The first objective of the two studies in the research herein was to evaluate growth, performance and carcass quality and composition traits from a group of spring born calves sired by Charolais, Braunvieh, or Simmental bulls. Growth traits analyzed included birth weight (BW), weaning weight (WW), and hip height (HH). Carcass quality and composition traits analyzed included hot carcass weight (HCW), rib eye area (REA), back fat thickness (BF), marbling score (MS), and yield grade (YG). Analysis revealed Simmental sired calves were significantly heavier (P<.05) at birth when compared to Charolais and Braunvieh sired calves. Braunvieh sired calves were reported to be significantly (P<.05) shorter than Simmental sired calves for hip height. Hot carcass weight analysis revealed that Charolais sired calves were significantly (P<.05) heavier when compared to Braunvieh sired calves. No individual sire breed group displayed any significant differences for weaning weight, rib eye area, back fat thickness, marbling score, or yield grade. The second objective was evaluate potential SNP associations on four candidate genes with growth, performance, and carcass composition traits in a population of crossbred steers sired by Charolais, Braunvieh, and Simmental bulls. Traits analyzed for growth, performance, and carcass traits were previously mentioned. Analysis was performed on 38 steer calves. Single nucleotide polymorphisms within four candidate genes including Thyroglobulin (TG), Adiponectin (ADPOQ), Insulin like growth factor-1 (IGF-1), and Calpastatin (CAST) were chosen for analysis. A total of 14 SNP on TG, ADPOQ, CAST, and IGF-1 genes were significantly associated with birth weight and weaning weight. Analysis revealed 13 SNP on TG, ADPOQ, IGF-1, and CAST genes significantly associated (P<.05) with HCW, BF, MS, and YG. No markers were reported to be significantly associated (P<.05) with HH or REA. A total of 11 markers with 3 markers located on the ADPOQ gene, 1 marker located on the IGF-1 gene, 3 markers located on the TG gene, and 5 markers located on the CAST gene were significantly associated with both growth and carcass traits.

Reducing the particle size of sodium chloride crystal would increase its dissolution rate leading to a more efficient transfer of the ions to the taste buds and hence perhaps a saltier perception of foods. The objective of this study was to develop submicrosalt by using a nanospray drying method, its use in surface salted cheese crackers and evaluating their physico-chemical, microbiological and sensory characteristics. The cheese cracker treatments consisted of 3 different salt sizes (regular, microsalt and submicrosalt) and 3 different concentrations (2, 1.5 and 1%). The 9 (3 sizes x 3 concentrations) different cheese cracker treatments were tested for salt concentration and sodium content at week 1. Water activity, yeast and mold counts, texture-fracturability, color, and consumer test were determined at week 1 and 4 months of storage. Completely Randomized Design (CRD) with repeated measures was used for water activity, yeast and mold counts, texture-fracturability, and color. A Balanced Incomplete Block Design was used to conduct the consumer analysis of cheese crackers for submicrosalt (2, 1.5 and 1%), microsalt (2, 1.5 and1%) and regular 2% (control as used by industry) using 476 participants. Submicrosalt treatments (2, 1.5 and 1%) had positive effect in yeast reduction at 4 months compared to regular salt (2, 1.5 and 1%). There was no mold growth in all treatments at all times. The L*, b*, C* and h* values in all treatments increased significantly (P<0.05) from 1 week to 4 months. At 4 months, submicrosalt treatments (2, 1.5 and 1%) resulted in having significantly (P<0.05) more preferred saltiness scores compared to control (regular 2%). At 4 months, submicrosalt (1.5 and 2%) showed significantly (P<0.05) more preferred just about right saltiness scores compared to control. The reduction of 25 and 50% salt content in cheese cracker through use of submicro particulated salt maintained low counts in yeasts, no counts in molds and did not adversely influence sensory color, aroma, crunchiness, overall liking and acceptability scores, which were the same compared to control and microsalt treatments (2, 1.5 and 1%). Reduction in sodium chloride particle size 1000 fold from regular salt to submicrosalt increased saltiness but reduction in salt size 10 fold from microsalt to submicrosalt did not increase the saltiness of surface salted cheese crackers.

In vitro maturation (IVM) is a reproductive technique critical to in vitro embryo production (IVP) in commercial livestock industries, research, and human infertility treatment. Currently, IVP has low efficiency due to an inadequate IVM system in which premature meiotic resumption results in low oocyte viability. Meiotic arrest is regulated primarily by 3,5-cyclic adenosine monophosphate (cAMP), and the most successful methods of improving IVM utilize cAMP modulators to maintain high intra-oocyte cAMP, delaying the onset of maturation. This thesis includes experiments comparing standard bovine IVM to a novel extended IVM method similar to the procedure described by Albuz and colleagues (Albuz et al., 2010). Bovine oocytes were obtained from mixed breed cattle by transvaginal ultrasound-guided aspiration. Oocytes from each cow were divided into two groups: standard IVM and extended IVM. Standard IVM consists of a 23-hour maturation composed of TCM-199 based media supplemented with 10% fetal bovine serum, sodium pyruvate, pen/strep, glutamine, and FSH, and cultured in 5% CO2 at 39⁰C. Extended IVM is composed of two steps: a pre-IVM of HEPES-TALP supplemented with 100 µM forskolin (FSK) and 500 µM 3-isobutyl-1-methylxanthine (IBMX) for 2 hours at 39⁰C, and then an extended IVM consisting of standard maturation medium supplemented with 20 µM cilostamide for 31 hours (5% CO2, 39⁰C). Oocytes were sampled at various times throughout maturation depending on the experiment. Data was collected either by staining with aceto-orcein to determine nuclear status or by a cAMP ELISA after freezing in groups of ten. Data from the initial experiments showed that cAMP modulators significantly delayed maturation, but overall maturation rates were significantly less than standard IVM (44.5% vs. 81%). Results of the cAMP assay indicated a significant increase in cAMP within the first three hours of oocyte collection after using FSK and IBMX in collection media, but cAMP was not maintained in the cilostamide-only extended IVM medium. Additionally, cilostamide may have had a negative effect on the oocytes since there was a higher percentage arrested at MI in extended IVM.

Sixty-three neonatal Holstein calves (45 female; 18 male) were assigned to one of 3 treatments at d 2 of age to study effects of milk replacer feeding frequency on growth, performance, and health. Treatments consisted of 1X, with total amount of reconstituted milk replacer fed 1X/day at 6:00 a.m.; 2X, with total amount of reconstituted milk replacer divided into 2 equal amounts and fed at 6:00 a.m. and 5:00 p.m.; or 3X, with total amount of reconstituted milk replacer divided into 3 equal amounts and fed at 6:00 a.m., 12:00 noon, and 5:00 p.m. Calves were housed in individual hutches and fed milk replacer until abrupt weaning at 42 d of age. Total daily amount of milk replacer offered was equal to 1.5% of birth weight and reconstituted to a total volume of 10% birth weight. An 18% crude protein calf starter was offered ad libitum beginning on d 3 and fed throughout the duration of the trial. Water was offered ad libitum on d 3. Calves remained in their hutches until d 56 to determine immediate post weaning performance. BW was determined at birth and weekly throughout the trial. Wither height (WH), hip height (HH), and hip width (HW). Feed intake, water intake, and fecal scores were recorded daily. Blood samples were collected on d 14, 28, 42, and 56 for plasma urea nitrogen, plasma glucose concentration (PUN), and â-hydroxybutyrate (BHBA). Effects of treatment, week, and their interactions were analyzed using the MIXED procedure of SAS® (Cary, NC). There was no effect (P > 0.05) of treatment on BW, HH, HW, WH, PUN, plasma glucose concentrations, or BHBA. There was a week effect (P < 0.05) for grain and water intake, with all calves increasing intake throughout the duration of the study. There was no treatment effect (P > 0.05) for fecal scores, with calves scoring similarly throughout the project. No treatment effects were observed (P > 0.05) for PUN, glucose, or BHBA. Glucose concentrations decreased (P < 0.05) and PUN and BHBA concentrations increased (P > 0.05) as calves aged. Overall, milk replacer feeding frequency had no significant effects on growth or performance of these Holstein dairy calves fed MR once, twice, or three times daily.

The objectives of this research were to determine 1) the effect of anise oil (AO) in pigs after exposure and re-exposure by dietary additions to sow and nursery diets; and 2) the maximum level of AO that could be fed to broilers and its effect on in-vitro growth of Clostridium perfringens (ClP); 3) to determine the effect of AO and diet type on growth performance of broilers after a challenge with ClP; and 4) to determine the effect of AO fed to broilers under commercial conditions. The results indicated that exposing lactating pigs to AO through the sow diet had a positive effect on pig feed intake after weaning, improved nursery feed efficiency, and had a positive influence on growth performance. Feeding broilers more than 4000 ppm AO in their diet reduced broiler feed intake, and more than 2500 ppm AO reduced growth. In an in-vitro Exp., the antibiotic Bacitracin and anticoccidial Salinomycin completely inhibited ClP growth, and AO linearly reduced ClP growth to undetectable levels. Thus, AO could have antimicrobial activity against ClP in-vitro. During a challenge with ClP (d 10 with 2 x 109 CFU/ml), broiler feeding AO reduced broilers ADFI and ADG during the first 10 days. Necropsy of all broilers indicated that feeding AO reduced the lesions of the jejunum (LS) related to ClP challenge. In a second ClP challenge (3 x 106 CFU/ml, on d 10 and 13), fish meal (FM) improved growth performance of broilers and had no effect on LS related to ClP challenge compared broilers fed vegetable protein. Feed intake was not affected by AO in this study. Broilers were fed a 3-phase feeding program in a floor pen study, and the treatment diets were antibiotic free, antibiotic added, or AO (1000 ppm). Feeding AO had a similar effect to feeding antibiotic added diet on growth performance of broilers. In summary, AO stimulated pig feed intake after weaning and growth performance after re-exposure. Also, AO had antimicrobial activity against ClP growth in-vitro, reduced jejunum lesions related to ClP in-vivo, and can be an alternative to antibiotics fed as growth promotants for broilers.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 5 uppsatser.

Thesis (MMedVet. (Production Animal Studies)--University of Pretoria, 2002. / Includes bibliographical references. Also available in print format.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007. / Source: Dissertation Abstracts International, Volume: 68-07, Section: B, page: 4186. Adviser: Mike Ellis. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph. D.)--University of California, San Diego, 1997. / Vita. Includes bibliographical references (leaves 122-130).

Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references (leaves 49-50). Also available on the Internet.