. There, recovery exceeded the amount of K applied at planting. K recovery with the higher rate of topdressing was poorer than with the lower rate. M. falcata was superior to Vernal in K recovery.Amounts of available K in the soil did not differ among treatments until the third harvest season, when K levels were higher in most plots that had received the higher rate of K topdressing.

Degree of Herbage Selection by Grazing Cattle

Summary An investigation was made of the degree of selective grazing exercised by growing steers. A series of 66 individual trials was conducted with six herbages, each at three to five different stages of growth. The degree of discriminate grazing was marked with almost all herbages examined. The diet selected by grazing steers was higher in crude protein, ether extract, and mineral matter and lower in crude fiber than the whole herbage available for consumption. All proximate constituents of grazed herbage were more digestible than those of clipped herbage from the same source fed to stall-confined steers. The extent to which animals selected was not related to the intake of dry matter. Digestibility of dry matter and the amounts of crude protein and ether extract decreased, and the amount of crude fiber increased, as first-growth herbage became more mature. Although aftermath herbage contained a high level of crude protein and a low level of crude fiber, it was somewhat less digestible than first-growth forage of comparable composition. The restriction of grazing to small areas containing small quantities of herbage tended to reduce the extent of selection, whereas providing large quantities of herbage increased the degree of selection. Certain characteristics of herbage, such as the kinds of plants present, stage of growth, proportions of leaves and stems, and accessibility of plant parts, may have influenced to some extent the results obtained. Preference of animals for herbage possessing certain physical qualities, or qualities affecting palatability, may have resulted in the consumption of a diet differing chemically from the whole herbage. The consistency with which animals grazed discriminately under a variety of herbage conditions suggests that certain qualities inherent in the animal may influence the degree of selection practiced. The results of this investigation demonstrate that the chemical composition of clipped herbage is an unreliable index of the chemical composition of herbage selected by grazing animals. Also, the digestibility of clipped herbage is of uncertain value and may be quite misleading in regard to estimating the value of pasture under grazing conditions.