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1.
Matua bromegrass (Bromus willdenowii Kunth. cv. Grasslands Matua) was introduced in 1973, but little information exists concerning its potential as a hay for horses. Thus, voluntary intake and apparent digestibility of OM, CP, and fiber components of Matua by 18 Quarter Horse yearlings (mean initial BW 354 kg; SE 5.8) were compared with alfalfa (Medicago sativa L.) and coastal bermudagrass (Cynodon dactylon L.) as hays in a randomized block design. A 15-d adjustment period was followed by a 5-d collection period during which the hays were consumed ad libitum. Voluntary intake of DM was greater (P<.01) for alfalfa (10.9 kg/d) than for the mean of the grasses, and intake of Matua (10.0 kg/d) was greater (P<.001) than that of bermudagrass (7.4 kg/d). Apparent digestibility of OM was greater (P<.001) for alfalfa (74%) than for the mean of the grasses but did not differ between Matua (64%) and bermudagrass (60%). At the end of the digestion trial, each yearling was offered each of the three forage hays during an 11-d period to determine subsequent preference and effect of previous hay experience. Yearlings preferred alfalfa over the grass hays and generally selected more Matua than bermudagrass. All yearlings consumed less of the forage species to which they had been previously exposed compared with unadapted yearlings. The Matua hay fed in this trial was palatable and met most of the nutritional needs for yearling horses.  相似文献   

2.
Fifteen yearlings, nine Thoroughbreds and six Quarter Horses, were used in a feeding trial to determine whether proteinated trace minerals were utilized advantageously over inorganic trace minerals for growth and development when included in the diet at normal supplementation levels. The animals were assigned randomly within breed and gender subgroups to one of two treatments. Group A received a 12% protein (as fed) concentrate containing a trace mineral premix providing inorganic trace minerals at concentrations appropriate to supplement Coastal Bermuda grass (Cynodon dactylon) hay and provide NRC1 or higher trace mineral intakes. Group B was provided the same concentrations of trace minerals but the Cu, Mn, and Zn were provided via a commercial proteinate. The concentrates were fed to appetite individually, twice daily during a 1.5-hour feeding period. The hay was group-fed in drylot paddocks at 1.0 kg/100 kg BW daily. The animals were housed three or four animals per paddock. Weight and body and hoof growth measurements were taken at the start of the experiment and at 28-day intervals for 112 days. Radiographs of the third metacarpal were made for estimating bone mineral and hoof samples were collected at the start and completion of the experiment. The yearlings gained 0.77±0.03 and 0.79±0.03 kg/d for the inorganic and proteinate groups, respectively. None of the body measurements were affected by diet (P > 0.10) except hip height gain which was higher for the animals receiving the proteinated minerals (7.0 vs 4.7 cm, P = 0.023). Hoof growth was greater for yearlings fed the mineral proteinate than for those fed the inorganic minerals (4.98 vs 4.78 cm, P = 0.016), and colts had greater hoof growth than did fillies (5.00 vs 4.72 cm, P = 0.003). Diet and gender did not affect hoof strength (P > 0.10), but Quarter Horses had greater hoof strength than Thoroughbreds (98.2 vs 88.8 kg, P = 0.046). No differences in bone mineral content or bone mineral deposition were detected (P > 0.10).  相似文献   

3.
Seventeen Thoroughbred and Quarter Horse yearlings were used in a 2×2 factorial experiment to determine 1) whether adding fat (5% corn oil) to the concentrate would influence feed intake, growth and development and 2) whether time of hay feeding would influence energy metabolism on the basal and added fat diets. Yearlings were assigned at random, within breed and gender subgroups, to one of four diets: B-I, basal concentrate with Coastal Bermuda grass (Cynodon dactylon) hay fed immediately after the concentrate; B-D, basal with hay fed 3.5 hr after the concentrate; F-I, basal + fat with the hay fed immediately; and F-D, basal + fat with the hay fed 3.5 hr after the concentrate. The basal concentrate was formulated to meet or exceed NRC (1989) recommendations when fed with the hay. The basal + fat concentrate was formulated at 9.7% higher digestible energy than the basal concentrate and all of the other nutrients were increased proportionately so if the intake was reduced, the yearlings would still meet nutrient needs. The concentrates were fed individually to appetite for two 1.5-hr feeding periods daily in 1.5×3.0 m slip stalls. Hay was group fed in the paddocks at a rate of 1.0 kg/100 kg BW daily divided into two equal feedings. Animals were housed in four 9.1×34.9-m drylot paddocks with three, four, or five animals in each paddock. The mean age at the start of the experiment was 377±8 days. Weight and body measurements for withers height, heart girth, body length, and hip height were taken at the start of the experiment and at 28-day intervals for 84 days. Radiographs for bone mineral estimates were made at the start and completion of the experiment. During the final 28-day period of the feeding trial, three animals from each experimental group were randomly selected for a 24-h period of blood sampling to evaluate the effects of the diets on blood glucose and insulin.Fat addition to the concentrate reduced the daily concentrate DM (P=0.0187) and total feed DM (P=0.0021) intake. When feed intake was expressed as a function of BW, concentrate and total feed intakes were 1.33 and 2.14 kg/100 kg BW daily and were not influenced by diet (P>0.1). Colts consumed more concentrate DM (P=0.0039) and total feed DM (P=0.0022) than fillies. The yearlings gained an average of 0.60 kg/d for the 84 days. Weight gain, body measurements and bone mineral deposition were not influenced by gender or diet. Mean plasma glucose concentrations were higher (P=0.05) in yearlings consuming the basal concentrate with hay fed immediately than when hay feeding was delayed. When fat was fed, the time of hay feeding had no effect on plasma glucose concentrations (P>0.05). Plasma glucose and insulin were lowest just prior to the morning feeding and peaked two to three hours after both morning and afternoon feedings. Fat supplementation reduced plasma insulin (P=0.001). Results suggest that the addition of 5% corn oil to a yearling concentrate may reduce feed intake but will not reduce growth and development of the animal if other nutrients are supplied at concentrations that provide for the animal's daily needs. Delaying hay feeding may be advantageous to growing horses as it may allow the concentrate to move down the tract at a slower rate reducing the glucose peaks.  相似文献   

4.
Sixteen Quarter Horse yearling fillies were used in a 112-day randomized block experiment to determine the comparative efficacy of alfalfa hay protein to support growth in young horses. The yearlings were divided into two groups of eight and paired according to weight and age, with one yearling from each pair randomly allotted to each diet. Group 1 was fed a diet of coastal Bermuda grass hay and concentrate. The corn-based concentrate was supplemented with soybean meal such that the total diet for group 1 contained approximately 13% CP. Group 2 was fed a diet that also contained approximately 13% CP and consisted of alfalfa hay and a similar concentrate without soybean meal. Yearlings were fed the diets in a 60:40 grain-to-hay ratio, and intakes between members of each pair were equalized. The calculated digestible energy density in both final diets was approximately 2.85 mcal/kg, and the protein:calorie ratio for both diets was approximately 45 gm/Mcal. Body weight, body length, heart girth, wither and hip heights, as well as forearm, gaskin and cannon bone circumferences were measured every 28 days. Rump fat thickness was measured ultrasonically every 28 days. Physical measures of growth were similar for horses eating each diet (P>0.05). Also, blood urea nitrogen was similar for horses eating each diet (P>0.05) and was not reflective of differences in nitrogen metabolism. The fillies fed the SBM-supplemented diet retained more nitrogen more efficiently than did fillies fed the alfalfa diet (P<0.05), and the SBM-fed fillies had higher concentrations of osteocalcin on days 14, 28, 42, and 112. It can be concluded that SBM and alfalfa proteins were equally effective in providing growth to young horses; however, the biological value of absorbed nitrogen appeared to be higher in the fillies fed the SBM-supplemented diet. also, differences in serum osteocalcin concentrations indicate that the SBM-fed fillies were experiencing a greater amount of osteoblastic activity than the alfalfa fed fillies.  相似文献   

5.
Forty-four weanling horses were used in two experiments to evaluate the effect of starch intake on growth and skeletal development. In Exp. 1, the weanlings were fed either a grain-based, high-starch (31.1%, DM basis) concentrate or a by-product-based, low-starch (0.0%) concentrate with coastal bermudagrass (Cynodon dactylon) hay. Corn oil was used to equalize the energy concentration of the concentrates. The concentrate:hay ratio was 64:36 (as-fed basis), and intake was the same for both diets. Body weight gains were greater by the weanlings consuming the high-starch concentrate (0.81 vs. 0.67 kg/d; P = 0.01). Total body length gain also was greater for the weanlings consuming the high-starch concentrate (15.5 vs. 13.2 cm; P = 0.045). Other body measurements and bone mineral deposition were not influenced by diet or gender. At the end of the experiment, postprandial blood glucose concentrations suggested that the horses on the low-starch diet were less efficient in metabolizing blood glucose than were those that had been consuming the high-starch diets. In Exp. 2, the weanlings were fed either a high-starch (34.7%) or medium-starch (17.0%) concentrate plus coastal bermudagrass hay. Corn oil again was used to equalize the energy content of the medium-starch concentrate to that of the high-starch concentrate. The concentrate:hay ratio was 64:36 (as-fed basis), and the intake was the same for both diets. The diets did not influence rate of gain (0.75 kg/d; P = 0.98), body measurements (P = 0.11 to 0.93), or bone mineral deposition (P = 0.66). Animals on the medium-starch diet tended to have blood glucose concentrations that peaked earlier and were lower at later times than those consuming the high-starch concentrate. Bone osteochondrotic lesions were not related to the diet and were found to decrease during the course of the experiment for both the high-starch and the medium-starch diets (P = 0.006 and 0.016, respectively).  相似文献   

6.
Two experiments were conducted to determine the dietary value of pellets containing kenaf (Hibiscus cannabinus cv. 'Everglade 41') hay. Averaged across both experiments, kenaf pellets contained 82.6% kenaf hay, 16.6% liquid molasses, and 0.8% mineral oil. The chemical composition of the kenaf pellet was 12.6% crude protein (CP), 41.2% neutral detergent fiber (NDF), and 14.4% acid detergent fiber (ADF). In Exp. 1 (digestion and N balance trial), 18 lambs (body weight [BW] = 36.4 kg) were blocked by BW. Lambs were randomly assigned within a block to Diet 1 (59.5% corn and 40.5% alfalfa pellet), Diet 2 (59.7% corn, 28.4% alfalfa pellets, and 11.9% kenaf pellets), or Diet 3 (59.6% corn, 16.5% alfalfa pellets, and 23.9% kenaf pellets). Diets were formulated so that CP was the first-limiting nutrient. Each diet was limit-fed at 2.4% of BW. Replacing alfalfa pellets with kenaf pellets tended to decrease (P = 0.10) CP and ADF intakes, but increased (P = 0.01) DM digestibility. Diet had no effect (P = 0.33) on N balance. In Exp. 2 (dry matter [DM] intake trial), 32 lambs (BW = 30.4 kg) were blocked by gender and BW. Within a block, lambs were randomly assigned to one of four diets in a 2 x 2 factorial arrangement. Main effects were hay (bermudagrass or fescue) and supplemental protein source (kenaf or alfalfa pellets). Lambs were housed in individual pens with ad libitum access to the assigned hay. Supplemental protein was fed (185 g of DM) once daily. Hay intake was measured weekly for 8 wk. Lambs consumed more (P = 0.002) fescue than bermudagrass hay (743 vs 621 g/ d). Lambs fed fescue hay gained weight more rapidly (P = 0.001) than lambs fed bermudagrass hay (120 vs 72 g/d). Hay intake and ADG were similar (P = 0.90) for lambs fed alfalfa or kenaf pellets. Kenaf hay mixed with molasses and mineral oil can be formed into a pellet. In the diets used in this experiments, kenaf pellets can replace alfalfa pellets in diets fed to lambs without altering forage intake, gain, or N retention.  相似文献   

7.
Beef cattle consuming bermudagrass hay were not supplemented or received a limited amount of ground corn alone or with a mix of protein meals to determine influences of concentrate supplementation on digestion and performance when the ionophore lasalocid (200 mg daily) was given. With limited feed intake, supplement treatment did not change the acetate to propionate shift in beef cows occurring with lasalocid (P < 0.06). Lasalocid did not affect sites of digestion of organic matter or nitrogen with any supplement treatment. However, lasalocid decreased (P < 0.10) ruminal digestion of neutral and acid detergent fibre. Live-weight gain by growing beef calves ingesting bermudagrass hay ad libitum was higher (P < 0.05) with than without supplementation and tended (P < 0.12) to be greater for corn plus protein meals than for corn alone. Lasalocid did not affect or interact with supplement treatment in feed intake or live-weight gain of heifers (236 kg; no growth stimulant) or steers (237 kg; treated with 200 mg progesterone and 20 mg estradiol benzoate). Lasalocid at 200 mg daily did not improve digestion characteristics or influence performance by beef cattle consuming a Basal diet of bermudagrass hay. Further, effects of lasalocid were not modulated by supplementation with concentrate, concentrate type or sex or growth stimulant usage.  相似文献   

8.
The consumption of solid feed is essential for successful transition from a pre-ruminant to a functional digestive tract. Lambs fed starter rations containing highly fermentable carbohydrates often experience dramatic changes in concentrations of rumen and blood metabolites. The optimal amount of roughage required in the diet of pre-ruminant animals is still unclear. The objective of this study was to determine the effect of feeding alfalfa hay on performance and rumen development in young Balouchi lambs. In a completely randomized design, 30 lambs were fed one of three experimental diets consisting of a control, without alfalfa hay (C), a diet containing 7.5% alfalfa hay (A1), and a diet containing 15% alfalfa hay (A2). Lambs fed A1 and A2 diets had lower dry matter intake during the pre-weaning period (P?P?=?0.02), but feed conversion ratio and average daily gain were not affected by feeding alfalfa hay. Concentration of beta-hydroxybutyric acid was higher in C compared with the A1 and A2 groups (P?P?=?0.04) and increased thickness of muscular layer (P?=?0.05). We concluded that including 15% alfalfa hay in the starter diet could reduce thickness of the keratinization layer and increase muscularity of rumen wall without adverse effects on growth and performance of newborn lambs.  相似文献   

9.
Three experiments were conducted with cattle consuming bermudagrass hay to determine whether low-level supplements of whey alone, corn alone, or whey plus corn affect feed intake, digestion, and(or) BW gain. Six ruminally and duodenally cannulated beef cows (574 kg), used in a Latin-square trial (Exp. 1), were fed bermudagrass hay without supplementation (control) or with 2.8% whey (low whey, LW), 5.6% whey (high whey, HW), 17.4% ground corn (C), 2.8% whey plus 14.9% corn (C-LW), or 5.6% whey plus 12.4% corn (C-HW). Supplementing with whey and(or) corn increased ruminal butyrate (8.8, 9.4, 10.0, 9.6, 10.5, and 11.0 mol/100 mol of total VFA for control, LW, HW, C, C-LW, and C-HW, respectively; SE = .20). Supplements did not affect microbial N flow at the duodenum. Six Holstein steer calves (158 kg) in a Latin square (Exp. 2) consumed bermudagrass hay ad libitum alone (control) or with .075 or .15% BW whey (LW and HW, respectively), .5% BW ground corn (C), or corn-whey mixes made by substituting whey for corn (C-LW and C-HW). Substituting .15% BW of whey for corn increased (P less than .05) total OM intake slightly (3.99, 3.84, 3.75, 4.11, 4.28, and 4.47 kg for control, LW, HW, C, C-LW, and C-HW, respectively; SE = .10). In an 84-d randomized block experiment (Exp. 3), 96 beef calves (194 kg) consumed (ad libitum) low-quality bermudagrass hay alone or with C, LW, HW, C-LW, or C-HW supplements.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

10.
Matua bromegrass hay (Bromus willdenowii Kunth) is a high quality forage, but its value for mares during gestation and lactation is not well known. Intake, rate of passage, performance, and reproduction by gestating and lactating Quarter Horse mares fed the hay was investigated. In this experiment, 12, 2- to 12-yr-old gravid mares (mean BW = 553 kg, SD = 36) were fed Matua hay (CP = 11.5%) or alfalfa hay (Medicago sativa L.) (CP = 15.4%) for variable days prepartum (mean 59.9 d; SD = 23.5) and for 70 d postpartum. Matua and alfalfa hay were fed as the roughage portion of the diet with a grain supplement. Mares, blocked by age, expected date of foaling, and BW, were assigned randomly within blocks to treatments (six mares per treatment). Forage type did not affect intake, gestation length, birth weight, number of foals, foal weight gain, day of first postpartum ovulation, cycles per conception, or pregnancy rate at 70 d. On d 1, milk from mares fed alfalfa hay contained less (P < 0.03) CP than milk from mares fed Matua hay. Milk CP decreased (P < 0.01) in all mares over time. In a separate experiment, voluntary intake and rate of passage of Matua (CP = 15.5%), alfalfa (CP = 24.9%), and Timothy (Phleum pratense L.) (CP = 4.1%) hays were determined in nine 2-yr-old pregnant mares (mean BW = 447 kg; SD = 21). Diets were 100% forage. Timothy hay did not meet CP requirements for mares. Voluntary intake of alfalfa hay was higher (P < 0.01) than Matua hay. Intake of Timothy hay was lower (P < 0.01) than the mean of alfalfa and Matua hay. Rate of passage offorage was measured by passage of Cr-mordanted fiber. Passage rate and retention time did not differ between Matua and alfalfa hay; however, the retention times of Matua and alfalfa hays were shorter (P < 0.01) than for Timothy hay. Our results indicate that Matua hay is a forage that can be used safely for mares during gestation and early lactation and for their young foals.  相似文献   

11.
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   

12.
Six lactating Holstein cows were divided into two groups (n = 3) and used in a double reversal trial with three periods of 14 days each to evaluate the rumen fermentation, milk production and milk composition of cows fed brewer's grain (BG). The control diets contained 14% chopped Sudangrass hay, 24% corn silage, 18% alfalfa hay cube, 34% concentrate mixture‐1 and 10% concentrate mixture‐2 (wheat bran, soybean meal and cottonseed). In the experimental diet, wet BG replaced the concentrate mixture‐2. The protozoal population, concentration of ammonia‐N and volatile fatty acids in the ruminal fluid did not differ between the control and BG diets. The molar percentage of acetic acid was significantly higher (P < 0.05) with the BG diet at 5 h after feeding. The milk yield, the percentage of protein, lactose, solids not‐fat and somatic cell counts of milk did not differ between the two diets. The percentage of milk fat tended to increase with the BG diet. The BG diet significantly increased the proportions of C18:0 and C18:1 in milk fat (P < 0.01, P < 0.05, respectively) and tended to increase that of conjugated linoleic acid.  相似文献   

13.
Three experiments using 63 Thoroughbred and Quarter Horse yearlings were conducted to evaluate the influence of level of feeding, and protein and calculated energy content of pelleted concentrates on growth and bone development. Animals were housed in drylot paddocks and individually fed concentrates twice daily. Coastal bermudagrass (Cynodon dyctylon) hay was group-fed. Yearlings offered a corn-based concentrate (3.56 Mcal digestible energy [DE]/kg) consumed levels of dry matter similar to yearlings fed a mixed-grain concentrate (3.32 Mcal DE/kg but consumed slightly more digestible energy. No differences in growth or bone development were detected. Yearlings fed restricted levels of concentrate that provided approximate National Research Council (NRC) recommendations for protein and DE had lower weight and girth gains (P less than .05) than those provided ad libitum concentrate intake during two 1.5-h daily feeding periods. Restricting concentrate intake had no effect on skeletal growth (P less than .05) but resulted in numerically lower values for bone radiographic density. Protein addition to a diet restricted to approximate NRC energy intake recommendations had no effect on weight gain, body measurements or bone mineral deposition (P greater than .05) and growth and development was less than that resulting from higher intakes of a lower protein concentrate.  相似文献   

14.
Effects of supplementing sheep consuming wheat straw with local agro-industrial by-products on feed intake, growth, digestibility and nitrogen utilization were determined. Thirty 1-year-old local wethers, with a mean (±SD) live weight of 19.8 (±1.06) kg, were assigned to five treatments: wheat straw + atella (T1), wheat straw + atella + poultry litter (T2), wheat straw + atella + coffee pulp (T3), wheat straw + atella + coffee pulp + poultry litter (T4), hay + concentrate (T5). A 7-day digestibility experiment and a 112-day growth trial were conducted. Total dry matter (DM) and organic matter (OM) intake as well as body weight gain was similar for all treatments. The highest (P < 0.05) nitrogen (N) intake was in sheep fed T1 and T4 diets, while the lowest was in those fed T2 and T5 diets. Sheep fed T1 and T2 diets had greater (P < 0.05) DM and OM digestibility than those fed T4 and T5 diets. The highest (P < 0.05) digestibility of N was for the T2, T4, and T5 diets, while the lowest was for the T1 diet. The highest N retention was in T4 diet, whereas the lowest was in T3 diet. In conclusion, in urban and peri-urban areas where atella, poultry litter, or coffee pulp are available, smallholder farmers could feed the mixtures as a supplement to straw with a good performance without using concentrate feeds.  相似文献   

15.
Two experiments were conducted with Polypay ewes nursing twin lambs to evaluate the effects of supplementing fat (calcium salts of palm oil fatty acids or hydrogenated tallow) on ewe lactation. In Exp. 1, ewes were fed a 52% concentrate:48% hay-based diet (as-fed basis) consisting of alfalfa hay (n = 4), endophyte-free fescue hay (n = 4), or fescue hay with 3.7% fatty acids (n = 4) from d 4 to 56 of lactation. In Exp. 2, ewes were fed similar diets that had endophyte-free fescue hay (n = 6), fescue hay with 3.7% fatty acids (n = 5), or fescue hay with 3.1% tallow (n = 6) from d 14 before lambing until d 57 of lactation. Diet formulations with supplemental fat were more nutrient dense, and treatments were fed to meet ewe nutrient requirements; this caused diets with added fat to be offered at 10 and 17% lower rates than unsupplemented diets in Exp. 1 and 2, respectively. Lambs were maintained to consume only ewe milk. Ewe milk production and composition were determined using a portable milking machine following a 3-h separation from lambs. In Exp. 1, milk fat content was increased (P < 0.01) when ewes consumed fescue hay with fatty acids vs. the fescue hay diet (11.4 vs. 8.3%). Ewes fed fescue hay with fatty acids lost the most (P < 0.05) weight over lactation (-8.6 kg) compared with ewes fed the alfalfa hay (-2.4 kg) and fescue hay (-3.8 kg) diets. Other milk measures, lamb gain, and production efficiencies were not changed. In Exp. 2, ewes supplemented with fatty acids produced more (P < 0.05) milk fat than those fed tallow (290 vs. 210 g/d). The proportion of synthesized milk fat 14:0 was decreased (P < 0.01), but the percentage of incorporated 16:0 increased (P < 0.05) when fatty acids were fed. Dietary fat digestibility by ewes was increased (P < 0.01) by fatty acid supplementation but decreased (P < 0.01) when tallow was added. Although ewe weight measures were not changed in Exp. 2, twin lamb gain per ewe organic matter intake was most efficient (P < 0.05) when ewes were supplemented with fatty acids. Results suggest that feeding hydrogenated tallow decreased nutrient availability for ewe milk fat production. A complete diet based on endophyte-free fescue hay can replace a traditional alfalfa hay diet, whereas supplementing with the calcium salts of palm oil fatty acids may be more feasible when energy is limiting during ewe lactation.  相似文献   

16.
A number of studies have shown that the rumenic acid (RA = cis-9 trans-11 C18:2 CLA) content of milk fat is usually higher in sheep than in goats, due partly to different dietary regimens. An experiment was conducted with 12 lactating dairy ewes and 12 goats with the objective to compare the two animal species (sheep/goats) fed diet with the same forage/concentrate (F/C) ratio, on their milk fatty acids (FA) profile with emphasis on RA and vaccenic acid (VA) production. The experiment was carried out in three consecutive phases, lasted 3 weeks each, immediately after weaning of lambs and kids. In phase I, the ewes and the goats were fed according to their maintenance and lactation requirements, with 14 kg alfalfa hay, 4 kg wheat straw and 12 kg concentrate the 12 ewes (F/C ratio = 60/40), and with 14 kg alfalfa hay, 4 kg straw and 24 kg concentrate the 12 goats (F/C ratio = 43/57). In phase II, 14 kg alfalfa hay, 4 kg straw and 14 kg concentrate were offered daily to each group of sheep and goats, with a F/C ratio = 56/44. In phase III, all ewes and goats were fed individually with 0.8 kg alfalfa hay, 0.2 kg wheat straw and 0.8 kg concentrate daily with a F/C ratio = 56/44. The results showed that the different F/C ratio between sheep and goats diets, in phase I, changed significantly the milk FA profile, with no significant difference in RA and VA milk fat content between sheep and goats in phase I. In phases II (group feeding) and III (individual feeding), where sheep and goats fed with the same amount of food of the same F/C ratio, the sheep milk fat had higher RA and VA content compared to goats. In conclusion, these findings support the hypothesis that there are species differences, as RA and VA production concerns, which needs further investigation.  相似文献   

17.
Thoroughbred and Quarter Horse yearlings (n = 24; 335+/-7 d of age) were used in a 112-d feeding trial to determine whether chromium (Cr) supplementation would alter growth, development, and energy metabolism of growing horses on high-concentrate diets. The horses were assigned at random within breed and gender subgroups to one of four treatment groups: A) basal concentrate; B) basal plus 175 microg of Cr/kg concentrate; C) basal plus 350 microg of Cr/kg concentrate; and D) basal plus 700 microg of Cr/kg concentrate. Chromium was provided via Cr tripicolinate (Prince Agri Products, Quincy, IL). The horses were weighed, measured for withers and hip height, heart girth, and body length and underwent ultrasound evaluation for croup fat thickness. The concentrate was fed for ad libitum consumption for two, 1.5-hr feeding periods daily. Coastal bermudagrass (Cynodon dactylon) hay was group-fed (six animals/group) at 1% of BW daily. Feed intake was 60% concentrate and 40% hay, resulting in a supplemental Cr intake of 0, 105, 210, and 420 microg/kg diet for groups A, B, C, and D, respectively. Colts consumed more concentrate and total feed than did fillies (P < .05), but no dietary effect on feed intake was detected. Colts weighed more than fillies at the completion of the experiment (P = .0754), but no dietary effects on weight, body measurements, or croup fat were detected. An i.v. glucose tolerance test (.2 g of glucose/kg BW) and an i.v. insulin sensitivity test (.1 IU of insulin/kg BW) were conducted on each animal during the third 28-d period of the experiment. Plasma glucose peaked immediately following injection and decreased more rapidly in animals consuming the high-Cr diet than in those consuming the control diet (P < .01). Mean glucose fractional turnover rate values increased (P = .0369) and mean half-life of glucose decreased (P = .0634) in response to the high Cr supplementation. Plasma glucose depletions in animals fed the other two diets were between and not different from (P > .10) the depletions in control animals or in those fed high-Cr diets. No difference in insulin sensitivity was detected (P > .10). Results indicate that Cr tripicolinate supplementation of yearling horses increases the rate at which glucose is metabolized and may lower the plasma glucose concentration. No effect of Cr supplementation on development of the animals was detected.  相似文献   

18.
Forty-four Thoroughbred and Quarter Horse weanlings were used in three experiments to evaluate the effects of energy content, protein content, and feeding levels of the concentrate on growth and development when fed with Coastal bermudagrass hay. The animals were confined to drylot paddocks and fed the assigned concentrate in individual feeding stalls. The hay was group-fed in the paddocks. In the first experiment, the concentrate was fed at 1.5 kg/100 kg BW daily or ad libitum for two 1.5-h feeding periods daily. The ad libitum-fed weanlings had greater withers height gain (P<0.01), and hip height gain (P<0.05) than the limit-fed weanlings. Bone mineral gains were numerically greater for the ad libitum-fed weanlings (P>0.10). None of the other body measurements were different (P>0.05). In Exp. 2, weanlings were fed a basal concentrate ad libitum for two1.5-h feeding periods daily or a fat-added concentrate at equal amounts to the hay intake. Nutrients were balanced to meet NRC recommendations. The fat-added concentrate resulted in numerically greater withers height (P>0.10), heart girth (P>0.10), body length (P>0.10), hip height (P>0.10), and bone mineral (P>0.10) gains. Weight gain and feed efficiency favored the basal diet. In Exp. 3, weanlings were fed concentrates providing either 14 or 18% CP as described previously. The BW gains favored the high protein diets for three of the first four periods (P<0.05), and some numerical advantage persisted to the end of the trial (P>0.10). None of the other growth measurements were different for the two diets. Calculations on nutrient intake and BW gains of the animals on the three experiments revealed that lysine intake appears to be a greater factor than energy or protein in influencing BW gain of weanlings.  相似文献   

19.
Two experiments were conducted simultaneously to evaluate the effects of different concentrates to roughage ratios on growth performance and attainment of puberty in Friesian–Boran crossbred heifers. Weaned 50% Friesian–Boran crossbred female calves were used in both experiments with 25 and 20 calves in experiments I and II, respectively. In experiment I, the calves were offered diets with concentrate to roughage ratios of 50:50 (treatment 1) or 30:70 (treatment 2). In experiment II, the calves grazed for 8 h a day and supplemented with 2 kg hay and 1 kg concentrate per head per day (treatment 1) or only 2 kg hay per head per day (treatment 2). The concentrate mixture was composed of 34% wheat bran, 31% wheat middling, 31% noug cake, 3% limestone, and 1% salt. In experiment I, heifers fed a ration with 50% concentrate and 50% roughage had higher (P < 0.05) daily body weight gain (0.532 kg) and attained puberty at 221 kg (65% of the mature body weight) in 15 months, while heifers fed a diet with 30% concentrate and 70% roughage gained 0.434 kg/day and reached puberty at 247 kg (70% of the mature body weight), about 3 months later. Heifers in treatments 1 and 2 of experiment II reached puberty 5 and 12 months later, respectively, than those in experiment I. In experiment II, heifers given 1 kg of concentrate supplement had higher (P < 0.05) daily body weight gain (0.346 kg) than those given only 2 kg hay in addition to grazing (0.278 kg). Growth rate of crossbred heifers was enhanced and age at puberty was reduced by changing the rearing management from outdoor to indoor and with increasing level of concentrate in the ration. This helps to bring the dairy heifer into production earlier and enhance to the overall productivity of the dairy industry.  相似文献   

20.
The present study evaluated the effects of two different methods of feed processing on growth and gastric ulceration in 16 weanling Standardbred horses. The two diets were composed of identical ingredients that were processed differently and fed at a rate of 3% body weight per day. The hay and grain diet (diet HG) consisted of 50% alfalfa hay cubes and 50% commercial texturized grain mix fed as is, without any further processing, with the cubes and grain fed in separate containers. The complete pelleted diet (diet CP) consisted of the same proportion of hay cubes and grain mix, which was ground, pelleted, and fed in a single container. The horses were divided into two groups and the study was divided into three periods of 30 days each. During period 1, all 16 horses consumed only free choice alfalfa hay (diet H). Group 1 was given diet CP during period 2 and diet HG during period 3. Group 2 was given diet HG during period 2 and diet CP during period 3. The horses were endoscopically examined for the baseline number and severity of stomach ulcers at the end of period 1, then again at the end of each treatment diet feeding period. Horses on diet CP in periods 2 and 3 had greater ulcer numbers (P = .0135) than diet HG. However, there was no significant difference (P = .30) in ulcer numbers when making a direct comparison between diets CP and HG. Despite the gastric ulceration found in horses on diet CP, the average daily gain was significantly greater (P = .016) for diet CP than for diet HG. Both diets containing grain were observed to cause gastric ulceration.  相似文献   

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