Manipulation of Rumen Fermentation

Thomas, P. C.; Rook, J. A. F.

doi:10.1016/b978-0-408-71010-7.50009-3

Cited by 61 publications

(8 citation statements)

References 86 publications

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“…The linear changes of VFA concentrations with time point to slow ruminal degradation of hay not altered by urea supplementation, and are consistent with the suggestion that with such forages the ruminal microbial population is relatively stable (Barry et al, 1977;Thomas and Hodgson, 1979). The high acetate and methane proportions reveal the inefficient pattern of ruminal fermentations relative to the metabolism of end-products of digestion in ruminants (Thomas and Rook, 1981). Theoretical methane production was calculated using the stoichiometry of formation of fermentation end-products (~rskov et al, 1968) and yielded values of methane proportions 5 to 13 percentage units lower than those measured experimentally.…”

Section: Discussionsupporting

confidence: 83%

“…These values are minimal estimates due to the uncertainties attached to calculating the energy cost of urea synthesis and excretion in the urine (Grisolia and Kennedy, 1966;Oldham and Lindsay, 1983). Ruminal fermentations, as determined from pH, VFA concentrations and molar proportions, and methane are characteristic of poorquality forage diets (Thomas and Rook, 1981) and showed only slight changes with supplementation. The linear changes of VFA concentrations with time point to slow ruminal degradation of hay not altered by urea supplementation, and are consistent with the suggestion that with such forages the ruminal microbial population is relatively stable (Barry et al, 1977;Thomas and Hodgson, 1979).…”

Section: Discussionmentioning

confidence: 99%

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Digesta Flows in Sheep Fed Poor-Quality Hay Supplemented with Urea and Carbohydrates

Ortigues¹,

Fontenot²,

Ferry³

1988

Journal of Animal Science

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Two metabolism trials were conducted with 12 yearling crossbred wethers per trial (34 and 38 kg for trials 1 and 2, respectively). The wethers, equipped with ruminal, abomasal and ileal cannulae, were randomly allotted for each trial to the following treatments: 1) bay alone or hay supplemented with 2) .9% urea, 3) 1% urea and 6.5% molasses or 4) 1% urea and 5.2% corn. Two digestive flow markers were used: Cr203 powder and Co-ethylenediaminetetraacetic acid (Co-EDTA). Urea and Co-EDTA were infused continuously into the rumen via cannula. Daily dry matter (DM) intake averaged 517 g. Urea supplementation improved N retention (P < .01). Apparent digestibility of DM, acid detergent fiber (ADF) and energy was not affected by treatment. Urea and carbohydrate supplementation increased ruminal propionic acid molar proportions (P < .05). Apparent ruminal DM digestion accounted for 41% of the total DM degraded, whereas 77.4% of the digestible ADF was degraded in the rumen. Urea supplementation increased ADF digestion in the large intestine (P < .01). Urea and carbohydrate supplementation resulted in a stepwise increase in N flowing with the liquid phase at the abomasum. Mean retention times of the solid and liquid phases of digestive contents were similar across treatments. Overall, benefits of supplementation of poor-quality fescue hay diets by small amounts of urea and readily available carbohydrates remain questionable for sheep fed at a fixed level of intake below maintenance.

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Section: Discussionsupporting

confidence: 83%

Section: Discussionmentioning

confidence: 99%

Digesta Flows in Sheep Fed Poor-Quality Hay Supplemented with Urea and Carbohydrates

Ortigues¹,

Fontenot²,

Ferry³

1988

Journal of Animal Science

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“…De modo geral, a não-significância dos coeficientes das digestibilidades, pode ser atribuída ao efeito associativo dos ingredientes da dieta, justificando as ações progressivas das bactérias e protozoários na digestão ruminal e na produção final de ácidos graxos voláteis -metano, dióxido de carbono, amônia e células microbianas (Thomas & Rook, 1981).…”

Section: Resultsunclassified

Xiquexique (Pilosocereus gounellei (A. Weber ex K. Schum.) Bly. ex Rowl.) em substituição à silagem de sorgo (Sorghum bicolor L. Moench) na alimentação de vacas leiteiras

Silva

Ferreira

et al. 2005

R. Bras. Zootec.

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RESUMO -O desempenho de vacas da raça Pardo-suíça em lactação e a digestibilidade aparente de dietas contendo níveis de 0; 12,5; 25; 37,5 e 50% de xiquexique (Pilosocereus gounellei (A. Weber ex K. Schum.) Bly. ex Rowl.) em substituição à silagem de sorgo (Sorghum bicolor L. Moench) foram avaliados utilizando-se cinco vacas com peso vivo (PV) médio de 520 kg e produção média diária de 15 kg de leite. O delineamento experimental foi em quadrado latino (5x5) e constou de cinco animais, cinco períodos e cinco níveis de inclusão de xiquexique na dieta. Cada período experimental teve duração de 17 dias ( dez destinados à adaptação dos animais às dietas e sete para coleta).Os consumos de matéria seca (MS), em kg/dia, % e em unidade de tamanho metabólico (g/kg 0,75 ), de matéria orgânica (MO), de proteína bruta (PB) e de carboidratos totais (CHT), em kg/dia, não foram influenciados pela inclusão de xiquexique na dieta, apresentando valores médios de 15,21; 2,83; 136,10; 13,64; 1,64 e 11,48 kg respectivamente. Os consumos de fibra em detergente neutro (FDN), extrato etéreo (EE) e nutrientes digestíveis totais (NDT), em kg/dia, diminuíram, enquanto o de carboidratos não-fibrosos (CNF), em kg/dia, elevou linearmente com a inclusão de xiquexique na dieta. A inclusão de xiquexique na dieta não influenciou as digestibilidades de matéria seca (DAMS), matéria orgânica (DAMO), proteína bruta (DAPB), extrato etéreo (DAEE), fibra em detergente neutro (DAFDN) e dos carboidratos totais (DACHT). Não houve efeito da inclusão de xiquexique na dieta sobre a produção (média de 14,80 kg/dia) e na composição química do leite e a eficiência alimentar (kg de leite produzido/kg de MS consumida).Palavras-chave: consumo, pilosocereus, produção de leite, semi-árido Replacement of Sorghum Silage (Sorghum bicolor L. Moench) with a Columnar Cactus (Pilosocereus gounellei (A. Weber ex K. Schum.) Byl ex Rowl.) on Diets of Lactating Dairy CowsABSTRACT -Five lactating Brown-Swiss cows averaging 520 kg of body weight (BW) and 15 kg of milk yield were assigned to a 5 x 5 Latin square to study the effects of replacing sorghum silage (Sorghum bicolor L. Moench) with a columnar cactus known as xiquexique (Pilosocereus gounellei (A. Weber ex K. Schum.) Byl ex Rowl.) on animal performance and apparent digestibility of nutrients. The experimental diets contained (DM basis): 0, 12.5, 25, 37.5, or 50% of xiquexique. Each experimental period lasted 17 days (10 days for diet adaptation and 7 days for sample collection). Intake of dry matter (DM) expressed as amount (kg/d), as percentage of BW, or as metabolic weight (g/kg 0.75 ) were 15.21 kg/d, 2.83% of BW, and 136.10 g/kg 0.75 and did not change by replacing sorghum silage with xiquexique in the diet. Similarly, intake of organic matter (OM), crude protein (CP), and total carbohydrates (TCH) did not differ and averaged 13.64, 1,64, and 11,48 kg/d across diets, respectively. However, intake (kg/d) of neutral detergent fiber (NDF), ether extract (EE), and total digestible nutrients (TDN) all decreased linearly (P...

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“…Equal portions of the daily feed allotment were offered to animals four times per day at 0400, 1000, 1600 and 2200 h. Permanganate lignin (Robertson and Van Soest 1981) was used as a niarker for calculating digestibilitv. Each Steel and Torrie (1980 Thomas and Rook (1981). (Teller et aI.1978).…”

Section: Experiments Imentioning

confidence: 99%

Effect of Forage Amount and Particle Size in Diets of Lactating Dairy Cows on Site of Digestion and Microbial Protein Synthesis

Rode¹,

Weakley²,

Satter³

1985

Can. J. Anim. Sci.

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Roor, L. M., Wnerlnv, D. C. eNo S.lrrnn, L. D. 1985. Effect of forage amount and particle size in diets of lactating dairy cows on site of digestion and microbial protein synthesis. Can. J. Anim. Sci. 65: l0l-111.Lactating Holstein cows fitted with ruminal and duodenal T-type cannulae were used in two studies to determine the effect of forage: concentrate ratio and forage particle size on site of nutrient digestion and microbial protein synthesis. In exp.1, cows were fed alfalfa hay at 24, 38,58 and SOVo of total dry matter intake.Organic matter (OM) digestion in the total tract (OMD) increased with increasing concentrate level but apparent ruminal OM digestion (AROMD) was unaffected by diet. Digestion of acid detergent fiber (ADF) was similar among the higher forage diets, but was depressed at the 24Vo forage level. Efficiency of microbial Protein synthesis (MPS) was depressed by high concentrate diets and was positively correlated (P<0.05) to turnover rate within the rumen. ln exp. 2, cows were fed 20Vo concentrate and SOVo alfalfa hay in long, chopped or ground and pelleted form.AROMD was lower with ground hay but OMD was unaffected by diet. Digestibility of ADF in the rumen was lower with ground hay, but was partially compensated for by increased hindgut digestion of ADF. Flow of feed plus endogenous nitrogen (N) at the duodenum was 37Va and 47Vo on N intake with long and ground hay, respectively. Efficiency of MPS increased 75Va and postruminal N digestion increased 36Vo when ground hay replaced long hay. Efficiency of MPS was directly related to ruminal solids turnover rate and inversely related to liquid dilution rate.These results demonstrate improvements in efficiency of MPS with either increasing amounts of forage in the diet or increased ruminal passage of solids.

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Manipulation of Rumen Fermentation

Cited by 61 publications

References 86 publications

Digesta Flows in Sheep Fed Poor-Quality Hay Supplemented with Urea and Carbohydrates

Digesta Flows in Sheep Fed Poor-Quality Hay Supplemented with Urea and Carbohydrates

Xiquexique (Pilosocereus gounellei (A. Weber ex K. Schum.) Bly. ex Rowl.) em substituição à silagem de sorgo (Sorghum bicolor L. Moench) na alimentação de vacas leiteiras

Effect of Forage Amount and Particle Size in Diets of Lactating Dairy Cows on Site of Digestion and Microbial Protein Synthesis

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