<p>Three studies were conducted to evaluate the nutritional value of different oat (Avena sativa) forage cultivars (Assiniboia, Bell and Baler) that were newly emerged cultivars as a result of extensive oat growing conditions in western Canada. A total tract digestibility trial using 24 sheep (n=6) in a completely random design was conducted to assess apparent digestibility of dry matter (DM), organic matter (OM), crude protein (CP), crude fat (EE), acid detergent fiber (ADF), neutral detergent fiber (NDF), hemicellulose, non-structural carbohydrate, acid detergent lignin (ADL), soluble crude protein (SCP), non-protein nitrogen (NPN) and neutral detergent insoluble crude protein (NDICP) in Assiniboia silage, Bell hay, Baler hay and Rosser (barley- Hordeum vulgare) silage. Rumen in situ degradability characteristics of DM, OM, CP, ADF and NDF were determined on Assiniboia silage, Bell hay, Baler hay and Rosser silage at 96 to 0 h using a Holstein cow fitted with a rumen fistula. A dairy production trial using 8 multiparous Holstein cows at 90±20 DIM averaging 41 kg d-1 milk yield, in a 2 × 3 switch-back design was conducted to compare the production response of the cows fed either 48 percent Assiniboia silage or Rosser silage (DM basis) in total mixed rations with the concentrate portion consisting mainly of rolled barley, canola meal and soy meal.</p> <p>Digestibility of DM, OM, NDF, NPN, NDICP and EE were not different for Assiniboia and Rosser silages. Digestibility of DM, NDF and ADF were similar for Baler hay and Rosser silage. Digestibility of hemicellulose, NSC and ADL were similar for all forages. Sheep voluntary intakes of DM, OM, NDF, ADF and EE, except CP were similar across the forages. Assiniboia silage provided more nutrients to the rumen than the hays due to the higher rumen disappearance and effective degradabilities of DM and CP, and lesser undegradable DM, CP, NDF and ADF (P<0.05). Estimated carbohydrate and protein fractions of Assiniboia and Rosser silages were similar. Assiniboia silage was typically comparable to Rosser silage whereas Baler hay was compatible to Bell hay which in contrast was chemically inferior to Baler hay in NDF and TDN content. An increase (8%, P<0.05) in milk fat percentage was observed in cows fed the Assiniboia diet. Milk protein and lactose percentages, and protein yield were higher (P<0.05) in the cows fed the Rosser diet. However, 3.5% fat corrected milk yields were similar. Milk fatty acids (FA) when Assiniboia diet was fed, showed a remarkable increase (P<0.05) in oleate percentage and yield while the others were not different. The increase in oleate content resulted in an increase (P<0.05) in unsaturated FA to saturated FA ratio. Therefore Assiniboia silage would be useful to increase unsaturated long chain milk fat content. It is concluded that Assiniboia silage could substitute for Rosser silage in dairy rations.</p>

<p>Three studies were conducted to evaluate the nutritional value of different oat (Avena sativa) forage cultivars (Assiniboia, Bell and Baler) that were newly emerged cultivars as a result of extensive oat growing conditions in western Canada. A total tract digestibility trial using 24 sheep (n=6) in a completely random design was conducted to assess apparent digestibility of dry matter (DM), organic matter (OM), crude protein (CP), crude fat (EE), acid detergent fiber (ADF), neutral detergent fiber (NDF), hemicellulose, non-structural carbohydrate, acid detergent lignin (ADL), soluble crude protein (SCP), non-protein nitrogen (NPN) and neutral detergent insoluble crude protein (NDICP) in Assiniboia silage, Bell hay, Baler hay and Rosser (barley- Hordeum vulgare) silage. Rumen in situ degradability characteristics of DM, OM, CP, ADF and NDF were determined on Assiniboia silage, Bell hay, Baler hay and Rosser silage at 96 to 0 h using a Holstein cow fitted with a rumen fistula. A dairy production trial using 8 multiparous Holstein cows at 90±20 DIM averaging 41 kg d-1 milk yield, in a 2 × 3 switch-back design was conducted to compare the production response of the cows fed either 48 percent Assiniboia silage or Rosser silage (DM basis) in total mixed rations with the concentrate portion consisting mainly of rolled barley, canola meal and soy meal.</p> <p>Digestibility of DM, OM, NDF, NPN, NDICP and EE were not different for Assiniboia and Rosser silages. Digestibility of DM, NDF and ADF were similar for Baler hay and Rosser silage. Digestibility of hemicellulose, NSC and ADL were similar for all forages. Sheep voluntary intakes of DM, OM, NDF, ADF and EE, except CP were similar across the forages. Assiniboia silage provided more nutrients to the rumen than the hays due to the higher rumen disappearance and effective degradabilities of DM and CP, and lesser undegradable DM, CP, NDF and ADF (P<0.05). Estimated carbohydrate and protein fractions of Assiniboia and Rosser silages were similar. Assiniboia silage was typically comparable to Rosser silage whereas Baler hay was compatible to Bell hay which in contrast was chemically inferior to Baler hay in NDF and TDN content. An increase (8%, P<0.05) in milk fat percentage was observed in cows fed the Assiniboia diet. Milk protein and lactose percentages, and protein yield were higher (P<0.05) in the cows fed the Rosser diet. However, 3.5% fat corrected milk yields were similar. Milk fatty acids (FA) when Assiniboia diet was fed, showed a remarkable increase (P<0.05) in oleate percentage and yield while the others were not different. The increase in oleate content resulted in an increase (P<0.05) in unsaturated FA to saturated FA ratio. Therefore Assiniboia silage would be useful to increase unsaturated long chain milk fat content. It is concluded that Assiniboia silage could substitute for Rosser silage in dairy rations.</p>

This thesis examines determinants of the adoption of total mixed ration (TMR), and the effects of the adoption of TMR on the farm level productivity and profitability of Ontario dairy farms. A sample of 320 farm level data from 2004-2008 is taken from the Ontario Dairy Farm Accounting Project (ODFAP). A probit model is estimated to examine the factors affecting the adoption of TMR; and the propensity score matching analysis is used to explore the influence of the use of TMR on sample farm’s productivity and profitability. Results from the probit model show that farmer’s age, herd size, region, breed type and feeding system have significant effect on the adoption of TMR. In turn, the adoption of TMR feeding practice has positive influence on both farm productivity and profitability. Under the propensity score matching method, the use of the TMR feeding practice has an economically significant effect on farm profits (i.e., for average farm with approximately 73 cows, the use of TMR feeding practice increases farm profits by CAD$37,091.30/year approximately) and a statistically significant increase in milk production by 1075.41 hl/cow per year.

Modifying milk fat composition to enhance its content of valuable fatty acids (FA) is required to meet the needs of a society which is becoming better informed about the relationship between diet and health. Manipulating the cow’s diet is an effective, natural way to modify the amount and composition of milk fat of cows. The two main factors that affect the cow’s diet concern management system (MS; pasture vs. confinement), and supplementation of diets with lipid supplements. Marine oils specifically are fed to enhance milk with n-3 long-chain polyunsaturated FA (n-3 LC-PUFA). The effects of source of marine lipid supplement (LS; fish oil vs. microalgae) in the cow’s diet and its interaction with MS on milk fat composition have not been studied. Thus, the main objective was to determine the interaction of MS and LS on milk FA profile and on expression of lipogenic genes in mammary, adipose and liver of lactating dairy cows. Compared with cows in confinement, grazing cows produced milk fat with lower content of unfavorable FA (12:0-16:0), while increasing the levels of beneficial FA including cis-9 18:1, 18:3 n-3 and conjugated 18:2. Feeding either fish oil or microalgae improved levels of n-3 LC-PUFA and reduced those of 16:0 in milk fat regardless of MS, but concurrently increased the level of other trans 18:1 isomers at the expense of trans-11 18:1. The reduced secretion of 12:0-16:0 in milk from grazing compared with confined cows was associated with lower mammary expression of lipogenic genes suggesting that part of the effect of MS on milk FA profile is mediated transcriptionally. The effect of LS on lipogenic gene expression was tissue specific with the greatest response to treatment observed in liver despite its minor role in lipogenesis in cattle relative to the mammary and adipose. Major conclusions were that milk produced in pasture systems has a more healthful FA profile than that of confinement systems, and that MS and LS have tissue specific effects on lipogenic gene expression in dairy cattle which have important effects on cow performance and healthfulness of the milk FA profile.

My diploma thesis is based on the observation of dairy cows nutrition at the farm, nutrition is the most important factor in the production of milk. The introduction of my thesis is focused on a literary overview, which briefly describes the process of digestion, evaluation of nutrients in feed doses and assessment of mixed feed doses. Attention is focused on feed technology in the farm, there was evaluated the intake of dry matter by dairy cows. Dairy cows were fed by total mixed ration (TMR), samples were sent for evaluation to an accredited laboratory and compared to NRC (2001). Another criterion was the evaluation of the particle structure by the Penn state separator (2002), the results were compared with the recommended standard, there was evaluated the homogeneity of the mixed feed structure too. The thesis evaluate composition of the feed ration, where maize silage is predominanting, there is described the variability of starch in maize silage in the monitored period. The thesis describes the evaluation of ungraded starch from bovine feces, samples were again analyzed in an accredited laboratory and evaluated according to the recommended standard, and the probable causes of increased content of unstressed starch in beef excrement are described. Some of the milk production indicators are also mentioned. There was used the informations of Czech and foreign authors.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第18659号 / 農博第2088号 / 新制||農||1027(附属図書館) / 学位論文||H26||N4882(農学部図書室) / 31573 / 京都大学大学院農学研究科応用生物科学専攻 / (主査)教授 廣岡 博之, 教授 松井 徹, 教授 久米 新一 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Thesis submitted in fulfilment of the requirements for the degree of Magister Technologiae: Agriculture in the Faculty of Applied Sciences at the Cape Peninsula University of Technology / Conjugated linoleic acid (CLA), a fatty acid (FA) present in the meat and milk of ruminant animals, is considered a functional nutrient for humans. The interest in CLA is attributed to its many health benefits, such as having anti-carcinogenic, anti-atherogenic, anti-diabetic and anti-adipogenic effects. Dairy products are a rich natural source of CLA, and preliminary research indicates that the levels in milk can vary based on cattle breed and feeding system. The Fleckvieh is a popular dual-purpose breed recently introduced to the Western Cape. It is used in crossbreeding programs with Holstein and Jersey herds to increase fertility and beef production. Holstein and Jersey cattle are the two most common South African dairy breeds, but little information is available on the effect of crossbreeding on FA content and CLA levels in the milk. The primary objective of this study was to compare milk FA composition and CLA content of these two dairy breeds and their respective Fleckvieh crosses. A second objective was to investigate the effect of lactation stage on CLA levels. Jersey (J) and Fleckvieh x Jersey (F×J) cows were kept in a pasture-based system (PBS) for the duration of the study. Holstein (H) and Fleckvieh x Holstein (F×H) cows were housed in a feedlot system and fed a total mixed ration (TMR) for the duration of the study. The FA and CLA content of feeds from these two feeding systems were also analysed and compared. All cows used in the study were housed at the Elsenburg Research Farm of the Western Cape Department of Agriculture. Milk samples were collected every 35 days from the cows in each feeding group, starting 10 days after calving. Samples were kept in a freezer at -20 °C until laboratory analyses. The total number of milk samples collected was 1044. The milk FA composition and CLA in particular were determined by gas chromatography. Differences between groups were statistically analysed by two-way repeated measures of analysis of variance (ANOVA). Results show that milk CLA levels are higher in Fleckvieh-crossbred cows when compared to purebred cows. The higher CLA content of milk from Fleckvieh crossbred cows demonstrates the feasibility of using Fleckvieh bulls in South African crossbreeding programs, and are also an indication that genetic selection for increased CLA content is possible. The analysis of lactation stage showed that milk CLA is higher during late lactation. A comparison of feed samples from the two feeding systems revealed that pasture feeding resulted in higher omega-3 FA in milk. Key words: Conjugated linoleic acid, milk fatty acids profile, diet, breed, health benefits, Fleckvieh, Holstein, Jersey, diet, pasture based system, total mixed ration system,

The theoretical part features an overview of the historical development of dairy cows feeding and introduces currently used trends in feeding. This part also outlines basic technologies in the production of roughage and describes modern feed distribution machinery. The practical part evaluates the accuracy of loading of individual components and the total weight of a feed ration loaded into a vertical suspension mixer feeder wagon by a front-end loader tractor. The observation was carried out at Mr. Kadlec's family farm in Velký Bor near Netolice and lasted four months. During this period, the actual weight of loaded components (grass-clover haylage, maize silage, grains meal) was being monitored daily. The evaluation came to a conclusion that grass-clover haylage stored in bales is loaded with a greater accuracy than maize silage stored in a clamp silo.

Estratégias de vedação tem sido adotadas com o intuito de reduzir a entrada de oxigênio para o interior dos silos. Aditivos químicos como o benzoato de sódio, que apresenta funções antimicrobianas também pode ser empregado para melhoria da estabilidade aeróbia de silagens. Porém, ainda não se sabe se pode causar efeitos adversos no consumo ou metabolismo dos animais alimentados e, consequentemente levar a alterações no desempenho animal. Desta forma no presente estudo, objetivou-se avaliar a influência de estratégias de vedação de silos trincheira sobre as perdas de MS e valor nutritivo de silagens de milho e, a adição de benzoato sódio na ração total no valor nutritivo para vacas leteiras. O experimento foi conduzido no Departamento de Zootecnia da Escola Superior de Agricultura \"Luiz de Queiroz\" (ESALQ/USP). A cultura do milho foi colhida com aproximadamente 35% de matéria seca (MS) e ensilada em silos trincheira (capacidade de 40 t). No momento do fechamento dos silos, dois tratamentos foram impostos: (1) lona dupla-face 200 &mu;m protegida com bagaço de cana-de-açúcar (camada com espessura de 10 cm) (BG) e, (2) aplicação superficial de benzoato de sódio 150 g/m2 (diluído em água 1:4) imediatamente antes da vedação com lona dupla-face 200 &mu;m (BZ). Vinte vacas Holandesas em lactação foram alocadas em cinco Quadrados Latinos 4 × 4 em períodos de 21 dias (14 d adaptação). As dietas experimentais continham (%MS): 8% de caroço de algodão, 9,5% de polpa cítrica, 18% de farelo de soja, 9,0% de milho moído seco, 2,5% premix mineral + vitaminas e 53% de silagem de milho: BG ou BZ ou silagem de milho BG + 0,15% de benzoato de sódio ou silagem de milho BZ mais 0,15% de benzoato de sódio. O benzoato de sódio foi diluído em água (0,3:1) e aspergido na ração total imediatamente antes de cada trato. Os dados foram submetidos à análise utilizando-se o procedimento MIXED do SAS, através de arranjo fatorial 2 × 2. A silagem com cobertura de bagaço de cana foi mais eficiente em reduzir a entrada de oxigênio durante o processo de fermentação e, consequentemente levou ao menor crescimento de microrganismos deterioradores e melhor conservação dos nutrientes da silagem, resultando em maior digestibilidade da MS. A adição de benzoato de sódio na dose de 0,15% na MN não altera o desempenho de vacas leiteiras. / Sealing strategies have been adopted to reduce oxygen entrance to silo. Chemical additives such as sodium benzoate have antimicrobial activity and it can also promote an aerobic stability on silage. Nevertheless it is still unknown if sodium benzoate supplementation on silage may affect animal consumption or cause deleterious effect on metabolism with influence on animal performance. The objective of this study was using different sealing strategies to assess dry matter loss and nutritional value on corn silage, and the influence of supplementing sodium benzoate on total mixed ration for dairy cattle. This trial was conducted at Animal Science Department of Luiz de Queiroz College of Agriculture (ESALQ/USP). Corn crop was harvested with 35% of dry matter (DM) and ensiled on horizontal silos (40 t capacity). A factorial design (2x2) for silo sealing and benzoate as an additive on dietary feed were evaluated. Silo sealing strategies were confected as follows: (1) Plastic film doubled-sized 200 &mu;m covered with bagasse (layer thickness 10 cm) (BG) and 2) application of sodium benzoate on top surface of ensiled mass pulverizing 150 g m-2 (dilution of 1:4) sealing it immediately with plastic film double-sided 200 &mu;m (BZ). After 343 days of storage, the silos were open and the lactation trial started. Two dietary treatments evaluated the addition sodium benzoate on feed mixture of total ration. Sodium benzoate was incorporated (+ 0.15 % on total feed) on corn silage from BG and BZ and no incorporation to BG and BZ were used as control treatment. Dietary sodium benzoate was diluted on water (0.3:1 ratio) and pulverized on total ration immediately before each meal. Feed formulation: 8% cottonseed meal, 9.5% citric pulp, 18% soybean meal, 9% dry corn meal, 2.5 % vitamin and mineral premix, and 53% of corn silage. Twenty Holstein cows lactating were allocated in five Latin squares (4 x 4) during 21 days (14 days to acclimate) and fed twice a day. Dry matter intake (DMI), milk yield and quality were recorded between day 15th and 21st from each experimental period. Data were subjected to MIXED procedure from SAS for factorial design (2x2). The silage with sugarcane bagasse coverage was more effective in reducing the oxygen input during the fermentation process and consequently led to lower growth of spoilage microorganisms and better conservation of silage nutrients, resulting in increased digestibility of dry matter. Adding 0.15 % of sodium benzoate on fresh matter diet doesn\'t affect the performance of dairy cows.

Estratégias de vedação tem sido adotadas com o intuito de reduzir a entrada de oxigênio para o interior dos silos. Aditivos químicos como o benzoato de sódio, que apresenta funções antimicrobianas também pode ser empregado para melhoria da estabilidade aeróbia de silagens. Porém, ainda não se sabe se pode causar efeitos adversos no consumo ou metabolismo dos animais alimentados e, consequentemente levar a alterações no desempenho animal. Desta forma no presente estudo, objetivou-se avaliar a influência de estratégias de vedação de silos trincheira sobre as perdas de MS e valor nutritivo de silagens de milho e, a adição de benzoato sódio na ração total no valor nutritivo para vacas leteiras. O experimento foi conduzido no Departamento de Zootecnia da Escola Superior de Agricultura \"Luiz de Queiroz\" (ESALQ/USP). A cultura do milho foi colhida com aproximadamente 35% de matéria seca (MS) e ensilada em silos trincheira (capacidade de 40 t). No momento do fechamento dos silos, dois tratamentos foram impostos: (1) lona dupla-face 200 &mu;m protegida com bagaço de cana-de-açúcar (camada com espessura de 10 cm) (BG) e, (2) aplicação superficial de benzoato de sódio 150 g/m2 (diluído em água 1:4) imediatamente antes da vedação com lona dupla-face 200 &mu;m (BZ). Vinte vacas Holandesas em lactação foram alocadas em cinco Quadrados Latinos 4 × 4 em períodos de 21 dias (14 d adaptação). As dietas experimentais continham (%MS): 8% de caroço de algodão, 9,5% de polpa cítrica, 18% de farelo de soja, 9,0% de milho moído seco, 2,5% premix mineral + vitaminas e 53% de silagem de milho: BG ou BZ ou silagem de milho BG + 0,15% de benzoato de sódio ou silagem de milho BZ mais 0,15% de benzoato de sódio. O benzoato de sódio foi diluído em água (0,3:1) e aspergido na ração total imediatamente antes de cada trato. Os dados foram submetidos à análise utilizando-se o procedimento MIXED do SAS, através de arranjo fatorial 2 × 2. A silagem com cobertura de bagaço de cana foi mais eficiente em reduzir a entrada de oxigênio durante o processo de fermentação e, consequentemente levou ao menor crescimento de microrganismos deterioradores e melhor conservação dos nutrientes da silagem, resultando em maior digestibilidade da MS. A adição de benzoato de sódio na dose de 0,15% na MN não altera o desempenho de vacas leiteiras. / Sealing strategies have been adopted to reduce oxygen entrance to silo. Chemical additives such as sodium benzoate have antimicrobial activity and it can also promote an aerobic stability on silage. Nevertheless it is still unknown if sodium benzoate supplementation on silage may affect animal consumption or cause deleterious effect on metabolism with influence on animal performance. The objective of this study was using different sealing strategies to assess dry matter loss and nutritional value on corn silage, and the influence of supplementing sodium benzoate on total mixed ration for dairy cattle. This trial was conducted at Animal Science Department of Luiz de Queiroz College of Agriculture (ESALQ/USP). Corn crop was harvested with 35% of dry matter (DM) and ensiled on horizontal silos (40 t capacity). A factorial design (2x2) for silo sealing and benzoate as an additive on dietary feed were evaluated. Silo sealing strategies were confected as follows: (1) Plastic film doubled-sized 200 &mu;m covered with bagasse (layer thickness 10 cm) (BG) and 2) application of sodium benzoate on top surface of ensiled mass pulverizing 150 g m-2 (dilution of 1:4) sealing it immediately with plastic film double-sided 200 &mu;m (BZ). After 343 days of storage, the silos were open and the lactation trial started. Two dietary treatments evaluated the addition sodium benzoate on feed mixture of total ration. Sodium benzoate was incorporated (+ 0.15 % on total feed) on corn silage from BG and BZ and no incorporation to BG and BZ were used as control treatment. Dietary sodium benzoate was diluted on water (0.3:1 ratio) and pulverized on total ration immediately before each meal. Feed formulation: 8% cottonseed meal, 9.5% citric pulp, 18% soybean meal, 9% dry corn meal, 2.5 % vitamin and mineral premix, and 53% of corn silage. Twenty Holstein cows lactating were allocated in five Latin squares (4 x 4) during 21 days (14 days to acclimate) and fed twice a day. Dry matter intake (DMI), milk yield and quality were recorded between day 15th and 21st from each experimental period. Data were subjected to MIXED procedure from SAS for factorial design (2x2). The silage with sugarcane bagasse coverage was more effective in reducing the oxygen input during the fermentation process and consequently led to lower growth of spoilage microorganisms and better conservation of silage nutrients, resulting in increased digestibility of dry matter. Adding 0.15 % of sodium benzoate on fresh matter diet doesn\'t affect the performance of dairy cows.