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Influence of energy concentration of fattening rations on nitrogen utilization by steersStone, Paul Alfred January 1964 (has links)
Six Angus steers were used in a series of three metabolism trials to study the effect of energy concentration on nitrogen metabolism and digestibility. The experimental design consisted of two randomly selected 3 x 3 Latin squares. Three fattening rations were ted which contained 1133, 1164 and 1222 kcal. digestible energy per lb. feed and 12.18, 12.51 and 12.29% crude protein, respectively. The rations were composed of 10% grass hay, shelled corn, corn cobs and cottonseed meal. An attempt was made to equalize calcium and phosphorus contents. Vitamins A and D were added at the rate or 30,000 I.U. and 3750 I.U. per steer per day, respectively. Energy concentration was varied by changing the proportions of shelled corn and corn cobs. Digestible and metabolizable energy and TDN were all significantly increased with each increase in energy concentration. Digestible energy concentration of feed had no significant effect on nitrogen retention. Biological value waa higher for the medium energy ration than for the low or high energy rations. The quadratic effect was significant (P < .05). The apparent digestibilities of crude protein and ether extract were not influenced by energy concentration. Digestibility of' dry matter, organic matter and NPE significantly increased and digestibility of crude fiber significantly decreased with each increase in energy concentration. / Master of Science
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Notes on wintering beef cattleLancaster, Dabney S. January 1915 (has links)
Master of Science
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Feeding 2 yr. old beef cattle / Feeding Two Year Old Beef CattleHunt, Ralph E. January 1916 (has links)
Thie experiment was conducted by the Virginia Agricultural Experiment Station for the purpose of comparing the values of several feeds for wintering beef steers with especial regard for local conditions.
1st. 28 lbs. silage and 1 lb. cottonseed meal will maintain 1000-pound steers during the winter without a loss of more than 25 lbs. per head.
2nd. 38 lbs. silage per steer per day will give about the same results as above.
3rd. Steers will change from grass to silage and from silage to grass again with practically no loss in weight.
4th. Steers fed silage alone, and stover and corn meal during the winter were the only steers to average 2 pounds gain per day on grass.
5th. Steers fed on silage alone made greatest total gain at the lowest cost per 100 pounds gain.
6th. Steers fed on stover and corn meal made the least total gain at the greatest cost per 100 pounds gain.
7th. Silage is a very economical feed for wintering steers, while stover and corn meal is a very costly feed.
8th. One pound of cottonseed meal will replace ten pounds of silage and it may be advisable to make this substitution when silage is scarce, or cottonseed meal cheap, or both, although cottonseed meal is not absolutely necessary.
9th. Winter steers so that they will not lose more than 25 pounds each during the winter months, for greater losses cannot be overcome during the grazing season. / Master of Science
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Selenium supplementation and selected immune responses of beef cattleSwecker, William S. 11 May 2006 (has links)
The effect of selenium (Se) supplementation, by ad libitum salt-mineral mixture (SMM) and/or Se injection, on bovine immune response was evaluated in three experiments. Sixty weaned beef calves, with marginal blood Se (67 μg Se/1), were allotted to one of six Se treatment groups in a 70-day experiment. Antibody responses to lysozyme were lower in calves fed 20 ppm Se salt-mineral mixture (SMM) ad libitum as compared to calves fed 20 ppm Se SMM and injected with 0.1 mg Se + 1.0IU vitamin E/kg body weight, IM, or with calves ad libitum fed 80, 120, 160, or 200 ppm Se SMM. Blood Se on day 70 was higher in calves fed 80, 120, 160, or 200 ppm Se SMM than calves fed 20 ppm Se and injected with 0.1 mg Se + 1.0 IU vitamin E/kg of body weight, IM.
An ad libitum 120 ppm Se SMM was compared to Se injection in 80 mid-gestation beef cows that were Se-deficient (50 μg Se/l blood). Supplementation with 120 ppm Se SMM increased blood Se in cows and calves to > 100 μg/l, increased IgG concentrations in colostrum, and increased IgG concentrations in serum of post-suckle calves. Calves from Se-adequate dams had higher Se concentrations in blood and higher average daily gains at 60 days than Se-deficient calves injected with Se at birth.
An ad libitum 120 ppm Se SMM was compared to Se injection in 60 Se-deficient (41 μg Se/l blood) weaned beef calves in a 56-day experiment. Calves fed 120 ppm Se SMM and unsupplemented control calves had higher antibody responses to lysozyme than calves injected with 0.1 mg Se + 1.0 IU vitamin E/kg body weight. Blood Se concentrations increased in calves fed 120 ppm Se SMM, did not change in calves injected with 0.1 mg Se/kg body weight, and decreased in control calves. Se treatment did not affect IgA response in tears of calves. / Ph. D.
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Profits from several feeding systems followed by beef cattlemen of Southwest VirginiaNelson, G. V. January 1930 (has links)
The farmer that fed silage made a profit of $606.20 for the twenty-six years or had received an average profit of $23.31 each year per steer. The farmer that fed hay and straw made a profit of $298.76 for the twenty-six years or an average profit of $11.49 each year per steer. The farmer that fed stover and corn meal made a profit of $140.56 for the twenty-six years or an average profit each year of $5.40 per steer.
From a survey of seventy farms and 4,380 head of cattle, we find that the average carload shipment is about three care per cattlemen in Southwest Virginia allowing twenty head to the car, this would mean sixty per year. At this rate the farmer that fed silage would have made $36,372.00. The farmer that fed hay and straw would have made $17,925.00 and the farmer that fed stover and corn meal would have made $8,433.60.
The cost of silage for the twenty-six years was $412.04, for hay and straw $521.54, and for stover and corn meal $439.70. / M.S.
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A genetic analysis of biological and economic efficiency of post-weaning feedlot performance in beef cattleVan der Westhuizen, Robert Rolfe 03 1900 (has links)
Thesis (PhD (Agric))--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: It is generally accepted that feed intake and growth (gain) are the most important economic
components when calculating profitability in a growth test or feedlot. Feeding cost of animals is a
major determinant of profitability in livestock production enterprises. Genetic selection to improve
feed efficiency aims to reduce the cost of feeding in beef cattle production and thereby improve
profitability.
The objective of this study was to define a clear selection objective to enable South African beef
breeders and especially the feedlot industry to select for post-weaning growth or feedlot
performance and to identify factors influencing profitability in a feedlot environment.
Because of the recording of individual feed intake and weight gain values in the South African
Agricultural Research Councils' centralized growth tests, it was also possible to calculate a
phenotypic value for feedlot profitability (R-value) for each bull tested in a centralized growth test.
(Co)variances, using multitrait as well as random regression models, for and between feedlot
profitability, weaning weight and other production, reproduction and efficiency traits were
estimated. Residual feed intake (RFI) and feed conversion ratio (FCR) as efficiency traits were also
compared to growth (average daily gain (ADG), weaning weight (WW) and shoulder height
(SHD)), reproductive (scrotum circumference (SCR)) and profitability (feedlot profitability) traits
measured in growth tests of young Bonsmara bulls.
Consequently, a single post-weaning growth selection index value based on the economic and
breeding values of different selection criteria related to feedlot profitability was composed.
(Co)variance components, heritabilities and genetic correlations for and between initial weight
(lW), final weight (FW), total feed intake (FI) and shoulder height (SHD) were estimated through
the use of multitrait restricted maximum likelihood (REML) procedures. These breeding values
(EBV s) were then used in a selection index to calculate a single economical value for each animal. This economical value is an indication of the gross profitability value or gross test value (GTV) of
the animal in a post-weaning growth test.
The heritability estimate of 0.36 for R-value, obtained from the multitrait analysis, shows that this
trait is genetically inherited and that it can be selected for. The heritability for R-value obtained
from the single trait random regression model varied between 0.57 and 0.62. The genetic
correlations between the R-value and the other traits, obtained from the multitrait analysis, varied
from negligible to high. The heritability estimated for FCR was 0.34 and for RFl 0.31 with a
genetic correlation estimate of 0.75 between the traits. The estimated genetic correlation between
profitability (R-value) and FCR and RFl were -0.92 and -0.59, respectively. The genetic
correlation estimate of -0.92 between FCR and R-value is largely due to the part-whole relationship
between these two traits. This is also shown in their genetic trends. The genetic correlations and
expected correlated responses between RFl and FCR with R-value suggest that indirect selection for
R-value through the direct selection for FCR and/or RFl will result in slower genetic progress in Rvalue
than direct selection for R-value. However, where the R-value cannot be calculated and/or
where direct selection for R-value is not possible, it would be better to select indirectly for R-value
through the use of FCR rather than RF!. Consequently, a regression equation was developed (with
an R2 of 0.82) to estimate a feed intake value for all performance-tested Bonsmara bulls which were
group fed and whose feed intakes were unknown. These predicted feed intake values made it
possible to calculate a feedlot or post-weaning growth profitability value (R-value) for all tested
bulls even where individual feed intakes were unknown. Subsequently, an R-value for each bull was
calculated in a favourable economic environment (FEE), an average economic environment (AEE)
and in an unfavourable economic environment (VEE). The high Pearson and Spearman correlations
between the EBV s based on AEE and the other two environments suggested that the average
economic environment could be used to calculate EBVs for R-value or feedlot growth profitability.
It is therefore not necessary to change the carcass, weaner or feed price on a regular basis to account
for possible re-rankings based on R-value EBVs.
Heritabilities for lW, FW, Fl and SHD were 0.41, 0.40, 0.33 and 0.51, respectively. The highest
genetic correlations between these traits were the 0.78 (between lW and FW) and 0.70 (between Fl
and FW). GTV values varied between -R192.l7 and R231.38, with an average of R9.31. The
Pearson correlations between EBVs (for production and efficiency traits) and GTV range from
-0.51 to 0.68. The lowest correlation (closest to zero) was 0.26 between the Kleiber ratio (KLB) and
GTV. Correlations of 0.68 and -0.51 were estimated between average daily gain (ADG) and GTV
and feed conversion ratio (FCR) and GTV, respectively. The heritabilities of the different traits
included in the selection index suggest that it is possible to select for a GTV. The selection index can benefit feedlotting In selecting offspring of bulls with high GTV values to maximize
profitability.
The Pearson and Spearman correlations between the R-value EBVs and the index values (GTV)
were very high (0.97). This high correlation of 97% indicates that it is not important which method
is used to calculate a genetic post-weaning growth of feedlot profitability value. The selection index
value is, however, more simplified than the feedlot profitability with less assumption. Therefore, it
is recommended that the post-weaning selection index value be used as a selection objective in
breeding programmes to improve post-weaning growth profitability rather than the more complex
feedlot profitability value. / AFRIKAANSE OPSOMMING: 'N GENETIESE ANALIESE VAN DIE BIOLOGIESE EN EKONOMIESE
DOELTREFFENTHEID VAN NASPEENSE GROEI IN VLEISBEESTE IN DIE VOERKRAAL: Dit word algemeen aanvaar dat voerinname en groei die twee ekonomies mees belangrike
komponente in die berekening van 'n naspeense groei- of voerkraalwinsgewindheidswaarde is.
Voerkostes is 'n bepalende faktor van winsgewindheid in enige lewendehawe boerderypraktyk.
Seleksie om voerdoeltreffendheid te verbeter, verminder dus die voerkostes in vleisbeesproduksie
en gevolglik 'n verhoging in die winsgewindheid.
Die doelwit van die studie was om faktore te identifiseer wat 'n invloed op winsgewindheid in die
voerkraaiomgewing het asook om 'n duidelike seleksiedoelwit te formuleer wat die Suid-
Afrikaanse vleisbeesteiers en veral die voerkraalbedryf instaat sal kan stelom vir naspeense groeidoeltreffendheid
ofvoerkraalwinsgewindheid te selekteer.
As gevolg van die aantekening en rekordhouding van weeklikse individuele voennnames en
gewigstoenames van alle prestasiegetoetsde bulle, in 'n gesentraliseerde groeitoets deur die Suid-
Afrikaanse Landbou Navorsingsraad getoets, was dit moontlik om vir elk van hierdie bulle 'n
fenotipiese voerkraalwinsgewindheidswaarde (R-waarde) te kon bereken.
(Ko)variansies is vir en tussen voerkraalwinsgewindheid, speengewig en ander produksie-,
reproduksie- en doeltreffendheidseienskappe bereken deur van meereienskap en ewekansige
regressie modelle gebruik te maak. Twee doeltreffendheidseienskappe naamlik residuele
voerinname (RFI) en voeromsetverhouding (FCR) is ook met groei (gemiddelde daaglikse toename
(ADG), speengewig (WW) en skouerhoogte (SHD)), reproduksie (skrotumomvang (SCR)) en
winsgewindheidseienskappe (voerkraalwinsgewindheid (R-waarde)) vergelyk, om sodoende te
bepaal watter een die mees geskikte eienskap is om indirek vir voerkraalwinsgewindheid of groei, gebaseer op teeltwaardes en ekonomiese waardes vir die verskillende eienskappe, wat 'n
invloed op naspeense groei winsgewindheid het, gestruktueer.
(Ko)variansiekomponente, oorerflikhede en genetiese korrelasies vir en tussen begingewig (lW),
eindgewig (FW), voerinname (FI) en skouerhoogte (SHD) is bereken deur van 'n meereienskap
(REML) ontleding gebruik te maak. Hierdie teelwaardes (EBVs) is vervolgens in 'n seleksie-indeks
gebruik om 'n enkele ekonomies of voerkraal-winsgewindheids seleksie-indekswaarde (GTV) vir
elke dier te bereken. Hierdie ekonomiese waarde is 'n aanduiding van die bruto
winsgewindheidswaarde ofbruto toetswaarde (GTV) van die dier in 'n naspeentoets.
Die oorerflikheid, vanuit die meereienskapontleding vir R-waarde beraam, was 0.36. Hierdie
oorerflikheid dui daarop dat die eienskap oorerflik is en dat dit wel moontlik is om daarvoor te
selekteer. Die ooreflikhede van R-waarde, voorspel vanuit die enkeleienskap ewekansige regressieontleding
varieer tussen 0.57 en 0.62. Die genetiese korrelasie tussen R-waarde en ander
eienskappe, vanuit die meereienskap ontleding beraam, varieer tussen weglaatbaar klein tot hoog.
Die oorerflikheid van FeR was 0.34 en van RFI 0.31 met 'n genetiese korrelasie van 0.75 tussen die
twee eienskappe. Die genetiese korrelasie tussen R-waarde en FeR, en R-waarde en RFI was
onderskeidelik -0.92 en -0.59. Die rede vir die hoë negatiewe genetiese korrelasie tussen R-waarde
en FeR van -0.92 is omdat dieselfde komponente in die berekening van die twee eienskappe
gebruik is. Dit word ook in die genetiese tendense weerspeël. Die genetiese korrelasies en verwagte
gekorreleerde responsies tussen R-waarde en FeR, en tussen R-waarde en RFI dui daarop dat
stadiger genetiese vordering verkry sal word in R-waarde deur direkte seleksie vir beide FeR en
RFI as wat verkry sal word deur die direkte seleksie vir R-waarde. Wanneer 'n R-waarde egter nie
bereken kan word nie of waar dit nie moontlik is om direk vir R-waarde te selekteer nie, sal
vinniger genetiese vordering in R-waarde gemaak word deur die direkte seleksie vir FeR as vir
RF!. 'n Regressievergelyking is geformuleer (met 'n R2 van 0.82) om vir alle prestasiegetoetsde
bulle, waar bulle in 'n groep gevoer is en individuele voerinnames onbekend is, 'n
voerinnamewaarde te voorspel. Hierdie voorspelde voerinnames maak dit moontlik om vir elke
prestasiegetoetsde bul ,'n naspeengroei- of voerkraalwinswaarde (R-waarde) te bereken, al is hulle
individuele voerinnames onbekend. Vervolgens is drie verskillende R-waarde vir vleisproduksie vir
elke bul bereken naamlik, in 'n gunstige ekonomiese omgewing (FEE), 'n gemiddelde ekonomiese
omgewing (AEE) en 'n ongunstige ekonomiese omgewing (VEE). Die hoë Pearson en Spearman
korrelasies tussen die EBVs vir R-waarde, bereken in die AEE en die EBVs in die ander twee
ekonomiese omgewings, dui daarop dat die AEE gebruik kan word om EBVs vir naspeense groeiof
voerkraalwins te bereken. Dit is dus nie nodig om op 'n gereelde grondslag die karkasprys,
lewendige speenkalfprys of die voerprys te verander nie. Oorerflikhede, vanuit die meereienskap ontledings VIr lW, FW, FI en SHD verkry, was
onderskeidelik 0.41, 0.40, 0.33 en 0.51. Die hoogste genetiese korrelasies tussen die eienskappe
was 0.78 tussen lW en FW en 0.70 tussen FI en FW. GTV indekswaardes varieer tussen -Rl92.17
en R231.38 met 'n gemiddelde waarde van R9.31. Die Pearson korrelasies tussen die EBVs van
produksie- en doeltreffenheidseienskappe en GTV het tussen -0.51 en 0.68 gevarieer. Die
korrelasie naaste aan zero, van 0.26, was die korrelasie tussen GTV en die Kleiber-verhouding. Die
korrelasies tussen GTV en ADG, en GTV en FeR was onderskeidelik 0.68 en -0.51. Die
oorerflikhede van die verskillende eienskappe wat in die seleksie-indeks ingesluit is, dui daarop dat
die indekswaarde weloorerflik is en dat seleksie hiervoor wel moontlik is. Hierdie indekswaarde
kan deur die voerkraaiindustrie gebruik word om nageslag van diere met hoë GTV waardes te
selekteer om sodoende maksimum wins uit die voerkraai te genereer.
Die Pearson en Spearman korrelasies tussen R-waarde EBVs en die indekswaardes (GTV) was
besonder hoog (0.97). Hierdie hoë korrelasie dui daarop dat dit geen verskil sal maak watter een
van die twee metodes gebruik word in die berekeninge van 'n naspeense groei- of
voerkraalwinswaarde nie. Die seleksie-indeks metode is egter minder gekompliseerd met minder
aannames as in die geval van die rekeningkundige fenotipiese benadering (R-waarde). As gevolg
hiervan, word die naspeense seleksie-indeks waardes (GTV) aanbeveel om te gebruik as 'n
teeldoelwit in telingsprogramme om naspeense groei- of voerkraaiwins geneties te verbeter, eerder
as die meer gekompliseerde fenotipiese voerkraaiwins (R-waardes) metode.
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An analysis of risk management strategies for southern Alberta feedlotsFreeze, Brian S. 30 June 1988 (has links)
Feedlot finishing of beef cattle in Southern Alberta involves
income risk due to the variability of prices of feeders, feed and
finished cattle. Several strategies are available to reduce this
risk, including hedging of cattle on feed, participation in a Federal-
Provincial government and producer established income stabilization
program for finished cattle (National Tripartite Stabilization Plan)
and diversification of production plans.
This study evaluated the efficacy and interaction effects of these
strategies in reducing net income variability in cattle feeding in
Southern Alberta. Concerns that were addressed included: (1) whether
participation in hedging or Stabilization would increase firm-level
slaughter cattle output, (2) whether portfolio effects exist between
production and marketing alternatives, (3) whether participation in
Stabilization would reduce participation in hedging (4) whether
hedging performance could be increased by hedging the Canadian dollar,
and (5) whether privately supplied hedging versus publicly supplied
Stabilization is better able to handle income risk in cattle feeding.
The theory of decision making under uncertainty was reviewed to
determine how to best incorporate the risk aspects of the feedlot ,
management problem. Expected Value-Variance (EV)and safety-first risk
analyses were identified as frameworks for formulation of the feedlot
management problem in a mathematical programming context. Using data
from 1976-87, linear risk programming (MOTAD and Target MOTAD) models
of the feedlot process were constructed to analyze the alternatives
for reducing income risk.
Results for the 1986-87 feeding year suggested that, at moderate
levels of risk aversion, feedlot managers should maintain high levels
of hedging of both live cattle and the Canadian dollar with moderate
participation (25 percent of cattle on feed) in the Stabilization
plan. Significant portfolio effects were present. Hedging, but not
Stabilization, was found to increase firm-level output by increasing
the average weight to which a group of cattle would be finished.
Participation in Stabilization was found to reduce hedging
participation by an average of 10 percent. Hedging of the Canadian
dollar improved the performance of live cattle hedging. Whether
hedging was better at reducing risk and maintaining income than
Stabilization depended on the definition of risk. / Graduation date: 1989
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IN VITRO AND IN VIVO EVALUATION OF RECONSTITUTED SORGHUM GRAIN FOR USE IN HIGH CONCENTRATE FEEDLOT DIETS.PROUTY, FRANK LOUIS. January 1983 (has links)
Studies were conducted to: (1) examine an in situ technique with sorghum grain substrates using monofilament nylon bags, (2) evaluate in vitro various reconstituted sorghum grain treatments, (3) determine digestibility and nitrogen balance of steers fed reconstituted sorghum grain and (4) evaluate sorghum grain processing methods on performance of finishing steers. Dry matter efflux, DME (water bath) and in situ dry matter disappearance, ISDMD (ventral sac of rumen) from nylon bags were higher (P < .05) as bag porosity (5 to 80 um) and incubation time (4 to 24 h) increased, and as substrate weight: bag surface area ratio (7 to 56 mg/cm²) decreased. High linear correlations were obtained between DME and ISDMD, and also between nitrogen efflux and in situ nitrogen disapperance. No permanent influx of ruminal dry matter into nylon bags were detected. In vitro dry matter digestibility (mixed rumen inoculum) of reconstituted whole sorghum grain was influenced (P<.001) by grain moisture level (18 to 31%), constant or variable temperature during storage (-18 to 41 C) and length of storage time (3 to 28 d). All interactions of these three factors were significant (P<.05 or higher). Short term flushing with O₂, CO₂ and N₂ did not affect (P>.10) the digestibility of reconstituted whole sorghum grain. With reconstituted whole sorghum grain, grain pH could be used as a satisfactory measure of quality control. Apparent digestion coefficients for dry matter, organic matter, protein and energy were similar (P>.05) for steers fed 90% concentrate diets containing reconstituted whole or flaked sorghum grain. Nitrogen retention as a percent of nitrogen intake was 35% higher (P<.05) for steers fed reconstituted than flaked sorghum grain diets. In two finishing trials with steers, feed intake and feed conversion were higher (P<.05) for dry rolled than for flaked or reconstituted sorghum grain.
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Factors influencing diet composition of beef cattle grazing mixed conifer mountain riparian areasDarambazar, Enkhjargal 10 October 2006 (has links)
Two trials were conducted to evaluate changes in the quantity, quality, and moisture of available forage in the pasture, and shrub utilization by cattle during a 30-d late summer grazing period (Trial 1) and the effect of cow age (experience) on grazing distribution and diet composition (Trial 2) in mountain riparian areas. In the trial 1, a pasture (44.7 ha) in the Catherine Creek site at OSU���s Hall Ranch in northeast of Oregon was grazed with 30 yearlings and 30 mature cow/calf pairs from early August to early September in 2001, and from late July to late August in 2002. Sampling dates were d 0, d 10, d 20, and d 30 of the grazing period. The forage availability before grazing was 1058 kg/ha and declined to 323 kg/ha at the end of the grazing period (P<0.10). Grasses dominated the pasture, followed by forbs, grasslikes, and shrubs. Kentucky bluegrass was the most prevalent forage species followed by timothy, sedges, and common snowberry. The highest percent disappearances of forage species was (83.7-92.7%) observed with quackgrass, western fescue, California brome, redtop, and heartleaf arnica, though their initial contributions to the available forage were less than 5%. High levels of shrub utilization were observed from d 20 through the end of the grazing period (45% for willow and 59% for alder). Forbs and shrubs did not vary in moisture content between the 10 d intervals and across the years averaging 59% and 61%, respectively (P>0.10). In contrast, the moisture content of grasses were over 50% at the beginning of the grazing period but declined dramatically to 34% from d 10 to d 20. Likewise, forbs and shrubs were higher (P<0.05) than grasses in CP (11, 14, and 6%,
respectively) and IVDMD (58, 49, and 42% respectively). In summary, our results suggest that cattle grazing late summer riparian pastures will switch to intensive shrub utilization when grasses decline in quality and quantity, and forbs decline in quantity. In the trial 2, thirty first calf heifers, and thirty mature cows were randomly assigned to four pastures (15 head per pasture, average 21.5 ha) in the Milk Creek site of Hall Ranch from late July to early September of 2000 and 2001. Botanical composition of diets was determined by analyzing the feces from 10 animals (5 per pasture) in each treatment during the fourth week of the trial using the microhistological procedure. Correction factors were calculated for the 22 major plant species. First calf heifers had higher portions of grasses (75% versus 71%; P<0.05), but lower portions of shrubs and trees (9% versus 13%; P<0.10) as compared to mature cow diets, respectively. On an individual species basis, ponderosa pine consumption was a major contributor with mature cows consuming greater quantities (P<0.10) than first calf heifers. In summary, mature cows seem to have selected diet less in the amount of grasses and more in the amount of shrubs and trees as compared to younger cows. / Graduation date: 2004
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Effect of soybean protein supplements with low quality roughage on performance and digestive characteristics of weaned beef steersAlbro, Jonathan D. 03 February 1992 (has links)
Graduation date: 1992
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