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1.
The effects of forage type and forage:concentrate ratio (F:C) on apparent nutrient digestibility, ruminal fermentation, and microbial growth were investigated in goats. A comparison between liquid (LAB) and solid (SAB)-associated bacteria to estimate microbial N flow (MNF) from urinary purine derivative excretion was also examined. Treatments were a 2 x 2 factorial arrangement of forage type (grass hay vs. alfalfa hay) and high vs. low F:C (70:30 and 30:70, respectively). Four ruminally cannulated goats were fed, at maintenance intake, 4 experimental diets according to a 4 x 4 Latin square design. High-concentrate diets resulted in greater (P < 0.001) nutrient digestibility except for ADF. However, CP digestibility increased (P < 0.001) only for the high-concentrate diets including grass hay. Likewise, N retention, ruminal NH(3)-N concentration, and urinary excretion of purine derivatives increased (P < 0.05) with increasing concentrate in animals fed diets based on grass hay (0.23 vs. 0.13 g of retained N/g of digested N, 30.1 vs. 12.9 mg of NH(3)-N/100 mL, and 11.5 vs. 8.40 mmol/d, respectively), but not (P > 0.05) when diets included alfalfa hay. Total protozoa numbers and holotricha proportion were greater and less (P < 0.001), respectively, in high- than in low-concentrate diets. The F:C affected (P < 0.001) ruminal pH but not total VFA concentration (P = 0.12). Ammonia-N concentration was similar (P = 0.13) over time, whereas pH, VFA concentration, and protozoa numbers differed (P < 0.001) among diets. Estimated MNF was strongly influenced by using either the purine bases:N ratio obtained in our experimental conditions or values reported in the literature for small ruminants. There was a F:C effect (P = 0.006) on MNF estimated from LAB but not from SAB. The effect of F:C shifting from 70:30 to 30:70 in goat diets depends on the type of forage used. The MNF measured in goats fed different diets was influenced by the bacterial pellet (LAB or SAB). In addition, the purine bases:N ratio values found were different from those reported in the literature, which underlines the need for these variables to be analyzed directly in pellets isolated from specific animals and experimental conditions.  相似文献   

2.
Ten 394-kg, ruminally fistulated Hereford steers were used in a replicated 5 x 5 Latin square design to evaluate the effects of source and level of dietary NDF on chewing activities during eating and rumination. Diets contained 62 to 64% TDN and included 1) 80% pelleted concentrate (control; contained ground grains, fibrous byproducts, molasses, and protein, vitamin, and mineral supplements; 36% NDF, 16% CP) and 20% long timothy hay (67% NDF, 8% CP), 2) 80% control concentrate and 20% alfalfa cubes (56% NDF, 15% CP), 3) 90% control concentrate and 10% alfalfa cubes, 4) a completely pelleted diet using corn cobs as the primary NDF source (40% NDF, 17% CP), and 5) 80% textured (coarse instead of ground grains; 42% NDF, 15% CP) concentrate and 20% hay. Diets were formulated to be similar in NDF content, and dietary protein satisfied NRC recommendations. Chewing during eating did not differ (P greater than .10) between diets containing supplemental roughage but decreased (P less than .001) with the corn cob diet. Rumination chewing decreased (P less than .001) with the corn cob and cube diets. The number of chews per day during eating corrected for NDF intake/BW.75 decreased (P less than .05) in the corn cob diet. Rumination periods and duration increased and latency before rumination decreased in hay diets. Steers fed the corn cob diet tended to be more (P less than .10) consistent in time spent eating across 4-h intervals than steers fed the traditional diet. Replacement of long hay with the completely pelleted corn cob diet decreased rumination activity.  相似文献   

3.
Crossbred wether goats (n = 24; 50% Boer, 6 per diet) initially averaging 27.4+/-0.4 kg were fed either wheat middlings (wheat midds), soybean hulls (soyhulls), or corn gluten feed at 1% BW (as-fed) along with orchardgrass hay (10.7% CP) offered to ad-libitum consumption for 72 d followed by 5 d total fecal collection. The Control (hay) diet was supplemented with 5.7% soybean meal to bring total dietary protein to 12.5%, by-products were brought to a higher Ca:P ratio with limestone or dicalcium phosphate to make total dietary Ca:P 1.5:1, and soybean meal was added to soyhulls to bring them up to 17% CP (wheat midds = 17% and corn gluten feed = 21% CP). Total DMI (916 g/d+/-57 or 3.2%+/-0.2 BW) did not differ (P > 0.92) among treatments. Initial BW (P = 0.25), final BW (P = 0.48), and ADG (P = 0.56) did not differ for the four treatments. Carcass weight was greater (P = 0.05) for goats fed soyhulls (16.0 kg) or wheat midds (15.6 kg) as compared with goats fed the hay diet (14.5 kg), with carcass weight from goats fed corn gluten feed being intermediate (15.3 kg, SEM = 0.3 kg). Carcass grade did not differ (P = 0.80) and averaged 5.42+/-0.4. Dressing percentage tended (P = 0.12) to be lower for goats fed the hay diet (46.4%) compared with soyhull (48.3%), corn gluten feed (48.3%), or wheat midd (48.8%) diets (SEM = 0.7). Ruminal pH was highest (P < 0.01) for goats fed the hay diet (6.52) and lowest for goats fed wheat midds (6.23) with soyhull (6.41) and corn gluten feed diets (6.35) being intermediate (SEM = 0.05). Digestibility of DM (70.1+/-2.5%), OM (70.3+/-2.6%,), CP (75.5+/-2.0%), GE (68.5+/-2.7%), NDF (68.1+/-3.0%), ADF (65.4+/-3.4%), cellulose (70.1+/-2.9%), and lignin (31.1+/-8.2%) did not differ (P > 0.15). Total ruminal VFA did not differ (86.0+/-6.1 mM, P = 0.59), but acetate:propionate ratio was higher (P < 0.01) for hay (3.1) and soyhull diets (3.3) than for corn gluten feed (2.4) and wheat midd diets (2.4, SEM = 0.11). Ruminal ammonia (mg/100 mL) was lower (P < 0.01) for goats fed hay (15.4) and soyhull diets (11.6) than those fed corn gluten feed (25.2) and wheat midd diets (23.0, SEM = 1.35). Ruminal pH was lower for goats fed the byproducts, but remained above 6. Serum urea nitrogen (mg/100 mL) averaged 21.0+/-1.0 (P = 0.11) with soyhulls tending to be lowest (19.3) and corn gluten feed tending to be highest (22.8). Soyhulls, corn gluten feed, and wheat midds appear to be viable feed ingredients for meat goat diets.  相似文献   

4.
The study examined the effects of blend of 80% canola oil and 20% palm oil (BCPO) on nutrient intake and digestibility, growth performance, rumen fermentation and fatty acids (FA) in goats. Twenty‐four Boer bucks were randomly assigned to diets containing 0, 4 and 8% BCPO on a dry matter basis, fed for 100 days and slaughtered. Diet did not affect feed efficiency, growth performance, intake and digestibility of all nutrients except ether extract. Intakes and digestibilities of ether extract, unsaturated fatty acids (FA) and total FA were higher (P < 0.05) while digestibility of C18:0 was lower (P < 0.05) in oil‐fed goats than the control goats. Total volatile FA, acetate, butyrate, acetate/propionate ratio and methane decreased (P < 0.05) with increasing BCPO but propionate, NH3‐N and rumen pH did not differ between diets. Ruminal concentration of C18:0, n‐3 FA and total FA increased (P < 0.05) while C12:0, C14:0, C15:0 and n‐6 FA decreased with increasing BCPO. Analysis of the FA composition of Triceps brachii muscle showed that concentrations of C16:0, C14:0 and C18:2n‐6 were lower (P < 0.05) while C18:1n‐9, C18:3n‐3 and C20:5n‐3 were higher in oil‐fed goats compared with control goats. Dietary BCPO altered muscle lipids without having detrimental effects on nutrient intake and digestibility and growth performance in goats.  相似文献   

5.
The aim of this experiment was to investigate the effect of dietary oak (Quercus persica) acorn (OA) level on dry matter intake (DMI), apparent nutrient digestibility, nitrogen (N) utilization, ruminal fermentation, protozoa population and urinary purine derivatives (PD) during the last 60 days of goat pregnancy. Twenty‐four multiparous pregnant goats (41.7 ± 2.3 kg BW) were assigned to one of three experimental diets consisted of control diet (C, without OA) and diets containing 20 (OA20) or 40 g/100 g of OA (OA40) on a DM basis in a completely randomized block design. Goats fed OA40 had lower DMI (p < .01), DM (p < .01), OM (p < .01) and NDF (p < .05) digestibility, ruminal NH3‐N concentration (p < .01), N intake (p < .01) and N retention (p < .01). Crude protein digestibility and ruminal acetate and total volatile fatty acid (VFA) concentration were lower in animals fed OA‐contained diets (p < .01), whereas ruminal propionate concentration was higher in goats fed the C diet (p < .01). Animals fed OA40 had higher faecal N excretion and lower urinary N excretion (p < .01). Urinary PD was lower in goats fed diets containing OA in relation to those fed the C diet (p < .01). Total protozoa population decreased linearly with increasing OA level in the diet (p < .05). These results suggest that feeding OA, especially high level, has negative impacts on DMI, nutrient digestibility, VFA concentration, N retention and urinary PD excretion that may have adverse effects on metabolism and performance of pregnant goats.  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.
The study assessed the value of Leucaena leucocephala bark in leucaena—grass hay diets fed to Thai goats. Thai goats in metabolism pens were fed diets containing leucaena leaf (55%) + pangola grass hay (hay, 45%); leucaena leaf (48%) + leucaena bark (9%) + hay (43%); leucaena bark (57%) + hay (43%); and hay only. Feed percentages are expressed on a dry weight basis. The digestibilities of dry matter (DM) and crude protein (CP) were measured for the four diets. Leucaena bark had lower CP concentration than the leaf (11.7 vs. 25.9), and the leucaena bark + hay diet had lower DM and CP digestibility than the other diets. The calculated bark digestibilities of DM and CP of 44.1% and 38.2%, respectively, were much lower than the values for the leucaena leaf of 62.9% and 89.1%, respectively. The lower than expected CP digestibility was attributed to higher tannin levels in the bark compared to the leaves. Despite this, the bark was well accepted by the goats and was often preferred to the hay. Stripping of the bark by goats also results in stems that dry quicker and have higher calorific value as fuel. However, if leucaena branches are fed as a sole diet, the goats may consume up to 30% of bark on a DM basis and this would reduce nutritive value and animal productivity.  相似文献   

8.
This experiment was carried out to study the effect of a directly fed exogenous fibrolytic enzyme on intake and digestion of DM, OM, protein, NDF, ADF, and hemicellulose of alfalfa and ryegrass hay by sheep. Four diets were randomly assigned to four ruminally cannulated lambs using a 4 x 4 Latin square design, repeated in time, with a factorial arrangement (2 x 2) of diets: 1) alfalfa hay; 2) alfalfa hay + exogenous fibrolytic enzymes (enzyme); 3) ryegrass hay; and 4) ryegrass hay + enzyme. Lambs consumed more DM and OM from alfalfa than from ryegrass hay (P < 0.001). The ADF intake was not different between the hays, but NDF intake was lower for alfalfa (P < 0.001). For both hays, the enzyme increased intake of DM (P < 0.01), as well as OM and CP (P < 0.05); however, NDF and ADF intake were not changed. Alfalfa hay had higher apparent digestibility of DM, OM, and CP (P < 0.001), but lower digestibility for NDF, ADF, and hemicellulose. The enzyme increased apparent digestibility of CP, hemicellulose (P < 0.05), and NDF (P < 0.10) for alfalfa. Also, for both hays, the enzyme improved N balance because lambs retained more N (P < 0.05). The enzyme increased (P < 0.05) total VFA concentration (3 and 6 h) for both hays. Results from this trial indicate that directly fed exogenous fibrolytic enzymes may change ruminal fermentation, intake, and digestibility of forages with different nutritive value.  相似文献   

9.
The effects of source and level of dietary NDF on intake, ruminal digestion in situ, ruminal fermentation, and total tract digestion were evaluated in Hereford steers using a replicated 5 x 5 Latin square design. Diets contained 62 to 64% TDN and included 1) 80% control concentrate (contained pelleted ground grains) and 20% timothy hay (traditional diet), 2) 80% control concentrate and 20% alfalfa cubes, 3) 90% control concentrate and 10% cubes, 4) a completely pelleted diet using corn cobs as the primary NDF source, and 5) 80% textured (rolled instead of ground grains) concentrate and 20% hay. Dry matter intake differed (P less than .05) between the traditional and cube diets due to limited acceptance of alfalfa cubes. Increased (P less than .05) ruminal osmolality, total VFA, and NH3 N and lower (P less than .01) ruminal pH in steers fed corn cob and cube diets relative to steers fed the traditional diet were due to preferential consumption of concentrate over supplemental roughage and the resultant rapid fermentation of concentrates. Potentially degradable DM in the traditional diet exceeded (P less than .06) all other diets, resulting in the increased (P less than .10) extent of DM disappearance despite a slower (P less than .05) rate of DM disappearance. Rate of NDF disappearance and all in situ starch disappearance parameters were similar between the traditional, corn cob, and cube diets. All ruminal digestion parameters involving NDF disappearance were similar between hay diets and between cube diets, whereas rate and extent of starch disappearance differed (P less than .05) between hay diets. Although formulation of diets with different sources of dietary NDF did not affect total tract digestion of nutrients, nutrient availability and ruminal fermentation were altered due to dietary differences in sources of dietary NDF and preferential selection of feedstuffs by steers.  相似文献   

10.
选用12只安装有永久性瘤胃瘘管的1.5岁杂交一代(无角陶赛特×小尾寒羊)肉用羯羊,随机分成3组,研究日粮中不同加工方式(整株、颗粒、草粉)苜蓿干草在瘤胃内的降解及其对肉羊消化代谢的影响。试验结果表明:苜蓿干草经粉碎及颗粒处理后,DM、CP、NDF在瘤胃内的降解率较整株组有显著提高(P<0.05),但ADF降解率未有明显变化(P>0.05)。不同加工方式(整株、颗粒、草粉)苜蓿干草对DM、OM、NDF、ADF表观消化率没有影响(P>0.05),但加工成颗粒及粉料使氮的利用率显著提高(P<0.05)。3种不同加工方式下DM、OM、NDF、ADF表观消化率分别高达71.74%～72.18%、73.67%～74.22%、66.69%～68.48%、45.64%～52.41%。  相似文献   

11.
The objective was to evaluate the effects of ramie conserved as forage supplementation on growth, digestion, and meat quality of Liuyang black castrated goats in a 60 days feedlot study. Forty‐eight goats were randomly assigned to each of four treatments: 24% rice straw + 36% ramie residues silage + 40% concentrate; 24% rice straw + 36% raw ramie silage + 40% concentrate; 24% rice straw + 36% ramie residues hay + 40% concentrate; 24% rice straw + 36% raw ramie hay + 40% concentrate. There was an increased tendency for ADG in ramie hay treatment than that of ramie silage treatment (p = 0.067). There was an increase for the apparent digestibility of DM, CP, NDF, and ADF in the ramie hay treatment than that of ramie silage treatment (p ≤ 0.034). An increased tendency was found for C18:1n?9c (% of total fatty acids) in the longissimus dorsi muscle of raw ramie treatment versus ramie residues treatment (p ≤ 0.087). These results indicate that the ramie hay or raw ramie treatment had a tendency for improving the nutrient digestibility and meat quality of goats than that of ramie silage or ramie residues treatment, respectively.  相似文献   

12.
The effect of feeding browse on growth and carcass characteristics was studied using thirty-two 10–12 months old growing Sahelian goats weighing an average of 15.6 kg. The treatments were four diets: Acacia senegal pods, Pterocarpus lucens leaves and pods and a positive control. The browses were offered ad libitum and supplemented with 200 g of hay of Schoenefeldia gracilis and 200 g of millet bran, while the control group received 200 g of millet bran, 200 g of cottonseed cake and hay ad libitum. The highest DM intake was observed for goats fed A. senegal pods, resulting in higher CP intake from this diet. The diet with P. lucens leaves gave a higher feed consumption than the control diet, but CP intakes were similar. The goats fed P. lucens pods diet had the lowest CP intake. The higher intake of the A. senegal pods diet resulted in higher growth rate (56 g/day), comparable to the P. lucens leaves and the control diets (55 and 51 g/day respectively). However, the feed conversion ratio was the lowest for the control diet. The carcass weight, dressing percentage and weight of the primal cuts were higher for goats fed A. senegal pods, P. lucens leaves and the control diet. In conclusion A. senegal pods and P. lucens leaves showed good intake characteristics for goats under stall-feeding conditions. Pods from P. lucens, resulting in lower performance, can be fed with small amounts of millet bran for maintenance of goats during the dry season.  相似文献   

13.
The objectives of this study were (a) to investigate the effect of body weight (BW) on available energy in fibre‐rich diets containing two NDF levels; and (b) to evaluate the effect of fibre type and NDF level on AA digestibility. In Exp. 1, barrows (24 at 33.4 ± 1.1 kg; 24 at 86.8 ± 3.3 kg) were randomly allotted to 4 diets containing a high protein basal (HPB), a low protein basal (LPB), 70% HPB + 30% wheat bran (WB) (HPB‐WB) and 70% LPB + 30% sunflower meal (SFM) (LPB‐SFM). In Exp. 2, barrows (24 at 33.5 ± 1.8 kg; 24 at 87.0 ± 3.8 kg) were randomly allotted to 4 diets containing no SFM with 12% NDF (SFM0LF), no SFM with 16% NDF (SFM0HF), 24% SFM with 12% NDF (SFM24LF) and 24% SFM with 16% NDF (SFM24HF). In Exp. 3, twelve barrows (35.5 ± 3.4 kg) fitted with T‐cannulas were allotted to two 6 × 4 Youden square design with 6 diets (4 same diets as in Exp. 2 and 2 nitrogen‐free diets). The concentration of DE, ME and ATTD of GE, CP, NDF and ADF in diets was greater (p < .01) when fed to 90 kg pigs compared with 30 kg pigs. The ME in ingredients was not affected by BW. The ATTD of NDF was negatively correlated with the CF (r = ?.98; p < .01), ADF (r = ?.99; p < .01) and ADL content (r = ?.96; p < .01). The ME of diets was negatively correlated with the ATTD of CF (r = ?.98; p < .01). The addition of SFM increased the standardized ileal digestibility (SID) of Met (p < .05). In conclusion, diets rich in fibre had different nutritional values at different pig weight stages. The AA digestibility depends mainly on chemical composition of diets.  相似文献   

14.
A study was undertaken to evaluate and compare the chemical composition of the cocoa byproducts CPH (cocoa pod husk), CS (cocoa shell) and CD (cocoa dust), and to establish a rational use of CS and CD in the diets of growing goats. CD had a high crude protein (CP) content of 15.9%, while CS and CPH had 13.8% and 6.7%, respectively. The byproducts were high in crude fibre (CF) content. Among the byproducts, CD had the highest ether extract value (22.0%). Fifteen growing goats, 18–20 months of age, with pre-experimental body weights of 20.9±0.33 kg, were randomly allotted to three diets in growth studies. In diet 1, dried brewers' grains (DBG) served as the control, while the other two diets had CS or CD plus DBG. The dry matter intake (DMI) was 570, 530 and 486 g/head per day for the control, CS+DBG and CD+DBG diets, respectively. The growth rate differed significantly among the goats offered the diets (p<0.05). Dry matter (DM), crude protein (CP), crude fibre (CF), organic matter (OM) and gross energy (GE) digestibility were significantly higher (p<0.05) in the goats on the control diet than in those on CS+DBG or CD+DBG. The DM, CP and OM in the CS+DBG diet were more digestible (p<0.05) than those in the CD+DBG diet. The inclusion of DBG in the CS and CD diets improved their use by the goats.  相似文献   

15.
Twenty-four purebred Boer (Capra hircus hircus) and 12 male kids of 1/2 Boer breeding (initial BW 21 +/- .5 kg) were used in a randomized complete block design to study the effects of increasing level of whole cottonseed (WCS) on ADG, serum urea N, plasma gossypol, live grades, and intake of DM, CP, NDF, ADF, hemicellulose, cellulose, lignin, ether extract, and free gossypol. A subgroup of 16 purebred goats was used to determine digestibility using a 5-d total fecal collection. Goats were blocked by BW and then assigned at random to one of four diets containing 0, 8, 16, or 24% WCS. All diets contained 71% chopped orchardgrass (Dactylis glomerata L.) hay and 29% concentrate; WCS replaced corn and soybean meal to maintain calculated TDN and CP concentrations at 68 and 15% of DM, respectively. Concentrations of NDF in diet DM were 52.4, 55.9, 59.3, and 62.1% with increasing WCS, and the Ca:P ratio was maintained at 2:0. Goats were given ad libitum access to feed and water. Over the 90-d performance phase, DMI (P < .05), CP intake (P < .02), and ADG (P < .01) decreased linearly with increasing WCS in the diet, whereas ether extract (EE) intake increased in a cubic fashion (P < .01). Gain:feed decreased linearly (P < .02) with increasing level of WCS. Addition of WCS resulted in linear decreases in apparent digestibility coefficients of DM (P < .02) and NDF (P < .05), a linear increase in total plasma gossypol (P < .01), and a quadratic increase in serum urea N (P < .04). Apparent digestibility of CP was not affected by WCS level. At the 16 and 24% WCS levels, EE constituted 4.2 and 4.8% of total DMI, respectively. Adding WCS to diets for growing goats had detrimental effects on animal performance, and, based on the possible negative effects of dietary EE and NDF rather than gossypol, economics should dictate whether to use WCS in feeding programs.  相似文献   

16.
The purposes of this study were 1) to assess the effects of 3 high-concentrate diets on enteric CH(4) production, total tract digestibility, and rumen fermentation of beef cattle, and 2) to evaluate, by life cycle assessment, the potential effects of these feeding systems on the environment. Six bulls (age of 12.4 mo and BW of 417 kg at midexperiment) of the Blond d'Aquitaine breed were assigned to 3 dietary treatments in a replicated 3 × 3 Latin square design. Diets consisted of 1) 49% natural grassland hay, 41% ground corn grain, and 10% soybean meal (hay); 2) 63% corn silage, 21% ground corn grain, and 16% soybean meal (CS); and 3) 70% ground corn grain, 16% soybean meal, and 14% wheat straw (CG). Daily CH(4) emission (g/d), measured using the sulfur hexafluoride tracer technique, was similar for the hay and CS diets and was 56% greater than for the CG diet (P < 0.001). This difference between diets was maintained when CH(4) output was expressed by unit of feed intake (P < 0.001) or digested feed (P < 0.001). Gross energy intake loss as CH(4) averaged 6.9% for the hay and CS diets and 3.2% for the CG diet (P < 0.001). Organic matter intake and GE intake did not differ between diets. Organic matter digestibility was less for the hay diet than for the CS and CG diets (P=0.008). Digestibility of NDF was greatest for the hay diet, intermediate for the CS diet, and least for the CG diet (P=0.02), with ADF digestibility being similar between the hay and CS diets and greater than for the CG diet (P < 0.001). The rumen pH at 5 h postfeeding was less for animals fed the CG diet compared with those fed the other 2 diets (on average, 5.1 vs. 5.9, respectively; P < 0.001). Total CH(4) emission (enteric + manure) was least for the CG diet, whereas N(2)O and CO(2) emissions were greatest for the CG diet. Total greenhouse gas emissions were least for the CG diet when C sequestration by grasslands was not taken into account.  相似文献   

17.
The objective of this experiment was to determine the effects of feeding varying levels of crude glycerine (CG) on dry matter intake (DMI), animal performance, carcass traits and rumen volatile fatty acids (VFA) concentration in meat goats. Twenty-four intact male Boer goats (23.9 ± 1.0 kg initial BW and 4–5 months of age) were randomly assigned to one of four experimental diets (n = 6) containing 30% bermudagrass hay plus 70% concentrate mix with 0, 5, 10 or 15% CG in the diet on an as-fed basis, substituted for the corn portion of the concentrate. Feed offered and refusals were monitored daily for 84 days. Goats were weighed at 28-days interval. Blood and rumen samples were collected on day 84. At the end of the 84-days feeding period, goats were harvested, and carcass characteristics measured. Feed intake, average daily gain (ADG), gain-to-feed ratio (G:F), carcass traits and VFA concentrations were analysed as a completely randomized design. The CG did not influence animal body weight (BW) changes, ADG and G:F ratio but tended to (p = 0.06) decrease DMI. Molar per cent propionic acid increased linearly (p < 0.05) with increasing CG. The acetate: propionate (A:P) ratio decreased (p < 0.05) with increasing amounts of CG in the diet. The CG addition tended to increase (p = 0.09) the longissimus muscle (LM area) in meat goats. In conclusion, CG can replace corn in diet for growing meat goats when fed up to 15% of diet, improving ruminal propionate concentration, but decreasing A:P ratio without affecting animal performance and carcass traits.  相似文献   

18.
There is an apparent reciprocal relationship between magnesium ammonium phosphate (MAP, struvite) and calcium oxalate (CaOx) urolithiasis incidence rate in cats. The number of struvite uroliths submitted for analysis over the past 35 years has been decreasing, with an increase in CaOx urolith submissions. Commercial diets aimed to dissolve struvite uroliths are typically acidified, and it has been suggested that dietary acidification increases urinary calcium excretion and the risk of CaOx crystallization. The objective of this study was to assess the effect of urine acidification on the relative supersaturation (RSS) of CaOx in cats, as a representation of crystallization risk. Four diets were extruded to contain identical nutrient contents, but with gradual acidification (0, 0.6, 1.3 and 1.9% sodium bisulphate substituted sodium chloride in diets A, B, C and D respectively). Thirteen adult cats were fed each diet sequentially for a minimum of 10 days. Average urine pH was 6.4, 6.2, 6.0 and 5.9 on diets A, B, C and D respectively (p < 0.0001). Struvite RSS decreased on diets inducing more acidic urine pH (p < 0.0001). Urinary calcium excretion and concentration increased with diets inducing lower urine pH (p < 0.0001), but oxalate excretion and concentration decreased (p < 0.001). CaOx RSS was not different between diets (p = 0.63). These results suggest that a lower diet base excess and resulting urine pH to support struvite dissolution do not increase the risk for CaOx crystallization in the range of urine pH representative of most commercial feline diets. Long-term studies are needed to confirm this.  相似文献   

19.
Four Japanese Black steers (16 months of age) were assigned to a 4 × 4 Latin square design to investigate the effect of graded levels of sweet‐potato condensed distillers solubles (SCDS) in their diets on intake and urinary excretion of minerals. The four diets consisted of 0%, 10%, 20% and 30% (dry matter (DM) basis) SCDS, with SCDS replacing commercial concentrate (CC). Intake of K, Cl, S, P and Mg increased linearly with increasing SCDS content. Urinary pH increased linearly with increasing dietary SCDS content. SCDS feeding increased urinary K concentrations (linear and quadratic effects). Urinary concentrations of Cl increased linearly with increasing SCDS content. In contrast, urinary concentrations of Mg decreased with increasing SCDS content. Feeding of SCDS did not apparently affect urinary NH3,P, Na or Ca concentrations. These results suggest that high SCDS feeding is not a risk for crystallization of minerals leading to the formation of magnesium‐phosphate type calculi: although SCDS contains large amounts of P and Mg, high SCDS feeding decreased the Mg concentration and did not affect the P concentration in urine. Additionally, high SCDS feeding had no apparent effects on plasma concentrations of Na, K, Cl, Ca or inorganic P.  相似文献   

20.
Irrigation agriculture of hot climates suffers from rapid soil organic carbon (C) turnover, high nitrogen (N) leaching and gaseous losses. In this context, we explored the possibility of supplementing ruminants with activated charcoal (AC) and condensed tannins (CT) to increase faecal concentration of long‐lived C and slowly decomposable N. For this purpose, we fed AC and quebracho tannin extract (QTE, source of CT) to goats and determined nutrient digestibility, digesta passage and composition of faeces. The feeding trial comprised three periods, with 24 male goats assigned to five treatments and a control. On dry matter (DM) basis, the basal diet (control) consisted of 50% hay, 46.5% crushed maize and 3.5% soya bean meal. Treatment diets contained (on DM basis) 2% and 4% QTE (QTE2, QTE4), 1.5% and 3.0% AC (AC1.5, AC3.0) and a mixture of 2% QTE plus 1.5% AC (QTEAC). Samples of feed, refusals and faeces were analysed for chemical constituents; digesta passage was computed with a one‐compartment Gamma‐2 model from pulse‐dose application of ytterbium‐mordanted fibre and quantitative collection of faeces during 7 days. Compared to the control, organic matter and N digestibility were reduced with QTE2 and QTE4 (p ≤ 0.001), that of neutral and acid detergent fibre (NDFom, ADFom) decreased with QTE4, QTEAC and both AC treatments (p ≤ 0.001). Ruminal particle passage ranged from 0.051 h?1 (QTEAC) to 0.056 h?1 (control; p > 0.05). Apart from the correlation between total tract mean retention time and faecal C/N ratio (r = ?0.35), passage parameters did not affect faeces quality. While faecal N concentration was not altered by both additives, AC enhanced faecal NDFom, ADFom and C concentrations (p ≤ 0.001). Whereas feeding up to 3% AC might slow down the decomposition of manure in the field without negatively affecting the digestive physiology of goats, including QTE seems not advantageous from a physiological and nutrient recycling perspective.  相似文献   

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