Protein Digestion and Intestinal Amino Acids in Dairy Cows Fed Fresh Lolium perenne with Different Nitrogen Contents

Vuuren, A.M. van; Krol-Kramer, F.; Lee, R.A. Van der; Corbijn, H.

doi:10.3168/jds.s0022-0302(92)77982-x

Cited by 104 publications

(65 citation statements)

References 17 publications

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“…Total VFA concentrations were within ranges reported for fresh forage diets, although the proportion of acetate was lower and propionate higher than has been reported (Beever et al 1986a(Beever et al , 1986bvan Vuuren et al 1992;Holden et al 1994;Berghazi et al 1996;Mackle et al 1996;Carruthers et al 1997). The ratio of acetate:propionate averaged 2.1 for all diets, ccompared with ratios of 3.0 to 4.2 reported for pasture.…”

Section: N Intakesupporting

confidence: 71%

“…However, van Vuuren et al (1991) also assumed that the efficiency of MPS increased on low N herbage because of the expected increase in carbohydrate content. Neither an increase in microbial protein yield nor efficiency of synthesis were apparent on LN compared with HN pasture, despite an NSC content of 27% compared with 22%, possibly because of slower OM degradation on low N pasture (van Vuuren et al 1992).…”

Section: N Intakementioning

confidence: 80%

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Milk production and ruminal metabolites from cows offered two pasture diets supplemented with non‐structural carbohydrate

Carruthers¹,

Neil²

1997

New Zealand Journal of Agricultural Research

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The effects on milk solids production, ruminal metabolites, and microbial protein synthesis of four pasture-based diets were investigated. Two pastures (high or low nitrogen content (HN, LN) each with and without nonstructural carbohydrate supplementation (+NSC, -NSC, at 10% of metabolisable energy intake) were offered to eight stall held, rumen-fistulated Friesian cows during four 14-day periods in early to mid lactation in a Latin square design. HN and LN pastures contained 2.8 and 2.1% N, respectively. Total daily dry matter intakes averaged 15.6, 14.5, 15.3, and 14.3 kg on HN+NSC, HN-NSC, LN+NSC, and LN-NSC, respectively. NSC supplementation had no effect on milk and milk fat yields but increased milk protein yield by 0.04 kg/ day on HN pasture. Yields of milk, fat, and protein were higher on HN than LN pasture but microbial protein synthesis (MPS, g N/day) was not affected by type of pasture. MPS and efficiency of MPS (g N/kg digestible organic matter intake) were increased by NSC supplementation on HN pasture but not on LN pasture. Ruminal ammonia concentration and total tract N digestibility were reduced by NSC supplementation on both pastures and were lower on LN compared with HN pasture. The results indicated that pasture type affected response to NSC supplementation and that on HN but not LN pasture NSC supplementation improved N utilisation in the rumen and increased milk protein output. A97013

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Section: N Intakesupporting

confidence: 71%

Section: N Intakementioning

confidence: 80%

Milk production and ruminal metabolites from cows offered two pasture diets supplemented with non‐structural carbohydrate

Carruthers¹,

Neil²

1997

New Zealand Journal of Agricultural Research

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“…Lowering N fertilisation did not modify in vivo OM digestibility, which is in agreement with the data reported by Demarquilly [11] on sheep and by Van Vuuren et al [42], and Peyraud et al [32] on dairy cows. Therefore, total digestible consumed OM was similar for both HN and LN treatments, which is in good agreement with the milk yields measured.…”

Section: N Fertilisationsupporting

confidence: 92%

“…The voluntary dry matter intake, the digestibility and the quantity of N entering in the intestines seems to be little affected by the level of N fertilisation [11,31,42].…”

Section: Introductionmentioning

confidence: 99%

Effect of nitrogen fertiliser rate and protein supplementation on the herbage intake and the nitrogen balance of grazing dairy cows

2002

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-The objective of this study was to examine the effect of the level of reducing nitrogen (N) fertiliser rate on herbage intake and N balance of dairy cows grazing a pure perennial ryegrass pasture. The addition of a protein supplement to cows grazing the low N fertilised sward was also evaluated. Three treatments were compared over three periods of 2 weeks using 9 fistulated cows in a 3 × 3 Latin square design: HN (80 kg N·ha -1 ·regrowth -1 ), LN (0-20 kg N·ha -1 ·regrowth -1 ), LN+S (LN + 2 kg of soybean meal (SBM)). Daily herbage organic matter (OM) intake was estimated by chromic oxide dilution in the faeces. Nitrogen and ADF contents in faecal OM were used to estimate the herbage digestibility. Herbage mass, grazing behaviour and rumen fermentation pattern were measured. Nitrogen intake was estimated by the chemical composition of the defoliated herbage and urinary N was calculated by subtracting milk N and faecal N output from N intake. Digestibility (0.79), daily intake (16.4 kg OM), grazing time (512 min) and the proportion of volatile fatty acid were not affected by reducing the N fertiliser rate. These results may be explained by the moderate effect of N fertilisation on herbage mass which remained high in the LN swards (3.9 vs. 4.7 t OM·ha -1 for HN) and the rather large herbage allowance which allowed the cows to graze a herbage with a crude protein content that still remained higher than 160 g·kg -1 DM. On the LN sward, N intake was significantly lower (-80 g·d -1 ) (P < 0.01), faecal N and milk N output remained unchanged, whereas urine N output decreased (-77 g·d -1 ) (P < 0.01). Protein supplementation did not depress HOMI or grazing time, supplemented cows consumed 2.4 kg OM more (P < 0.01) and this increased milk yield by 1.3 kg·kg -1 SBM (P < 0.01). SBM supplementation largely increased N intake, and finally N excreted in the urine. It was concluded that N fertilisation, and N supplementation are efficient means to manipulate animal performances and N balance in grazing dairy cows. . Res. 51 (2002) 279-293  INRA, EDP Sciences, 2002 DOI: 10.1051/animres:2002022Résumé -Influence du niveau de fertilisation azotée et de la complémentation azotée sur l'ingestion et le bilan azoté des vaches laitières pâturant du ray-grass anglais. L'effet du niveau de fertilisation azotée et de la complémentation avec du tourteau de soja (50 % normal et 50 % tanné) a été étudié chez des vaches laitières pâturant un ray-grass anglais. Trois traitements ont été comparés avec 9 vaches fistulées au niveau du rumen, selon un schéma en carré latin 3 × 3 sur des périodes de 2 semaines : HN (80 kg N·ha -1 ·cycle -1 ), LN (0-20 kg N·ha -1 ·cycle -1 ), LN+S (LN + 2 kg de tourteau de soja (SBM)). Les quantités d'herbe ingérée ont été calculées en mesurant la quantité de fèces par dilution de l'oxyde de chrome et en estimant la digestibilité de l'herbe ingérée à partir de la teneur en N et en ADF des fèces. L'azote ingéré a été estimé à partir de la composition chimique de l'herbe dé-foliée et l'azote urinaire a été ...

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“…In animals fed fresh ryegrass, the flow of Met has been reported to be less than 5% of the essential amino acids flowing to the duodenum (Ulyatt et al 1975;Van Vuuren et al 1992, 1993. According to Schwab (1996), Met must contribute 5.3 to 5.6% of the duodenal essential amino acids for optimal milk protein production.…”

mentioning

confidence: 99%

The effects of methionine supplementation upon milk composition and production of forage-fed dairy cows

D¹,

McNabb²,

Hill³

et al. 1999

Can. J. Anim. Sci.

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. 1999. The effects of methionine supplementation upon milk composition and production of forage-fed dairy cows. Can. J. Anim. Sci. 79: [235][236][237][238][239][240][241]. Two experiments (mid-and late lactation) were conducted to test whether methionine (Met) limited milk production in Friesian cows fed sole diets of fresh perennial ryegrass-white clover pasture. In mid-lactation (exp. 1), 26 cows were assigned to one of three treatments: ruminally protected oral DL-Met (15 g d -1 ), continuous intrajugular infusion of L-Met (15 g d -1 ) and control. Twelve animals from exp. 1 were used during late lactation (exp. 2) and distributed in two experimental groups: ruminally protected oral DL-Met (15 g d -1 ) and control. Dry matter, metabolizable energy, crude protein and Met intakes, milk yield and composition and blood Met, cysteine and urea were measured. Oral and intravenous Met supplementation increased blood Met concentration by 50-90% compared with controls. Met supplementation did not alter the concentration of milk fat, protein or lactose in either experiment. Met supplementation had no significant effects on yields of fat, lactose, casein, whey proteins or non-protein nitrogen during mid-lactation. In late lactation, Met supplementation did not affect milk protein composition or yield of milk components, with exception of a decrease (P < 0.05) in the yield of β-casein. Intravenous Met supplementation increased (P < 0.05) the efficiency of conversion of pasture N to milk protein in mid-lactation. ) sur la composition et la production de lait ont été déter-minés chez les vaches de race Frisonne en mi-lactation (expérience 1) et fin de lactation (expérience 2). Les vaches ont été alimentées exclusivement avec du pâturage de raygrass et trèfle blanc fraîchement coupé dans les deux expériences. Dans l'expérience 1, 26 vaches en mi-lactation ont reçu un des trois traitements suivants: administration orale de la DL-méthionine protégée contre le dégradation ruminale, perfusion intraveineuse continue de la L-méthionine ou témoin. Dans l'expérience 2, 12 vaches de l'expérience 1 ont été utilisées en fin de lactation et distribuées en deux groupes expérimentaux: administration orale de la DL-méthionine protégée ou témoin. La complémentation orale et intraveineuse en méthionine a augmenté la concentration sanguine de méthionine. La complémentation orale et/ou intraveineuse en méthionine n'a pas modifié la concentration du gras, de la protéine et du lactose dans le lait en mi-et fin de lactation. La complémentation en méthionine n'a pas eu des effets significatifs sur la production de gras, de lactose, caséine, des protéines du lactosérum et de la fraction azotée non-protéique en mi-lactation. En fin de lactation, la complémentation orale en méthionine n'a pas affecté la production des constituants du lait ainsi que sa composition protéique à l'exception d'une diminution (P < 0.05) de la production de la β-caséine. La complémentation intraveineuse en méthionine a augmenté (P < 0.05) l'efficacité de la conversion de l...

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Protein Digestion and Intestinal Amino Acids in Dairy Cows Fed Fresh Lolium perenne with Different Nitrogen Contents

Cited by 104 publications

References 17 publications

Milk production and ruminal metabolites from cows offered two pasture diets supplemented with non‐structural carbohydrate

Milk production and ruminal metabolites from cows offered two pasture diets supplemented with non‐structural carbohydrate

Effect of nitrogen fertiliser rate and protein supplementation on the herbage intake and the nitrogen balance of grazing dairy cows

The effects of methionine supplementation upon milk composition and production of forage-fed dairy cows

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