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1.
The effects of specific nutrients on secretion and plasma concentrations of gut peptides (glucagon-like peptide-1((7-36)) amide (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and cholecystokinin-8 (CCK)) differ across species, but are not reported for cattle. Our objective was to determine acute (hours) and chronic (1 week) effects of increased abomasal supply of protein, carbohydrate, or fat to the small intestine on dry matter intake (DMI) and plasma concentrations of GLP-1, GIP, CCK, and insulin. Four mid-lactation Holstein cows were used in a 4 x 4 Latin square design experiment. Treatments were 7-day abomasal infusions of water, soybean oil (500 g/d), corn starch (1100 g/d), or casein (800 g/d). Jugular vein plasma was obtained over 7h at the end of the first and last day of infusions. Oil infusion decreased DMI on day 7, but total metabolizable energy (ME) supply (diet plus infusate) did not differ from water infusion. Casein and starch infusion had no effect on feed DMI; thus, ME supply increased. Decreased DMI on day 7 of oil infusion was accompanied by increased plasma GLP-1 concentration, but decreased plasma CCK concentration. Increased plasma GIP concentration was associated with increased ME supply on day 7 of casein and starch infusion. Casein infusion tended to increase plasma CCK concentration on both days of sampling, and increased plasma GLP-1 and insulin concentration on day 1 of infusion. The present data indicate a sustained elevation of plasma concentration of GLP-1, but not CCK, may contribute to the reduced DMI observed in dairy cows provided supplemental fat.  相似文献   

2.
Two experiments were conducted to determine the effects of supplementing ruminally degradable intake protein (DIP) or ruminally undegradable intake protein (UIP) on N balance (Exp. 1; n = 6 wethers; initial BW = 48.7 +/- 4.6 kg) and site and extent of digestion (Exp. 2; n = 5 wethers; initial BW = 36.9 +/- 3.1 kg) in whiteface wethers consuming (as-fed basis) 69% blue grama and 31% love grass hay (mixture = 7.5% CP, 73.0% NDF, 36.0% ADF [DM basis]). Treatments were 1) no supplement (Control), 2) a supplement (219 g/d, as-fed basis) low in UIP (70 g/d of CP; 24.8 g/d of UIP), and 3) a supplement (219 g/d, as-fed basis) high in UIP (70 g/d of CP; 37.1 g/d of UIP). Both experiments were replicated 3 x 3 Latin square designs, with identical feeding and supplementation. Wethers had ad libitum access to the forage mixture and fresh water, and received supplement once daily. In Exp.1, forage intake (percentage of BW) was greatest (P = 0.04) for control, but total DMI (g/d) was greatest (P = 0.05) for lambs consuming supplement. Apparent total-tract OM digestibility was numerically greater (P = 0.11) for supplemented wethers than for controls, whereas total-tract ADF digestibility tended (P = 0.08) to be greater for control wethers. Lambs fed supplements consumed and retained more (P < or = 0.01) N (% of N intake) compared with controls, but no difference (P = 0.22) was observed between low and high UIP treatments. Similar to Exp. 1, forage intake (percentage of BW) tended (P = 0.06) to be greater for control than for supplemented wethers in Exp. 2. Ruminal NDF digestibility was 16.3% greater (P = 0.02) for supplemented wethers than for controls. Postruminal NDF and N digestibilities were greatest (P < or = 0.03) for controls, but apparent OM digestibility did not differ among treatments at all sites. Duodenal N flow was greatest (P = 0.05) for high UIP and least for control wethers. Nonmicrobial N flow was greater (P = 0.02) for high UIP compared with low UIP or controls. Control wethers had greater (P = 0.05) microbial efficiency. Ruminal ammonia concentration tended (P = 0.08) to be greatest for wethers fed low UIP and least for controls, with high-UIP wethers having intermediate ammonia concentrations. Results from these experiments suggest that in lambs fed low-quality forage there was no difference in apparent total-tract digestion or N balance (percentage of N intake) between lambs fed supplements that had the same CP but differed in the proportion of UIP and DIP; however, supplementing protein (regardless of UIP:DIP ratio) to wethers consuming low-quality forage increased N balance.  相似文献   

3.
Two experiments were conducted to compare the performance and physiological responses of forage-fed beef females supplemented with either a molasses-based (ML) or a citrus pulp-based (CT) supplement. In Exp. 1, BW gain, reproductive performance, and concentrations of blood urea N (BUN), plasma glucose, insulin, IGF-I, and progesterone (P4) were assessed in 60 Brahman x Angus heifers supplemented 3 times weekly with either ML or CT. Supplement intakes were formulated to be isocaloric and isonitrogenous. Reproductive performance was not affected by treatments, but mean BW gain was greater (P < 0.01) for heifers fed CT than for those fed ML (0.40 vs. 0.30 kg/d). Mean plasma concentrations of glucose, insulin, and IGF-I were greater (P < 0.05) for heifers fed CT, whereas BUN was greater (P < 0.05) for heifers fed ML. Mean plasma P4 concentration did not differ between treatments, but both groups had lower plasma P4 concentrations during days that supplements were offered (P < 0.01). In Exp. 2, forage DMI and concentrations of BUN, plasma glucose, insulin, IGF-I, and P4 were assessed in 24 Brahman x British mature cows supplemented with the same treatments described in Exp. 1. Overall forage DMI did not differ between treatments, but a day effect and a treatment x day interaction were detected (P < 0.05). Both groups consumed less forage during the days on which the supplements were offered (P < 0.01), and forage DMI for cows fed CT was less (P < 0.05) than for cows fed ML during those days. No differences were detected in any blood or plasma measurement. In addition, no differences in concentrations of P4 were detected between CT- and ML-fed cows. We concluded that CT-supplemented heifers had greater BW gain compared with ML-supplemented heifers, but no differences in reproductive performance were observed. We also observed that CT-supplemented cows had a greater variability in forage DMI compared with ML-supplemented cows.  相似文献   

4.
Two experiments were conducted to determine the effects of dietary Cr tripicolinate (CrPic) or Cr propionate (CrProp) on growth, carcass traits, plasma metabolites, glucose tolerance, and insulin sensitivity in pigs. In Exp. 1, 36 barrows (12 per treatment; initial and final BW were 20 and 38 kg) were allotted to the following treatments: 1) corn-soybean meal basal diet (control), 2) as 1 + 200 ppb Cr as CrPic, or 3) as 1 + 200 ppb Cr as CrProp. Growth performance data were collected for 28 d, and then 23 pigs (seven, eight, and eight pigs for treatments 1, 2, and 3, respectively) were fitted with jugular catheters and a glucose tolerance test (500 mg glucose/kg BW) and an insulin challenge test (0.1 IU of porcine insulin/kg BW) were conducted. Both CrPic and CrProp decreased (P < 0.05) ADG and ADFI but did not affect gain:feed (P > 0.10). Fasting plasma glucose, total cholesterol, urea N, insulin, and high-density lipoprotein cholesterol:total cholesterol concentrations were not affected (P > 0.10) by either Cr source. Pigs fed CrPic had lower (P < 0.02) fasting plasma NEFA concentrations than control pigs, but plasma NEFA concentrations of pigs fed CrProp were not affected (P > 0.10). During the glucose tolerance test, glucose and insulin kinetics were not affected by treatment (P > 0.10). During the insulin challenge test, glucose clearance was increased (P < 0.01) in pigs fed CrProp but not affected (P > 0.10) in pigs fed CrPic. Glucose half-life was decreased (P < 0.03) in pigs fed CrPic or CrProp, but insulin kinetics were not affected (P > 0.10). In Exp. 2, 48 barrows (four replicates of four pigs per replicate; initial and final BW were 23 and 115 kg) were allotted to the same dietary treatments in a growing-finishing study. Average daily gain, ADFI, and gain:feed were not affected (P > 0.10) by treatments. Carcass length tended (P = 0.10) to be greater in pigs fed CrPic than in pigs fed CrProp, but other carcass measurements were not affected (P > 0.10). Glucose kinetics from the insulin challenge test indicate that both CrPic and CrProp increase insulin sensitivity and that both Cr sources are bioavailable.  相似文献   

5.
Sixty wethers (average BW = 45 kg) fitted with fecal collection bags were used in four experiments to evaluate the ability of a intraruminal continuous-release chromic oxide bolus to predict fecal DM output. In Exp. 1, 18 wethers housed in metabolism crates were fed barley at either 0, 100, or 200g/d and allowed ad libitum consumption of alfalfa pellets. In Exp. 2, 18 wethers were housed in metabolism crates and fed alfalfa pellets at either 70, 85, or 125% of pre-study ad libitum consumption. In Exp. 3, 12 wethers grazed a sagebrush-bunchgrass range and were individually fed barley at 0 or 200 g/d. In Exp. 4, 12 wethers grazed either an ungrazed (383 kg/ha herbaceous biomass) or a heavily grazed (175 kg/ha herbaceous biomass) sagebrush-bunchgrass range. Experiments 1 and 2 were balanced 3 x 3 Latin squares, and Exp. 3 and 4 were crossover designs. Chromium content was determined in rectal grab samples. Treatment effects were compared using marker-estimated fecal output divided by total fecal collection, multiplied by 100, as the dependent variable. Accuracy of the estimate was verified by comparing marker-estimated fecal output with total fecal collection using a paired t-test. In Exp. 1 and 2, treatments were different (P less than .05). No differences (P greater than .50) were detected in Exp. 3 and 4. In Exp. 1, 2, and 3 accuracy was different (P less than .02) among wethers within study and treatment. Only in Study 4 were minor or no differences (P greater than .09) in accuracy found.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

6.
Three studies were conducted to evaluate the effects of supplemental fat and salt (sodium chloride) on DMI, daily water intake (DWI), body temperature, and respiration rate (RR) in Bos taurus beef cattle. In Exp. 1 and 2, whole soybeans (SB) were used as the supplemental fat source. In Exp. 3, palm kernel meal and tallow were used. Experiment 1 (winter) and Exp. 2 (summer) were undertaken in an outside feedlot. Experiment 3 was conducted in a climate-controlled facility (mean ambient temperature = 29.9 degrees C). In Exp. 1, three diets, 1) control; 2) salt (control + 1% sodium chloride); and 3) salt-SB (control + 5% SB + 1% sodium chloride), were fed to 144 cattle (BW = 327.7 kg), using a replicated 3 x 3 Latin square design. In Exp. 2, 168 steers (BW = 334.1 kg) were used. In Exp. 2, the same dietary treatments were used as in Exp. 1, and a 5% SB dietary treatment was included in an incomplete 3 x 4 Latin square design. In Exp. 3, three diets, 1) control; 2) salt (control + 0.92% NaCl); and 3) salt-fat (control + 3.2% added fat + 0.92% NaCl) were fed to 12 steers (BW = 602 kg) in a replicated Latin square design. In Exp. 1, cattle fed the salt-SB diet had elevated (P < 0.05) tympanic temperature (TT; 38.83 degrees C) compared with cattle fed the control (38.56 degrees C) or salt (38.50 degrees C) diet. In Exp. 2, cattle fed the salt and salt-SB diets had less (P < 0.05) DMI and greater (P < 0.05) DWI than cattle in the control and SB treatments. Cattle fed the salt-SB diet had the greatest (P < 0.05) TT (38.89 degrees C). Those fed only the salt diet or only the SB diet had the least (P < 0.05) TT, at 38.72 and 38.78 degrees C, respectively. Under hot conditions (Exp. 3), DMI of steers fed the salt and salt-fat diets declined by approximately 40% compared with only 24% for the control cattle. During hot conditions, DWI was greatest (P < 0.05) for steers on the salt-fat diet. These steers also had the greatest (P < 0.05) mean rectal temperature (40.03 +/- 0.1 degrees C) and RR (112.7 +/- 1.7 breaths/min). The RR of steers on the control diet was the least (P < 0.05; 98.3 +/- 1.7 breaths/min). Although added salt plus fat decreased DMI under hot conditions, these data suggest that switching to diets containing the combination of added salt and fat can elevate body temperature, which would be a detriment in the summer but a benefit to the animal during winter. Nevertheless, adding salt plus fat to diets resulted in increased DWI under hot conditions. Diet ingredients or the combination of ingredients that can be used to regulate DMI may be useful to limit large increases in DMI during adverse weather events.  相似文献   

7.
Two experiments were conducted to determine the effects of dietary Cr, as Cr propionate, on growth, carcass traits, pork quality, and plasma metabolites in growing-finishing swine. Ninety-six crossbred gilts (Exp. 1; initial and final BW of 28 [SEM = 0.41] and 109 [SEM = 2.11] kg) or 144 PIC Cambrough 22 barrows (Exp. 2; initial and final BW of 26 [SEM = 0.39] and 111 [SEM = 2.52] kg) were allotted to six or four dietary treatments, respectively, with six replications and four (Exp. 1) or six (Exp. 2) pigs in each replicate pen blocked by weight in randomized complete block designs. The six dietary treatments for Exp. 1 were 1) corn-soybean meal (C-SBM), 2) C-SBM + 50 ppb Cr, 3) C-SBM + 100 ppb Cr, 4) C-SBM + 200 ppb Cr, 5) C-SBM low NE diet, and 6) C-SBM low NE diet + 200 ppb Cr. The four dietary treatments for Exp. 2 were C-SBM with 0, 100, 200, or 300 ppb Cr. Growth, carcass traits, and plasma metabolite (collected on d 29 and at each phase change) data were taken at the end of both experiments and pork quality data were taken at the end of Exp. 1. There was no effect (P > 0.10) on overall growth performance when pigs were fed graded levels of Cr (Exp. 1 and 2) or Cr in the positive control or low NE diets (Exp. 1). Longissimus muscle area, ham weight, ham fat-free lean, and total carcass lean were increased in pigs fed 200 ppb in the positive control diets but decreased in pigs fed 200 ppb Cr in the low NE diets (Cr x NE, P < 0.08). There was no effect of Cr concentration (P > 0.10) on carcass traits in Exp. 2. In Exp. 1, cook loss of a fresh or a frozen chop was decreased (P < 0.10) by 200 ppb Cr. In Exp. 1, NEFA concentration was decreased (P < 0.05) in pigs fed Cr in the positive control or low NE diets during the early-finishing period. In Exp. 2, the addition of Cr decreased NEFA (quadratic, P < 0.09) and plasma urea N (linear, P < 0.02) concentrations and tended to increase total cholesterol and high density lipoproteins (quadratic, P < 0.09). In these experiments, Cr propionate had no effect on overall growth performance, variable effects on carcass traits and plasma metabolites, and some positive effects on pork quality, especially water holding capacity of a fresh or frozen chop.  相似文献   

8.
Two experiments were conducted to determine the effects of whole soybean supplementation on intake, digestion, and performance of beef cows of varying age. Treatments were arranged in a 2 x 3 factorial with 2 supplements and 3 age classes of cows (2-yr-old, 3-yr-old, and mature cows). Supplements (DM basis) included 1) 1.36 kg/d of whole raw soybeans, and 2) 1.56 kg/d of a soybean meal/hulls supplement. Supplements were formulated to provide similar amounts of protein and energy, but a greater fat content with the whole soybeans. Supplements were individually fed on Monday, Tuesday, Thursday, and Saturday mornings. During the treatment period, cows had free choice access to bermudagrass hay [Cynodon dactylon (L.) Pers.; 8.4% CP; 72% NDF; DM basis]. In Exp. 1, 166 spring-calving Angus and Angus x Hereford crossbred beef cows were individually fed supplements for an average of 80 d during mid to late gestation. During the first 50 d of supplementation, cows fed soybean meal/hulls gained more BW (10 kg; P < 0.001) and body condition (0.18 BCS units; P = 0.004) than cows fed whole soybeans. However, BW change (P = 0.87) and BCS change (P = 0.25) during the 296-d experiment were not different between supplements. Although calves from cows fed soybean meal/hulls were 2 kg heavier at birth, there was no difference in calf BW at weaning between supplements. Additionally, first service conception rate (68%; P = 0.24) and pregnancy rate (73%; P = 0.21) were not different between supplements. In Exp. 2, 24 cows from Exp. 1 were used to determine the effect of supplement composition on forage intake and digestion; cows remained on the same supplements, hay, and feeding schedule as Exp. 1. Crude fat digestibility was the only intake or digestibility measurement influenced by supplement composition; fat digestibility was higher for cows fed whole soybeans compared with cows fed the soybean meal/hulls supplement (58.1 vs. 48.8%). Hay intake and DMI averaged 1.63 and 1.92% of BW daily, respectively. Dry matter, NDF, and CP digestibility averaged 54.1, 55.1, and 63.2%, respectively. Compared with supplementation with soybean meal/ hulls, whole soybean supplementation during mid to late gestation resulted in reduced BW weight gain during supplementation, inconsistent effects on reproduction, no effect on calf weaning weight, and no effect on forage intake or digestion.  相似文献   

9.
Two 160-d feedlot experiments, each consisting of 20 Angus-Hereford steers (216 +/- 5 kg BW, Exp. 1; 258 +/- 5 kg BW, Exp. 2) and 20 Angus-Hereford heifers (208 +/- 5 kg BW, Exp. 1; 236 +/- 5 kg BW, Exp. 2), were used to investigate the effects of supplementing diets with either roasted soybeans (RSB, roasted at 127 degrees C for 10 min) or soybean meal (SBM) and implanting or not implanting with an estrogenic growth promoter (SYN; Synovex-S, 20 mg of estradiol benzoate plus 200 mg of progesterone or Synovex-H, 20 mg of estradiol benzoate plus 200 mg of testosterone) on performance. The cattle were fed a basal diet of 15% orchardgrass silage, 15% corn silage, and 70% corn-based concentrate. Treatments were 1) no SYN and fed a SBM-supplemented diet, 2) no SYN and fed a RSB-supplemented diet, 3) SYN and SBM, and 4) SYN and RSB. Cattle in the SYN groups were reimplanted at 80 d. Four additional Angus-Hereford steers were used in a digestion and nitrogen balance experiment conducted during the first half of Exp. 1. For the total 160-d feedlot experiments, DMI for RSB compared with SBM was lower (P < .01; 8.5 vs 9.2 kg/d, SEM = .07) and ADG/DMI tended to be higher (P < .10; 165 vs 157 g/kg, SEM = 1.3). Final BW of steers fed RSB was similar (P > .10) to that of steers fed SBM (473 vs 478 kg, SEM = 5.6), as was ADG (1.39 vs 1.43 kg/d, SEM = .02). Dry matter intake for SYN-implanted steers was higher (P < .01) than for steers not implanted (9.2 vs 8.5 kg/d). Likewise, final BW (491 vs 460 kg) and ADG (1.49 vs 1.33 kg/d) were higher (P < .01), and ADG/DMI (166 vs 157 g/kg) tended to be higher (P < .10), for SYN-implanted steers than for steers not implanted. During the more rapid muscle growth period (0 to 80 d), DMI for RSB compared with SBM was lower (P < .01; 7.8 vs 8.6 kg/d, SEM = .07) and ADG/DMI was similar (P > .10; 181 vs 172 g/kg, SEM = 1.8). Dry matter intake for SYN-implanted steers was higher (P < .05) than for steers not implanted (8.4 vs 8.0 kg/d), as was ADG/DMI (P < .01, 182 vs 171 g/kg). During this more rapid growth period, the supplement x implant interaction for ADG was significant (P < .05; 1.35, 1.36, 1.59, and 1.44 kg/d for Treatments 1, 2, 3, and 4, respectively, SEM = .04). There were no differences in digestibilities or N balance. The results suggest that there is no improvement in performance under feedlot conditions when RSB replaces SBM in the diet of beef cattle, and, in young cattle, RSB may reduce the response expected by an estrogenic growth promoter.  相似文献   

10.
Six experiments were conducted to evaluate dietary cation-anion difference (DCAD) in concentrate diets on urinary pH, feedlot performance, and N mass balance. In Exp. 1, 15 wether lambs (33.5 ± 3.0 kg) in five 3 × 3 Latin squares were fed a basal diet of 82.5% dry-rolled corn (DRC), 7.5% alfalfa hay, 5% molasses, and 5% supplement with different proportions of anionic and cationic salts. The DCAD was -45, -24, -16, -8, 0, +8, +16, +24, +32, and +40 mEq per 100 g of DM with the control basal diet (DCAD = +8) included in each square. Urinary pH increased (cubic, P < 0.01) as DCAD increased and DMI increased linearly (P < 0.01) with increasing DCAD. In Exp. 2 and 3, 8 Holstein steers (312 ± 24 kg) were used in 2 consecutive 4 × 4 Latin squares. Steers were fed either the same basal diet as Exp. 1 or a basal diet with 20% wet distillers grains (WDGS) replacing DRC. In Exp. 2, DCAD was adjusted to -2, -12, and -22 mEq per 100 g of DM from the basal diet (DCAD = +8) and DCAD was adjusted in Exp. 3 to -12, -22, and -32 mEq per 100 g of DM from the basal WDGS diet (DCAD = -2). Urinary pH decreased linearly as DCAD decreased (P < 0.01) in both experiments, whereas DMI decreased linearly in Exp. 2 (P = 0.02) but not Exp. 3 (P = 0.96). In Exp. 4, 6 crossbred steers (373 ± 37 kg) were used in a 2-period crossover design. Steers were fed the same basal diet as Exp. 3 with DCAD of -16 (NEG) and +20 (POS) mEq per 100 g of DM. Urinary pH and DMI (P < 0.05) were less for cattle fed the NEG diet compared with POS. In 2 experiments, steers (n = 96 each) were fed NEG or POS as calves (260 ± 22 kg of BW) for 196 d from November to May (Exp. 5) or as yearlings (339 ± 32 kg of BW) for 145 d from June to October (Exp. 6). Final BW, DMI, ADG, and HCW were not different (P > 0.11) among treatments in either experiment. Efficiency of BW gain was increased (P = 0.05) for steers fed NEG compared with POS in Exp. 5 but was not different (P = 0.11) in Exp. 6. Amount of N intake, retention, excretion, and manure N (kg/steer) were not different (P > 0.11) among treatments in either experiment. Manure pH (soil, feces, and urine) was decreased (P < 0.01) in pens fed NEG compared with POS in both experiments. Amount of N lost (kg/steer) was not different (P = 0.44) in Exp. 5, but tended (P = 0.09) to be 10.6% greater for POS compared with NEG in Exp. 6. Urinary pH was decreased by reducing DCAD, but this had minimal effect on N losses in open feedlot pens in these experiments.  相似文献   

11.
Two experiments were conducted to determine the effect of nonwaxy (amylose and amylopectin starch) or waxy (amylopectin starch) sorghum on growth, carcass traits, and glucose and insulin kinetics of pigs. In Exp. 1 (95-d), 60 crossbred barrows or gilts (initial and final BW of 24 and 104 kg) were allotted to three treatments with five replications of four pigs per replicate pen in a randomized complete block design. The dietary treatments for Exp. 1 were 1) corn-soybean meal (C-SBM) diet, 2) sorghum-SBM (red pericarp, non-waxy), and 3) sorghum-SBM (red pericarp, waxy). In Exp. 2, 28 crossbred barrows (initial and final BW of 24 and 64 kg) were allotted to two treatments with three replications of four or five pigs per replicate pen in a randomized complete block design. Growth data were collected for 49 d, and then 20 barrows were fitted with jugular catheters, and then a glucose tolerance test (500 mg glucose/kg BW), an insulin challenge test (0.1 IU of porcine insulin/kg BW), and a feeding challenge were conducted. The dietary treatments for Exp. 2 were 1) sorghum-SBM (white pericarp, nonwaxy) and 2) sorghum-SBM (white pericarp, waxy). In Exp. 1, ADG (P = 0.10) and ADFI (as-fed basis; P = 0.02) were increased (P = 0.10) and gain:feed was decreased (P = 0.04) in pigs fed the sorghum-SBM diets relative to those fed the C-SBM diet. These responses may have resulted from the lower energy content of sorghum relative to corn. Plasma NEFA concentration (collected after a 16-h fast on d 77) was decreased (P = 0.08) in pigs fed the waxy sorghum-SBM diet relative to those fed the nonwaxy sorghum-SBM diet. Kilograms of carcass fat was decreased (P = 0.07) in pigs fed the waxy sorghum-SBM diet relative to those fed the nonwaxy sorghum-SBM diet. In Exp. 2, there was no effect (P = 0.57 to 0.93) of sorghum starch type on growth performance by pigs. During the glucose tolerance and insulin challenge tests, there were no effects (P = 0.16 to 0.98) of diet on glucose or insulin kinetics. During the feeding challenge, glucose (P = 0.02) and plasma urea N (P = 0.06) area under the response curves from 0 to 90 min were decreased in pigs fed the waxy sorghum-SBM diet. Feeding waxy sorghum had minimal effects on growth and carcass traits relative to pigs fed corn or nonwaxy sorghum. Waxy sorghum vs. nonwaxy sorghum had no effect on glucose or insulin kinetics in pigs.  相似文献   

12.
Two experiments were conducted at the Kansas State University Beef Cattle Research Center to determine the effects of feeding ground flaxseed (flax) during the receiving period on the growth, health, and subsequent finishing performance of heifers. Crossbred heifers (Exp. 1: n = 363, 214 +/- 1 kg of initial BW; Exp. 2: n = 377, 222 +/- 1 kg of initial BW) were purchased during January and April of 2006. Heifers were fed receiving rations based on steam-flaked corn with 0, 2, 4, or 6% ground flax (DM basis) for 56 d. Following the receiving period, cattle in Exp. 1 and 2 were fed steam-flaked corn-based diets for 150 and 147 d, respectively, and then slaughtered. Heifers were implanted 91 and 109 d before slaughter for Exp. 1 and 2, respectively. In Exp. 1, DMI during the receiving period tended to increase linearly (P = 0.09) with increasing flax in the diet. Average daily gain was 1.46, 1.56, 1.58, and 1.61 kg for heifers fed 0, 2, 4, and 6% flax, respectively (linear, P = 0.03). Final BW in Exp. 1 after the finishing period was increased (linear, P = 0.04) with increasing inclusion of flax in the receiving diets. In Exp. 2, growth performance and mortality during the receiving period were not different among treatments (P > 0.12). During the receiving period in Exp. 2, incidence of the first respiratory treatment tended to be greatest (P = 0.09) for heifers fed 4% flax. During the finishing period, DMI were 8.4, 8.4, 8.0, and 8.1 kg/d for 0, 2, 4, and 6% flax, respectively (linear, P = 0.05). In Exp. 2, LM areas were greatest (quadratic, P = 0.04) for cattle fed 2% flax at receiving. In general, feeding flax during the receiving period may have the potential to improve growth performance; however, performance between experiments was variable, and many factors excluding flax feeding may have contributed to this response.  相似文献   

13.
Three experiments were conducted to determine effects of restricting intake of the final finishing diet as a means of dietary adaptation compared with diets increasing in grain over a period of 20 to 22 d on overall cattle performance, carcass characteristics, digestibility, digesta kinetics, and ruminal metabolism. In Exp. 1, 84 Angus x Hereford yearling steers (initial BW = 418 +/- 29.0 kg) were fed for 70 d. Restricting intake during adaptation had no effect (P > 0.10) on overall ADG:DMI, but decreased (P < 0.05) DMI compared with ad libitum access to adaptation diets, which resulted from differences during the initial 28 d of the experiment. In Exp. 2, 150 mixed crossbred steer calves (initial BW = 289 +/- 22.9 kg) were fed for an average of 173 d. Restricting intake decreased (P < 0.01) overall daily gain (1.51 vs 1.65 kg/d) and DMI (8.68 vs 9.15 kg/d) compared with ad libitum fed steers; however, ADG:DMI was not influenced (P > 0.10) by adaptation method. Experiment three used eight ruminally and duodenally fistulated steers (initial BW = 336 +/- 20 kg) in a completely random design. Total tract digestibility, digesta kinetics and ruminal metabolism were determined. Restricting intake reduced (P < 0.10) daily DMI variation from d 1 through 7, 8 through 14, and 22 through 28 compared with ad libitum feeding of three adaptation diets. Restricted steers had reduced (adaptation method x period interaction, P < 0.05) intakes and fecal excretions of ADF and greater OM digestibilities on d 4 through 7, 11 through 14, and 18 through 21. Digesta kinetics and ruminal metabolism were generally not affected (P > 0.10) by adaptation method. Our results suggest that restricted-feeding of the final diet as a means of dietary adaptation can be used in finishing cattle with few problems from acidosis or related intake variation. In light-weight steers (Exp. 2), disruptions in intake during the adaptation period might have resulted in restriction for an extended period, which decreased (P < 0.01) hot carcass weight compared with calves fed ad libitum. Effects of limit feeding during the initial 28 d of the feeding period on site and extent of digestion, digesta kinetics, and ruminal metabolism were minimal, supporting few differences in performance across the finishing period for yearling cattle.  相似文献   

14.
Two experiments were conducted with lactating Angus x Gelbvieh beef cows to determine the effects of postpartum lipid supplementation, BCS at parturition, and day of lactation on fatty acid profiles in plasma, adipose tissue, and milk. In Exp. 1, 36 pri-miparous cows (488 +/- 10 kg of initial BW; 5.5 +/- 0.02 initial BCS) were given ad libitum access to hay and assigned randomly to a low-fat (control) supplement or supplements with cracked, high-linoleate safflower seeds (linoleate) or cracked, high-oleate safflower seeds (oleate) from d 3 to 90 of lactation. Diets were formulated to be isonitrogenous and isocaloric; safflower seed diets provided 5% of DMI as fat. Plasma and milk samples were collected on d 30, 60, and 90 of lactation. Adipose tissue biopsies were collected near the tail-head region of cows on d 45 and 90 of lactation. In Exp. 2, 3-yr-old cows achieving a BCS of 4 +/- 0.07 (479 +/- 36 kg of BW) or 6 +/- 0.07 (580 +/- 53 kg of BW) at parturition were used in a 2-yr experiment (n = 36/yr). Beginning 3 d postpartum through d 61 of lactation, cows were fed diets similar to those of Exp. 1. Adipose tissue and milk samples were collected on d 30 and 60, and plasma was collected on d 31 and 61 of lactation. Responses to postpartum dietary treatment were comparable in both experiments. Cows fed linoleate and oleate had greater (P < 0.001) total fatty acid concentrations in plasma than cows fed control. Except for 15:1, milk fatty acids with <18 carbons were greatest (P < or = 0.01) for cows fed control, whereas milk from cows fed linoleate had the greatest (P < or = 0.02) 18:1trans-11, 18:2n-6, and cis-9, trans-11 CLA. Milk from cows fed oleate had the greatest (P < 0.001) 18:1cis-9. In Exp. 1, total fatty acid concentrations in adipose tissue samples decreased at d 90 compared with d 45 of lactation, but the fatty acid profile of cow adipose tissue was not affected (P = 0.14 to 0.80) by dietary treatment. In Exp. 2, the percentage of cis-9, trans-11 CLA in adipose tissue of cows with a BCS of 6 decreased (P = 0.001) from d 30 to 60 of lactation. Plasma and milk fatty acid composition reflected alterations in postpartum diet. Less medium-chain fatty acids and more 18-carbon fatty acids in milk were indicative of reduced de novo fatty acid synthesis in the mammary gland of beef cows fed lipid supplements; however, the metabolic demands of lactation prevented the deposition of exogenously derived fatty acids in adipose tissue through d 90 of lactation.  相似文献   

15.
Two experiments were conducted to evaluate the effects of Cu and Zn source on performance, morbidity, and humoral immune response in lightweight, newly received beef heifers. A 2 x 2 factorial arrangement of treatments was used in both experiments, with either a sulfate or a polysaccharide mineral complex (SQM) source of both Cu and Zn as the factors. Supplemental Cu and Zn were included in the receiving diet at concentrations designed to provide 10 mg of Cu/kg and 75 mg of Zn/kg (DM basis). In Exp. 1, 219 newly received beef heifers (British x Continental, average initial BW = 208 kg) were given ad libitum access to a 65% concentrate diet for 35 d to determine treatment effects on DMI, ADG, G:F, and bovine respiratory disease (BRD) morbidity. In Exp. 2, 24 heifers (average initial BW = 272 kg) were fed a diet with no supplemental Cu or Zn for 35 d, followed by fasting-refeeding-fasting stress, after which the same treatment diets used in Exp. 1 were fed for 21 d to examine the effects on humoral immune response (plasma IgG titer determined by ELISA on d 7, 14, and 21) to an ovalbumin (OVA) vaccine given on d 0 and 14. Copper source x Zn source interactions were not detected in either experiment. In Exp. 1, neither Cu nor Zn source affected (P > 0.10) DMI, ADG, G:F, or BRD morbidity. In Exp. 2, d 14 (P = 0.02) and 21 (P = 0.06) OVA titers were greater for heifers that received SQM Zn compared with heifers receiving ZnSO4, but heifers receiving CuSO4 had greater OVA titers than did heifers on the SQM Cu treatment on d 14 (P = 0.01) and 21 (P = 0.001). In summary, neither supplemental Cu nor Zn source affected performance or morbidity of lightweight, newly received heifers; however, source of both Cu or Zn affected the humoral immune response to OVA, although source effects were not consistent for the two minerals.  相似文献   

16.
Targhee x Hampshire lambs (average BW 23 +/- 1 kg) were used in two experiments to determine the effects of finishing on concentrate with an anabolic implant or forage grazing after concentrate feeding on growth, organ and viscera weights, and carcass tissue accretion. In Exp. 1 and 2 lambs were penned by sex and assigned for slaughter at initial (23 kg), intermediate (37 kg), or end BW (ewes, 47.7; wethers 50.4 kg). From 23 to 37 kg BW, lambs were fed all-concentrate diets in drylot (DL) or grazed on alfalfa (ALF). Experiment 1 was a 2 x 2 factorial with 28 lambs; factors were wether vs ewe lambs and unimplanted vs DL implanted with trenbolone acetate-estradiol benzoate. There were no differences in organ and viscera weights due to implant status. However, ADG (P < .03) and lean gain (P < .02) were greater for implanted than for unimplanted wethers (507 vs 357 g and 1,314 vs 656 g, respectively). Ewes did not respond to the implant. Fat accretion was not affected by implantation. Experiment 2 was a 2 x 3 factorial with 42 lambs; factors were wether vs ewe lambs and drylot during growing and finishing phases (DL-DL) vs drylot during growing and alfalfa grazing during finishing (DL-ALF) vs alfalfa grazing during growing and finishing phases (ALF-ALF). In Exp. 2, ADG of DL-DL lambs was greater (P < .01) than ADG of DL-ALF or ALF-ALF lambs. Lambs on ALF-ALF had smaller (P < .05) livers and rumen/reticulum weights but heavier (P < .04) kidney, omasum, small and large intestine, and cecum weights than those on DL. In Exp. 2, DL-ALF and ALF-ALF lambs had overall hindsaddle lean gain equal to those on DL-DL with less mesenteric fat and 100 g less separable fat. Finishing lambs on alfalfa reduced fat accretion without decreasing lean accretion, whereas trenbolone acetate implants for lambs fed concentrate increased BW gain and lean accretion without affecting fat accretion.  相似文献   

17.
Three experiments were conducted to evaluate plasma concentrations of glucose, insulin, IGF-I, and progesterone (P4) in pubertal beef heifers receiving exogenous glucose, insulin, or sometribove zinc. All heifers used had no luteal P4 synthesis but received a controlled internal drug-releasing device containing 1.38 g of P4 to estimate treatment effects on hepatic P4 degradation. In Exp. 1, 8 pubertal, nulliparous Angus × Hereford heifers (initial BW = 442 ± 14 kg; initial age = 656 ± 7 d) were randomly assigned to receive, in a crossover design containing 2 periods of 10 h, intravenous (i.v.) infusions (10 mL) of insulin (1 μg/kg of BW; INS) or saline (0.9%; SAL). Treatments were administered via jugular venipuncture in 7 applications (0.15 μg insulin/kg BW per application) 45 min apart (from 0 to 270 min). Blood samples were collected immediately before each infusion as well as at -120, -60, 330, 390, and 450 min relative to the first infusion. Heifers receiving INS had greater (P < 0.01) plasma insulin, reduced (P ≤ 0.04) plasma glucose and IGF-I, and similar (P = 0.62) plasma P4 concentrations compared with SAL heifers. In Exp. 2, the same heifers were assigned to receive, in a similar experimental design as Exp. 1, i.v. infusions (10 mL) of 1) insulin (1 μg/kg BW) and glucose (0.5 g/kg BW; INS+G) or 2) SAL. Heifers receiving INS+G had greater (P ≤ 0.02) plasma insulin, glucose, and P4 but reduced (P = 0.01) plasma IGF-I concentrations compared with SAL heifers. In Exp. 3, the same heifers were assigned to receive, in a crossover design containing 2 periods of 14 d, subcutaneous (s.c.) injections of 1) 250 mg of sometribove zinc (BST) or 2) SAL. Blood samples were collected 3 h apart (0900, 1200, 1500, and 1800 h) from heifers on d 6, 8, and 10 relative to treatment administration (d 1). Heifers receiving BST had greater (P < 0.01) plasma glucose and IGF-I and similar (P ≥ 0.67) plasma insulin and P4 concentrations compared with SAL heifers. Results from this series of experiments suggested that concurrent increases in glucose and insulin are required to reduce hepatic catabolism and increase plasma concentrations of P4 in bovine females.  相似文献   

18.
Two experiments were conducted to examine the effect of previous BW gain during winter grazing on subsequent growth, carcass characteristics, and change in body composition during the feedlot finishing phase. In each experiment, 48 fall-weaned Angus x Angus-Hereford steer calves were assigned randomly to one of three treatments: 1) high rate of BW gain grazing winter wheat (HGW), 2) low rate of BW gain grazing winter wheat (LGW), or 3) grazing dormant tallgrass native range (NR) supplemented with 0.91 kg/d of cottonseed meal. Winter grazing ADG (kg/d) for HGW, LGW, and NR steers were, respectively, 1.31, 0.54, 0.16 (Exp. 1) and 1.10, 0.68, 0.15 (Exp. 2). At the end of winter grazing, four steers were selected randomly from each treatment to measure initial carcass characteristics and chemical composition of carcass, offal, and empty body. All remaining steers were fed a high-concentrate diet to a common backfat end point. Six steers were selected randomly from each treatment for final chemical composition, and carcass characteristics were measured on all steers. Initial fat mass and proportion in carcass, offal, and empty body were greatest (P < 0.001) for HGW, intermediate for LGW, and least for NR steers in both experiments. Live BW ADG and gain efficiency during the finishing phase did not differ (P = 0.24) among treatments, but DMI (% of mean BW) for NR and LGW was greater (P < 0.003) than for HGW steers. Final empty-body composition did not differ (P = 0.25) among treatments in Exp. 1. In Exp. 2, final carcass and empty-body fat proportion (g/kg) was greater (P < 0.03) for LGW and NR than for HGW steers. Accretion of carcass fat-free organic matter was greater (P < 0.004) for LGW than for HGW and NR steers in Exp. 1, but did not differ (P = 0.22) among treatments in Exp. 2. Fat accretion in carcass, offal, and empty body did not differ (P = 0.19) among treatments in Exp. 1, but was greater (P < 0.05) for LGW and NR than for HGW steers in Exp. 2. Heat production by NR steers during finishing was greater (P < 0.02) than by HGW steers in Exp. 1 and 2. Differences in ADG during winter grazing and initial body fat content did not affect rate of live BW gain or gain efficiency during finishing. Feeding steers to a common backfat thickness end point mitigated initial differences in carcass and empty-body fat content. However, maintenance energy requirements during finishing were increased for nutritionally restricted steers that were wintered on dormant native range.  相似文献   

19.
Four experiments were conducted to determine the effects of dietary fat on lipolysis in lactating sows. In Exp. 1, a 6 x 6 Latin square was used to determine the optimal dosage of epinephrine for use in a subsequent epinephrine challenge. Peak concentrations of plasma glucose and response area increased linearly (P < .10) with epinephrine dosage. However, plasma NEFA peak and response area were quadratically affected (P < .05 and .06, respectively) by epinephrine dosage, with a minimum NEFA peak concentration observed at .4 microg/kg and a maximum at 1.6 microg/kg. In Exp. 2, the effect of dietary tallow on the response to epinephrine infusion (1.6 microg/kg BW) was examined. No differences (P > .10) between treatments were observed in NEFA, glycerol, or peak concentrations of plasma glucose following epinephrine administration. In Exp. 3, the effect of dietary fat on hormone-sensitive lipase activity was examined. Sows (n = 36) were fed diets containing either 0 or 10% added tallow. Hormone-sensitive lipase activity on d 28 of lactation was increased by the addition of tallow to the diet (P = .06). No effect of dietary tallow was observed on hormone-sensitive lipase activity of adipose tissue on d 21 of lactation (P > .10) in Exp. 3 (n = 16 sows) and Exp. 4 (n = 30 sows). In summary, diets containing 10% added tallow did not alter the rate of lipolysis, as measured by exogenous epinephrine challenge, in adipose tissue of lactating sows.  相似文献   

20.
Seventy-three crossbred steers (initial BW = 170.5 +/- 5.5 kg) from The Ohio State University (Exp. 1) and 216 crossbred steers (initial BW 135.4 +/- 4.4 kg) from the University of Illinois (Exp. 2) were used to determine the effect of source of energy and rate of growth on performance, carcass characteristics, and glucose and insulin profiles on early-weaned steers. Effects of the diets used in Exp. 1 and 2 on ruminal pH and VFA concentrations were quantified using ruminally fistulated steers (Exp. 3). Cattle were weaned at an average age of 119 d in all experiments and were allotted by age, BW, and breed to one of four diets: high-concentrate, fed ad libitum (ALCONC), high-concentrate fed to achieve a gain of either 1.2 kg/d (1.2CONC) or 0.8 kg/d (0.8CONC), or high-fiber, fed ad libitum (ALFIBER). At 218 d of age, all steers were placed on the ALCONC diet until slaughter. Steers were implanted with Compudose at the initiation of all experiments and with Revalor-S when they were estimated to be 100 d from slaughter. When steers in Exp. 1 averaged 181 and 279 d of age, serum samples were collected to determine glucose and insulin concentrations. Steers were slaughtered when a fat thickness of 1.27 cm was reached (Exp. 1) or after 273 d on feed (Exp. 2). In Exp. 1, days in the feedlot (P < 0.01) and age at slaughter (P < 0.01) were lowest for ALCONC and ALFIBER steers, and greatest for 0.8CONC steers. Overall, ADG was greatest for ALCONC and lowest for 0.8CONC steers; feed efficiency was lowest (P < 0.01) for ALFIBER steers. Final BW did not differ (P > 0.57) among treatments. At 181 and 218 d of age, serum insulin was increased (P < 0.10) and intramuscular fat percentage was greatest (P < 0.07), respectively, for ALCONC steers. In Exp. 2, overall ADG (P < 0.06) and final BW (P < 0.04) were greatest for ALCONC and lowest for 1.2CONC and 0.8CONC steers. Overall feed efficiency was greatest for 0.8CONC and lowest for ALFIBER (P < 0.01). Growing phase diet did not affect marbling score at 218 d of age or at slaughter (P > 0.81). In Exp. 3, differences in ruminal pH after feeding may have been a consequence of increasing acetate (ALFIBER), propionate (ALCONC), or a combination of VFA (0.8CONC and 1.2CONC), respectively (diet x time after feeding, P < 0.10). Controlling growth by limit-feeding a high-concentrate diet for only 100 d does not extend the growth curve of early-weaned steers or enhance intramuscular fat deposition at slaughter compared to ad libitum intake of a high-concentrate or high-fiber diet.  相似文献   

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