Hay Mixture Research Articles

The utilization of diets containing increasing levels of dried brewers' grains by growing lambs

AbstractAn experiment was conducted to evaluate the feeding characteristics and the productive responses of lamb diets containing increasing levels of dried brewers' grains (DBG). Five groups of six 70-day-old Bergamasca lambs were housed in individual pens and givenad libitumfor 9 weeks pelleted diets containing 200 g/kg of concentrate and 800 g/kg of a mixture of DBG and lucerne hay in the ratios of 0:80 (DBG0), 20:60 (DBG20), 40:40 (DBG40) 60:20 (DBG60) and 80:0 (DBG80). During the last 12 days of the experimental period, a digestibility trial was carried out for each diet. After this, all the lambs were slaughtered and the composition of the empty body weight was determined. The initial composition of the empty body was estimated from the composition of a sixth group of lambs slaughtered at the beginning of the trial.The apparent digestibility of dry matter (DM), organic matter, crude protein, ether extract, neutral-detergent fibre and energy increased with the proportion of DBG. The daily DM intake relative to metabolic body weight (M0·75) diminished significantly with the increasing proportion of DBG in the diet, from 127 g/kg M0·75for diet DBG0 to 83 g/kg M0·75for diet DBG60. The daily live-weight gain and food DM conversion efficiency were highest with the intermediate diets (414 g/day with diet DBG40 and 240 g/kg DM with DBG60), showing a quadratic trend, an indication of a positive interaction between DBG and lucerne hay. The fat content of the live-weight gain was particularly high in the lambs given the diet with the highest proportion of DBG. It was concluded that DBG may be profitably used in growing-fattening diets for lambs in a proportion not exceeding about 400 g/kg DM.

Relationship between the gas production profiles of mixtures of hay and maize and the patterns of rumen fermentation observed in sheep fed those mixtures

The gas production (GP) technique has been developed to assess dynamics of ruminant digestion. Relationships have been observed between a feed's GP profile and in vivo parameters such as digestibility (Khazaal et al., 1993), feed intake and growth rate (Blümmel and Ørskov, 1993), and in situ degradability (Sileshi et al., 1997). However, there are few studies which relate GP data to the in vivo pattern of rumen fermentation (in terms of the rate of pH decline 2 h post-feeding and the mean rumen pH, concentration of total VFA and molar proportion of individual VFA). The object of this experiment was to determine whether such a relationship existed between a feed's GP profile and the pattern of rumen fermentation observed in animals fed that feed.

Relationship between the gas production profiles of mixtures of hay and maize and the patterns of rumen fermentation observed in sheep fed those mixtures

The gas production (GP) technique has been developed to assess dynamics of ruminant digestion. Relationships have been observed between a feed's GP profile and in vivo parameters such as digestibility (Khazaal et al., 1993), feed intake and growth rate (Blümmel and Ørskov, 1993), and in situ degradability (Sileshi et al., 1997). However, there are few studies which relate GP data to the in vivo pattern of rumen fermentation (in terms of the rate of pH decline 2 h post-feeding and the mean rumen pH, concentration of total VFA and molar proportion of individual VFA). The object of this experiment was to determine whether such a relationship existed between a feed's GP profile and the pattern of rumen fermentation observed in animals fed that feed.

Lipid-induced depression of methane production and digestibility in the artificial rumen system (RUSITEC)

An artificial rumen (RUSITEC) equipped with eight fermenters was used to examine the effects of canola oil (CA), cod liver oil (CD) and coconut oil (CO) on methane production, dietary digestibility and rumen microbial populations. The experiment, repeated three times, involved two diets (100% grass hay or a 90%:10% wheat:hay mixture) either untreated (controls) or sprayed with CA, CD or CO (10%, wt/wt) in a 2 × 4 factorial arrangement. Dry matter disappearance and CH4 production were greater (P < 0.05) from untreated concentrate diet than from untreated hay. There were significant interactions (P < 0.05) between diet and lipid type for DM digestion and several of the fermentation parameters. Coconut oil decreased (P < 0.05) DM and neutral detergent fibre disappearance of hay but did not affect digestion of concentrate. All oils, especially CO, depressed (P < 0.05) CH4 production (mmol g−1 digestible DM) and methanogenic populations regardless of diet. Methanogens on CO-treated diets numbered less than 1% of those on CA- and CD-treated diets. Total viable, amylolytic, and cellulolytic bacterial numbers were also substantially reduced (P < 0.05) by CO, but not by CA or CD for both diets. Bacterial colonization and digestion of CO-treated hay was markedly less extensive than that observed on untreated, CA- or CD-treated hay. The molar proportion of propionate produced was increased (P < 0.05) by CA and CD, for the hay diet, but not for the concentrate diet. Coconut oil decreased (P < 0.05) the molar proportion of propionate produced on the hay diet and increased (P < 0.05) it on the concentrate diet. Of the three oils, CO was most inhibitory to CH4 production and depressed fibre digestion. The CA and CD also decreased CH4 production, but did not affect feed digestion in either diet. Consequently, the amount of metabolizable energy of feeds may be increased when diets are supplemented with these oils. Key words: Lipids, methane, digestibility, artificial rumen, bacteria, VFA

Urinary Allantoin: Creatinine Ratios as a Dietary Index for Elk

This study was conducted to evaluate the relation between digestible dry matter intake (DDMI) and urinary allantoin:creatinine (A:C) ratios in elk. The experiment was conducted from August 1993 through March 1994 and involved 18, 2-year-old cow elk divided into 3 groups of 6 animals each. Groups were randomly assigned to 1 of 3 dietary treatments involving mixtures of alfalfa hay and pelleted rations providing digestible dry matter intakes ranging from 1.2 to 4.0 kg/day. Animals were weighed twice weekly and urine samples were collected from each animal at about 3-week intervals throughout the experiment for a total of 10 samples per animal. Animals fed an ad libitum diet gained an average of 6.8% of their initial body mass (BM), while elk on 2 restricted dietary treatments lost an average of 9.3 and 11.2% of their initial BM over the course of the experiment. A significant (P < 0.001) curvilinear relation between urinary A:C ratios and DDMI, consistent with observations with domestic ruminants, was detected. These results suggest that urinary A:C ratios may provide a useful diagnostic tool to study the DDMI of free-ranging elk.

Pelodera dermatitis in sheep

were removed twice a year, in spring and autumn, and produced a high level of humidity especially in areas close to the drinking places. The disease was seasonal with the problem occurring between December and April in each of the three consecutive years. The body areas affected were those in contact with the floor or bedding when the animals were lying down. Feeding was based on a mixture of cereals, granulated alfalfa and hay, and no variation of the ingredients occurred during the year. Lambs born from affected sheep did not develop the skin disease and were raised normally by their mothers. Affected animals were calm and the only apparent sign of pruritus was erythema. Clinical parameters were normal and no abnormalities of the organs were found. Detailed clinical examination revealed large areas of lichenified, exfoliating skin with hyperhydrosis at the edges of the lesions. There was loss of wool from the ventral abdomen and thorax and from the extremities (Fig 1). Animals could be divided into three groups according to the distribution and type of lesions. Out of the 58 animals present during the final winter 15 were free of lesions, 21 had lesions on the ventral thorax, eight had lesions of the axilla, thorax and ventral abdomen, and 14 showed lesions on all the ventral areas of the body and also on the lateral aspects of the hindlegs. Some animals of this last group also had lesions of the tail and perineal region and wool around these areas was easily epilated. Seventy-four per cent of animals were affected, but in no case was there involvement of the head or dorsal trunk. Skin scrapings, skin biopsies, blood and faecal samples and samples of bedding were taken. The skin scrapings were negative, as were bacterial and fungal cultures. No parasites were observed. Total and differential blood cell counts, packed cell volume and haemoglobin concentration were all normal, as were serum levels of copper and zinc. Total proteins and protein fractions were analysed and no abnormalities found. Histopathology was performed on biopsies from a number of sheep. All the biopsies contained a perivascular dermatitis characterised by eosinophils and mast cells in loose connective tissue. Some lymphocytes and plasma cells were present. In addition there was a severe perifolliculitis and folliculitis with accumulations of neutrophils, lymphocytes and plasma cells. In each case, both superficially and deeply within the hair follicles, fragments of parasites consistent with Pelodera species in transverse and oblique section were found (Figs 2 and 3). Some organisms were also found outside the hair follicle and within the dermis. The inflammatory infiltrate also affected the sebaceous and sweat glands, but to a lesser degree, and the sweat glands were dilated. The epidermis showed hyperkeratosis and slight acanthosis into the hair follicles. In the faeces no eggs of Bunostomun trigonocephalum, Strongyloides papillosus or any other parasite were found. In contrast, large numbers of larvae of the nematode P strongyloides were found in the bedding samples. FIG 1: Loss of wool and areas of lichenified, exfoliating skin on the ventral abdomen and thorax

Salivary cortisol in nursery-reared rhesus monkey infants

Palatability of feed affects voluntary intake. The objectives were to evaluate preference by bovine for sweet (sucrose) or sour (citric acid) blended with a mixture of ground switchgrass (42 g crude protein/kg dry matter) and alfalfa hay (176 g crude protein/kg dry matter). Flavors were dissolved in 50 mL deionized water per kg of hay for blending. In Experiment 1, sucrose hay (S100) had 100 g sucrose added per kg hay. Citric acid hay (CA50) had 50 g citric acid added per kg hay. Control hay (CON) had 50 mL deionized water added per kg hay. In Experiment 2, treatments were CON, sucrose added at 25 g per kg hay (S25), S100, 150 g per kg hay (S150). Citric acid added at 25 g per kg hay (CA25), and CA50. Hays were mixed in a horizontal mixer 3 d prior to each experimental period. Twelve beef cattle (initial BW = 283 ± 25 kg) were housed under a roof on expanded metal flooring with access to six feed locations designated I through VI, west to east. Cattle consumed 1 kg/day of supplement (corn, soybean hulls, and trace mineralized salt) that was fed daily, after hay orts were removed and weighed at 0800. Cattle were offered treatment hay equal to 6 g per kg BW at each feed slot and treatments were randomly assigned to two of the six locations at 0830. Cattle were given a 14-d adaptation to CON followed by a 7-d offer of treatments. In Experiment 1, cattle preferred S100 (3.42 ± 0.04 kg/d) over CON (2.8 ± 0.04 kg/d, P<0.01) and CA50 (0.32 ± 0.04 kg/d, P<0.01) and preferred CON over CA50 (P<0.01). In Experiment 2, cattle preferred CA10 over CON (P<0.02) and CA25 (P<0.02), and S100 was preferred over S150 (P<0.02) and S25 (P<0.02). Compared with control, cattle preferred hay flavored with sucrose up to 100 g per kg of hay, and preferred hay flavored with citric acid up to 10 g per kg of hay. Flavored feeds that are nutritionally adequate can be used to provide variety in the diet of cattle, where total intake increases when different feeds are presented together. Adding sugar may increase intake of undesirable feeds, or citric acid may be added at greater than 10 g per kg hay to limit intake of desirable feeds.

Long-term spring wheat response to summerfallow frequency and organic amendment in southern Alberta

A long-term rotation experiment was established in 1951 to determine the influence of summerfallow frequency and organic amendment on the yield and quality of unfertilized spring wheat (Triticum aestivum L.) on a Dark Brown Chernozem (Typic Haploboroll) at Lethbridge, Alberta. Wheat was grown either continuously (W), in a 2-yr summerfallow-wheat rotation (FW), or in a 3-yr fallow-wheat-wheat rotation (FWW). No fertilizer N was applied and P, at 22 kg ha−1, was applied to all wheat crops starting in 1985. The 3-yr rotation was also amended with livestock manure (FmWW) and modified to include a hay mixture of alfalfa (Medicago sativa L.) and crested wheatgrass (Agropyron cristatum L.) (FWWHHH). Annual grain production was affected by summerfallow frequency and organic amendment, with the lowest grain production obtained in the FW rotation. Amendment with livestock manure resulted in the highest grain yields for wheat grown on summerfallow, while 3 yr of hay in the rotation produced the highest stubble wheat yields. These higher grain yields were accompanied by a 12–31% increase in grain N uptake. Decomposing hay roots increased plant-available N as reflected in the highest grain N concentration and grain N yield in the FWWHHH rotation. Evaluation of grain yields under a range of moisture deficit conditions revealed that a year of summerfallow was often insufficient to recharge soil water depleted by 3 yr of hay in the FWWHHH rotation. Both summerfallow and stubble wheat yields were positively influenced by May rainfall. Overwinter precipitation contributed significantly to the variability observed in stubble wheat and hay yields. In the absence of fertilizer N additions, organic amendments such as animal manures and hay residues are effective means of increasing crop productivity and grain quality in semiarid regions. Key words: Hay, manure, rotation, spring wheat, summerfallow, Triticum aestivum L.

Digestion characteristics, feed intake and live weight gain by cattle consuming forage supplemented with defatted rice bran or other feedstuffs

Effects of supplementing cattle with defatted rice bran compared with full-fat rice bran, ground corn or wheat middlings on feed intake, digestibility and live weight gain (LWG) were determined. In Experiment 1, in situ (ruminal) dry matter disappearance in two steers consuming forage was 75, 45, 77 and 53% at 12 h (standard error (SE) 4.4), and 86, 95, 83 and 82% at 48 h (SE 0.6) for full-fat rice bran, corn, wheat middlings and defatted rice bran, respectively. In Experiment 2, six Holstein steer calves (193 ± 1.3 kg average trial body weight (BW); 6 × 6 Latin square) consumed a 1:1:1 mixture of alfalfa, orchardgrass and bermudagrass hay ad libitum without supplementation (Control), or with 0.80% of BW of full-fat rice bran (FR), 0.62% of BW of corn (C), 0.81% of BW of wheat middlings (W), 0.80% of BW of defatted rice bran (L-DR) or 1.10% of BW of defatted rice bran (H-DR). Total organic matter intake was lower ( P < 0.05) for FR than for C, W, L-DR and H-DR (5.65, 5.48, 5.96, 5.90, 6.03 and 5.86 kg per day; SE 0.127), digestibility of neutral detergent fiber was 53.3, 49.5, 53.7, 51.4, 50.9 and 49.8% (SE 1.13), and digestible organic matter intake was 2.96, 2.98, 3.35, 3.32, 3.17 and 3.11 kg per day (SE 0.088) for Control, FR, C, W, L-DR and H-DR, respectively (C and W greater than Control and FR; P < 0.05). In Experiment 3, six mature beef cows (564 ± 37 kg BW) with cannulae in the rumen and duodenum (6 × 6 Latin square) were fed the same hays with similar dietary proportions of supplement. True ruminal nitrogen disappearance was greatest ( P < 0.05) for W (62.5, 60.2, 63.0, 79.6, 68.1 and 65.7% for Control, FR, C, W, L-DR and H-DR, respectively; SE 3.24), microbial efficiency was similar among treatments ( P > 0.10), and acetate: propionate in ruminal fluid was decreased ( P < 0.05) by FR, L-DR and H-DR relative to Control (4.06, 3.69, 4.00, 4.09, 3.89 and 3.80 for Control, FR, C, W, L-DR, and H-DR, respectively; SE 0.053). In Experiment 4, crossbred beef calves (48 steers and 48 heifers; 232 ± 2.1 kg initial BW) grazed paddocks with fescue, clover and bermudagrass in the spring for 84 days and were supplemented as in Experiment 2. LWG was lower ( P < 0.05) for W, L-DR and H-DR than for FR and C (1.06, 1.18, 1.14, 0.99, 1.04 and 0.98 kg per day for Control, FR, C, W, L-DR and H-DR, respectively; SE 0.027).

Effect of ammonia treatment of barley straw on the dynamics of its degradation in the rumen

AbstractTwo experiments were designed to examine the effects of ammonia treatment of barley straw on rumen environmental conditions for fibre degradation, and to determine the effect of treatment on the soluble and insoluble fractions of straw. In experiment 1, rumen pH, and ammonia-nitrogen and volatile fatty acid concentrations in the rumen of sheep receiving untreated (US1) or ammonia-treated (TS1) straw were recorded. Also, both straws were incubated in the rumen of both groups of animals. There were no significant differences (P&amp;gt; 0·05) within rumen parameters, except for butyrate proportion, which was higher (P&amp;lt; 0·01) with TS1. Dry matter and neutraldetergent fibre disappearances of TS1 were higher (P&amp;lt; 0·001) than those of US1 at all the incubation times. Degradation of both straws in US1-fed sheep was not smaller, and in some periods of incubation was even greater, than in TS1-fed animals. In experiment 2, samples of untreated (US2) and treated (TS2) straw were incubated in wethers offered a mixture (50:50) of alfalfa hay and straw. Samples of US2 and TS2 were soaked in autoclaved rumen fluid to measure their solubility. It was clear that, although treatment increased the soluble fraction of US2 and TS2 by 52 and 65 g/kg respectively, from 0 to 72 h of incubation, increasing the differences between straws from 45 to 58 g/kg in that period, actual microbial action on the treated roughage was the more important factor, accounting for a difference between US2 and TS2 of 131 g/kg after 72 h incubation.

Growth of and digestibility by sheep fed diets comprising mixtures of grass and legume hay compared with those fed high-grain diets

A digestibility trial with 24 mature wethers and a growth trial with 54 weaned lambs were conducted to evaluate the utilization of ground diets containing varying proportions of grass and legume hay relative to a 90% grain diet. The forage and grain diets were (1) 100% crested wheatgrass hay (CWG); (2) 75% CWGand25% alfalfa hay (AA); (3) 50% CWGand50% AA; (4) 25% CWGand75% AA; (5) 100% AA; and (6) 90% barley and 10% barley straw. Even though apparent digestibility of dry matter (DM) and fiber fractions of AA-containing diets was lower than that of the grain diet and the 100% CWG diet, weight gain was similar for all diets. Consumption of the grain and 100% CWG diet was lower (P &lt; 0.05) than that of the 100% AA diet. Conversion of feed DM to liveweight gain for lambs fed the grain diet was only 4.9 and was lower (P &lt; 0.05) than that of the forage diets, which ranged between 6.1 and 7.0. Dressing percentages of lambs at slaughter for the animals fed the grain and 100% AA diet were 45.0 and 43.2%, respectively, which were higher (P &lt; 0.05) than that of animals fed the CWG-containing diets. These data suggest that inclusion of AA in CWG diets did not result in the expected positive associative effect on growth and feed efficiency in sheep. Key words: Sheep, crested wheatgrass, alfalfa, digestibility, growth

The effects of barley vs. barley fibre with or without distiller's solubles on site and extent of nutrient digestion in cattle fed grass-silage-based diet

A 4 × 4 Latin square experiment with a 2 × 2 factorial arrangement of treatments was carried out to determine the effects of by-products from integrated starch-ethanol production on the digestion of organic matter (OM), nitrogen (N) and cell wall carbohydrates in cattle fitted with rumen and duodenal cannulae. The diets consisted of 500 g kg −1 dry matter (DM) of a mixture of grass silage and hay (3:1 on DM basis) plus one of four concentrates: barley (BU), barley + wet distiller's solubles (WDS) (BD), barley fibre (FU) and barley fibre + WDS (FD). WDS comprised 150 g kg −1 of the total DM. The mean amount of DM given was 6.7 kg day −1. The amounts of OM entering the duodenum and voided in faeces were higher ( P < 0.001) with F diets than with B diets, and thus both rumen and total OM digestibility were lower ( P < 0.001) for F diets. Inclusion of WDS in the diet improved ( P < 0.001) rumen but not total OM digestibility. Because barley fibre has a higher fat content than has barley, the difference in digestible energy content between the diets was smaller than the difference in digestible OM content. Non-ammonia N (NAN) flow at the duodenum was higher ( P < 0.05) with F diets than with B diets, and was not increased by increasing dietary N content with WDS. The amount of microbial N entering the small intestine was greater ( P < 0.05) with B diets, whereas estimated feed N flow was higher ( P < 0.01) with F diets. The efficiency of microbial N synthesis increased ( P < 0.001) when F diets were fed and was decreased ( P < 0.01) by inclusion of WDS. The differences between B and F diets in their effects on the total digestibility of cell wall carbohydrates were small. The cattle fed F diets had higher rumen pH values ( P < 0.05) and molar proportions of propionate ( P < 0.001), and lower concentrations of total volatile fatty acids ( P < 0.05) and molar proportions of butyrate ( P < 0.001) than those fed B diets. Feeding WDS in the diet increased rumen ammonia concentration ( P < 0.01) and molar proportions of propionate ( P < 0.001) and butyrate ( P < 0.05) and decreased ( P < 0.001) that of acetate. Rumen protozoal number was lower ( P < 0.001) in cattle fed F diets than in those fed B diets. It is concluded that replacement of barley with barley fibre in the diet resulted in large changes in the digestion of dietary components and in rumen fermentation, and that duodenal NAN flow was not increased by including WDS in the diet.

Effect of physical form and level of alfalfa in corn-based diets for finishing steers (1992)

One hundred-eighty British crossbred steers (760 lb) were used in a 3x2 factorially arranged experiment to evaluate the main effects of alfalfa form (chopped hay, dehydrated pellets, or a 50:50 mixture of hay:dehy) and level (5 or 10% of diet DM) on finishing steer performance. Alfalfa (third-cutting, 23.9% CP) was harvested in alternate rows from a common field. No interactions between alfalfa form and level were detected. Steers fed chopped hay or the 50:50 mixture gained faster (P < .05), consumed more feed (P < .05), and had heavier final and carcass weights (P < .05) than steers fed dehy pellets. Steers fed 10% alfalfa gained faster (P < .05), consumed more feed (P < .0003), and had heavier carcass weights (P < .02) vs those fed 5% alfalfa. Feed efficiency was unaffected by alfalfa form or level. Lower feed intakes and numerically higher incidences of liver abscesses indicated less ruminal tactile stimulation and more subacute acidosis for dehy pellets vs hay or the 50:50 mixture and for 5 vs 10% alfalfa, respectively. Positive associative responses of 5.1% (P = .07) on daily gain and 2.9% (P = .11) on dry matter intake suggested that the 50:50 mixture provided enough long particles for adequate rumen function at the alfalfa levels studied. Our results suggests more dehy pellets than chopped hay must be fed to provide similar roughage value.

Performance and Ruminal Function Development of Young Calves Fed Diets with Aspergillus oryzae Fermentation Extract1,2

Neonatal Holstein heifer (n=72) and bull (n=40) calves were used to study the effects of Aspergillus oryzae fermentation extract (Amaferm) on their performance and on rumen development. The starter diets were formulated to achieve Amaferm consumption of 0, .5, 1, or 3g per calf daily. Calves were fed milk daily and allowed to consume starter and a mixture of alfalfa and bromegrass hay ad libitum. Weaning was when calves consumed 550g of starter on 2 consecutive d. Weight gain and feed consumption were recorded weekly. Forty of the heifer calves, 10 from each treatment, were selected randomly to study the effects of Amaferm on ruminal fermentative development. Ruminal fluid samples were collected for pH, ruminal fermentation products, and for bacterial enumerations.Overall, Amaferm-supplemented calves were weaned 1 wk earlier than unsupplemented calves. They had higher total VFA, propionate, and acetate concentrations in the rumen than unsupplemented calves. Total anaerobic, hemicellulolytic, and pectinolytic bacterial counts were higher; cellulolytic bacterial counts tended to be higher for the Amaferm-supplemented calves than for controls. In general, Amaferm-supplemented calves had greater ruminal microbial activity than those not fed Amaferm.

Effects of concentrate supplementation and lasalocid on serum chemistry and hormone profiles in Rambouillet ewes

Rambouillet ewes were fed a 50:50 mixture of alfalfa and prairie hay ad libitum and either no concentrates (C), 0.4 kg concentrates per head per day (S), or 0.4 kg concentrates containing 73 mg lasalocid/kg diet per head per day (SL), during the last 50 d of pregnancy and through 60 d of lactation. Blood samples were collected at d 21 and d 7 prepartum, and d 6, 27 and 55 postpartum. Ewes fed supplement (S and SL) tended to have higher (15%) serum thyroxine (T4) and lower (19%) serum insulin during lactation compared with controls (C) ( P>0.1). Lasalocid tended to increase (14%, P>0.1) serum T4 and decrease (19%, P>0.1) serum insulin in SL compared with S ewes. Ewes of S and SL treatments had slightly higher (6–17%) serum glucose than C ewes and SL ewes were slightly higher (4–10%) in glucose than S ewes ( P.>0.1). Serum albumin concentration was 14% greater (P < 0.1) during late pregnancy and similar (P>0.1) during lactation in S and SL compared with C. Conversely, serum globulin tended to be lower (10–25%, P>0.1) in S and SL compared with C. Serum cholesterol was elevated by 30% (P<0.1) during late pregnancy in S and SL vs. C. Serum total bilirubin during lactation was 33% lower ( P<0.05) in S and SL compared with C, and 29% lower ( P>0.1) in S than in SL. Serum gamma-glutamyl transpeptidase (GGTP) was 44% greater ( P<0.1) during late pregnancy and 18% greater ( P>0.1) during lactation in S and SL compared with C. Increased serum Na (P<0.01), K (P<0.01) and Cl (P<0.10) concentrations were noted in S and SL compared with C. In conclusion, lasalocid fed at 29 mg per head per day had no apparent adverse effects on serum chemistry and hormone profiles of ewes. Therefore, lasalocid could be fed to ewes, pending appropriate approval, for enhanced production.

Effect of Feeding Sheep on Naturally Spoiled Rice Straw, Clover Hay and Concentrate Feed Mixtures

The effects of feeding naturally contaminated feedstuffs to sheep were investigated through feeding of contaminated and uncontaminated clover hay, rice straw, and concentrate feed mixture were compared. The highest level of contamination with fungi was observed in the concentrate feed mixture followed by clover hay and rice straw. The most dominant mycotoxin in the contaminated feedstuffs was zearalenone. Contamination resulted in increases of crude protein, ash and silica in feedstuffs while both ether extract and crude fibre decreased. In vivo digestibility of different diet constituents in both contaminated and uncontaminated feedstuffs were determined using four mature Rahmani rams. Contamination resulted in significant increase in the digestibility of dry matter, crude fibre and energy. Contamination affected feed intake of the different feedstuffs particularly the concentrate feed mixture. A metabolism trial was also conducted to study the nitrogen and mineral balance. Retention of nitrogen and calcium was reduced when mouldy feeds were given. On the other hand, magnesium was relatively increased. Blood analysis for sheep at the end of the trials resulted in elevated values of inorganic phosphorus and phospholipid phosphorus and declined total nitrogen, calcium, cholesterol, calcium/phosphorus ratio and cholesterol/calcium ratio due to feeding on mouldy ration. Results of the urine analysis during the metabolism trials proved that mouldy ration increased the estimated values of the concentration of calcium, magnesium and vitamin C; whereas pH values, total nitrogen, ammonia nitrogen and inorganic phosphorus were declined during the feeding on the mouldy ration. Mouldy feeds tested, seemed to have toxic, nephritic and hepatic effect.

Differential passage rates and digestion of neutral detergent fiber from grain and forages in 30, 60 and 90% concentrate diets fed to steers.

Six ruminally cannulated steers were used to determine the effects of altering dietary concentrates on fiber digestion. Diets contained 30, 60 or 90% of a concentrate based on flaked sorghum grain plus a 50:50 mixture of wheat straw and alfalfa hay. Total tract digestibility of NDF was not altered, but digestibility of potentially digested NDF (PDF) decreased (P less than .05) from 92 to 48% as concentrates increased from 30 to 90% of diet DM. Ruminal passage rate for straw (3.4 and 3.0%/h) and for hay (4.6 and 4.7%/h) was unchanged when concentrate was increased from 30 to 60%, but it decreased by 28 (2.2%/h) and 13% (4.1%/h), respectively (P less than .05), when concentrates were increased to 90%. Passage rate for grain (5.3, 5.1 and 4.4%/h) and fluid (9.3, 10.0 and 8.2%/h) was not influenced by concentrate percentage. Calculated ruminal digestibilities of NDF in individual ingredients did not differ between 30 and 60% concentrates, but they decreased (P less than .05) by 72, 57 and 34% for straw, hay and grain when concentrate was increased to 90%. Because of their relative contribution to total diet NDF, straw, hay and grain accounted for 28, 18 and 54% of the total decrease in estimated fiber digestion. It is concluded that PDF as well as NDF should be evaluated in studies of concentrate effects on fiber digestion, and that dietary concentrate level has more influence on passage rate of low-quality forage than on passage rate of grain or high-quality forage. In 90% concentrate diets, although fiber digestibility was depressed more for forage than for grain, grain accounted for most of the depression in fiber digestion because grain was the primary source of dietary fiber.

Post-ruminal digestion of starch in the presence of phenolic monomers

The capacity for phenolic monomers to influence starch digestion was examined in six lambs (21.0 kg) fitted with abomasal and ileal cannulae and fed 455 g dry matter per day of a mixture of alfalfa meal (60%), cottonseed hulls (20%) and tall fescue hay (19%). An average of 68.3 g starch per day was infused continuously into the abomasum and ferulic and p-coumaric acids were administered orally in gelatin capsules. Dietary influences were determined in a replicated Latin square crossover design using both Cr 2O 3: nutrient and lignin: nutrient ratios to calculate digestibility values. Pre-ileal starch digestion coefficients were 97.9, 97.9 and 97.8% for control, ferulic acid and p-coumaric acid treatments, respectively, by Cr 2O 3: nutrient ratio, and 98.5, 98.5 and 98.5% by lignin: nutrient ratio. Total tract strach digestion coefficients were 99.4, 99.5 and 99.4% for control, ferulic acid and p-coumaric acid treatments, respectively, by Cr 2O 3: nutrient ratio, and 99.5, 99.7 and 99.5% by the lignin: nutrient ratio method. No significant effects of phenolic compounds upon post-ruminal digestion of starch, neutral detergent fiber or acid detergent fiber were observed.

USE OF THE IN SITU TECHNIQUE AND PASSAGE RATE CONSTANTS IN PREDICTING VOLUNTARY INTAKE AND APPARENT DIGESTIBILITY OF FORAGES BY STEERS

The in situ bag technique was evaluated as a method of predicting the voluntary intake and digestibility of forages. Nine feedstuffs including three cereal straws, three alfalfa (Medicago sativa L.) and grass hay mixtures, two alfalfa-grass silages, and a prairie (Festuca hallii L.) grass hay were each fed to five steers (350 ± 49.5 kg) at ad libitum and approximately maintenance feeding levels. Hays and silages were also fed at near the twice maintenance feeding level. Voluntary forage dry matter (DM) intakes ranged from 1.00 to 2.85% of body weight. Apparent forage DM digestibilities ranged from 37 to 64%. At the lower feeding level fractional rates of particulate passage through the digestive tract were higher (P &lt; 0.05) for 37% DM silage (0.037 h−1) than for two of the straw-based diets (0.020–0.023 h−1). Particulate passage rates were not (P &gt; 0.05) affected by feeding level. Predictions from in situ results were most accurate when 24 and 36 h degradation values were used to estimate DM digestibility (R2 = 0.92) and intake (R2 = 0.86), respectively. The neutral detergent fiber content of forage was equally well correlated with DM digestibility (R2 = 0.86) and voluntary DM intake (R2 = 0.85). Inclusion of information on rates of passage in prediction equations did not (P &gt; 0.05) improve accuracies of predictions over those obtained using in situ results or chemical feed components. Key words: Steers, in situ, voluntary intake, digestibility, passage rates, prediction

Influence of Native Shrubs on Nutritional Status of Goats: Nitrogen Retention

In vivo digestibility trials were conducted to evaluate the influence of shrubs containing low and high levels of soluble phenolic/tannins on digestibility and nitrogen retention by Angora goats. Each of 6 shrubs and alfalfa hay (Medicago sativa L.) were fed to goats at 30% (dry matter basis) of the diet in a barley straw-prairie hay mixture. The mixture was regulated so that all diets contained about 8% crude protein. High soluble phenolic shrubs used included big sagebrush (A rtemisia tridentata Nutt. ssp. tridentata), gray oak (Quercus grisea Liebm.), true mountain mahogany (Cercocarpus montanus Raf.), and one-seed juniper (Juniperus monosperma [Engelm.] Sarg). Low-soluble phenolic species included common winterfat (Ceratoides lanata [Pursh.], J.T. Howell), fourwing saltbush (A triplex canescens [Pursh.], Nutt.), and alfalfa. Nitrogen digestibilities of winterfat, gray oak, mountain mahogany and one-seed juniper diets were less (P .05) compared with the alfalfa control. Retained nitrogen (g/d) differed (P<.05) only among alfalfa, juniper, and mountain mahogany diets. Goats fed juniper had greater (P<0.05) retained nitrogen than the alfalfa control. Shrubs high in soluble phenolics, with the exception of big sagebrush, had elevated fecal nitrogen losses, but reduced urinary nitrogen losses compared with the alfalfa control. Forage organic matter intake (% body weight) and nitrogen intake (g/d) were correlated more highly with nitrogen retention than dietary crude protein (%) or digestible protein (%). Present data indicate that protein found in palatable native shrubs is assimilated with similar efficiency to that in alfalfa hay if these shrubs are consumed at