Effects of faba bean, blue lupin and rapeseed meal supplementation on amino acid metabolism of dairy cows fed grass silage-based diets.

Information about the amino acid (AA) supply of locally produced protein supplements to dairy cow metabolism is needed to design sustainable diets for milk production. In this dairy cow experiment, grass silage and cereal-based diets supplemented with isonitrogenous amounts of rapeseed meal (RSM), faba beans (FB) and blue lupin seeds (BL) were compared with a control diet (CON) without protein supplementation. The diets were arranged as a 4 × 4 Latin Square using periods of 21 days, and four rumen-cannulated Nordic Red dairy cows were used in the experiment. The intake of all AAs increased in response to protein supplementation and was for many individual AAs higher when RSM rather than the grain legumes FB and BL were fed. The total AA flow at the omasal canal was 3 026, 3 371, 3 373 and 3 045 g/day for cows fed CON, RSM, FB and BL, respectively, but only RSM resulted in higher milk protein output. This may be explained by the higher provision of essential AA for milk protein synthesis when RSM was fed. The cows fed FB showed some positive features such as a tendency for greater omasal flow of branched-chain AA compared with BL. Overall, low plasma methionine and/or glucose concentrations in all treatments suggest that their supply was possibly limiting further production responses under the dietary conditions of the current study. It seems that the benefits of grain legume supplementation are limited when high-quality grass silage and cereal-based diets are used as the basal diet, but higher responses in amino acid supply and subsequent production responses can be expected when RSM is used.

Effects of forage and grain legume-based silages supplemented with faba bean meal or rapeseed expeller on lactational performance, nitrogen utilization, and plasma amino acids in dairy cows.

The objective of this experiment was to investigate the effect of forage type [red clover (51%)-grass silage, i.e., RCG; vs. faba bean (66%)-grass silage, i.e., FBG] and concentrate type (faba bean, FB; vs. rapeseed expeller, RE) on lactational performance, milk composition and nitrogen (N) utilization in lactating dairy cows. Eight lactating multiparous Nordic Red cows were used in a replicated 4 × 4 Latin Square experiment, with 21-d periods, in a 2 × 2 factorial arrangement of treatments. The experimental treatments were as follows: (1) RCG with RE, (2) RCG with FB, (3) FBG with RE, and (4) FBG with FB. Inclusion rates of RE and FB were isonitrogenous. Crude protein contents of the experimental diets were 16.3, 15.9, 18.1, and 17.9% of dry matter, respectively. All diets included oats and barley and were fed ad libitum as total mixed rations with forage-to-concentrate ratio of 55:45. Dry matter intake and milk yield were recorded daily, and spot samples of urine, feces, and blood were collected at the end of each experimental period. Dry matter intake did not differ across diets, averaging 26.7 kg/d. Milk yield averaged 35.6 kg/d and was 1.1 kg/d greater for RCG versus FBG, and milk urea N concentration was lower for RCG compared with FBG. Milk yield was 2.2 kg/d and milk protein yield 66 g/d lower for FB versus RE. Nitrogen intake, urinary N, and urinary urea N excretions were lower, and milk N excretion tended to be lower for RCG compared with FBG. The proportion of the dietary N excreted as fecal N was larger in cows fed RCG than for those fed FBG, and the opposite was true for urinary N. We detected an interaction for milk N as percentage of N intake: it increased with RE compared with FB for RCG-based diet, but only a marginal increase was observed for FBG-based diet. Plasma concentration of His and Lys were lower for RCG than for FBG, whereas His tended to be greater and Lys lower for FB compared with RE. Further, plasma Met concentration was around 26% lower for FB than for RE. Of milk fatty acids, saturated fatty acids were decreased by RCG and increased by FB compared with FBG and RE, respectively, whereas monounsaturated fatty acids were increased by RCG versus FBG, and were lower for FB than for RE. In particular, 18:1n-9 concentration was lower for FB compared with RE. Polyunsaturated fatty acids, such as 18:2n-6 and 18:3n-3, were greater for RCG than for FBG, and 18:2n-6 was greater and 18:3n-3 was lower for FB versus RE. In addition, cis-9,trans-11 conjugated linoleic acid was lower for FB compared with RE. Faba bean whole-crop silage and faba bean meal have potential to be used as a part of dairy cow rations, but further research is needed to improve their N efficiency. Red clover-grass silage from a mixed sward, without inorganic N fertilizer input, combined with RE, resulted in the greatest N efficiency in the conditions of this experiment.

Effects of faba bean, blue lupin and rapeseed meal supplementation on nitrogen digestion and utilization of dairy cows fed grass silage-based diets.

There is increasing interest in using locally produced protein supplements in dairy cow feeding. The objective of this experiment was to compare rapeseed meal (RSM), faba beans (FBs) and blue lupin seeds (BL) at isonitrogenous amounts as supplements of grass silage and cereal based diets. A control diet (CON) without protein supplement was included in the experiment. Four lactating Nordic Red cows were used in a 4 × 4 Latin Square design with four 21 d periods. The milk production increased with protein supplementation but when expressed as energy corrected milk, the response disappeared due to substantially higher milk fat concentration with CON compared to protein supplemented diets. Milk protein output increased by 8.5, 4.4 and 2.7% when RSM, FB and BL were compared to CON. The main changes in rumen fermentation were the higher propionate and lower butyrate proportion of total rumen volatile fatty acids when the protein supplemented diets were compared to CON. Protein supplementation also clearly increased the ruminal ammonia N concentration. Protein supplementation improved diet organic matter and NDF digestibility but efficiency of microbial protein synthesis per kg organic matter truly digested was not affected. Flow of microbial N was greater when FB compared to BL was fed. All protein supplements decreased the efficiency of nitrogen use in milk production. The marginal efficiency (amount of additional feed protein captured in milk protein) was 0.110, 0.062 and 0.045 for RSM, FB and BL, respectively. The current study supports the evidence that RSM is a good protein supplement for dairy cows, and this effect was at least partly mediated by the lower rumen degradability of RSM protein compared to FB and BL. The relatively small production responses to protein supplementation with simultaneous decrease in nitrogen use efficiency in milk production suggest that economic and environmental consequences of protein feeding need to be carefully considered.

Grass silage pulp as a dietary component for high-yielding dairy cows.

Green biorefineries provide novel opportunities to use the green biomass efficiently and utilize the ecosystem services provided by grasslands more widely. The effects of the inclusion of fractionated grass silage solid fraction (pulp) on feed intake, rumen fermentation, diet digestion and milk production in dairy cows were investigated. Pulp was separated from grass silage using a screw press simulating a green biorefinery. Partial removal of liquid from forage increased DM concentration from 220 to 432 g/kg and NDF from 589 to 709 g/kg DM while CP decreased from 144 to 107 g/kg DM. A feeding trial using an incomplete changeover design with 24 Nordic Red cows and two 3-week periods was conducted. The pulp replaced grass silage in the diet at 0 (P0), 25 (P25) and 50 (P50) percentage of total forage, which was fed ad libitum with 13 kg of concentrate for all treatments. The forage DM intake was highest on P25 (14.1 kg/day) while P0 and P50 did not differ from each other (13.2 and 13.0 kg/day, respectively). There were no differences between the treatments in rumen pH or ammonia N, but the proportion of acetate increased with increasing pulp inclusion. The digestibility was measured using acid insoluble ash and indigestible NDF (iNDF) as internal markers. Neither of the markers detected differences in NDF digestibility, but according to iNDF, apparent total tract organic matter digestibility decreased with increasing pulp inclusion. The cows maintained milk production at P25, but it showed some decline at P50 (energy-corrected milk at P0 and P25 was 39.8 kg/day while for P50, it was 38.5 kg/day, P = 0.056) and the milk protein yield significantly declined with higher pulp inclusion. Simultaneously, the nitrogen use efficiency in milk production increased. It seems that the fibrous grass-based fraction from a biorefinery process has potential to be used as a feed for ruminants.

Dairy cow responses to graded levels of rapeseed and soya bean expeller supplementation on a red clover/grass silage-based diet.

The effects of rapeseed and soya bean expeller (SBE) supplementation on digestion and milk production responses in dairy cows were investigated in an incomplete Latin square design using five cows and four 3-week periods. The experimental diets consisted of five concentrate treatments fed at a rate of 9 kg/day: a mixture of barley and oats, which was replaced with rapeseed or SBE at two levels (CP concentration (g/kg dry matter (DM)) of 130 for the control concentrate and 180 and 230 for the two protein supplemented levels). A mixture of grass and red clover silage (1:1) was fed ad libitum and it had a CP concentration of 157 g/kg DM. Supply of nutrients to the lower tract was measured using the omasal canal sampling technique, and total digestion from total faecal collection. Protein supplementation increased omasal canal amino acid (AA) flows and plasma concentrations of AA, and was also reflected as increased milk production. However, N use efficiency (NUE) decreased with increased protein supplementation. Rapeseed expeller (RSE) tended to increase silage DM intake and elicited higher milk production responses compared with SBE and also resulted in a higher NUE. The differences between the protein supplements in nitrogen metabolism were relatively small, for example, there were no differences in the efficiency of microbial protein synthesis or omasal canal flows of nitrogenous components between them, but plasma methionine concentration was lower for soya bean-fed cows at the high CP level in particular. The lower milk protein production responses to SBE than to RSE supplementation were at least partly caused by increased silage DM and by the lower methionine supply, which may further have been amplified by the use of red clover in the basal diet. Although feed intake, diet digestion, AA supply and milk production were all consistently improved by protein supplementation, there was a simultaneous decrease in NUE. In the current study, the milk protein production increased only 9% and energy-corrected milk production by 7% when high level of protein supplementation (on average 2.9 kg DM/day) was compared with the control diet without protein supplementation showing that dairy production could be sustained at a high level even without external protein supplements, at least in the short term. The economic and environmental aspects need to be carefully evaluated when decisions about protein supplementation for dairy cows are taken.

The effect of harvesting strategy of grass silage on digestion and nutrient supply in dairy cows.

This study examined the effects of primary growth (PG) and regrowth (RG) timothy-meadow fescue silages harvested at 2 stages of growth on feed intake, cell wall digestion and ruminal passage kinetics in lactating dairy cows. Four dairy cows equipped with rumen cannulas were used in a study designed as a 4 x 4 Latin square with 21-d periods. The experimental silages were offered ad libitum with 8 kg/d of concentrate. Ruminal digestion and passage kinetics were assessed by the rumen evacuation technique. Silages of PG were on average more digestible than RG silages. The concentration of neutral detergent fiber (NDF) and indigestible NDF (iNDF) increased and the concentration of digestible organic matter in dry matter (DM) of silages decreased with advancing maturity in PG and RG. Cows consumed more feed DM, energy, and protein and produced more milk when fed PG diets rather than RG diets. Delaying the harvest decreased DM intake and milk production in PG and RG. There were no differences between PG and RG in rumen pH, ammonia N, or total volatile fatty acid concentrations. The intake of N, omasal canal flow of total nonammonia N and microbial N, excretion of N in feces, and ruminal true digestibility of N were higher for PG than for RG diets. The efficiency of microbial N synthesis was not different between PG and RG. Intake and omasal canal flow of organic matter, NDF, and potentially digestible NDF (pdNDF) were higher in PG than in RG. Whole-diet digestibility of organic matter, NDF, or pdNDF in the rumen or in the total tract was not different between PG and RG despite the higher digestibility of PG silages measured in sheep. Rumen pool sizes of crude protein and iNDF were lower for PG diets, whereas the pool size of pdNDF was higher for PG diets than for RG diets. The rate of passage of iNDF was higher for PG diets than for RG diets, with no difference between them in rate of digestion or passage of pdNDF. The lower milk production in cows fed regrowth grass silages compared with primary growth silages could be attributed to the lower silage DM intake potential. Chemical composition of the silages, rumen fill, digestion and passage kinetics of NDF, or the ratio of protein to energy in absorbed nutrients could not explain the differences in DM intake between silages made from primary and regrowth grass.

Effects of feeding grass or red clover silage cut at two maturity stages in dairy cows. 1. Nitrogen metabolism and supply of amino acids.

This study investigated the effects of plant species (red clover vs. timothy-meadow fescue) and forage maturity at primary harvest (early vs. late cut silage) on rumen fermentation, nutrient digestion, and nitrogen metabolism including omasal canal AA flow and plasma AA concentration in lactating cows. Five dairy cows equipped with rumen cannulas were used in a study designed as a 5 x 5 Latin square with 21-d periods. The diets consisted of early-cut and late-cut grass and red clover silage, respectively, and a mixture of late-cut grass and early-cut red clover silages given ad libitum with 9 kg/d of a standard concentrate. Grass silage dry matter intake tended to decrease but that of red clover silages tended to increase with advancing maturity. Milk yields were unchanged among treatments, milk protein and fat concentrations being lower for red clover than for grass silage diets. Rumen fluid pH was unchanged but volatile fatty acid and ammonia concentrations were higher for red clover than for grass silage diets. Intake of N, and omasal canal flows of total nonammonia N (NAN), microbial NAN, and dietary NAN were higher for red clover than for grass silage diets but were not affected by forage maturity. However, microbial NAN flow and amount of N excreted in the feces decreased with advancing maturity for grass diets but increased for red clover diets. Apparent ruminal N degradability of the diets was unchanged, but true ruminal N degradability decreased and efficiency of microbial synthesis increased with red clover diets compared with grass silage diets. Omasal canal flows of AA, except those for Met and Cys, were on average 20% higher for red clover than grass silage diets. Omasal canal digesta concentrations of Leu, Phe, branched-chain, and essential AA were higher but those of Met lower for red clover than for grass silage diets. Plasma AA concentrations, except for His (unchanged) and Met (lower), were higher for red clover than for grass diets. However, none of these AA-related variables were affected by forage maturity. Total digestibility of N and excretion of N in the urine were higher for red clover than for grass diets and decreased with advancing maturity. It was concluded that despite the higher total AA supply of cows fed red clover versus grass silage diets, further milk production responses on red clover diets were compromised by an inadequate supply of Met as evidenced by lower Met concentration in the AA profile of omasal digesta and plasma.

Effects of feeding grass or red clover silage cut at two maturity stages in dairy cows. 2. Dry matter intake and cell wall digestion kinetics.

This study examined the effects of red clover or grass silages cut at 2 stages of growth on feed intake, cell wall digestion, and ruminal passage kinetics in lactating dairy cows. Five dairy cows equipped with rumen cannulas were used in a study designed as a 5 x 5 Latin square with 21-d periods. Diets consisted of early-cut and late-cut grass and red clover silages and a mixture of late-cut grass and early-cut red clover silages offered ad libitum. All diets were supplemented with 9 kg/d of concentrate. Ruminal digestion and passage kinetics were assessed by the rumen evacuation technique. Apparent total-tract digestibility was determined by total fecal collection. The silage dry matter intake was highest when the mixed forage diet was fed and lowest with the early-cut red clover diet. Delaying the harvest tended to decrease DMI of grass and increase that of red clover. The intake of neutral detergent fiber (NDF) and potentially digestible NDF (pdNDF) was lower but the intake of indigestible NDF (iNDF) was higher for red clover diets than for grass diets. The rumen pool size of iNDF and the ratio of iNDF to pdNDF in the rumen contents were larger, and pool sizes of NDF and pdNDF were smaller for red clover than for grass silage diets. Outflow of iNDF and the ratio of iNDF to pdNDF in digesta entering the omasal canal were larger, and the outflow of pdNDF was smaller for red clover than for grass silage diets. The digestion rate (k(d)) of pdNDF was faster for red clover diets than for grass silage diets. Delaying the harvest decreased k(d) for grass but increased it for red clover silage diets. Observed differences in fiber characteristics of red clover and grass silages were reflected in ruminal digestion and passage kinetics of these forages. The low intake of early-cut red clover silage could not be explained by silage digestibility, fermentation quality, or rumen fill, but was most likely related to nutritionally suboptimal composition because inclusion of moderate quality grass silage improved silage intake. Increasing the maturity of ensiled red clover does not seem to affect silage dry matter intake as consistently as that of grasses.

Microcatheter embolization of intractable idiopathic epistaxis.

PURPOSE: To assess the efficacy and safety of microcatheter embolization in the treatment of intractable idiopathic epistaxis. METHODS: Thirty-seven patients underwent microcatheter embolization in 1991-1998. We evaluated retrospectively the technical and clinical outcome, the number of complications, the duration of embolization in each case, and the number of blood transfusions needed. All embolizations were done with biplane digital subtraction angiography (DSA) equipment. The procedure was carried out under local anesthesia using transfemoral catheterization, except in one case where the translumbar route was used. Tracker 18 or 10 microcatheters were advanced as far as possible to the distal branches of the sphenopalatine artery. Polyvinyl alcohol (PVA) particles were used for embolization in most cases, while platinum coils or a combination of these two materials were occasionally used. The primary outcome was always assessed immediately by angiography. Follow-up data were obtained from patient records, by interviewing patients on the telephone or by postal questionnaires when necessary. The mean follow-up time was 21 months. RESULTS: The embolization was technically successful in all 37 cases. A curative outcome was achieved in 33 cases (89%). The mean duration of the procedure was 110 min. Four patients (8%) had mild transient complications, but no severe or persistent complications were encountered. Twenty-three patients needed a blood transfusion. Slight rebleeding occurred in three patients during the follow-up; all responded to conservative treatment. One patient suffered two episodes of rebleeding within 2 months after primary embolization. Re-embolizations successfully stopped the bleeding. CONCLUSION: Embolization is the primary invasive modality for treating intractable idiopathic epistaxis. It proved both safe and effective over a relatively long follow-up.