Thesis (Ph. D.)--University of Wisconsin--Madison, 1968. / Typescript. Vita. Includes bibliographical references.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 53-58). Also available on the Internet.

This study was conducted to determine the effect of modified crude protein (CP) concentrations and a supplemental directed microbial in the milk replacer fed to Holstein calves during elevated ambient temperatures. Fortyour Holstein calves were randomly assigned treatments in a 2x2 factorial arrangement of treatments. Weekly and daily measurements were taken and analyzed using PROC MIXED in SAS. Calves fed increased CP concentrations in the milk replacer had greater body weight and frame measurements during the pre-weaning phase and at weaning. Directed microbial supplementation led to increased ADG during the post-weaning phase. Directed microbial supplementation and milk replacer modification helped alleviate heat stress through decreased rectal temperatures and rectal scores. Directed microbial supplementation increased fecal scores. Calves fed the control diet had greater volatile fatty acid concentrations in the rumen fluid, showing signs of increased rumen papillae development.

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The objective was to summarize management practices, identify factors associated with bacterial counts, and describe the variation in total solids concentrations of milk or milk replacer in automated feeders. Six dairy calf operations in Virginia and 4 in Minnesota employing 1 to 2 sophisticated automated calf feeders were visited biweekly for 26 to 28 wk. An initial management survey was conducted for each farm. Observations on facilities, calf weights and heights, blood samples to estimate serum total proteins, treatment records, digital feeding behavior records, and milk or milk replacer (MMR) samples were collected at each visit. Additional milk replacer (MR) samples were collected for 4 wk pre- and post-circuit cleaning. Samples of MMR were plated on Aerobic Plate Count (APC) and Coliform Count (CCP) Petrifilms. Total solids concentration was estimated for MR samples by refractometry. Feeding plans varied widely between farms. Estimates of calf growth were near industry standards, but the proportion of calves receiving treatment was elevated. Least squares mean APC and CCP were 5.26 and 3.01 log10 cfu/ml for Virginia and 3.80 and 0.61 log10 cfu/ml for Minnesota. Circuit cleaning (CC) caused 13 and 16% log reduction in APC and CCP. However, more frequent CC/wk increased bacteria. Mixer/heat exchanger cleanings decreased bacteria during biweekly farm visits. Chlorine bleach reduced bacteria. Use of silicone feeder hoses increased bacteria. A quadratic effect of MMR liters delivered/d was observed; liters delivered > 147 L decreased APC. Automated feeders delivered 12.26% of MR samples > 2% over and 25.71% > 2% under target solids concentration. / Master of Science

Twenty four Jersey calves were randomly blocked according to sex and birth date, to determine the effects of supplementing Carica papaya seed (Linn) meal (CPSM) on health and growth performance of calves. In the first study, calves were fed CPSM for only 2 days to determine faecal pathogen population. In the second study; calves were randomly assigned at birth to three treatments and fed until weaning at 42 days. Each treatment had six calves. Treatments were; 1) a control group, which did not receive additive; 2) a group that was supplemented 5 g/d of Carica papaya seed meal (CPSM) and 3) the last group that was supplemented 5 g/d of a commercial product containing Lactobacillus acidophilus (Lact). After receiving milk with colostrum from their dams for 3 consecutive days after birth, calves had commercial starter pellet and fresh water ad lib. Treatments were added to whole milk from day 4 and fed to calves before being allowed to suckle from the dams for 30 min three times a day (08:00; 12:00 and 17:00). Calf starter dry matter intake (DMI) was evaluated daily while body weight (BW) and body structural growth were measured weekly. Faecal samples were collected directly from the rectum on day 7 and 10, before and after receiving CPSM respectively. The DMI; DMI/BW; BW and BWG of calves did not differ among treatments, and averaged 305.4 g/d; 7.7 g/d per BW; 39.4 kg and 32.1 kg, respectively. The initial BW, 22.2 ± 1.49 kg did not differ among groups, but the weaning BW was higher (p<0.05) for CPSM fed calves compared to control diet fed calves. It did not differ between control and Lact calves. Calves in Lact and CPSM treatments had similar average daily gain (ADG) and heart girth (HG), which were higher (p<0.05) than calves fed the control treatment. Calves fed CPSM had higher (p<0.05) hip width (HW) and shoulder height (SH) than control calves. There were effects of time (p<0.001) for starter DMI/BW, ADG and all structural body parameters, and effects (p<0.05) of interaction between time and treatments for only starter DMI/BW, ADG and HG. The CPSM treatment reduced faecal coliforms and E. coli (p<0.05) by 93.6% and 96.1%, respectively; and tended to reduce Enterobacteriaceae (p=0.056) by 96.4%. The present study revealed that feeding CPSM to calves during the pre-weaning period increased growth performance by improving average daily gain, feed efficiency and enhancing health status due to low faecal pathogen count / Agriculture, Animal Health and Human Ecology / M. Sc. (Agriculture)

Thesis (MScAgric)--University Stellenbosch, 2001. / ENGLISH ABSTRACT: The aim of this study was to estimate genetic parameters as well as to evaluate the influence of some genetic factors on preweaning growth traits in a multi breed beef cattle population. These preweaning growth traits were birth weight (BW), weaning weight (WW) and average daily gain (ADG). Three aspects were addressed in this particular study; namely the Estimation of (co)variance components and genetic parameters, the effect of sire breeds and dam genotypes and the contribution of Charolais and Angus breeding levels on weaning traits in a multibreed beef cattle herd. Variance components and resulting genetic parameters of BW, WW and ADG in the population were estimated by Restricted Maximum Likelihood (REML) procedures. Four different unitrait and multitrait animal models were fitted ranging from a simple model with the animal direct effects as the only random effect to the model allowing for both genetic and permanent maternal environmental effects. The model that included directgenetic and permanent maternal environmental effects generally best described the data analysed. The simple model ignoring maternal effects most likely inflated direct heritability estimates. Direct heritability estimates were 0.11, 0.19, and 0.15 for BW, WW and ADG, respectively, fitting a multitrait model that comprised of both the genetic and maternal environmental effects. Under this comprehensive model, maternal heritabilties were low under both analyses, ranging from 0.02 to 0.10. Permanent maternal environmental effects were more important than maternal additive genetic effects for WW and ADG. Direct and maternal genetic correlations range from 0.42 to 0.44 for BW, -0.22 to -0.25 for WW and -0.17 to -0.23 for ADG, while the corresponding estimates ofunitrait analysis varied from 0.58 to 0.61 for BW, -0.43 to-0.53 for WW and -0.49 to -0.79 for ADG. The effect of Charolais and Hereford sires and dam breed genotypes on BW and WW in calves of Hereford, F I, two and three breed rotational as well as terminal crosses among the Charolais, Hereford, Angus and Bonsmara breeds were investigated. BW and WW of the Charolais sired calves were significantly (P<O.OOl) heavier than the Hereford sired calves. Angus dams produced calves of smaller (P<0.05) BW than those of purebred and crossbred dams. The majority of the crossbred dams were not significantly different in BW of calves. With regard to WW, with the exception of 3/4H1I4A, all crossbred dams were superior (P<0.05) to Angus and Hereford dams. Calves of crossbred dams were on the average 8% heavier at weaning than calves of purebred dams. Crossbred dams, with intermediate Charolais contribution tend to wean heavier calves. Data collected were also analysed to determine the optimum breeding levels of Charolais and Angus, fitting a unitrait animal model. Further, the estimated heritabilities were subsequently used to predict direct and maternal breeding values (Best linear unbiased predictions) for individual animals. Best linear unbiased estimates (BLUEs) were also calculated for the traits. BLUEs, direct and maternal breeding values per genetic group estimated were regressed on proportions of Charolais and Angus breeding, respectively. BLUEs of BW, WW and ADG increased with increasing the proportion of Charolais while they decreased with increasing Angus breeding levels. In general, maternal breeding values increased with increasing the proportions of both breeds. Direct breeding values of Charolais increased and reached maximum values at 35, 38, and 45% proportion of Charolais for BW, WW and ADG, respectively. No optimal Angus proportion was found within these specific environmental conditions. In this herd it may be suggested that increasing the proportion of Charolais to intermediate levels would tend to improve the performances of preweaning traits. / AFRIKAANSE OPSOMMING: Die doel van die studie was om genetiese parameters in 'n meerras vleisbeeskudde te beraam, sowel as om die invloed van sekere genetiese faktore te evalueer. Die voorspeense groei-eienskappe het geboortegewig (BW), speengewig (WW) en gemiddelde daaglikse toename (ADG) ingesluit. Drie aspekte is in dié betrokke studie ondersoek, naamlik; die beraming van (ko )variansiekomponente en genetiese parameters, die invloed van ras van vader en moedergenotipe en die invloed van Charolais en Angus bydrae op speeneienskappe in 'n meerras vleisbeeskudde. Variansiekomponente en afgeleide genetiese parameters vir BW, WW en ADG in die kudde is met behulp van die Beperkte Maksimum Waarskynlikheidsprosedure (REML) beraam. Vier verskillende enkel- en meereienskapmodelle is gepas, wat vanaf 'n eenvoudige model wat slegs die direkte effek as enigste toevallige effek, tot dié model waarin beide die genetiese en permanente mateme omgewingseffekte ingesluit is. Die model wat beide die direkte en permanente mateme effekte ingesluit het, het die data die beste gepas. Die eenvoudige model, wat die mateme effekte nie insluit nie, het in alle waarskynlikheid die direkte oorerflikhede oorberaam. Die direkte oorerflikheidsberamingsas onderskeidlik 0.11, 0.19 en 0.15 vir BW, WW en ADG met dié meereienskapmodel wat beide genetiese en mateme effekte ingesluit het. Met die omvattende model was die mateme oorerflikhede laag en het van 0.02 tot 0.10 gewissel. Die permanente mateme omgewingseffekte was belangriker as die direkte mateme effekte vir WW en ADG. Die genetiese korrelasies tussen direkte en mateme effekte het vir BW tussen 0.42 en 0.44, vir WW tussen -0.22 en -0.25 en vir ADG tussen -0.49 en -0.79 gewissel. Die invloed van Charolais en Hereford bulle en moederrasgenotipes op BW en WW van Hereford, F 1, twee- en drieras rotasie sowel as terminale kruisings tussen die Charolais, Hereford, Angus en Bonsmara is ondersoek. BW en WW van kalwers van Charolais bulle was betekenisvol (P<O.OOl) swaarder as kalwers van Hereford bulle. Angus koeie het kalwers met laer (P<0.05) BW as die van ander suiwer en kruisraskoeie geproduseer. Kalwers van die meerderheid kruisraskoeie het egter nie in BW verskil nie. Wat WW betref, maar met die uitsondering van %HYtA, was alle kruisraskoeie beter (P<0.05) as beide Angus en Hereford koeie. Kalwers van kruisraskoeie was gemiddeld 8 % swaarder met speen as kalwers van suiwerraskoeie. Kruisraskoeie met intermediêre vlakke van Charolaisbydrae het geneig om die swaarste kalwers te speen. Die data is verder ook geanaliseer om die optimum vlakke van Charolais en Angus, deur die passing van 'n enkeleienskap dieremodel, te bepaal. Die beraamde oorerflikhede is vervolgens gebruik om direkte en mateme teelwaardes (Beste liniêre onsydige voospellers ) vir individuele diere te voorspel. Beste liniêre onsydige beramings (BLUE's) is ook vir elke eienskap bereken. Die regressies van BLUE's, direkte en mateme teelwaardes per genetiese groep bereken, is vervolgens op proporsie Charolais en Angus bydraes onderskeidelik gepas. BLUE's vir BW, WW en ADG het met toename In Charolaisproporsie toegeneem, terwyl dit met toename in Angusbydrae afgeneem het. In die algemeen het mateme teelwaardes met toename in die bydrae van beide rasse toegeneem. Direkte teelwaardes van die Charolais het toegeneem en maksimum waardes by 35, 38 en 45 % proporsie Charolais vir onderskeidelik BW, WW en ADG bereik. Vir die Angus is geen optimum proporsie in dié spesifieke omgewing gevind nie. In dié kudde word intermediêre Charolais vlakke vir die verbetering van voorspeense eienskappe aanbeveel.

Master of Science / Department of Animal Sciences and Industry / Christopher Reinhardt / Crossbred bull calves at high risk for morbidity (n = 190; BW = 159 ± 68 kg) were received at a commercial stocker operation to evaluate the effects of meloxicam administered at the time of castration on performance and health through d 30 post-arrival. Calves were assigned randomly to receive either a whey-powder placebo (CON), 0.5 mg/kg BW meloxicam (LOW), or 1.0 mg/kg BW meloxicam (HIGH) administered orally. Calves were vaccinated, knife-castrated, and received experimental treatments on d 0. Meloxicam had no effect on ADG (P ≥ 0.63), morbidity (P = 0.66), or mortality (P = 0.62). A second study was conducted using crossbred calves from the southeastern US and Mexico (n = 472; BW = 227 ± 45 kg) to evaluate effects of an injectable trace-mineral solution administered at time of arrival at a commercial stocker operation on animal performance, health, and serum concentrations of Cu, Mn, Se, and Zn on d 0 and d 45. Calves were assigned randomly to receive saline (CON; 1.0 mL/45 kg BW) or injectable trace mineral (ITM; 1.0 mL/45 kg BW) on d 0. Average daily gain from d 0 to d 42, overall ADG from d 0 to d 139, mortality, and morbidity were not different (P ≥ 0.31) between treatments. Calves originating from the Southeastern US had greater (P < 0.01) overall ADG from d 0 to 139. There were no source effects (P ≥ 0.21) on initial serum mineral concentrations for Mn or Zn; however, cattle originating in Mexico had lesser serum Cu (P < 0.01) and cattle originating in the Southeastern US tended to have lesser serum Se (P = 0.06). On d 45, there were no treatment differences (P ≥ 0.20) in serum concentrations of Cu, Mn, or Zn but cattle that received ITM tended (P = 0.09) to have elevated serum Se concentrations compared to those that received CON.