Manure Production and Nitrogen Excretion in Lactating Cows Fed Grass Silage-based Diets

An effective strategy for milk production is to supplement silage with small amounts of high-protein concentrate based on mixed carbohydrate sources and fish and soyabean meals (Aston et al 1992). Recent work at Trawsgoed by Sargeant and McAllan (1993) using growing steers given high-digestibility grass silage supplemented with rapeseed meal (a source of highly rumen degradable protein) produced similar live-weight gains to those obtained with fish meal. Jacobs and McAllan (1992) concluded that microbial protein yield is greater when the more degradable protein source is given, indicating a better balance in the supply of nitrogen and energy nutrients within the rumen. Lactating cows given grass silage diets have a high requirement for Metabolisable Protein (MP). The source of rumen fermentable carbohydrate may be important when MP supply is derived from degradable dietary protein and hence microbial growth. This study therefore examined the effects of varying the sources of carbohydrate and protein in low levels of concentrate given with high-digestibility grass silage. The main effects observed in the milk production experiment are presented here.

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Digestibility of diets of grass silage and whole crop wheat in the rumen of lactating cows

Proceedings of the British Society of Animal Science ◽

10.1017/s0308229600030154 ◽

1996 ◽

Vol 1996 ◽

pp. 42-42

Author(s):

A.L. Abdalla ◽

J.D. Sutton ◽

D.J. Humphries ◽

R.H. Phipps

Keyword(s):

Dairy Cows ◽

Present Experiment ◽

Grass Silage ◽

Lactating Cows ◽

Forage Mixtures

Forage mixtures containing urea-treated whole crop wheat (WCW) have been shown to be used less efficiently than expected by dairy cows due to low digestibility, particularly of the starch. The purpose of the present experiment was to measure the contribution of the rumen to the digestibility of diets based on grass silage or mixtures of grass silage and urea-treated WCW.

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Effects of sources of carbohydrate and protein given at low levels with grass silage ad libitum on the performance of lactating dairy cows

Proceedings of the British Society of Animal Science ◽

10.1017/s0308229600029299 ◽

1995 ◽

Vol 1995 ◽

pp. 163-163

Author(s):

K. Aston ◽

R.J. Dewhurst ◽

W.J. Fisher ◽

D.W.R. Davies ◽

A.B. McAllan

Keyword(s):

Milk Production ◽

Live Weight ◽

Rapeseed Meal ◽

Grass Silage ◽

Lactating Cows ◽

Lactating Dairy Cows ◽

Production Experiment ◽

Low Levels ◽

Main Effects ◽

Degradable Protein

An effective strategy for milk production is to supplement silage with small amounts of high-protein concentrate based on mixed carbohydrate sources and fish and soyabean meals (Aston et al 1992). Recent work at Trawsgoed by Sargeant and McAllan (1993) using growing steers given high-digestibility grass silage supplemented with rapeseed meal (a source of highly rumen degradable protein) produced similar live-weight gains to those obtained with fish meal. Jacobs and McAllan (1992) concluded that microbial protein yield is greater when the more degradable protein source is given, indicating a better balance in the supply of nitrogen and energy nutrients within the rumen. Lactating cows given grass silage diets have a high requirement for Metabolisable Protein (MP). The source of rumen fermentable carbohydrate may be important when MP supply is derived from degradable dietary protein and hence microbial growth. This study therefore examined the effects of varying the sources of carbohydrate and protein in low levels of concentrate given with high-digestibility grass silage. The main effects observed in the milk production experiment are presented here.

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The effects of intraruminal infusions of urea on the voluntary intake and milk production of cows receiving grass silage diets

Journal of Dairy Research ◽

10.1017/s0022029900029502 ◽

1990 ◽

Vol 57 (4) ◽

pp. 455-464 ◽

Cited By ~ 19

Author(s):

Jai-Jun Choung ◽

David G. Chamberlain ◽

Phillip C. Thomas ◽

Ian Bradbury

Keyword(s):

Dairy Cows ◽

Milk Production ◽

Crude Protein ◽

Clinical Symptoms ◽

Factors Associated ◽

Grass Silage ◽

Lactating Cows ◽

Insulin In Plasma ◽

Voluntary Intake ◽

Higher Doses

SummaryResponses of dairy cows given silage diets to the intraruminal infusion of urea in progressively increasing doses were studied in four experiments, two with non-lactating cows and two with lactating cows. No clinical symptoms of NH3 toxicity were observed in any of the experiments. When urea was infused continuously, silage intake was depressed (P < 0·05) when the total supply of N exceeded the equivalent of 250g crude protein (CP)/kg DM in the total diet. However, when the urea load was administered twice daily, as opposed to continuously, intake depression (P < 0·05) occurred at the equivalent of 170g CP/kg DM. At the higher doses of urea, concentrations of NH3 in peripheral blood increased and were accompanied by increased concentrations of glucose and reduced levels of insulin in plasma. In general, responses of milk production followed those of silage intake but there was evidence of greater proportional reductions in the yield of lactose relative to that of fat and protein. It is concluded that the voluntary intake of high-protein silages may be depressed by factors associated with high rates of absorption of NH3 from the rumen.

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Effect of camelina oil or live yeasts (Saccharomyces cerevisiae) on ruminal methane production, rumen fermentation, and milk fatty acid composition in lactating cows fed grass silage diets

Journal of Dairy Science ◽

10.3168/jds.2014-7976 ◽

2015 ◽

Vol 98 (5) ◽

pp. 3166-3181 ◽

Cited By ~ 41

Author(s):

A.R. Bayat ◽

P. Kairenius ◽

T. Stefański ◽

H. Leskinen ◽

S. Comtet-Marre ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Fatty Acid Composition ◽

Fatty Acid ◽

Acid Composition ◽

Methane Production ◽

Rumen Fermentation ◽

Milk Fatty Acid ◽

Camelina Oil ◽

Grass Silage ◽

Lactating Cows

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Effect of incremental levels of sunflower-seed oil in the diet on ruminal lipid metabolism in lactating cows

British Journal Of Nutrition ◽

10.1017/s0007114507853323 ◽

2008 ◽

Vol 99 (5) ◽

pp. 971-983 ◽

Cited By ~ 80

Author(s):

K. J. Shingfield ◽

S. Ahvenjärvi ◽

V. Toivonen ◽

A. Vanhatalo ◽

P. Huhtanen ◽

...

Keyword(s):

Lipid Metabolism ◽

Milk Fat ◽

Sunflower Seed ◽

Seed Oil ◽

Latin Square ◽

Grass Silage ◽

Sunflower Seed Oil ◽

Lactating Cows ◽

Potential Benefits ◽

Nutritional Strategies

Based on the potential benefits ofcis-9,trans-11-conjugated linoleic acid (CLA) for human health there is interest in developing sustainable nutritional strategies for enhancing the concentration of this fatty acid in ruminant-derived foods. Most evidence to date suggests that endogenous synthesis is the major source ofcis-9,trans-11 in milk fat and ruminal outflow is limited and largely independent of dietary 18 : 2n-6 supply. Four lactating cows fitted with a rumen cannula were used in a 4 × 4 Latin square with 14 d experimental periods to examine the effects of sunflower-seed oil (SFO) as a source of 18 : 2n-6 on ruminal lipid metabolism. Cows were offered grass silage-based diets supplemented with 0, 250, 500 or 750 g SFO/d. Supplements of SFO had no effect on DM intake, milk fat or protein secretion, but increased linearly (P < 0·01) milk yield and milk lactose output and shifted (P < 0·001) rumen fermentation towards propionate at the expense of acetate. SFO supplements increased linearly (P < 0·05) the flow of 18 : 0, 18 : 1, 18 : 2n-6 and total CLA at the omasum and enhanced ruminalcis-9-18 : 1, 18 : 2n-6 and 18 : 3n-3 metabolism. Flows of all-trans- (Δ4–16) andcis- (Δ9–16) 18 : 1 isomers were elevated, while increases in ruminal CLA outflow were confined totrans-8,trans-10 and geometric 9,11 and 10,12 isomers. It is concluded that supplementing grass silage-based diets with plant oils rich in 18 : 2n-6 enhances ruminal outflow oftrans-11-18 : 1 andcis-9,trans-11-CLA in lactating cows.

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THE EFFECT OF THE ADDITIVE "SILOGEN" ON THE INTAKE AND DIGESTIBILITY OF GRASS SILAGE

Canadian Journal of Animal Science ◽

10.4141/cjas84-078 ◽

1984 ◽

Vol 64 (3) ◽

pp. 709-715 ◽

Cited By ~ 3

Author(s):

L. J. FISHER ◽

G. C. L. PENNELLS ◽

J. A. SHELFORD

Keyword(s):

Organic Matter ◽

Key Words ◽

Aspergillus Oryzae ◽

White Clover ◽

Lactobacillus Acidophilus ◽

Feeding Trial ◽

Acid Detergent Fiber ◽

Grass Silage ◽

Lactating Cows ◽

Silage Additives

A silage additive (Silogen) consisting of a dried culture of Lactobacillus acidophilus and Aspergillus oryzae was tested in a feeding trial with lactating cows and a digestibility trial with sheep, as a means of improving the conservation of nutrients during the ensiling of an orchardgrass-white clover forage. The additive did not influence the composition of the effluent nor the silage with the exception that ADIN/N was 5.4% for the treated compared to 9.0% for the control silage. Lactating cows consumed significantly (P < 0.05) less of the treated silage (10.70 vs. 12.95 kg DM/day) but produced the same amount of milk (25.2 vs. 25.0 kg/day) as the cows fed the control silage, indicative of a greater efficiency of utilization. The silage treated with the additive had a significantly higher (P < 0.05) digestibility of organic matter, acid detergent fiber and nitrogen compared to the control silage. It was concluded that the additive was effective in preserving a greater proportion of forage nutrients for utilization by the lactating cow. Key words: Silage additives, intake, digestibility, lactating cows, sheep

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Histidine Promotes the Glucose Synthesis through Activation of the Gluconeogenic Pathway in Bovine Hepatocytes

Animals ◽

10.3390/ani11113295 ◽

2021 ◽

Vol 11 (11) ◽

pp. 3295

Author(s):

Tianyu Yang ◽

Zhiqiang Cheng ◽

Maocheng Jiang ◽

Xiaoyu Ma ◽

Osmond Datsomor ◽

...

Keyword(s):

Mrna Level ◽

Regulatory Effect ◽

Hepatic Glucose Output ◽

Grass Silage ◽

Lactating Cows ◽

Hepatic Glucose ◽

Glucose Synthesis ◽

Limiting Amino Acid ◽

Glucose Output

Histidine (His) is considered to be the first-limiting amino acid (AA) on grass silage-based diets in lactation cows, which correlate positively with lactose yield. The higher glucose requirements of lactating cows can be met through a combination of increased capacity for gluconeogenesis and increased supply of gluconeogenic precursors. However, the effect of His on the expression of gluconeogenic genes in the bovine hepatocytes is less known. Therefore, this study aimed to investigate the regulatory effect of His on the key gluconeogenic genes and glucose output in bovine hepatocytes. The addition of 0.15, 0.6, and 1.2 mM His in a medium significantly enhanced (p < 0.05) the viability of bovine hepatocytes. Remarkably, 1.2 mM His induced profound changes (p < 0.05) in the mRNA level of key genes involved in gluconeogenesis, including PCK1, PCK2, FBP1, and G6PC in vitro. Furthermore, the mRNA expression of PCK1 was significantly elevated (p < 0.05) by the addition of 1.2 mM His at 3, 6, 12, and 24 h of incubation. The hepatic glucose output increased (p < 0.05) linearly with increasing His concentration. These findings indicate that the addition of His may be efficiently converted into glucose via the upregulation of genes related to the gluconeogenic pathway.

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