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1.
The aim of this study was to investigate the effect of increasing the intake of starch on the glycaemic and insulinaemic responses of horses. A cross-over study design was used in which four horses were fed increasing amounts of a compound feed (0.5–3.5 kg) to provide 0.3, 0.6, 0.8, 1.1, 1.4 and 2 g starch/kg bodyweight (BW)/meal. The glycaemic response increased with starch intake (P < 0.05), while feeding <1.1 g starch/kg BW resulted in a lowered response, compared to when 1.1–2 g starch/kg BW was fed (P < 0.01). The results suggested that insulin responses may be more appropriate to define the effect of feeding different starch levels than glycaemic responses. A starch intake of <1.1 g/kg BW/meal produced only moderate glucose and insulin responses, even though highly processed cereals were used. It is therefore recommended that a starch intake of <1.1 g/kg BW/meal or a meal size of 0.3 kg/100 kg BW (starch content of 30–40%) is used for horses.  相似文献   

2.
This study was conducted to evaluate the effects of different corn processing techniques on the glycaemic and insulinaemic responses in horses. It was hypothesized that the changes in pre-caecal starch digestibility caused by various types of corn processing would alter the post-prandial glycaemic and/or insulinaemic response. Six horses were fed in random order: untreated, finely ground, steamed, micronized, steam-flaked and popped corn. The total corn intake was adjusted to 630 g starch/horse/day (1.2-1.5 g starch/kg BW/day). During a stabilization period of 10 days, horses also received 6 kg grass hay/horse/day. At blood collection day horses were fed their test diet (exclusively corn), and blood samples were taken at defined times. Corn feeding resulted in a significant increase in mean plasma glucose and insulin concentration, but glucose and insulin peaks as well as areas under the curve (AUC) were not clearly influenced by corn processing. The glycaemic index (in which each test diet's plasma glucose AUC was expressed relative to untreated corn) varied between 91.4 +/- 9.4% (steamed corn) and 108.4 +/- 11.8% (popped corn, treatment n.s.), the insulinaemic index (in which each test diet's plasma insulin AUC was expressed relative to untreated corn) ranged between 98.2 +/- 12.6% (steamed corn) and 121.0 +/- 29.9% (micronized corn, treatment n.s.). However, the well-established improvement in pre-caecal starch digestibility was not reflected by differences in the glucose or insulin responses.  相似文献   

3.
Effects of processing barley on its digestion by horses   总被引：1，自引：0，他引：1  
Four horses were randomly fed a diet containing rolled, micronised or extruded barley; the barley intake was adjusted to supply 2 g starch/kg bodyweight per day. During a 10-day acclimatisation period the horses were also fed 1 kg grass hay/100 kg bodyweight per day. Samples of blood and breath were collected at the end of each period after the test meal of barley had been fed after a 12-hour overnight fast. The glycaemic and insulinaemic responses of the horses were measured as an indication of the pre-caecal digestibility of starch, and postprandial breath hydrogen and methane were measured to detect microbial fermentation of starch. The highest peak serum glucose and serum insulin concentrations were observed after feeding the extruded barley, lower concentrations were observed after feeding the micronised barley and the lowest concentrations were observed after feeding the rolled barley. Breath hydrogen increased within four hours of feeding all the barley diets, and the mean (sd) peak hydrogen concentrations were 98.3 (55.2) ppm for rolled barley, 59.3 (31.5) ppm for micronised barley and 96.1 (51.9) ppm for extruded barley. There were wide variations within individual horses but these concentrations were not significantly different. Breath methane concentrations were very variable and, although there were no significant differences, there was a trend for higher methane concentrations after the feeding of rolled barley.  相似文献   

4.
This study was conducted to evaluate the effects of different barley processing techniques on the glycaemic and insulinaemic responses in horses. It was hypothesized that the changes in pre-caecal starch digestibility caused by barley processing would affect metabolic responses. Six horses were fed in random order: whole (WB), finely ground (FGB), steamed (SB), steam-flaked (SFB) and popped barley (PB). The total barley intake was adjusted to 630 g starch/horse/day (1.2-1.5 g starch/kg BW/day). During a 10-day stabilization period, the horses also received 6 kg grass hay/horse/day. On the blood collection day, the horses were fed their test diet (exclusively barley), and blood samples were taken at defined times for glucose and insulin analysis. The degree of starch gelatinization (DG) in the untreated or thermally processed barley was analysed using the glucoamylase method. In general, barley feeding resulted in a significant increase in mean plasma glucose and insulin concentrations within 30-45 min after feeding. While the highest glucose and insulin responses occurred after intake of SFB with a DG of 28.7%, the changes in glucose and insulin were more pronounced with PB with a DG of 95.6%, with SB (DG: 22.2%), FGB (DG: 14.9%) and WB (DG: 14.9%). The peak plasma glucose varied between 5.72 +/- 0.67 mmol/l with FGB and 6.52 +/- 0.64 mmol/l with SFB (treatment p < 0.05). These results confirm the post-prandial changes in plasma glucose and insulin after intake of the different barley products, but also show that there was no association of the highest degree of gelatinization in the different barley diets with the most pronounced glycaemic or insulinaemic response.  相似文献   

5.
Effects of oat processing on the glycaemic and insulin responses in horses   总被引：3，自引：0，他引：3  
This study was conducted to evaluate the effects of different oat processing techniques on the plasma glucose and insulin response in horses. In a cross-over design, six horses (ages 4-15 years, mean body weight+/-SD: 450+/-37 kg) were fed in random order: untreated oats, finely ground, steam-flaked and popped oats. The total oat intake varied between 1.05-1.5 kg/day, and the amount of diet was adjusted to a starch content of 630 g starch per day and horse (1.2-1.5 g starch/kg BW/day). During the stabilization period of 10 days, horses additionally received 6 kg grass hay. Following this adaptation period, plasma glucose and insulin responses to the respective dietary treatments were tested. Horses were fed their test diet (exclusively oats), and blood samples were collected at defined times to determine glycaemic and insulin response. Oat feeding resulted in a significant increase in mean plasma glucose and insulin concentration. However, glucose and insulin peaks as well as their respective areas under the curves were not clearly influenced by oat processing. The glycaemic index varied between 94.7+/-11.2% (steam-flaked oats) and 102.6+/-14.5% (finely ground oats, n.s.), the insulin index ranged between 93.8+/-18.9% (popped oats) and 150.0+/-77.6% (finely ground oats, n.s.). The insulin reaction to oat feeding showed a high variability between the horses. The results of this study indicate that the glucose and insulin responses are not clearly altered by the different types of oat processing. However, the glucose and insulin responses tended to be lower in thermally treated oats when compared with untreated or finely ground oats.  相似文献   

6.
The aim of this study was to investigate the effect of the addition of a purified soluble (pectin) and insoluble (lignocellulose) fibre to a starchy meal on post‐prandial glucose and insulin responses in healthy horses. Four horses were fed in a randomized order three different diets: (i) cracked corn, (ii) cracked corn mixed with purified lignocellulose, and (iii) cracked corn mixed with purified pectin. Each diet was adjusted to a starch intake of 2 g/kg bodyweight (BW). Lignocellulose was aligned to an intake of 0.2 g/kg BW, and pectin was fed in a dosage of 0.1 g/kg BW. Each period consisted of a 10‐day acclimatization to the diet (fed once per day); during this time, the horses were fed 1.2 kg hay/100 kg BW/day. Blood was collected after each acclimatization period before and after the test meal was fed, without any hay. The increase in plasma glucose and insulin, peak values, and area under the curves were similar for all diets. The present findings suggest that adding purified soluble or insoluble fibre to a corn meal does not affect post‐prandial glucose and insulin responses in healthy horses. Feeding strategies for horses with a high energy requirement should include a starch reduction per meal, rather than the addition of purified fibre.  相似文献   

7.
The aim of this study was to determine whether the glycaemic/insulinaemic responses to hay with non-structural carbohydrate (NSC, soluble carbohydrate) of 17% (HC), 10% (MC) or 4% (LC) differs in control horses and whether these responses differ between control and horses with polysaccharide storage myopathy (PSSM). Five clinically normal control horses and seven PSSM horses, all unfit and of Quarter Horse breeding (age 9.4 ± 3.4 years, body condition score range: 4.5-6). A crossover design compared the HC and LC hay, with horses randomly assigned to hay type for 5 days, and all horses fed the MC hay during washout, after which the diets were switched. Horses were fed 1.5% BW (as fed) divided into 2 feeding per day, no grain. On morning of the fifth day of each block (seventh day for washout), horses were given 0.5% BW in hay, blood was drawn before and every 30 min for 5 h after feeding, and the rate of intake was measured. Whole blood glucose and plasma insulin were measured. The intake rate was significantly higher for HC. In control horses, the insulin area under the curve (6891.7 ± 3524.2 HC vs. 1185.4 ± 530.2 LC) was significantly higher than LC. Polysaccharide storage myopathy horses had significantly higher glycaemic and insulinaemic responses to HC vs. LC, however; the magnitude of insulin response was lower and glucose response higher in PSSM vs. control horses. Results suggest that insulin responses can differ significantly with the NSC content of hay. Feeding hay with 17% NSC produces elevations in insulin that could be detrimental for PSSM horses.  相似文献   

8.
This trial was conducted to determine the extent of prececal starch digestibility depending on the botanical origin of starch and on diet characteristics (i.e., composition and feeding pattern). The prececal disappearance of six substrates (oats, barley, corn, horse bean, potato, and wheat) was measured in four cannulated horses fed (as-fed basis) 11.8 g/kg BW of a high-fiber (HF) or high-starch (HS) pelleted feed and 10.0 g/kg BW of meadow hay using the mobile bag technique (MBT). The daily feeding pattern was either three meals (two meals of pellets and one meal of hay) or five meals (three meals of pellets and two meals of hay). The experimental procedure was a 2 x 2 factorial arrangement tested in a Latin square design. After 2 wk of adaptation to the diet, collections were made on 5 d. Thirty nylon bags, composed of five bags of each substrate, were intubated to each horse during the ingestion of the morning meal. Bags were collected in the cecum, using a magnet, at 9 h postintubation. In spite of strong interindividual differences, approximately 80% of the intubated bags were collected. On average, the mean retention time of the bags was 6.2 h (+/-0.17). Regardless of the feeding pattern, the transit of the bags was faster when the fiber content of the diet was higher (P = 0.003). Likewise, regardless of the meal composition, transit was also faster when the ration was split into five daily meals (P = 0.001). The DM disappearance, corrected with particulate losses (DMD(c)), differed depending on the substrate tested (33.5, 57.1, 63.8, 67.7, 78.6, and 86.2% for potato, horse bean, oats, barley, corn, and wheat, respectively; P = 0.001). The DMD(c) of corn, barley, and potato was higher when HS was fed (P = 0.020); regardless of the substrate, DMD(c) was higher with five daily meals (P = 0.001). The starch disappearance (StarchD(c)) was different depending on the substrate (P = 0.001; 36.1, 71.2, 86.6, 89.2, 99.0, and 99.7% for potato, horse bean, barley, corn, wheat, and oats, respectively). Whatever the substrate, StarchD(c) was higher when HS was fed (P = 0.007), but it was not affected by the feeding pattern of the diet. Although passage rate was modified and feed intake was different, the botanical origin of starch was the main factor that affected prececal starch disappearance in horses.  相似文献   

9.
Effects of level and frequency of supplementation with alfalfa (A) on feed intake and digestion by steers fed bermudagrass (B) or orchardgrass (O) were determined in two Latin square experiments. In Exp. 1, six Holstein steers (224 kg) were fed B (2.25% N; 71.4% NDF) or O (2.52% N; 64.3% NDF) with 0, 15 or 30% (DM) A (2.70% N; 44.0% NDF). Total DMI was 2.43, 2.72 and 2.85% BW for B and 2.98, 3.00 and 2.87% BW for O with 0, 15 and 30% A, respectively. Total DMI was affected by forage (P less than .05), A level (linear; P less than .06) and a forage x A level (linear) interaction (P less than .05). Digestible OM intake increased .42 (15%) and .67 kg (24%) with feeding of 15 and 30% A, respectively, for B, but for O, only dietary inclusion of 30% A elevated digestible OM intake (.14 kg and 4% increases). In Exp. 2, five Holstein steers (165 kg) were fed B (1.81% N; 78.6% NDF) alone or with A (2.76% N; 52.8% NDF). Morning meals consisted of ad libitum B (OA), .3% BW of A daily (.3A), .6% BW of A every 2nd d (.6A), .9% BW of A every 3rd d (.9A) or 1.2% BW of A every 4th d (1.2A). All steers received B in the afternoon ad libitum, and B was given in the morning when A was not fed. Total DMI was 2.31, 2.12, 2.12, 2.26 and 2.29% BW for OA, .3A, .6A, .9A and 1.2A, respectively (SE .049). Grass characteristics affected response in feed intake to legume supplementation. Frequency of dietary legume addition may alter feed intake.  相似文献   

10.
A 5 x 5 Latin square design was used to determine the effects of restricted and ad libitum intake of diets containing wheat middlings on the site and extent of digestion compared to ad libitum intake of a corn-based diet and ad libitum intake of chopped alfalfa hay. Five ruminally and duodenally cannulated Angus steers (519 +/- 41.5 kg BW) were used to compare five dietary treatments. The five treatments were as follows: ad libitum access to a corn-based finishing diet (control), the control diet with 25 percentage units of the corn and soybean meal replaced with wheat middlings offered ad libitum (WM), the WM diet restricted to 75% of predicted ad libitum intake (RWM), the RWM diet with wheat middlings replaced with ammoniated wheat middlings (RNWM), and ad libitum access to a chopped alfalfa hay diet. Although RWM steers were fed to consume 75% of ad libitum intake, RWM steers consumed 15.5% less DM than WM. Steers fed ad libitum hay consumed 28.6, 31.7, and 37.2% less (P < 0.01) DM, OM, and nitrogen than RWM steers. No differences in apparent or true ruminal digestibility were observed among steers fed the control vs WM, WM vs RWM, RWM vs RNWM, or RWM vs hay diets. However, the steers fed the hay diet had 32.5, 33.4, and 36.9% lower (P < 0.01) apparent total tract digestibilities of DM, OM, and N than those fed the RWM diet. Average ruminal pH was lower (P < 0.01) for control steers than those fed the WM diet and for those fed RWM compared to the hay diet. The acetate:propionate ratio was higher for cattle fed hay vs the RWM diet. Microbial DM and OM flow to the small intestine was higher (P < 0.02) for steers fed the RWM diet than those fed the hay diet. In addition, bacterial N flow to the small intestine was higher (P < 0.01) for cattle receiving the RWM diet than the hay diet. Feeding diets containing 25 percentage units of wheat middlings at 75% ad libitum intake had no effect on ruminal digestibility.  相似文献   

11.
Prairie hay supplemented with various amounts of corn and soybean meal was fed to steers in two experiments. Effects of supplementation on hay OM intake, digestion, and ruminal fermentation and kinetics were measured. A preliminary study was conducted to attain accurate values for OM intake and digestibility of prairie hay to be used in ration formulation using the NRC (1996) level 1 model. Ten steers (284 +/- 9 kg) given ad libitum access to chopped prairie hay (75% NDF, 6% CP) were supplemented with dry-rolled corn (0.75% of BW/d) plus soybean meal (0.25% of BW/d). Hay OM intake was 1.85% of BW and hay OM digestibility was 48%. Based on results from the preliminary study, eight ruminally cannulated beef steers (317 +/- 25 kg) received a sequence of eight different supplementation combinations (2 x 4 factorial arrangement of treatments). These supplements consisted of dry-rolled corn at either 0 or 0.75% of BW (DM basis) daily combined with one of four amounts of added soybean meal to provide between 0 and 1.3 g of degradable intake protein (DIP)/kg of BW. After supplements had been fed for 10 d, feces were collected for 4 d. Intake of hay and total OM increased quadratically (P < 0.01) in response to added DIP with or without supplemental corn. Hay OM digestibility increased quadratically (P = 0.03) as DIP was added when corn was fed in the supplement. Intake of digestible OM was greater (P < 0.01) with than without corn supplementation. Increasing DIP increased (P < 0.01) digestible OM intake regardless of whether corn was fed. Inadequate ruminally degraded protein in grain-based supplements decreased forage intake, digestibility, and energy intake of cattle fed low-quality prairie hay. Providing adequate supplemental DIP to meet total diet DIP needs seemed to overcome negative associative effects typically found from supplementing low-quality forages with large quantities of low-protein, high-starch feeds.  相似文献   

12.
Fifty-eight Holstein and 58 crossbred beef steers were individually fed one of four isonitrogenous diets to evaluate the effects of forage source (corn silage and alfalfa haylage) and protein source (soybean meal and fish meal) on feedlot performance. Phase 1 diets (up to 354 kg of BW) were 40% forage and 60% concentrates and were fed for 70 to 136 d (depending on diet and breed group). Phase 2 diets (354 kg of BW until slaughter) were 20% forage and 80% concentrates and were fed for 127 to 150 d (depending on diet and breed group). Slaughter end points were .6 cm of 12th rib fat for Holsteins and 1.0 cm of rib fat for crossbreds using real-time ultrasonic estimates. The steers were fed for a maximum of 330 d each year. Forage source was a significant component of variation for most growth, efficiency, and carcass traits. Holstein and crossbred steers fed alfalfa haylage had significantly lower average daily gain, feed efficiency, dressing percentage, and empty body fat and required more days on feed to reach slaughter end points, but had higher total feed energy intake available for production. Steers fed corn silage diets had significantly greater energetic efficiency (P less than .05) than those fed alfalfa haylage, due to increased use of ME to produce fat in the carcass. Protein type did not influence gain, feed or energetic efficiency, energy intake, or most carcass traits. A significant protein system x forage source interaction among the four diets was detected for crossbred steers fed corn silage and fish meal, for which there was significantly greater feed conversion with lower energy intake above maintenance, possibly due to better fiber digestion and(or) amino acid flow to the lower tract. Alfalfa haylage plus soybean meal diets decreased (P less than .05) the percentage of Holsteins grading USDA Choice or higher. These results indicate that corn silage, because of greater energy concentration, was a more desirable forage in feedlot diets composed of less than or equal to 40% forage and that protein type (soybean meal and fish meal) in growing diets is not an important factor in feedlot performance or carcass traits of Holstein or crossbred steers that are fed these diets.  相似文献   

13.
The aim of this study was to compare the effects of two different carbohydrate sources (fructose and glucose) on the metabolic responses in resting and exercising horses. The following regimes were fed in randomized order to five trained horses at rest and immediately before or during exercise. The resting regime comprised 0.6 kg grass meal pellets (control) or 0.6 kg grass meal pellets supplemented with either 50% glucose or 50% fructose. The exercise regime comprised 0.3 kg grass meal (control) or 0.6 kg grass meal pellets supplemented with either 50% glucose or 50% fructose fed immediately before or during simulated endurance exercise on a treadmill (30 km, total running time 120 min; 15 min rest after 60 min running time). Blood samples were collected for the analysis of glucose, insulin, free fatty acids (FFA) and lactate. In resting horses, glucose supplementation resulted in a significantly higher glycaemic and insulinaemic response than the control or fructose feedings (treatment P < 0.05). Plasma glucose levels were significantly higher after glucose supplementation given before or during exercise. Similar plasma glucose concentrations were observed after fructose was fed before exercise, whereas fructose supplementation during exercise resulted in a lower glycaemic response than glucose feeding (P < 0.05). Plasma insulin, FFA and lactate levels showed exercise-related changes (time P < 0.05), but treatment did not effect these results. Plasma glucose concentrations were elevated during the simulated endurance exercise after glucose feeding, and no counter-regulation by insulin occurred. The higher glycaemic response might be beneficial as exogenous glucose can be used as an energetic substrate during prolonged exercise. Fructose exhibited no clear advantages in comparison with glucose as a carbohydrate source for exercising horses.  相似文献   

14.
To determine the influence of feeding frequency on apparent digestibility and blood metabolites in horses, four geldings were fed a complete ration either once (at 08:00 h) or three times a day (at 08:00, 13:00 and 18:00 h). Horses were provided with a mixture of cereals and chopped alfalfa hay at maintenance level for energy supply, 344 kJ/kg BW(0.75) on a daily basis. After three weeks' adaptation, total amounts of faeces and urine were collected for five days, using collection harnesses. Serial blood samples were taken at -30, -15, 0, 5, 15, 30, 45, 60, 90, 120, 180, 240, 300, 360, 480 and 600 min after feeding and analysed for glucose, L-lactate, triglycerides (TG), non-esterified free fatty acids (NEFA) and triiodothyronine (T(3)). Apparent digestibility coefficients of dry matter (DM), crude protein (CP), ether extract (EE), crude fibre (CF), ash and nitrogen-free extract (NFE) were not significantly different (P>0.05) between the two feeding frequencies. Basal plasma glucose, plasma glucose curves and other plasma blood metabolites were not affected by meal frequency. The horses fed the whole ration in one morning feeding did not consume the entire meal at once, but spared feed for ingestion throughout the day, which may explain the lack of effect. Feeding frequency did not affect plasma glucose response (area under curve :AUC) (P=0.705), but AUC (glucose) was negatively correlated with CP (R(2)=0.76; P=0.005) and CF digestibility (R(2)=0.61; P=0.022). Further research is needed to clarify whether different endocrine responses or differences in passage rate can explain these correlations.  相似文献   

15.
In order to study the main effects of particle size, three ruminally fistulated cows (550 to 580 kg BW) were fed a constant low concentrate level (3.56 kg DM/d, 20% of total DMI) and a fibre-rich hay (approximately 60% NDF in DM) in long (28.7 mm), chopped (9.2 mm) and fine ground (2.9 mm) form in a 3 x 3 Latin square design. In another three factorial experiment with 8 wethers (4 animals were ruminally fistulated, mean BW = 68 kg) the main effects and interactions of the above mentioned hay particle sizes at two concentrate levels (10.4 to 13.3% and 29.5 to 40.1% of DMI, resp.) and two intake levels (restricted and ad libitum) were investigated. In comparison to long hay (28.7 mm), feeding of chopped hay (9.2 mm) at low concentrate levels, increased not only the hay intake (7% in dairy cows and 13% in sheep) but also the intake of digestible organic matter (12% in dairy cows and 32% in sheep), due to an increase in the apparent digestibility of OM by 3.8% in dairy cows and 8.2% in sheep. Ad libitum feeding of fine ground hay in combination with low concentrate amount in the ration increased the passage rate in the hindgut and consequently the hay intake, but not the intake of DOM, due to a significant depression of digestibility, especially of fibre fractions (4 to 7% in dairy cows and 4.5 to 14% in sheep), in comparison to 28.7 and 9.2 mm hay particle sizes. The digestibility decreased significantly with restricted feeding of fine ground hay in sheep only in comparison to 9.2 mm particle size. A threefold increase of concentrate amount leveled out all effects of the particle size reduction. The effect of particle size was more pronounced in sheep than in dairy cows.  相似文献   

16.
Two experiments were conducted to evaluate digestion kinetics of alfalfa (Medicago sativa L.) substitution for grass hay in beef cattle. In Exp. 1, forage combinations evaluated in situ consisted of 0% alfalfa-100% big bluestem (Andropogon gerardi Vitman), 25% alfalfa-75% big bluestem, 50% alfalfa-50% big bluestem, and 100% alfalfa-0% big bluestem. Nonlinear regression was used to determine the immediately soluble fraction A, the potentially degradable fraction B, the undegraded fraction C, and the disappearance rate of DM and NDF. Dry matter fraction A increased linearly (P = 0.03), and DM and NDF fraction B decreased linearly (P = 0.01) with increasing alfalfa substitution. Rate of DM and NDF disappearance increased linearly (P /= 0.23) on total tract apparent digestibility of all nutrients except CP. Steers fed orchardgrass plus alfalfa had 33% greater (P = 0.01) total tract apparent digestibility for CP than those fed orchardgrass alone. Lag time of DM and NDF disappearance was not affected (P >/= 0.20) by alfalfa supplementation or intake level. Rate of DM and NDF disappearance of orchardgrass was faster (P 相似文献   

17.
Three experiments were conducted to determine the effect of receiving diets containing alfalfa meal and certain feed additives on performance of comingled feeder pigs transported 900 to 1,100 km. In Exp. 1, the inclusion of 9.4% dehydrated alfalfa meal in receiving diets for 2 wk resulted in no difference (P greater than .1) in gain or feed conversion from purchase to market compared with pigs fed a basal corn-soybean meal (CS) diet or a diet containing 20% ground whole oats (O). In Exp. 2, pigs fed receiving diets containing 10% dehydrated alfalfa meal had no improvement (P greater than .1) in gain (.60 vs .61 kg/d) or conversion (3.25 vs 3.17) compared with CS-fed pigs. In Exp. 3, pigs fed a receiving diet for 2 wk containing 10% mid-bloom alfalfa ate more (P less than .002) feed daily for 2 wk (.82 vs .76 kg) and overall (P less than .04; 1.92 vs 1.85 kg) and had an improved (P less than .03) daily gain from purchase to market (.61 vs .59 kg) compared with CS-fed pigs. In Exp. 2, pigs fed diets containing 44 mg/kg tylosin (T) gained similar to pigs fed no additive (O) and slower (P less than .01) than pigs fed 110 mg/kg chlortetracycline (CTC; .59, .60 and .63 kg/d), with no significant differences in feed to gain conversion (3.12, 3.23 and 3.18).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

18.
To compare the effects of a low-starch, high-fibre diet [LSHF; 51.6% neutral detergent fibre (NDF), 3.0% starch, 14.8% crude protein (CP)] and a high-starch, low-fibre diet (HSLF; 33.3% NDF, 20.0% starch, 19.6% CP) on the nutritional status of captive exotic ruminants, 16 mule deer (Odocoileus hemionus) were fed one of these two diets ad libitum with ≤25% alfalfa hay cubes from 10 days to 68 weeks of age. During five sampling periods beginning in November and spaced 6-12 weeks apart thereafter, feed intake, rumen and blood chemistry, faecal scores, growth and body condition were measured. Dry matter intake, digestible energy intake, time spent ruminating and feeding and blood acetate concentration were greater for deer fed LSHF (p < 0.05 for all). Lower dietary CP led to reduced blood urea nitrogen for deer consuming LSHF (p = 0.004). Deer had the same faecal scores, growth and body fat among treatments (all p > 0.05). These findings show pelleted diets with less starch, more fibre, and reduced protein met the energy and protein requirements of growing mule deer, a medium-sized browsing ruminant, as well as traditional grain-based diets while more closely mimicking natural forages and stimulating a more natural feeding behaviour.  相似文献   

19.
Three experiments were conducted to compare soybean meal/sorghum grain (SBM/SG), alfalfa hay or dehydrated alfalfa pellets (DEHY) as supplemental protein sources for beef cattle grazing dormant range forage. In Exp. 1 (35-d digestion study), 16 ruminally cannulated steers were stratified by weight (average BW 259 kg) and assigned randomly within stratification to: 1) control, no supplement; 2) SBM/SG (25% CP) fed at .48% BW; 3) alfalfa hay (17% CP) fed at .70% BW; or 4) DEHY (17.4% CP) fed at .67% BW. Steers receiving protein supplements displayed at least a twofold increase in forage intake (P less than .10). In addition, steers supplemented with DEHY consumed approximately 15% more forage (P less than .10) than SBM/SG- or alfalfa hay-supplemented steers. Digestible DM intake (kg/d), however, was similar between alfalfa hay- and DEHY-supplemented steers and 20% greater (P less than .10) than for SBM/SG-supplemented steers. In Exp. 2, 82 mature, nonlactating Hereford x Angus cows (average BW 489 kg) were assigned randomly to SBM/SG, alfalfa hay or DEHY supplement treatments, which were replicated in three pastures. Cows supplemented with DEHY gained more weight (P less than .05) during the first 84 d of supplementation and displayed the least amount of weight loss at calving (d 127; P less than .05) and just prior to breeding (P less than .10). In contrast, calving interval (361 d) and pregnancy rate (94%) were unaffected (P greater than .10) by dam's previous supplemental treatment. In Exp. 3, one block (pasture) of cows from Exp. 2 was selected at random and grazing behavior was monitored during week-long periods in January and February. A treatment X time interaction (P less than .05) occurred for total time spent grazing; treatments did not differ in January, but cows supplemented with alfalfa hay spent less time grazing in the February grazing period. In conclusion, DEHY and alfalfa hay appear to be at least as effective as SBM/SG as a supplemental protein source for pregnant grazing cows when supplements are fed on an equal CP and ME basis.  相似文献   

20.
Soybean hulls have been used as a feed ingredient for horses for many years and are generally used as a fiber source. The NRC (11) gives them an energy value of 1.88 Mcal DE/kg DM, which is comparable with a medium quality grass hay. Recent evidence suggests that soybean hulls may have a higher energy value. Two feeding trials were conducted to evaluate the energy value of soybean hulls by using them to replace oats in a concentrate for weanling horses. In Exp. 1, 16 Thoroughbred and Quarter Horse weanlings, 145.2 4.1 d of age, were paired within breed and gender subgroups and assigned at random to either the oats or soybean hull-based concentrate. Soybean hulls replaced oats at 25% of the concentrate. Concentrates were fed individually to appetite for two, 1.5-h feeding periods daily with the concentrate restricted to the lesser amount consumed by the pair based on percentage of BW. Coastal bermudagrass (Cynodon dactylon) hay (12.8% CP) was group fed at 1.0 kg/100 kg BW daily. The BW and measurements of the weanlings were made at 14-d intervals for 112 d, and the weanlings were radiographed for bone mineral deposition determinations at the start and conclusion of the study. Experiment 2 used 13 weanlings starting at 143.8 ± 4.2 d of age and was identical to Exp. 1 except the source of the Coastal bermudagrass hay was different and the concentrate intake was fed ad libitum during the two, 1.5-h feeding periods. In Exp. 1, no differences in feed or nutrient intake, BW, or body measurement gains were detected (P > 0.05) except for body length gain, which was greater for the weanlings on the oat-based concentrate (P < 0.05). The weanlings gained 0.73 and 0.70 kg/d on the oat and soybean hull-based concentrates, respectively. In Exp. 2, the protein content of the hay (7.0% CP) was less than the previous year, resulting in a protein intake below NRC (11) recommendations. No differences in BW, withers height, or body length gain were detected (P < 0.05), but heart girth (P < 0.05) and hip height gain (P < 0.05) were both greater for the weanlings fed the oat-based concentrate. The weanlings gained 0.74 and 0.61 kg/d on the oat and soybean hull-based concentrates, respectively. Bone mineral deposition was not different between diet groups for either experiment. Results suggest that soybean hulls have an energy value for weanling horses that is similar to oats when fed with medium quality grass hay. When fed with low quality grass hay, soybean hulls do not seem to be as valuable as oats, perhaps because of either the slow energy release or the availability of protein in the foregut.  相似文献   

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