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PubMed1989

Utilization of three maturities of alfalfa by dairy cows fed rations that contain similar concentrations of fiber.

The effect of alfalfa maturity on ration utilization and lactation performance by high producing dairy cows was measured in a 13-wk lactation study. Eighteen multiparous Holsteins were fed one of three rations containing first crop alfalfa hay harvested at early vegetative (36.1% NDF), late bud (51.7% NDF), or full bloom (51.7% NDF) maturity. Forage to concentrate ratios were 68:32, 53:47, and 45:55 for early vegetative, late bud, and full bloom rations, respectively. As offered, the late bud ration was higher in fiber (34.6% NDF) than either the early vegetative (31.8% NDF) or full bloom (30.6% NDF) rations. Cows fed the ration with early vegetative hay produced as much 4% FCM (32.5 kg) as cows fed the ration containing more fiber (late bud, 32.9 kg) or the later maturity hay (full bloom, 32.2 kg). Milk fat and protein composition were not affected by ration fiber concentration or forage maturity. Average dry matter intake per day and body weight change were similar across treatments. Time spent ruminating was similar for the three rations (6.8 h/d), but eating time was affected by forage maturity (early vegetative, 4.4 h/d vs. full bloom, 5.7 h/d). Cows receiving the higher fiber diet (late bud, 6.2 h/d) spent more time eating than cows receiving the lower fiber diets. Fiber concentration and forage maturity did not affect milk production, milk composition, or body weight change of high producing dairy cows in early lactation.

Animal Feed↗

PubMed1989

Ammonia-treated alfalfa silage for lactating dairy cows.

Alfalfa was treated (3.3% of forage wet weight) with an aqua-NH3 (14% N) mix prior to ensiling in 2 consecutive yr. In the 1st yr, NH3-treated silage containing 30.5% DM was higher in pH, N, NH3N, acetic acid and butyric acid contents, and lower in amino acids, soluble carbohydrates, and lactic acid than two untreated silages having 32.8 and 47.5% DM. Milk composition and DM intake did not differ among treatments when these silages constituted 50% of the dietary DM and were fed to lactating cows. In situ and in vitro, but not in vivo, digestion of NDF was greater for NH3 silage. Dry matter content of NH3-treated silage in the 2nd yr was 36.1% and that of the two untreated silages was 37.8 and 54.9%. Silage N, NH3N, and acetic acid content were greater in treated silage. However, pH and butyric acid content were similar among treatments and lactic acid was greater for treated silage. Similar to findings in the 1st yr, milk production and DM intake were not different among treatments. Adding NH3 to alfalfa decreased proteolysis; however, when DM was low (30.5%), the buffering effect of NH3 apparently resulted in increased clostridial fermentation. This did not occur when silage DM was increased to 36.1%, presumably due to higher osmotic pressure. Ammonia addition enhanced fiber digestibility but had no effect on milk production.

Ammonia↗

PubMed1991

Effect of forage to concentrate ratio and intake level on utilization of early vegetative alfalfa silage by dairy cows.

Two experiments were conducted to measure the effects of intake and forage: grain ratio on utilization of early maturity alfalfa silage in dairy cows. In Experiment 1, diets with three forage: concentrate ratios (percentage of silage, percentage NDF): low (56, 28.3), medium (71, 31.0), or high (86, 33.4) were fed ad libitum to six lactating, ruminally cannulated cows in a replicated 3 x 3 Latin square. The same diets were then fed at 1.3 x maintenance intake to six gestating dry cows. Dairy milk yield and percentage and yield of milk protein and casein were higher for cows fed the low silage diet than for cows receiving other treatments. Fat percentage and yield were not different among diets. Lactating cows consumed more DM on low silage (23.0 kg/d) than on medium or high silage diets (21.4 kg), but NDF intake as percentage of BW was higher for the high silage diet. Digestibility of DM in the lactating (70.7, 69.9, and 67.5% for low, medium, and high) and dry cows (76.7, 73.5, and 69.0%, respectively) decreased as the level of silage increased. Depression in digestibility was greater as dietary concentrate increased. Cows fed the high silage diet had a faster fractional passage rate of solids and higher rumen fill. Digestion of concentrate cell walls appeared to be depressed more than alfalfa cell walls as intake increased.

Ammonia↗

PubMed1991

Chemical drying agents for alfalfa hay: effect on nutrient digestibility and lactational performance.

Effects of chemical drying agents for hay on plasma profile, lactational performance, and nutrient digestibility by cows were studied. First-cutting alfalfa (late bud) was harvested as hay and treated when cut by applying untreated control, a commercial drying agent (7.64 kg/ha), or a mixture of active ingredients, potassium carbonate and sodium carbonate (7.47 kg/ha). Six multiparous Holstein cows (120 to 150 d postpartum) were fed diets (two cows per treatment) containing 55% hay and 45% concentrate (DM basis) in a balanced two period changeover design. Plasma profiles were similar for all cows, regardless of hay treatment. There were no differences in milk yield, milk fat, or milk protein percentages for control, drying agent, or mixture. Intake of DM was not different among treatments. Apparent digestibilities of DM, OM, CP, NDF, and ADF were not different among treatments. Treatment of alfalfa hay with chemical drying agents did not alter plasma profile, milk production, or nutrient digestibility in midlactation cows.

Animals↗

PubMed1991

Effect of fiber content and particle size of alfalfa silage on performance and chewing behavior.

A low NDF drought-stressed 1988 alfalfa silage (32.6% NDF) and a higher fiber 1988 alfalfa silage (46.4% NDF) were fed to lactating cows to evaluate effects on feed intake, fat test, and chewing behavior. Two groups of Holstein cows, 16 primiparous housed in tie stalls and 16 multiparous in free stalls, were assigned to diets based on parity and milk yield. The low NDF silage was fed for 6 wk in a TMR with 21.5% NDF and was compared with a TMR with 31.9% NDF. During an additional 4-wk period, one-half of each dietary group was fed a ration in which one-half of each silage was rechopped to reduce particle size. All rations contained a 1:1 ratio of forages to concentrates (DM basis) and were fed for ad libitum intake. Diets with 21.5% NDF and reduced particle size had no influence on milk fat percentage, 4% FCM yield, or plasma glucose. Cows fed these diets had reduced chewing time, due largely to decreased rumination time. Rumination and total chewing times per unit DMI and FCM also were lowest on these diets. Intake of DM on a BW basis was lowest for cows fed the low NDF rechopped silage diet. Cows fed in tie stalls had more eating bouts than those in free stalls, but total eating times were similar. Sufficient amounts of effective fiber appeared to be present in low NDF and rechopped silage diets to prevent the systemic events leading to milk fat depression but not to prevent a reduction in chewing time.

Animals↗

PubMed1992

Responses of dairy cows to additions of distillers dried grains with solubles in alfalfa-based diets.

Twenty-four Holstein cows in wk 3 through 12 of lactation were used to evaluate distillers dried grains with solubles as a protein source for alfalfa-based diets. Diets were formulated containing 0, 10.1, 20.8, or 31.5% distillers dried grains with solubles. Crude protein in these diets was 13.9, 16.0, 18.1, and 20.3%. Milk yield increased linearly with increasing dietary CP, whereas DMI was not affected. Dry matter intake averaged over 4% of BW for all treatments. Intake of undegraded intake protein was .93, 1.27, 1.63, and 1.97 kg/d. Yields of milk protein, casein, and lactose all increased linearly with increasing dietary CP. The proportion of milk N as whey N decreased, whereas N as NPN increased, with increasing dietary CP. Plasma urea N and essential and branched-chain AA increased linearly, and nonessential AA decreased linearly, with increasing dietary CP. Increasing the concentration of CP in the diet from 13.9 to 18.1% by the addition of distillers dried grains with solubles was beneficial to cows fed alfalfa-based diets in early lactation. Little additional benefit was observed by feeding greater than 18.1% dietary CP.

Amino Acids↗

PubMed1994

Effects of alfalfa silage chop length and supplementary long hay on chewing and milk production of dairy cows.

Twelve lactating, multiparous Holstein cows were used to evaluate the effects of silage chop length and proportion of long hay in low and adequate forage fiber diets on chewing activities and productivity of cows fed barley-based concentrates. Diets were designed with two forage:concentrate ratios (low forage fiber, 35:65; adequate forage fiber, 65:35), combined with two theoretical chop lengths of alfalfa silage (fine, 5 mm; coarse, 10 mm), and three proportions of long-stemmed alfalfa hay (0, 10, and 20% of DMI). Increasing the chop length of silage in low forage fiber diets did not affect DMI but increased FCM; in adequate forage fiber diets, it decreased DMI and FCM. Addition of hay to silage diets increased DMI, but not FCM yield. Increasing silage chop length in diets formulated below the recommended minimal amount of NDF from forage promoted rumination and increased milk production while maintaining milk fat content and DMI. Addition of a small amount of hay to low forage fiber diets was less effective than increased particle length of silage. In adequate forage fiber diets, finely chopped silage can be used effectively.

Animal Feed↗

PubMed1996

Effect of fungal biomass in moldy alfalfa hay on preference by dairy calves with no previous exposure to moldy feeds.

A study of 141-kg dairy calves evaluated their preference for alfalfa hay that contained different amounts of fungal biomass, which was estimated by the glucosamine assay. Alfalfa that was harvested at different maturities and stored at varying DM contents was chopped and blended to produce four forage treatments. The four forage treatments included hay that had 1) low NDF content and a low amount of fungal biomass, 2) high NDF and low fungal biomass, 3) high NDF and moderate fungal biomass, and 4) high NDF and high fungal biomass. Forage treatments were offered in pair combinations with two feeders per calf; treatments were switched from one feeder to the other on alternate days. The four forage treatments were offered in such a way that all six pair combinations were tested in each period. Each of the two trials was designed as a 6 x 6 Latin square. Preference data were collected for the 6-d periods and were analyzed as a split plot. Difference in intake of paired forage treatments was the response variable. Hay preference declined as either fiber content of hay or amount of fungal biomass in hay increased. Forage intake of each treatment relative to mean intake was 3.3, 0.8, -0.5 and -3.7 kg/6 d for forage treatments 1, 2, 3, and 4, respectively. Low preference for molded hay would probably result in greater feed sorting and lower intakes when calves have a choice of feedstuffs.

Alternaria↗

PubMed1996

Kinetics of cell-wall digestion of orchardgrass and alfalfa silages treated with cellulase and formic acid.

The objectives of this study were to determine the effects of cellulase (from Trichoderma longibrachiatum) combined with formic acid, applied before ensiling, on the subsequent concentration and composition of the cell wall and on the extent and rate of in situ cell-wall digestion of orchardgrass (Dactylis glomerata L.) and alfalfa (Medicago sativa L.). Treated and control forages of both plant species were ensiled for at least 60 d before being ruminally digested by two fistulated cows. Analyses of NDF, ADF, and acid detergent lignin were conducted sequentially on original and digested samples. Data were fitted with a first-order, nonlinear model to estimate extents and rates of digestion of potentially digestible NDF, cellulose, and hemicellulose. The concentration of indigestible residue and the discrete lag time before digestion were also determined for the cell-wall components. After ensiling, the mean NDF concentration of treated silages was 19% lower than that of control silages; the effect was greater for orchardgrass than for alfalfa. The extent of digestion of NDF, cellulose, and hemicellulose, respectively, was 33, 37, and 27% lower for treated silages than for control silages. Treatment effects on the extent of digestion varied between plant species. Cellulose from treated orchardgrass was digested 19% more slowly than cellulose from the control silage. Indigestible residue concentrations of NDF, cellulose, and hemicellulose, respectively, were 7, 8, and 7% lower in treated silages than in control silages. Thus, extensive cell-wall degradation by cellulase during ensiling resulted in less digestible cell-wall material for ruminal digestion but greater total cell-wall degradation, including that during ensiling and ruminal incubation, especially during early digestion in the rumen.

Cell Wall↗

PubMed1997

Response of lactating cows to methionine or methionine plus lysine added to high protein diets based on alfalfa and heated soybeans.

Lactation diets based on wilted alfalfa silage and heated whole soybeans are common in the midwestern US. We examined the milk production response of multiparous Holstein cows to the addition of ruminally protected methionine at two percentages to a basal total mixed ration. An additional total mixed ration included both methionine and lysine supplementation. Sixteen Holstein cows in early lactation were used in a replicated 4 x 4 Latin square design with 21-d periods. Milk production, milk composition, and dry matter intake were determined for the last 5 d of each period. Milk production (41.5 kg/d), dry matter intake (25.9 kg/d), and milk fat concentration (3.26%) were unaffected by the supplementation of amino acids. The addition of methionine increased milk protein concentration and yield linearly. Each gram of methionine increased milk protein yield by 4 g, and milk protein concentration increased from 2.89 to 2.99% with the addition of 10.5 g/d of methionine. The proportion of casein N in total milk N was unaffected by treatment. The addition of lysine did not elicit a response. Total mixed rations based on alfalfa haylage, heated soybeans, and animal proteins were clearly limited by their methionine content but were adequate in their lysine content.

Ammonia↗

PubMed1998

Milk production of Holstein heifers fed either alfalfa or corn silage diets at two rates of daily gain.

Seventy-five prepubertal heifers were fed diets based on either alfalfa silage or corn silage plus soybean meal for daily gains of either 725 or 950 g/d in a 2 x 2 factorial. Heifers were fed from 175 to 325 kg of body weight (BW). The alfalfa diet contained more digestible protein and less digestible energy than did the diet containing corn silage plus soybean meal. Actual gains were preexperimental BW gain, 633 g/d; lowest experimental BW gain, 785 g/d; highest experimental BW gain, 994 g/d; lowest postexperimental BW gain, 494 g/d; and highest postexperimental BW gain, 546 g/d. Compensatory postexperimental BW gains of heifers fed a common diet allowed the heifers to calve at 732 d of age. The postcalving BW was 508 kg, and precalving height at withers was 134 cm. A total mixed diet containing 17.1% CP and digestible energy at 3.12 Mcal/kg of dry matter was fed during lactation. Feed intake, milk and milk component production, and milk composition were not affected by either experimental diet or growth rate. As covariates, milk production was related to age at calving and was more strongly related to BW after calving, but no differences were observed among growth diets. Differences in protein and energy concentrations in experimental growth diets did not affect lactation performance. About 75% of total BW gains during the treatment period occurred before puberty, but rate of gain did not affect milk production. This lack of an effect of prepubertal growth rates on the milk production of primiparous heifers is consistent with six other similar studies that were conducted recently.

Animal Nutritional Physiological Phenomena↗

PubMed1980

Variability in metabolic plus endogenous energy losses of adult cockerels and in the true metabolizable energy values and rates of passage of dehydrated alfalfa.

An experiment with four groups of 12 adult cockerels allowed true metabolizable energy (TME) to be estimated in several ways. The birds were alternately fed one of two samples of dehydrated alfalfa meal or starved to serve as a negative control for the measurement of metabolic and endogenous energy loss (FEm + UEe). Each bird was fed twice and served as a control twice. The correction for FEm + UEe, therefore, could be estimated from the same bird, at a different period, or from a different bird at the same period. The FEm + UEe was largely characteristic of the bird. The correlation of the first observation with the second observation for each bird was .744 (44 DF). Variation in body weight did little to explain variation in FEm + UEe (r = .069, 90 DF). The most precise TME estimates were obtained by using each bird as its own negative control. A group mean value for FEm + UEe was somewhat inferior but the decrease in precision may be offset by reduced time and cost. The TME values provided additional evidence that the FEm + UEe output is characteristic of the bird. Although some birds consistently voided alfalfa residues more slowly than other birds, the pattern was not sufficiently consistent between birds to be significant.

Animals↗

PubMed1983

Effect of added methionine and lysine on the performance of chicks fed different alfalfa protein concentrates.

Experiments were conducted to determine the limiting amino acids in chick diets containing 40% spray-dried heat coagulated alfalfa protein concentrate (APC) and 40% spray-dried fermented alfalfa protein concentrate (FAPC). Significant improvements in chick gains were observed when methionine (met) was supplemented to the 40% APC (82 vs. 119 g) and 40% FAPC (72 vs. 95 g) diets. Feed efficiency (gain/feed) was also improved by met supplementation (.233 vs. .343) to APC and (.236 vs. .299) in FAPC diets. Supplementation of lysine (lys) alone did not improve the gain in body weight in either APC or FAPC, but the addition of lysine improved the feed efficiency of chicks fed the FAPC + Met (.323).

Animals↗

PubMed1999

Comparison of chemical treatments to eliminate enterohemorrhagic Escherichia coli O157:H7 on alfalfa seeds.

The focus of this study was to determine the efficacy of various chemicals in eliminating 2.04 to 3.23 log10 CFU/g of Escherichia coli O157:H7 from alfalfa seeds and to determine the survivability of the pathogen on seeds stored for prolonged periods at three temperatures. Significant (P < or = 0.05) reductions in populations of E. coli O157:H7 on inoculated seeds were observed after treatments with 500 and 1,000 ppm of active chlorine (as Ca[OCl]2) for 3 but not 10 min and with > or =2,000 ppm of Ca(OCl)2 regardless of pretreatment with a surfactant. Treatment with 20,000 ppm of active chlorine failed to kill 2.68 log10 CFU/g of seeds. Acidified NaClO2 (500 ppm) was effective in reducing populations of the pathogen by >2 logs per g. Acidified ClO2 significantly reduced populations of E. coli O157:H7 on seeds at concentrations > or =100 ppm, and 500 ppm of ClO2 reduced the pathogen from 2.7 log10 CFU/g to <0.5 CFU/g. Chlorine (as NaOCl) was not effective at concentrations < or =1,000 ppm; significant reduction was achieved only after treatment with 2,000 ppm for 3 or 10 min. Notable reduction in populations was observed after treatment with 30 or 70% C2H3OH, but there was a dramatic decrease in germination percentage. Treatment with 0.2% H2O2 significantly reduced populations, and the organism was not detected by direct plating after treatment with > or =1% H2O2. Significant reduction in population of E. coli O157:H7 occurred after treatment with 1% trisodium phosphate, 40 ppm of Tsunami and Vortexx, and 1% Vegi-Clean. A significant decrease in the number of E. coli O157:H7 on dry seeds was observed within 1 week of storage at 25 and 37 degrees C, but not at 5 degrees C. Between 1 and 38 weeks, populations on seeds stored at 5 degrees C remained relatively constant. The pathogen was recovered from alfalfa seeds initially containing 3.04 log 10 CFU/g after storage at 25 or 37 degrees C for 38 weeks but not 54 weeks.

Calcium Compounds↗

PubMed1999

Detection and isolation of Salmonella from naturally contaminated alfalfa seeds following an outbreak investigation.

Naturally contaminated alfalfa seeds, epidemiologically linked to foodborne disease outbreaks in Oregon and British Columbia, were tested for the presence of Salmonella. Ten sample units from the suspected lot were sprouted and grown for 4 days. After enrichment of the grown sprouts, an enzyme immunoassay (EIA) and culture method (modified procedure of the Food and Drug Administration Bacteriological Analytical Manual) were used for the detection and isolation of Salmonella. Four of the 10 sample units were positive with the EIA; however, 5 of the 10 sample units were culture positive (four were positive for Salmonella serotype Newport and a fifth was positive for Salmonella serotype Albany and serotype Schwarzengrund). The positive alfalfa seed sample units were further tested after shredding, soaking, and washing before culturing. Results suggest that sprouting and shredding methods may yield greater detection and recovery rates of Salmonella, but more research with a larger sample size is warranted.

British Columbia↗

PubMed2001

Reduction of Escherichia coli O157:H7 and Salmonella typhimurium in artificially contaminated alfalfa seeds and mung beans by fumigation with ammonia.

Sprouts eaten raw are increasingly perceived as hazardous foods because they have been vehicles in outbreaks of foodborne disease, often involving Escherichia coli O157:H7 and Salmonella Typhimurium. Although the source of these pathogens has not been established, it is known that the seeds usually are already contaminated at the time sprouting begins. Earlier studies had shown that ammonia was lethal to these same pathogens in manure, so it seemed reasonable to determine whether ammonia was effective against them when associated with seeds to be used for sprouting. Experimentally contaminated (10(8) to 10(9) CFU/g) and dried seeds, intended for sprouting, were sealed in glass jars in which 180 or 300 mg of ammonia/liter of air space was generated by action of ammonium sulfate and sodium hydroxide. Samples were taken after intervals up to 22 h at 20 degrees C. Destruction of approximately 2 to 3 logs was observed with both bacteria associated with alfalfa seeds, versus 5 to 6 logs with mung beans. Greater kills are apparently associated with lower initial bacterial loads. Germination of these seeds was unaffected by the treatment. It appears that this simple treatment could contribute significantly to the safety of sprout production from alfalfa seeds and mung beans.

Ammonia↗

PubMed2001

Use of spent irrigation water for microbiological analysis of alfalfa sprouts.

Numerous outbreaks of foodborne illness have been linked to the consumption of raw sprouts. Sprout producers have been advised by the Food and Drug Administration to include microbiological testing of spent irrigation water during production as part of an overall strategy to enhance the safety of sprouts. Alfalfa sprouts and irrigation water were analyzed to show the feasibility of using irrigation water for monitoring the microbiological safety of sprouts. Sprouts and water were produced and harvested from both commercial-scale (rotary drum) and consumer-scale (glass jars) equipment. Rapid increases of aerobic mesophiles occurred during the first 24 h of sprouting, with maximum levels achieved after 48 to 72 h. The counts in irrigation water were on average within approximately 1 log of their respective counts in the sprouts. Similar results were obtained for analysis of Escherichia coli O157:H7 in irrigation water and sprouts grown from artificially inoculated seeds. Testing of spent irrigation water indicated the contamination status of alfalfa sprouts grown from seeds associated with outbreaks of Salmonella infection.

Colony Count, Microbial↗

PubMed2001

Two processing methods for the isolation of Salmonella from naturally contaminated alfalfa seeds.

Two processing methods were examined for the recovery of Salmonella from naturally contaminated alfalfa seed. Seed samples, from each of three investigations, were processed by sprouting and shredding before preenrichment and culture. In lot A, Salmonella serotype Newport was isolated from 3 of 30 sample units with the sprouting method and 2 of 30 with the shredding method. In lot B, three serotypes in various combinations were isolated from 10 of 30 sample units with the sprouting method and 9 of 30 with the shredding method. In lot C, Salmonella group C1 was isolated from 27 of 30 sample units with the sprouting method and 24 of 30 with the shredding method. Additionally, serotype Newport was found in one lot C sample unit. Using shredded seed data, a most probable number (MPN) for Salmonella contamination per lot was calculated. Serotype Newport was estimated at 0.07 MPN/100 g in lot A; the concentration for three serotypes was estimated to be 0.36 MPN/100 g in lot B; Salmonella group C1 was estimated at 1.8 MPN/100 g in lot C. Our success in isolating Salmonella from alfalfa seeds was likely attributed to the volume of material tested and the quick acquisition of the seeds after the outbreak was identified. Shredding the seeds was easier and yielded definitive results more quickly than sprouting.

Disease Outbreaks↗