No description available.

No description available.

The objective of this study was to determine the effect of nutrient density and housing on E. coli populations in beef and dairy production systems. In the first trial, sixty second trimester beef cows were housed in two different overwintering environments and provided dry hay which was either bale grazed or placed in a feed bunk. Selected pens had supplemented with dried distiller’s grain with soluble (DDGS; 2.5 kg/cow/every third day) or rolled barley (1 kg/cow/day). In the second trial, six rumen and caecal-cannulated, non-lactating, multiparous Holstein cows received one of the following diets: i) 70% forage ii) grain pellet or iii) alfalfa pellet. The latter two diets were formulated to induce subacute ruminal acidosis (SARA). All animals were randomly sorted to pens and treatments. Fecal samples were collected and cultured on selective media. E. coli were enumerated and three isolates were chosen for PCR to detect the presence of 18 selected genes encoding a range of virulence factors. These same isolates were tested for their ability to invade the human adenocarcinoma epithelial cell line HT-29. Diet did not significantly affect E. coli abundance but did influence the prevalence of virulence genes involved in adhesion of bacteria to epithelial surfaces. When the diet contained grain, cows shed isolates which were more invasive than those from cows in the other treatments. The data suggest that diet may affect the abundance of E. coli shed in the feces and increase the presence of E. coli harbouring particular virulence genes that mediate adhesion and invasion of epithelial surfaces.

The objective of this study was to determine the effect of nutrient density and housing on E. coli populations in beef and dairy production systems. In the first trial, sixty second trimester beef cows were housed in two different overwintering environments and provided dry hay which was either bale grazed or placed in a feed bunk. Selected pens had supplemented with dried distiller’s grain with soluble (DDGS; 2.5 kg/cow/every third day) or rolled barley (1 kg/cow/day). In the second trial, six rumen and caecal-cannulated, non-lactating, multiparous Holstein cows received one of the following diets: i) 70% forage ii) grain pellet or iii) alfalfa pellet. The latter two diets were formulated to induce subacute ruminal acidosis (SARA). All animals were randomly sorted to pens and treatments. Fecal samples were collected and cultured on selective media. E. coli were enumerated and three isolates were chosen for PCR to detect the presence of 18 selected genes encoding a range of virulence factors. These same isolates were tested for their ability to invade the human adenocarcinoma epithelial cell line HT-29. Diet did not significantly affect E. coli abundance but did influence the prevalence of virulence genes involved in adhesion of bacteria to epithelial surfaces. When the diet contained grain, cows shed isolates which were more invasive than those from cows in the other treatments. The data suggest that diet may affect the abundance of E. coli shed in the feces and increase the presence of E. coli harbouring particular virulence genes that mediate adhesion and invasion of epithelial surfaces.

Ūkininkų ir šeimos ūkių svarba mėsinių galvijų auginimo srityje didėja. Mėsinių ir mišrūnų veislių galvijų skaičius per penkerius metus (2007-2011 m.) padidėjo (Žemės ūkio informacijos ir kaimo verslo centro duomenys). Lietuvos šeimos ūkiai turi ilgalaikę patirtį galvijų auginimo srityje, tačiau mėsinių galvijų auginimas yra besivystanti sritis, kurios plėtrai reikia paskatų ir optimizavimo. Šio darbo tikslas yra remiantis atlikta Lietuvos žemės ūkio sektoriaus analize ir jautienos rinkos analize, išanalizuoti mėsinės galvijininkystės šeimos ūkyje veiklą ir nustatyti mėsinių galvijų auginimo šeimos ūkyje optimizavimo būdus. Darbo tikslui pasiekti keliami tokie uždaviniai: 1. Atlikti Lietuvos žemės ūkio sektoriaus analizę; 2. Atlikti pasaulio, Europos Sąjungos ir Lietuvos jautienos rinkos analizę; 3. Išanalizuoti jautienos kokybės vertinimo sistemas; 4. Išanalizuoti mėsinių galvijų auginimo šeimos ūkyje galimybes; 5. Nustatyti mėsinių galvijų auginimo šeimos ūkyje optimizavimo būdus. Darbe naudojami tyrimo metodai: 1. Pirminių duomenų šaltinių analizė; 2. Antrinių duomenų ir mokslinės literatūros studijavimas ir analizė; 3. Finansinės analizės metodas. Praktinė baigiamojo darbo reikšmė. Šis darbas supažindina su dabartine Lietuvos žemės ūkio būkle bei išskiria mėsos sektorių, konkrečiai mėsinę galvijininkystę. Atlikta išsami Lietuvos žemės ūkio analizė, orientuota į šeimos ūkius aptaria problemas, investicijas, ūkininkų gaunamas ES paramas šiai vėslo šakai plėtoti. Ši... [toliau žr. visą tekstą] / The livestock sector is a significant supplier of food to Lithuanian consumers and an important source of export in Lithuania. Lithuanian family farms have a long experience in the production of cattle, but beef cattle is a developing area which requires development incentives and optimization The main objective of this thesis is after the analysis of Lithuanian agriculture sector and beef market, to analyze beef production family farm performance and to determine beef production in family farm optimization opportunities. The main tasks of this thesis are: 1. To analyze the Lithuanian agriculture sector; 2. To analyze world, EU and Lithuanian beef meat market; 3. To analyze the measurement systems of beef meat quality; 4. To analyse the production opportunities of beef in family farm; 5. To determine the ways to optimize the beef production in family farm. Used methods: 1. The primary data analysis; 2. The secondary data analysis; 3. The financial analysis. This work consists of three chapters. The first part defines the agricultural sector of Lithuania, as well as family farm’s situation in Lithuania. The second part analyzes the main trends in the beef meat market. The third part analyses the opportunities for beef cattle production in Lithuanian family farms. In the last part you will find beef cattle growing in family part analysis and ways to optimize the farm’s performance.

This study was performed to test the viability of administering a single 40 mg dose of Folltropin-V® (FSH, Bioniche Animal Health) diluted in SRF (MAP-5 50, Sodium Hyaluronate, Bioniche Animal Health) on day 5 of a recipient synchronization protocol to beef cows to evaluate its effect on recipient fertility. All recipients were administered an estradiol 17beta (2.5 mg, IM) and progesterone (50 mg, IM) combination injection on day 0 and a CIDR® (progesterone 1.34 g, Pfizer Animal Health) was inserted. Lutalyse® (dinoprost tromethamine, Pfizer Animal Health, 25 mg, IM) was administered at the time of CIDR removal on day 7, and estradiol 17beta (1 mg, IM) was administered on day 8. On day 16, the presence of at least one corpus luteum (CL), detected via ultrasound, resulted in the recipient receiving an embryo (both fresh and frozen-thawed embryos were used). Embryos were not transferred into cows that did not show the presence of a CL. Dependent variables for which data were collected included circulating progesterone levels at the time of transfer, number of CLs and CL diameter, circumference, and area; measured in millimeters. The study (n=572) consisted of a treatment group (n=268) and a control group (n=304), and included both Bos indicus (Brahman influenced) crossbred (n=115) and Bos taurus (Angus based) cows (n=457). Pregnancy rates for Treated recipients (40.67%A) and Control recipients (52.96%B) differed (P<.05). There was no difference in the mean number of CLs per recipient for Treated (1.14 +/- .03) and Control (1.10 +/- .02) cows, nor was there a difference in progesterone (P4) at the time of transfer for Treated (3.14 +/- .40 ng/mL) and Control (3.23 +/- .18 ng/mL) recipients. Overall, the inclusion of Folltropin-V® diluted in hyaluronan in a FTET synchronization protocol did not improve the fertility of beef recipients.

A candidate gene approach was used to identify single nucleotide polymorphisms (SNPs) and their associations with body fat deposition and carcass merit traits in beef cattle. In total, 37 SNPs from 9 candidate genes have been genotyped on 463 hybrid, 206 Angus and 187 Charolais steers for association analyses with 10 different fat deposition and carcass merit traits. In single SNP analyses, 28 SNPs of 9 genes have been found significantly (P<0.05) associated with different traits in the cattle populations. Gene-specific linkage disequilibrium assessment of SNPs revealed the existence of haplotype blocks within 4 genes. Haplotype analyses have identified 31 haplotypes of 6 genes having significant associations (P<0.05) with different fat deposition and carcass merit traits in the cattle populations. These findings will provide insight into the genetic mechanism regulating body fat deposition in beef cattle and will assist the beef industry to improve beef quality through marker assisted selection. / Animal Science

No description available.

202 p. : ill. ; 28 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Physiology, 1967

No description available.