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1.
The effect of including high or low tannin forage peas as an alternative to soyabean meal on performance and N efficiency was investigated using 18 dairy cows in two Latin square design studies. Two varieties of forage pea; Racer (coloured flowers; high tannin) and Croma (white flowers; low tannin), were ensiled 12 weeks post sowing. The in situ degradability characteristics of the pea silages were determined using 4 cannulated sheep. The low tannin forage had a higher soluble N (a) fraction and a greater extent of degradation (a + b), resulting in a greater amount of N being predicted to be released in the rumen than the high tannin forage. In experiment 1, cows were fed one of three treatments in each of 3 periods of 28 d duration in a Latin square design; grass silage/whole-crop wheat (0.50:0.50, DM basis) and 8 kg/d of a high protein concentrate (GWH); grass silage/whole-crop wheat/high tannin forage pea silage (0.25:0.25:0.50 respectively, DM basis) and 8 kg/d of a high protein concentrate (HTH) or 8 kg/d of a low protein supplement (HTL). The inclusion of forage peas increased (P < 0.05) DM intake by 1.2 kg DM/d, but there was no effect of dietary treatment on milk yield (average of 23.0 kg/d), composition or live weight change. The efficiency of use of dietary N (N output in milk/N intake) was highest (P < 0.001) in cows when fed GWH (0.289) and lowest in HTH (0.234). In experiment 2, cows were fed one of three treatments in each of 3 periods of 28 d duration in a Latin square design; grass silage/whole-crop wheat (0.50:0.50, DM basis) and 8 kg/d of a high protein concentrate (GWH); grass silage/whole-crop wheat/low tannin forage pea silage (0.25:0.25:0.5 respectively, DM basis) and 8 kg/d of a high protein concentrate (LTH) or 8 kg/d of a low protein concentrate (LTL). Compared with GWH, the inclusion of forage peas increased (P < 0.05) DM intake by 2.0 kg/d, but there was no effect of dietary treatment on milk yield (average of 24.5 kg/d). Milk fat content was highest (P < 0.05) in cows when fed LTL (45.7 g/kg) and lowest in LTH (41.9 g/kg), but there was no effect (P > 0.05) of treatment on daily fat yield or any other milk component. The efficiency of dietary N use was highest (P < 0.001) in cows when fed GWH (0.300) and lowest in LTH (0.234). It is concluded that either high or low tannin forage pea silages can replace approximately 1.1 kg/d of soyabean meal in the diet of mid-late lactation dairy cows without affecting animal performance, but N efficiency for milk production is decreased.  相似文献   

2.
The effect of maturity at harvest on the digestibility and intake of large bale silage made from whole-crop barley and wheat when fed to growing heifers was evaluated. Two crops of spring barley (Hordeum distichum cv. Filippa and Kinnan) and 1 of winter wheat (Triticum aestivum cv. Olevin) were harvested at the heading, milk, and dough stages of maturity. The silage was fed to 36 dairy heifers in a balanced crossover experiment with 3 periods and 9 treatments (diets based on 3 crops and 3 stages of maturity), organized into 6 pairs of 3 × 3 Latin squares. No clear relationship was observed between intake and stage of maturity of whole-crop cereal silage, but intake was positively correlated to silage DM content (P < 0.001, r = 0.46) and negatively correlated to NDF content (P < 0.001, r = -0.42). Organic matter digestibility decreased between the heading and milk stages of maturity in all crops (P < 0.001), did not differ between the milk and the dough stages in the 2 barley crops, but increased in the wheat silage (P = 0.034). The NDF digestibility decreased between the heading and milk stages in all crops (P < 0.001), whereas it decreased in 1 barley crop (P < 0.001), increased in the other barley (P = 0.025), and was unchanged in the wheat between the milk and dough stages of maturity. Starch digestibility was less in the 2 barley crops compared with the wheat at the dough stage of maturity (P < 0.001). The feeding value of the whole-crop barley and wheat declined between the heading and milk stages of maturity, but thereafter the effect of maturity on the feeding value was minor.  相似文献   

3.
Two silages were prepared from the primary growth (PG) of timothy-meadow fescue sward at early (E) and late (L) stage of growth. The subsequent regrowth (RG) areas were further harvested at early (EE and LE) and late (EL and LL) stages of growth resulting in six silages in total. The silages were fed ad libitum to 24 lactating Finnish Ayrshire cows and supplemented with 8 or 12 kg concentrate per day in a cyclic change-over experiment with four 21-day periods and 6 × 2 factorial arrangement of treatments. The quality of silages varied markedly within and between the harvests although variation was greater within PG than RG. Postponing the harvest in PG decreased silage dry matter (DM) intake by 0.48 kg and energy corrected milk yield (ECM) by 0.61 per 10 g decrease in silage D-value (concentration of digestible organic matter in DM), while responses and the range between the diets were clearly smaller when RG silages were fed. On average, ECM yield was higher when PG rather than RG silages were fed. The mean response to increased concentrate DM intake was 0.62 kg ECM using diets based on PG. The response increased with increasing growth stage of grass being 0.34 and 1.01 kg ECM / kg additional concentrate DM for E and L, respectively. The difference was mainly mediated by the differences in substitution rates (reduction in silage DM intake per increase in concentrate DM intake, kg/kg), which were 0.71 and 0.22 for E and L, respectively. The ECM response to increased concentrate allowance was on average greater when RG rather than PG silages (0.92 vs. 0.62 kg/kg concentrate) were fed. Milk production of dairy cows reflected the intake of metabolizable energy and no differences in the utilization of it were found between diets based on silages harvested from PG and RG. However, intake of RG silages was slightly lower than that of comparable PG silage, but definite reasons for that could not be identified.  相似文献   

4.
The study investigated the effect of the following maize:legume (70:30) mixed crop silages: maize:cowpea, maize:velvet bean, and maize:lablab on milk production during the 2016 dry season. Using a 5?×?5 double Latin square design, five Holstein-Friesian crossbred cows in early lactation (30?±?15 days) and five Jersey crossbred cows in early lactation (25?±?10 days) were given the supplementary mixed crop silage diets at 0.5 kg/l of milk produced over 105 days. Commercial dairy meal and sole maize silage were used as positive and negative controls, respectively. Milk yield was significantly higher (P?< 0.05) in cows given the dairy meal compared to mixed crop silages; however, milk yield was also significantly higher (P?< 0.05) for cows given the three mixed crop silages compared to cows given sole maize silage. Cows given mixed crop silages produced milk of significantly higher protein content (P?< 0.05) than those given sole maize silage. There was no significant difference (P?> 0.05) in butterfat content of milk across all the dietary treatments. The dietary cost of producing 1 l of milk was highest at 0.31USD/l for cows given commercial dairy meal and lowest for cows given maize:velvet bean and maize:cowpea silage at 0.19USD/kg. The highest dietary gross margins of 68% were observed when cows were given maize:velvet mixed silage compared to commercial dairy meal (47%) and sole maize silage (57%). The 70:30 maize:legume mixed crop silages showed the capability to increase milk quantity and quality at very low production costs in smallholder dairy schemes.  相似文献   

5.
Effects of grass–clover silage (GCS) alone or combined with whole-crop cereal silage, maize silage (MS) or ensiled pressed sugar beet pulp (EPSB) on faecal characteristics and performance of early-lactation dairy cows were studied in 26 herds. Data were analysed with herd as the experimental unit and correlation coefficients among the variables were estimated. Feeding MS combined with GCS resulted in faeces of a firmer consistency (P?P?r?=?0.83, P?r?=??0.54, P?r?=?0.63, P?相似文献   

6.
The aim of this study, which was part of the EU-financed project Life Ammonia, was to evaluate the effects of dietary components and milk production on nitrogen efficiency of dairy cows. The study included examining the effects of decreased crude protein (CP) concentration in a grass-clover silage based diet and results of mixing whole-crop barley silage (WCBS) with grass-clover silage in the diet, on feed intake, milk production and nitrogen efficiency. Rations were formulated and milk production data were registered individually each month for 42 cows of the Swedish Red Cattle breed during four indoor periods from 1999 to 2003. The range in nitrogen efficiency by the cows, 11 to 398 days in milk, was 18 to 40%, when fed a diet containing 135 to 184 g CP/kg DM, 44 to 56% of NDF as rumen degradable fibre (RDF) and milking 13 to 57 kg of ECM daily. The average CP concentration of the diet, containing mainly grass-clover silage and concentrate, was decreased from 168 g/kg DM (170 g in early lactation) in the control treatment period to 160 g/kg DM (163 g in early lactation) during the following treatment period. The CP concentration was 170 g/kg DM (171 g in early lactation) during the third treatment period, when the grass-clover silage was fed in a mixture with WCBS. Using the whole data set (n = 284 for primiparous, n = 440 for multiparous cows based on measurements each month) resulted in models, in which total DM intake, ECM yield, dietary CP concentration and RDF were the most important factors affecting nitrogen utilisation of primiparous and multiparous cows. Increases in both average DM intake and milk yield by multiparous cows and no changes in average intake and milk yield by primiparous cows fed the low CP diet or the normal CP diet containing WCBS, compared to cows fed the normal CP diet, resulted in similar nitrogen efficiencies among the treatments. Hence, dietary CP concentrations of 160 to 170 g/kg DM can be used for cows in early lactation in commercial herds to improve nitrogen utilisation without causing a simultaneous decrease in milk yield.  相似文献   

7.
Nine multiparous Holstein cows were used in a replicated 3 × 3 Latin square design to determine the effects of substituting corn grain with brown rice (BR) grain in total mixed ration (TMR) silage on milk yield, ruminal fermentation and nitrogen (N) balance. The TMR silages were made from the ensiling of TMR containing (dry matter basis) 50.1% forage in rice silage and corn silage combination, and 49.9% concentrate. The grain portion of the diets contained 31.2% steam‐flaked corn, 31.2% steam‐flaked BR or an equal mixture of corn and BR. Dietary treatments did not affect dry matter intake, milk yield and milk fat, protein and lactose yields. The ruminal pH and total volatile fatty acid concentrations were not affected by dietary treatment. The urinary N excretion decreased linearly (P < 0.01) in response to increased levels of BR, with no dietary effect on N intake, N secretion in milk and fecal N excretion. Our results indicate that steam‐flaked BR is a suitable replacement for steam‐flaked corn in dairy cow diets, and that it can be included in rations to a level of at least 31.2% of dry matter without adverse effects on milk production, when cows were fed rice silage and corn silage‐based diets.  相似文献   

8.
The effects of replacing grass silage by sainfoin silage in a total mixed ration (TMR) based diet on fatty acid (FA) reticular inflow and milk FA profile of dairy cows was investigated. The experiment followed a crossover design with 2 dietary treatments. The control diet consisted of grass silage, corn silage, concentrate and linseed. In the sainfoin diet, half of the grass silage was replaced by a sainfoin silage. Six rumen cannulated lactating multiparous dairy cows with a metabolic body weight of 132.5 ± 3.6 kg BW0.75, 214 ± 72 d in milk and an average milk production of 23.1 ± 2.8 kg/d were used in the experiment. Cows were paired based on parity and milk production. Within pairs, cows were randomly assigned to either the control diet or the sainfoin diet for 2 experimental periods (29 d per period). In each period, the first 21 d, cows were housed individually in tie-stalls for adaptation, then next 4 d cows were housed individually in climate-controlled respiration chambers to measure CH4. During the last 4 d, cows were housed individually in tie stalls to measure milk FA profile and determine FA reticular inflow using the reticular sampling technique with Cr-ethylenediaminetetraacetic acid disodium salt dihydrate (EDTA) and Yb-acetate used as digesta flow markers. Although the dietary C18:3n-3 intake was lower (P = 0.025) in the sainfoin diet group, the mono-unsaturated FA reticular inflow was greater (P = 0.042) in cows fed the sainfoin diet. The reticular inflow of trans-9, trans-12-C18:2 and cis-12, trans-10 C18:2 was greater (P ≤ 0.024) in the sainfoin diet group. The cows fed sainfoin diet had a lower (P ≤ 0.038) apparent ruminal biohydrogenation of cis-9-C18:1 and C18:3n-3, compared to the cows fed the control diet. The sainfoin diet group had greater (P ≤ 0.018) C18:3n-3 and cis-9, cis-12-C18:2 proportions in the milk FA profile compared to the control diet group. Transfer efficiencies from feed to milk of C18:2, C18:3n-3 and unsaturated FA were greater (P ≤ 0.0179) for the sainfoin diet. Based on the results, it could be concluded that replacing grass silage by sainfoin silage in dairy cow rations reduces ruminal C18:3n-3 biohydrogenation and improves milk FA profile.  相似文献   

9.
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   

10.
The objective of this experiment was to investigate the influence of ground date seed (GDS) on intake, digestibility, and milk yield and milk fatty acid (FA) composition of lactating Holstein cows. The experimental design was a 4?×?4 replicated Latin square with eight lactating dairy cows with an average milk production of 35.5?±?1.5 kg and 75?±?5 days in milk (DIM). Dairy cows were fed one of the four treatments contained 0, 2, 4, and 6% of diet dry matter (DM) GDS in replacement of wheat bran. All diets contained the same amount of forages (alfalfa hay and corn silage). Dietary treatments had no effect on DM intake (DMI), total tract apparent digestibility, milk yield, and milk composition. Increasing GDS linearly decreased concentration of C13:0 and increased cis-9 C14:1 and trans-11 C18:1 (vaccenic acid) (P?<?0.05). A linear tendency for more C16:1 content in milk fat was observed with increasing GDS (P?=?0.06). Feeding GDS resulted in a linear decrease (P?<?0.01) in saturated FA (SFA) but increased milk fat monounsaturated FA (MUFA) and trans FA (TFA) (P?<?0.05). Therefore, low levels of GDS (up to 6%) in the diet of Holstein dairy cows can beneficially modify milk FA composition without any adverse effects on intake, digestibility, and milk yield.  相似文献   

11.
Red (RC) or white (WC) clover were grown in mixture with grasses, ensiled and offered to dairy cows in early lactation over two successive years (48 cows per year) to compare grassland yield, feed intake, milk production and milk quality. The crops were ensiled in round bales and proportional mixtures of the second and third cut prepared each year were used to ensure that the silage treatments were representative of the crop. In addition to silage type, concentrate supplementation, without and with (10 kg/day), was included as a factor in a 2 × 2 factorial, continuous experiment. Total dry matter (DM) yield, silage chemical composition and total DM intake was hardly affected by silage type. There was no effect of silage type on milk yield and milk constituents either, except for higher milk protein content (P < 0.05) on WC and higher milk fat content of C18:3n-3 (P < 0.001), C18:2n-6 (P < 0.05) fatty acids (FAs) and sum of polyunsaturated FA (P < 0.001) and lower n-6/n-3 FA ratio (P < 0.01) on RC. Concentrate supplementation increased total DM, N and net energy intakes (P < 0.001), milk yield (P < 0.001), milk fat (P < 0.01) and protein (P < 0.001) content, decreased the milk urea content (P < 0.001), and increased the milk fat content of short- and medium-chained FAs (< C16, P < 0.001), C18:0 (P < 0.01) and C18:2n-6 (P < 0.001), decreased the content of C16:0 (P < 0.05), C18:1t11 (P < 0.001) and C18:3n-3 (P < 0.001), and increased the n-6/n-3 FA ratio (P < 0.001). The effect of concentrate supplementation was not affected by silage type, except for milk protein content where the positive effect of supplementation was stronger on WC than on RC diets (P < 0.05). This study illustrates that the white- and red clover-grass mixtures investigated were widely similar with regard to their effects on grassland yield, silage intake and milk production and milk constituents, except for a higher milk fat content of C18:3n-3 and C18:2n-6 and lower n-6/n-3 FA ratio on red clover diets. Our findings also show that N conversion efficiency from feed to milk on pure forage diets is more sensitive to changes in dietary protein intake than silage diets containing cereal based concentrates.  相似文献   

12.
Thirty‐six Holstein‐Friesian crossbred lactating dairy cows were used to determine the effects of linseed oil supplementation on performance and milk fatty acid (FA) profile. Three treatments were as follows: basal diet (56:44 Roughage:concentrate [R:C] ratio, dry matter basis) supplemented with 500 g of palm oil as control (PO), 500 g mixture (1:1, w/w) of palm oil and linseed oil (POLSO) and 500 g of linseed oil (LSO). The LSO supplementation had no effects on total dry matter intake (DMI), milk yield and milk composition. Compared to control cows, cows supplemented with LSO increased milk concentrations of cis‐9,trans‐11 conjugated linoleic acid (CLA) and n‐3 FA (P < 0.05), particularly C18:3n‐3, C20:5n‐3 and C22:6n‐3. Feeding LSO reduced concentrations of milk short‐ and medium‐chain saturated fatty acids (P < 0.05) while it increased concentration of milk unsaturated fatty acids (P < 0.05). Milk proportions of n‐3 FA increased, whereas n‐6/n‐3 ratio decreased in the LSO as compared with the control (P < 0.05). In conclusion, supplementing dairy cows' diet based on corn silage with LSO at 500 g/day could improve the nutritional value of milk with potential health‐beneficial FA without detrimental effect on milk composition or cow's performance.  相似文献   

13.
The effects of barley flour on the fermentation parameters of alfalfa silage and on the productivity of dairy cows were investigated. Alfalfa forage was ensiled either with or without barley flour. Barley flour was soaked in water for 24 h before being mixed with alfalfa (12 kg: 100 kg dry matter bases) at ensiling. Eighteen multi-parous cows were assigned to three equal treatment groups using a completely randomized design. Three isocaloric and isonitrogenous total mixed rations containing alfalfa hay, ordinary alfalfa silage or barley flour mixed alfalfa silage were then prepared. The concentrations of ammonia nitrogen, acetic acid and butyric acid were lower in barley flour mixed alfalfa silage compared to that in ordinary alfalfa silage but the concentration of lactic acid was lower in the ordinary alfalfa silage. Feeding behavior, milk yield and composition, ruminal fermentation and blood metabolites were measured. Although dry matter intake and milk production were not affected, the effect of preparation of alfalfa influenced feeding behavior and rumen fermentation parameters. Cows on alfalfa silage diets spent longer ruminating compared to those fed alfalfa hay. The ruminal ammonia nitrogen and blood urea were affected by ensiling (alfalfa hay versus alfalfa silages) while both parameters were lower in cows fed on barley flour mixed alfalfa silage than those fed on ordinary silage. Although similar blood glucose was recorded for cows fed on alfalfa silages, it was higher in cows fed on alfalfa hay. It is concluded that the addition of barely flour when making alfalfa silage may improve both the fermentation process during ensilage and the ruminal ammonia nitrogen utilization with no significant effects on productivity.  相似文献   

14.
The objective was to determine the effect of including silages of annual ryegrass (Lolium multiflorum) intercropped with winter vetch (Vicia villosa) (ARG-VV) or with common vetch (Vicia sativa) (ARG-VS) compared with maize silage (MS) on milk yield and milk composition of dairy cows grazing cultivated perennial ryegrass–white clover pastures with supplemented concentrate during the dry season. Six Holstein dairy cows with a mean yield of 19.0 kg/cow/day at the beginning of the experiment were randomly assigned to a 3 × 3 repeated Latin square. Treatments were: 8 h/day intensive grazing, 3.6 kg of dry matter (DM) per cow per day of concentrate plus MS, and ARG-VV or ARG-VS ad libitum at a stocking rate of 3.0 cows/ha for three experimental periods of 3 weeks each. Milk yield (MY) and milk composition, live weight and body condition score as well as silage and concentrate intakes were recorded during the third week of each experimental period, and pasture intake was estimated indirectly from utilised metabolisable energy. Economic analysis was obtained by preparing partial budgets. There were no statistical differences (P > 0.10) in MY, milk fat or protein content nor for live weight, but there was significant difference (P < 0.10) in body condition score. There were non-statistical differences in silage DM intake (P < 0.11); however, significant differences (P < 0.10) were obtained for estimated grazed herbage intake whilst no differences for total DM intake. Slightly higher economic returns (10%) were obtained with ARG-VS over MS, and this was 7% higher than ARG-VV. It is concluded that ARG-VS could be an option for complementing grazing for small-scale dairy production systems in the dry season as it is comparable to MS in animal performance and slightly better in economic terms.  相似文献   

15.
The objective of this experiment was to evaluate the effect of concentrate/milk yield ratios on feed intake, nutrient digestibility, rumen fermentation efficiency, and milk production in dairy cows fed with a basal diet of whole crop rice silage (WCRS). Sixteen crossbred cows (75 % Holstein-Friesian (HF) and 25 % Thai cows) in mid-lactation were assigned to four dietary treatments in a completely randomized design. Treatments corresponding to four concentrate/milk yield ratios (0, 1:1, 1:2, and 1:3 (kg/kg)) were used. All cows were offered WCRS (with 1.5 % urea and 3 % molasses) ad libitum. Silage and concentrate were fed individually twice a day. Results revealed that dry matter intake (12.8–14.5 kg/day), nutrient digestibility (62.5–68.7 %), and rumen fermentation efficiency were not significantly affected by concentrate supplementation. Milk yield (10.2–11.5 kg/day) and milk composition were similar between cows fed with sole WCRS and those supplemented with concentrate mixture, although milk fat tended to increase in cows fed with sole WCRS. In conclusion, sole WCRS fed to dairy cows without concentrate supplementation resulted in similar feed intake, nutrient digestibility, rumen fermentation, and milk production as compared to those supplemented with concentrate in lactating dairy cows. These results suggest that in tropical areas where rice crop is surplus, WCRS could sustain reasonable levels of milk production among dairy cows with little or no concentrate supplementation provided that urea and molasses are included in the silage.  相似文献   

16.
To evaluate the feasibility of bamboo shoot shell (BSS) application in total mixed ration silage (TMR) production, the effects of BSS substitution for whole-crop corn on the fermentation characteristics, nutritive value, aerobic stability and in vitro parameters of TMR silage were studied. Four TMR formulations were designed based on dry matter: (1) 0% bamboo shoot shell + 23% whole-crop corn (BSS0); (2) 4% bamboo shoot shell + 19% whole-crop corn (BSS4); (3) 8% bamboo shoot shell + 15% whole-crop corn (BSS8); and (4) 12% bamboo shoot shell + 11% whole-crop corn (BSS12). After 90 days of ensiling, the silos were opened and sampled for fermentation characteristics, nutritive value and in vitro analyses, and subsequent 14-day aerobic stability test. All TMR silages were well preserved except BSS12, characterized by high lactic acid content and V-score, low pH and NH3-N and butyric acid content. With increasing proportion of BSS, crude protein increased (p <.05), and water soluble carbohydrate decreased (p < .05). Under aerobic exposure, BSS-substituted (BSS4, BSS8 and BSS12) silages were more stable than BSS0 silage, as characterized by relatively low silage temperature and high water soluble carbohydrate content. No obvious (p> .05) difference of BSS substitution was observed on in vitro ruminal gas production, digestibility, metabolizable energy and net energy for lactation. The substitution of whole-crop corn with 4% BSS and 8% BSS had no undesired effect on the fermentation characteristics and in vitro digestibility, and efficiently improving the aerobic stability of TMR silages. The BSS8 substitution level is recommended to maximize the BSS utilization.  相似文献   

17.
Abstract

The effects of including wheat in the total mixed rations of dairy cows were evaluated using a 4×4 Latin square dose response experiment with 28 dairy cows (Swedish red). The animals were averaging 150 days in milk at the start of the experiment. Diets consisted of mixtures of maize and grass silage with wheat grain at four levels (8, 16, 24 and 32% of dry matter (DM)). The animals consumed 17.8, 19.7, 21.1 and 23.8 kg of DM and produced 28.1, 29.1 29.6 and 30.2 kg of energy corrected milk, respectively. Digestibility of DM and neutral detergent fibre (NDF) was determined using indigestible NDF (iNDF) as a marker. DM digestibility, feed intake and milk and protein yields increased with increasing wheat content while the milk fat concentration, the digestibility of NDF and the feed efficiency of the diets decreased.  相似文献   

18.
We evaluated the effects of replacement of heading stage harvested timothy silage with early‐harvested orchardgrass–perennial ryegrass mixed (OP) silage while maintaining or reducing concentrate input on dry matter intake (DMI), milk production, nutrient digestibility, and N balance in dairy cows. Nine multiparous Holstein cows were used in a replicated 3 × 3 Latin square design with three dietary treatments: TYL, a diet containing timothy silage where forage‐to‐concentrate ratio (FC) was 50:50; OPL, a diet containing OP silage where FC ratio was 50:50; and OPH, a diet containing OP silage where FC ratio was 60:40. We observed that an equal replacement of timothy with OP silage increased DMI, milk yield, milk protein production, and nutrient digestibility but decreased milk fat content (TYL versus OPL). We observed that replacing timothy with OP silage while reducing concentrate input increased milk fat and protein yield, nutrient digestibility, and feed efficiency and reduced urinary N loss with no effect on DMI or milk fat content (TYL versus OPH). These results show that replacing timothy with OP silage can be a good approach to improve milk production, feed efficiency, and N utilization and reduce concentrate input. However, milk fat depression should be considered when an equal substitution is performed.  相似文献   

19.
We studied the feed intake and milk production of Holstein × Zebu crossbred cows fed sorghum silage diets and concentrates, with and without the addition of crambe meal. Using a change-over design for a total of 120 days, eight cows were fed two diets (concentrates + silages with and without crambe meal) in four 30-day periods, with four replications (animals). The crambe meal diet increased (P < 0.05) the dry matter intake (DMI), crude protein intake (CPI), and non-fibrous carbohydrates intake (NFCI) as well as milk production (4.3%). No difference was noted (P > 0.05) for the milk composition between the treatments. Crambe meal as an additive in sorghum silage (100 g/kg in natural matter) showed a great potential for introduction in dairy farming as it substantially increases CP intake, does not reduce food intake, raises animal productivity, and does not affect milk composition.  相似文献   

20.
This study was undertaken to develop models which could be used in conjunction with the near infrared reflectance spectroscopy (NIRS) analysis of grass silage to accurately predict the intake potential of grass silage when offered to lactating dairy cows as part of a mixed diet. Empirical models were developed with data collected from two large-scale studies carried out at the Institute. The models comprised of (1) a linear equation for converting the NIRS-based predicted intake of a given silage for beef cattle to dairy cows and (2) a model which corrected the intake potential of the grass silage for supplementary concentrates. Furthermore, a milk yield adjustment factor of 0.14 kg DM/kg milk was utilised to standardise milk yields. Both linear and exponential models were developed to describe the decrease in silage intake as concentrate intake increased, with y-axis intercepts corresponding to unsupplemented silage intakes (NIRS-based predictions for beef cattle adjusted for dairy cows) and common x-axis intercept of 168.0 (SE=20.50) and 203.8 (SE=5.64) g/kg W0.75, respectively, corresponding to concentrate intake when offered as a sole feed. A common r parameter (model curvature) of 1.0047 (SE=0.00397) was assumed for the exponential model. When the models were validated against the data from an independent study, the predictions from the two models were not significantly different, giving R2 values of 0.70. The intercept and slope from the linear model were 5.39 and 1.01, respectively, and the intercept and slope from the exponential model were 6.10 and 0.98, respectively. Both intercepts and slopes were not significantly different from 0 and 1, respectively. Ninety-three percent of predictions were within 10% of observed intakes in the validation data.  相似文献   

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