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Sex differences in bovine lipoprotein amplitude and its components during growth and development.Ochoa, Mario Fontes January 1988 (has links)
Three (intact) Angus males and three females which were half-sibs and born within 21 days of each other were selected for this study. Each animal was bled and biopsied periodically from suckling calves to mature slaughter weights, to determine the qualitative composition of lipoproteins and to differentiate the lactate lipogenic activity of subcutaneous tissue during growth and development. At slaughtered, a sample of intramuscular adipose tissue was taken to determine the lactate lipogenic activity at this location. Two days later, one side of each carcass was separated into wholesale cuts. Each wholesale cut was dissected into separable bone and soft tissue and sampled for protein, lipid and moisture determinations. The elution profiles of lipoproteins were similar for all animals. Major peaks observed were (1) very low density (VLDL), (2) low density (LDL) and (3) high density lipoproteins (HDL). Triglycerides, cholesterol and protein were not significant (P < .05) between males and females for the VLDL. At one year of age, females had large (P < .05) amounts of protein for the HDL. In both groups of cattle, largest (P > .05) amounts of protein were greater in the HDL at 9 months of age. Profiles of HDL apoproteins at all ages showed that in both groups of cattle, a distinct band with a weight of about 28,000 was present representing apo-AI. Apo-protein components of pooled LDL fractions showed a protein which was unable to enter the acrylamide gel (7.5 – 20%) used. The component may represent apo-B with a molecular weight of about 250,000. The lactate lipogenic activity of subcutaneous adipose tissue was larger in the males and only significant (P < .05) at 9 months of age. The lipogenic activity was higher (P > .05) in the subcutaneous tissue when compared to the intramuscular tissue at slaughter. In both cases, males showed to use more (P > .05) lactate for fatty acid synthesis in intramuscular and subcutaneous tissue than the females. Magnitude of quality and yield for carcass traits were better for the males than females. Bone, meat and lean weights were significantly (P < .05) greater for the males, however, on a percentage basis per side weight, differences were eliminated. In addition, no significant (P > .05) effect was present between male and female wholesale and side carcass composition.
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Effect of age on the accuracy of selection among beef calves for growth rate and typeMeyerhoeffer, David Clyde 01 August 2012 (has links)
The data for this study were taken from the calf crops born from 1950 through 1958 at the Beef (Battle Research Station, Front Royal, Virginia. These included 556 Angus, 556 Hereford, and 590 Shorthorn calves. / Master of Science
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Genetic variability of growth curves in dairy heifersYeboah, Charles Asomaning. January 2009 (has links)
The objective of this study was to evaluate the variability of growth curves of dairy heifers and estimate genetic parameters. 15066 records taken from birth until 26 months (808 days) on 2754 heifers of Quebec were considered. The pedigree file comprised 10123 animals. The Mixed procedure of SAS with ordinary polynomials was used for simple phenotypic analyses, fitting fixed linear, quadratic and cubic regressions of body weight (in kilograms) on age (in months) as well as random intercept, and random linear and quadratic regressions for each animal. The Wombat program (Meyer, 2007), with Legendre polynomials was used to estimate the genetic parameters by fitting fixed herd-year-season of birth and quartic regression of body weight on age in days, as well as random regressions for quadratic additive genetic and cubic permanent environmental effects. Heritability estimates of body weight ranged from 0.22 at around 70 days to 0.45 at around 210 days. Heritabilities of body weight at birth and 808 days were 0.35 and 0.32, respectively. The additive genetic correlations between body weights at different ages ranged from -0.37 to 1.00. In general, the genetic correlations were higher than the permanent environmental and phenotypic correlations.
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Genetic variability of growth curves in dairy heifersYeboah, Charles Asomaning. January 2009 (has links)
No description available.
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A study of growth rate and type score of offspring of four different sires in Hereford cattleLester, John Carson January 1949 (has links)
M.S.
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A study of growth rate and type score of offspring of four different sires in Hereford cattleJanuary 1949 (has links)
M.S.
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Genetic analyses of growth traits for the Simbra composite breedSmith, Algina Maria Johanna 03 1900 (has links)
Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The aim of this study was to evaluate the Simbra breed of cattle for certain non-genetic as well as
genetic parameters influencing live weight traits in the breed. Live weight traits included birth weight
(BW), weaning weight at 200 days of age (WW), yearling weight at 400 days of age (YW) and 600
day weight. The Simmental and Simbra Breeders’ Society of Southern Africa availed 148751 records
for analysis from the year 1987 till 2009. Due to deficiencies of various kinds in the data and the
restrictions imposed for the purposes of the analysis, 56.44% of the records were discarded for BW,
76.55% for WW, 91.54% for YW and 96.32% for 600-day weight.
Non-genetic parameters affecting BW, WW, YW and 600-day weight were analysed using the
General Linear Models procedure of the Statistical Analysis System (SAS, 2004) software. During
this procedure sex of calf, breed composition of calf, breeder of calf, month of birth, year of birth and
dam age were fitted in the models. BW, WW, YW and Mature Cow Weight (MCW) were fitted as
covariates where possible. It was determined that the fixed effects of sex, dam age, breeder, year
and month had a significant (P < 0.05) effect of BW and WW while dam age was not significant (P >
0.05) for YW or 600-day weight. Breed was found non significant for YW. Breeder of the calf
accounted for the most variation in BW, WW, YW as well as 600-day weight with a contribution of
17.55%, 25.77%, 18.35% and 10.71% respectively. Tukey’s multiple range tests were performed for
testing differences between least square means. Results indicated male calves to be significantly
heavier than females for all four traits measured. Breed composition differences were found
significant until WW. Calves with higher Brahman percentage weighted more at birth while calves with
higher Simmental percentage weighed more at weaning. Middle-aged dams were found to account
for heavier calves at both BW and WW while very young dams and very old dams produced lighter
calves for the two live weight traits. A number of years showed a significant difference from each
other for all the traits measured as well as month of birth.
(Co) variance components and the resulting genetic parameters were estimated using single-traits
and three-traits analysis by means of Restricted Maximum Likelihood procedures (Gilmour et al., 2002). Appropriate models were selected by means of Log likelihood ratios tests and implemented to
estimate genetic parameters for each of the traits studied. Direct additive heritabilities for BW, WW,
YW and 600-day weight in the Simbra were respectively 0.56 ± 0.08, 0.67 ± 0.09, 0.70 ± 0.11 and
0.10 ± 0.03 when the most suitable animal model was fitted in single-trait analyses for each trait.
Single traits analysis also included maternal additive as well as the correlation between direct additive
and maternal additive for BW, WW and YW. Maternal additive heritability estimates of 0.24 ± 0.07,
0.33 ± 0.06 and 0.38 ± 0.07 was obtained for BW, WW and YW. Correlation estimates between direct
additive and maternal additive were -0.75 ± 0.07, -0.93 ± 0.07 and -0.85 ± 0.08 for BW, WW and YW
respectively. Furthermore, dam permanent environment was included as an additional random effect
that increased the log likelihood value significantly. A value of 0.04 ± 0.05 was obtained for dam
permanent environment estimate for WW. When a three traits analysis was done for the same traits,
but using a significantly smaller data set, direct additive heritabilities of 0.24 ± 0.07 for BW, 0.33 ±
0.06 for WW and 0.38 ± 0.07 for YW were obtained. Genetic and environmental correlation estimates
of 0.18 ± 0.16 and 0.09 ± 0.06 between BW and WW; 0.27 ± 0.16 and 0.07 ± 0.06 between BW and
YW; as well as 0.52 ± 0.10 and 0.45 ± 0.05 between WW and YW were obtained during the three-trait
analysis. The magnitude of the heritabilities obtained in this study indicates that the opportunity exists to make genetic progress through proper selection objectives. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die Simbra bees ras te evalueer op grond van sekere niegenetiese
so wel as genetiese parameters wat lewende gewig beïnvloed. Gereelde en akkurate
opnames van lewende gewig, is ‘n goeie indikasie van groei potensiaal en is ‘n minimim vereiste vir
meeste beesras telings genootskappe. Lewende gewigs eienskappe sluit in geboorte gewig (BW),
speen gewig gemeet op 200 dae (WW), jaaroue gewig gemeet op 400 dae (YW) en finale gewig
gemeet op 600-dag gewig. Die Simmentaler en Simbra genootskap van Suid Afrika het 148751
rekords beskikbaar gestel vir evaluasie vanaf die jaar 1987 tot 2009. Daar was egter groot tekort
komings aan die gewewe data en dus is daar 56.44% van die rekords vir BW nie gebruik nie, 76.55%
vir WW, 91.54% vir YW en 96.32% vir 600-dag gewig.
Nie-genetiese parameters wat die onderskeie lewende gewigte beïnvloed het, is geanaliseer deur
Algemene Lineêre Modelle met behulp van die Statistiese Analitiese Sisteem (SAS, 2004) sagteware.
Gedurende die analise is geslag van die kalf, ras samestelling, teler van die kalf, maand van
geboorte, jaar van geboorte asook moeder ouderdom gepas in die modelle vir die onderskeie
gewigte. Geboorte gewig, speen gewig, jaaroue gewig asook volwasse koei gewig is gepas in elk
van die modelle as ko-variate. Volgens die resutate is daar vasgestel dat geslag van die kalf, moeder
ouderdom, teler, jaar, maand en volwasse koei gewig almal ‘n betekenisvolle (P < 0.05) invloed
gehad het op BW en WW. Die moederouderdom was nie betekenisvol (P > 0.05) vir YW of 600-dag
gewig nie. Die ras samestelling was ook nie betekenisvol gevind vir YW. Teler van die kalf was
verantwoordelik vir die meeste variasie in BW, WW, YW asook 600-dag gewig met ‘n bydrae van
17.55%, 25.77%, 18.35% en 10.71% onderskeidelik. Tukey se veelvuldige vergelykings toets is
gebruik om onderskeid te tref tussen “least square means”. Resultate het aangedui dat manlike diere
swaarder weeg as vroulike diere tot en met finale gewig. Ras samestelling vir BW en WW was
betekenisvol verskillend vir die diere. Kalwers met ‘n hoër Brahmaan persentasie het swaarder BW
opgelewer as dié met ‘n hoër Simmentaler persentasie, terwyl kalwers met ‘n hoër Simmentaler
persentasie swaarder geweeg het met speen en dus ideal is vir speen kalwer produksie stelsels.
Middel-jarige moeders het swaarder kalwers geproduseer met geboorte en speen as baie jong en -
ou moeders. Sommige jare waarin van die kalwers gebore is, het ook betekenisvol van mekaar
verskil asook die maand waarin die kalf gebore is. Ko) variansie faktore en opeenvolgende genetiese parameters is bepaal met behulp van enkeleienskap
analises asook meervuldige-eienskap analises deur middel van die “Restricted Maximum
Likelihood” prosedure (Gilmour et al., 2002). Modelle is opgestel vir elk van die gewigte deur die
geskikte genetiese terme toe te voeg en te toets met behulp van “Log likelihood tests” om sodoende
die onderskeie genetiese parameters te bepaal. Direkte genetiese oorerflikhede bepaal deur enkeleienskap
analises vir die Simbra ras was as volg, 0.56 ± 0.08 vir BW, 0.67 ± 0.09 vir WW, 0.70 ± 0.11
vir YW en 0.10 ± 0.03 vir 600-dag gewig. Die direkte maternale genetiese oorerflikhede tydens
dieselfde enkel-eienskap analise vir die onderkeie gewigte was 0.24 ± 0.07 vir BW, 0.33 ± 0.06 vir
WW en 0.38 ± 0.07 vir YW. Korrelasies tussen direkt genetiese en direk maternale eienskappe was
sterk negatief. ‘n Waarde van -0.75 ± 0.07 is bepaal vir BW, -0.93 ± 0.07 vir WW en -0.85 ± 0.08 vir
YW. ‘n Adisionele faktor was ook ingelsuit vir WW, naamlik die permanente omgewing van die
moeder, wat ‘n waarde opgelewer het van 0.04 ± 0.05. Tydens die veelvuldige-eienskap analise het
die oorerflikhede merkwaardig verminder vir die betrokke gewigte en kan ook waargeneem word as
die meer korrekte genetiese weergawe. Direkte genetiese oorerflikhede van 0.24 ± 0.07 vir BW, 0.33
± 0.06 vir WW en 0.38 ± 0.07 vir YW was bepaal. Hierdie matig tot hoë parameters dui op genetiese
vordering deur middel van korrekte seleksie prosedures. Genetiese- en omgewing korrelasies is ook
bepaal tydens die analise en het positiewe waardes opgelewer. ‘n Genetiese korrelasie waarde van
0.18 ± 0.16 tussen BW en WW is bepaal asook ‘n waarde van 0.27 ± 0.16 tussen BW en YW en ‘n
waarde van 0.52 ± 0.10 tussen WW en YW. Hierdie korrelasies dui daarop dat na-speengewigte
vermeerder kan word deur te selekteer vir verhoogde WW sonder om BW dramties te vermeerder.
Omgewings korrelasie waardes van 0.09 ± 0.06 tussen BW en WW, 0.07 ± 0.06 tussen BW en YW
asook ‘n waarde van 0.45 ± 0.05 tussen WW en YW is gevind. Genetiese neigings is bepaal vir die
onderskeie gewigte deur die gemiddelde voorspelde teelwaardes aan te teken teenoor elke jaar wat
bereken was tydens die enkel-eienskap analises vir die onderskeie gewigte. Groot variasie asook
negatiewe tendense vir WW en YW is ondervind van jaar tot jaar en dui daarop dat die seleksie
doelwitte vir lewendige gewig nie in plek gestel is nie en is dit nodig om te her evalueer.
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The effects of different dietary fibre levels on methane production and growth performance of Bonsmara and Nguni steersJiyana, Sanele Thabani 12 1900 (has links)
The aim of the study was to determine the effects of different dietary fibre levels on methane production and growth performance of Bonsmara and Nguni steers. Nine Bonsmara and nine Nguni male weaners aged 8 – 9 months were used for the study. On arrival, animals were fed Eragrostis curvula hay on ad libitum basis for the first 14 days as part of adaptation to the feedlot environment. Animals were gradually adapted to treatments to prevent metabolic disorders. The study was conducted as a 3 x 3 x 2 factorial experiment. Treatments were allocated in a completely randomised design. Data were submitted to analysis of variance (ANOVA). Student's t-LSD was calculated at the 5 % level (P < 0.05) to compare treatment means for significant effects. Feeding a diet that is low in crude fibre content had significantly increased (P < 0.05) growth performance in both breeds. Bonsmara steers had significantly higher growth performance (P < 0.0001) across all treatment diets compared to Nguni steers. High rumen total microbial count was observed in animals that received diets with low crude fibre. Reducing dietary crude fibre resulted in reduced methane production. Low dietary fibre showed low rumen archaea counts. There was a positive correlation between rumen pH and methane emission for both Bonsmara (R2 = 0.9105) and Nguni (R2 = 0.9517) steers. However, a negative correlation was observed between rumen total microbial count and feed conversion ratio for both Bonsmara (R2 = 0.8286) and Nguni (R2 = 0.7208) steers. The low rumen archaea counts were detected from the Bonsmara. Feeding diets with low fibre levels is recommended for improving growth performance and reducing methane production for Bonsmara and Nguni steers. / Agriculture and Animal Health / M. Sc. (Agriculture)
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The financial and management implications of bovine somatotropin on the Arizona dairy industrySchoeffling, James Robert, 1959- January 1988 (has links)
This study examines how Bovine Somatotropin (BST) may impact Arizona dairy producers. The results of dairy scientists experimenting with BST are summarized in terms of reported milk yields and possible changes in feeding and herd management. Dairy enterprize budgets representative of Arizona are constructed to examine how income statements may change if BST is approved. The effects of increased milk supply on Arizona milk prices are estimated using the institutional structure of the Central Arizona Order and the United Dairyman of Arizona. Results of experiments with BST in Arizona are used to generate net returns at several rates of adoption under changing milk prices for three dairy farms in Arizona.
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Effects of estradiol-17β implants from birth to slaughter on performance, carcass, sensory traits and endocrine aspects of young bulls and steersHopkins, Trudy D. January 1986 (has links)
Call number: LD2668 .T4 1986 H66 / Master of Science
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