Objectives were to determine dry matter, fiber and nitrogen fractions, and in vitro and in situ degradability of forages and by-product feeds, and to compare in vitro methods of estimating rumen degradability with the in situ bag technique. Feeds analyzed with number of samples in parentheses included alfalfa as baled hay (23), alfalfa ensiled in conventional (43), and. oxygen limiting silos (39), ammonia· treated (25), and untreated corn silage from conventional (17) and bunker silos (17), rye (25), sorghum (7), wheat (6), barley (5), and orchardgrass (4) silages, orchardgrass (19) and fescue hay (3), and dried distillers grains dark colored (2) and light (1), wet brewers grains (1), and whole cottonseeds (3). Samples were analyzed for dry matter, crude protein, buffer-soluble protein, protease insoluble nitrogen, neutral and acid detergent fiber and insoluble nitrogen, and in situ degradability of nitrogen, dry matter, and fiber. Protease insoluble nitrogen, buffer-insoluble protein, and neutral detergent insoluble nitrogen were lowest for alfalfa from conventional upright silos. Oxygen limiting silo samples had greater dry matter, insoluble protein, and bound nitrogen compared to conventional upright silo samples. Oxygen limiting silos had 35.9% of samples with bound nitrogen greater than 15% of total nitrogen compared to 14% of conventional upright silo samples. Baled hay and oxygen limiting silo samples had similar protease insoluble nitrogen, however, ensiled samples had greater bound nitrogen. In situ nitrogen degradability was greatest for ensiled forages compared to hays. Ensiled forages had the greatest A fraction (rapidly solubilized), alfalfa hay the greatest B fraction (slowly degraded), and orchardgrass hay the greatest C fraction (not degraded). Degradation of dry matter and fiber followed similar patterns for each forage and by-product. Significant results were found by comparing in vitro and in situ techniques for estimating degradability. Due to differences between hay and silage, use of one technique can not be recommended at this time to predict degradability. For silage, the best measure related to in situ degradability was buffer-soluble protein; for hay, the best measure was neutral detergent insoluble nitrogen. / Ph. D. / incomplete_metadata

Call number: LD2668 .T4 1986 T39 / Master of Science / Animal Sciences and Industry

O objetivo deste trabalho foi avaliar o efeito de um preparado de anticorpos policlonais (PAP) contra bactérias ruminais específicas, Streptococcus bovis e Fusobacterium necrophorum, em parâmetros ruminais da fermentação, em vacas canuladas, adaptadas ou não a uma dieta de alta proporção de carboidratos prontamente fermentescíveis, após indução à acidose. O delineamento experimental utilizado foi o quadrado latino 3X3 replicado em arranjo fatorial de tratamentos 3X2, sendo 2 aditivos alimentares (PAP na apresentação em pó - PAPP e PAP na apresentação líquida - PAPL) mais um grupo controle (CON) e dois manejos de adaptação à dieta, resultando em seis tratamentos. O primeiro quadrado latino foi submetido a um protocolo de adaptação à dieta do tipo gradual ou step-up: dos dias D0 a D4 os animais receberam 100% de forragem; do D5 ao D9, 30% de concentrados e do D10 ao D14, 60% de concentrados. O segundo quadrado latino recebeu 100% de forragem do D0 ao D14 (sem adaptação). Nos D15 e D16, todos os animais receberam dieta com 80% de concentrados. Para as análises foram coletadas amostras de líquido ruminal a cada 3 horas a partir da 0h antes da alimentação até as 36h (D15 e D16) durante o desafio com uma dieta de 80% de concentrados. Os dados foram analisados pelo procedimento Mixed do SAS com nível de significância de 0,05. Foi observada interação entre tempo e adaptação (P<0,05) para pH ruminal com diferença entre método de adaptação nas 0, 3, 6, 9, 12 e 36 horas pós alimentação, quando o grupo não adaptado teve valores maiores que o grupo adaptado, sendo que na hora 24 ocorreu o contrário. Para a concentração de ácidos graxos de cadeia curta (AGCC), nas horas 0, 3, 6, 9 e 36 pós alimentação o grupo adaptado obteve maiores valores comparado ao grupo não adaptado. Para proporção molar de acetato, a 0 hora o grupo sem adaptação obteve valores maiores comparado ao grupo adaptado. Já nas horas 24, 27 e 30 o grupo com adaptação que obteve maiores valores. Para a proporção molar de propionato o grupo sem adaptação teve valores mais altos em comparação ao outro grupo das 3 às 36 horas pós alimentação. Quanto à proporção acetato:propionato (Ac:Pr) às 6, 12, 24, 27, 30 e 36 horas pós alimentação, o grupo de animais adaptados teve valores mais altos que o grupo não adaptado. Na proporção molar de butirato, o grupo de animais adaptados obteve maiores valores nas horas 0, 3, 6, 9, 12, 33 e 36. Para os valores de nitrogênio amoniacal (N-NH3), às 6 horas pós alimentação, o grupo não adaptado obteve maiores valores que o grupo adaptado (26,1 vs. 19,3, respectivamente). Nas horas 9, 30, 33 e 36 ocorreu o contrário. Observou-se também interação entre tempo e aditivo (P=0,0430) para a proporção molar de butirato. Porém, quando a análise foi realizada por tempo, nenhum efeito foi observado. Para os valores relativos de protozoários mensurados (Dasytricha, Isotricha, Epidinium, Diplodinium e Entodinium) apenas o Entodinium apresentou efeito de adaptação (P<0,0236) tendo sua proporção maior no grupo adaptado. Os valores de haptoglobina também não foram influenciados nem por aditivo nem por adaptação. O preparado de anticorpos policlonais não foi tão eficaz quanto a adaptação gradual à dieta de alto concentrado para controlar alterações dos parâmetros ruminais. / The objective of this trial was to evaluate the effects of polyclonal antibodies preparation (PAP) against specific rumen bacteria Streptococcus bovis and Fusobacterium necrophorum on rumen fermentation parameters in ruminally cannulated cows adapted or not to highly fermentable carbohydrates diets (HFC) after an acidosis challenge. The experimental design was two 3X3 Latin squares in a factorial arrangement of treatments 3X2 regarding two feed additives (PAP in powder presentation - PAPP and PAP in liquid presentation - PAPL) plus control group (CON) and two managements of diets adaptation, resulting in six treatments. The first Latin square had a step-up diet adaptation: from D0 to D4 100% forage; D5 to D9 30% of concentrates and D10 to D14 60% of concentrates. The second Latin square received 100% forage from D0 to D14. On D15 and D16, all animals received a diet with 80% of concentrates. For analysis, rumen fluid was sampled at 0 and every 3 h posfeeding totaling 36 h (D15 and D16) of challenge with a diet with 80% of concentrates. Data were analyzed by MIXED procedure with a significance level of 0.05. An interaction between time and adaptation (P<0,05) was observed for ruminal pH. At 0, 3, 6, 9, 12 and 36 h postfeeding, the non-adapted group had higher values compared to the adapted group and at 24 h postfeeding, the inverse was observed. For total short-chain fatty acids concentration, at 0, 3, 6, 9 and 36 h postfeeding, the adapted group had higher values compared to non-adapted group. For molar proportion of acetate at 0h postfeeding, the non-adapted group had higher values than the adapted group, and at 24, 27 and 30h, the adapted group had greater values than the non-adapted group. For molar proportion of propionate the non-adapted group had greater values compared to the adapted group from 3 to 36h postfeeding. For acetate:propionate (Ac:Pr) ratio at 6, 12, 24, 27, 30 and 36 h postfeeding, the adapted group had greater values compared to the nonadapted group. For butyrate molar proportion at 0, 3, 6, 9, 12, 33 and 36h postfeeding the adapted group had greater values than the non-adapted group. For ammonia nitrogen (NH3- N) concentration at 6h, the non-adapted group had greater values than the adapted group (26.1 vs. 19.3, respectively), however at 9, 30, 33 and 36h postfeeding, the adapted group had higher values compared to the non-adapted group. It was also observed an interaction between time and additive (P=0.0430) for butyrate molar proportion, but when the analysis was performed by time no effect was observed. For the relative values of protozoa measured (Dasytricha, Isotricha, Epidinium, Diplodinium and Entodinium) only Entodinium presented adaptation effect (P<0.0236) with a higher proportion in the adapted group. Haptoglobin values was also not influenced (P>0.05) by additive or adaptation effect. Polyclonal antibodies preparation was not as effective as the gradual adaptation to the diet high concentrate to control changes of ruminal parameters.

"January 2003" / Includes bibliographical references (leaves 172-204) / xx, 204 leaves : ill. ; 30 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 Science, 2003

Bibliography: leaves 226-261. Investigates nitrogen utilization in some species of rumen bacteria with the object of understanding the role of ammonia versus exogenous amino acids in relation to microbial growth.

Three duodenally cannulated lactating Holstein cows fed cotton-seed meal (CSM), corn gluten meal (CGM) or blood meal (BM) as protein supplement were used in a 3 x 3 Latin Square experiment to determine microbial crude protein (MCP) in duodenal digesta. Diets, formulated to contain 15% crude protein (CP) on a dry matter basis, consited of 60% concentrate, 31% corn silage and 9% alfalfa hay. Chromium oxide was employed as flow marker. Microbial protein fraction of digesta CP (MCP/DCP) was estimated by three microbial markers: ¹⁵N, diaminopimelic acid (DAP) and ribonucleic acid (RNA). The isotopic method gave the most reliable results. Variability was higher with DAP and RNA. Results from RNA were lower (P < .01) and unreasonable. Based on ¹⁵N, MCP/DCP differed among treatments (P < .10) with means of 61.5, 59.4, and 50.0% for CSM, CGM, and BM, respectively, but differences were not significant for absolute amounts of total CP and MCP in duodenal digesta.

The effect of untreated roughages on digestibility and rumen fill of the gut was reviewed as physical mechanism influencing the regulation of roughage intake. The review of literature also focused on identifying factors that affect the way in which urea-ammoniation alters the roughage intake, digestibility and performance of ruminant animals. Trials were carried out with fistulated cows to address to what extent concentrate proportion and urea-ammoniation affected microbial colonization and degradation of roughage diets in the rumen. One interest of this study was to develop a model that would help to predict the benefit associated with urea-treatment of roughages. The first trial (Chapter 3) investigated the effect of urea-ammoniation of roughage and concentrate proportion of the diet on degradation of roughages, and the benefit associated with the treatment of roughages. Four rumen-fistulated Jersey cows were fed on a basal diet composed of either urea treated (3 kg of urea per 100 kg of straw) or untreated Eragrostis curvula hay. These basal diets were supplemented with concentrate composed of maize meal (78%) and cotton seed cake (22%). The concentrate contributed 0, 25, 50 and 75% of the total ration and hay the rest. The experiment consisted of 6 periods. Each period lasted 19 days, comprising 12 days of adaptation to the experimental diet followed by 6 days degradability measurements and 1-day rumen fluid collection. During each period the 4 Jersey cows were randomly allocated to 4 of the 8 dietary treatments, ensuring that each diet was fed to 3 animals during the entire experimental period. The experimental roughages used in this trial were wheat (Triticum sativum) straw, barley (Hordeum Vulgare) straw, coastcross (k11) (Cynodon hybrid) hay, veld hay (natural grass), oat (Avena sativa) straw, oat (Avena sativa) hay, maize (Zea mays) stover, kikuyu (Pennisetum clandestinum) grass, weeping love grass (Eragrostsis curvula) and Italian rye (Lolium multiflorum) grass. Each roughage (sample) was subdivided into two equal portions, one of which was then treated with urea. The urea solution was prepared by dissolving 30 g of urea in 0.4 liter of water. The solution was fully distributed over I kg of roughage. Treated roughages were sealed tightly and stored at room temperature for 5 weeks in plastic bags. Immediately after opening, the different roughages, including the untreated ones, were sun dried, chopped fine by hand and ground through a 2-mm screen in a laboratory mill. About 3 g of each sample was weighed into labeled nylon bags. The bags were tied to a stainless steel disc with 10 evenly spaced small holes drilled through the periphery of the disc serving as anchor points. The bags were incubated (in duplicate per time interval) in the rumen for 120, 96, 72, 48, 24, 12, 6 and 3 h, sequentially. The treated samples were incubated in animals fed treated hay, while untreated samples were incubated in animals given untreated hay. Immediately after removal from the rumen, the bags, including the 0 hour ones, which had not been incubated but soaked in warm water for I hour, were washed in 6 cycles (each lasting 4 minutes) in a semi-automatic washing machine. The washed bags were then dried in a forced draught oven at 60 degrees C for 48 hours, cooled in a desicator and weighed. The pH of the rumen fluid ranged between 6.5 and 6.8 for all diets. Rumen ammonia concentration was higher (P<0.002) when the basal diet consisted of urea treated hay. Increasing the concentrate proportion in the diet had the desired effect of increasing rumen ammonia concentration without severely affecting pH. Urea-ammoniation increased (P<O.OOO1) the slowly degradable fraction (B), potential degradability (PD), effective degradability (ED) of dry matter and neutral detergent fiber (NDF), decreased (P>0.05) lag time (LT) but had no effect on the rate of degradation (c) of dry matter. Concentrate proportions affected (P<0.05) the slowly degradable fraction, potential degradability, lag time and effective degradability but had no effect (P>0.05) on the rate of degradation of dry matter (DM). Maximum and minimum values of the slowly degradable fraction, potential degradability and effective degradability of DM and NDF were obtained at the 25 and 75% concentrate levels, respectively. Within urea-ammoniation, roughage type affected (P<O.OO1) the B-fraction, PO and EO of OM and NDF degradation. Rate of degradation of DM of untreated roughages varied from 0.022 h(-1) in wheat straw to 0.087 h(-1) in rye grass, while for urea treated roughages it varied from 0.022 h(-1) in oat straw to 0.082 h(-1) in rye grass. Rye grass degraded almost three to four times faster than urea treated oat or untreated wheat straw. Urea-ammoniation was less effective in increasing DM and cell wall degradation rates (c) of rye grass compared to wheat straw. The results showed that low quality roughages such as wheat straw benefited relatively the most from urea-ammoniation. The effect of urea-ammoniation and dietary manipulation on microbial colonization (Chapter 4) of fiber particles in the rumen of animals was also investigated in two experiments. In Experiment 1, the cows were fed on rations comprising either urea-ammoniated or untreated Eragrostis curvula hay supplemented with concentrate at hay to concentrate ratio of 100:0, 75:25, 50:50, 25:75, resulting in eight different rumen environments. The experiment consisted of two periods. Each period lasted 12 days of adaptation to the experimental diet followed by one-day incubation of urea-ammoniated and untreated barley straw. Experiment 2 consisted of two urea-ammoniated (7.5 kg of urea per 100 kg of hay) hay levels (20 and 40% of the total ration) and concentrate levels (60 and 80%). Fistulated Jersey cows were adapted for 12 days after assigning to the dietary treatment. Feed was given at the rate of 9.0 kg day(-1) per animal portioned into equal meals of 4.50 kg each and offered at 08:00 and 16:00 every day. About 3 g of urea-ammoniated or untreated barley (Hordeum vulgare) straw, ground through a 2-mm screen, was weighed into a labelled nylon bag and incubated for 3, 6 or 12 h in the rumen of the fistulated cows. Microbes adhering to incubated fiber particles were examined under the Environmental Scanning Electron Microscopy (ESEM) and analysed on the image analyser. Depending on morphology , the microbes were divided into three groups: bacilli (rod), cocci (round) and others (spiral, fimbrea and cluster ; not specifically defined or undefined microbes). Urea-ammoniation of dietary roughage decreased (P<O.OO1) bacilli counts and total bacteria count but had no effect on count of the undefined group of microbes on fiber particles in the rumen of cows (Experiment 1). Concentrate proportions had no effect (P>0.05) on bacilli, cocci and total bacterial count on fiber particles. However, the results from electron micrograph observations revealed that the total bacterial count tended to decrease as the concentrate level increased in the diet of cows. Bacilli, cocci, undefined group of microbes and total count of microbes increased (P<0.05) as length of incubation increased. In Experiment 2, incubated feed, concentrate proportion and time of incubation had no effect (P>O.05) on bacilli , others (undefined group of microbes) and total count of fiber-adhering microbes in the rumen of cows. However, increasing concentrate in the diet of cows tended to decrease (P<O.07) the count of fiber-adhering cocci. The total count of microbes on fiber particles was higher in animals fed 80% concentrate as compared to 60% concentrate. The benefit derived from urea treatment in terms of B-fraction, effective degradability and potential degradability of DM and fiber of roughages increased with increasing the NDF content. Therefore, the important conclusions drawn from the results of the present study is that urea-ammoniation of roughages should be done strategically and that high quality roughages may give little return per unit of cost of ammoniation. This means that the benefit associated with urea-ammoniation would be justified for poor quality roughages only. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.

Includes bibliographical references (leaves 226-261). / xxiii, 261 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Investigates nitrogen utilization in some species of rumen bacteria with the object of understanding the role of ammonia versus exogenous amino acids in relation to microbial growth. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 1996?

Bibliography: leaves 189-205. / xi, 205 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The aim of this PhD project is to screen feral goat rumen fluid for the presence of new organisms that may play a role in the detoxification of tannins and to investigate their mechanisms of action. An enrichment experiment is conducted to screen rumen fluid for anaerobic bacteria capable of growing in the presence of high levels of "Acacia" condensed tannin. Four morphologically-distinct bacteria are isolated, confirming that resistance is a property shared by more than one organism. One isolate is chosen at random for further characterisation and is identified as a strain of "Selenomonas ruminantium" subspecies "ruminantium". It is arbitrarily designated strain K2. "Selenomonas ruminantium" K2 is shown to be not only tannin-resistant but also able to grow on tannic acid. It is proposed that this bacterium obtained energy for growth from tannic acid. The thesis examines the molecular mechanisms controlling tannin resistance or tannin degradation in rumen microorganisms. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 1997

Bibliography: leaves 189-205. / xi, 205 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The aim of this PhD project is to screen feral goat rumen fluid for the presence of new organisms that may play a role in the detoxification of tannins and to investigate their mechanisms of action. An enrichment experiment is conducted to screen rumen fluid for anaerobic bacteria capable of growing in the presence of high levels of "Acacia" condensed tannin. Four morphologically-distinct bacteria are isolated, confirming that resistance is a property shared by more than one organism. One isolate is chosen at random for further characterisation and is identified as a strain of "Selenomonas ruminantium" subspecies "ruminantium". It is arbitrarily designated strain K2. "Selenomonas ruminantium" K2 is shown to be not only tannin-resistant but also able to grow on tannic acid. It is proposed that this bacterium obtained energy for growth from tannic acid. The thesis examines the molecular mechanisms controlling tannin resistance or tannin degradation in rumen microorganisms. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 1997