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1.
The aim of this study was to compare the effects of rotational and continuous grazing on herbage mass (HM), organic matter digestibility (dOM) and intake (OMI) and live weight gain (LWG) of sheep grazing on the inner Mongolian steppe, China at a stocking rate of 4.5 sheep/ha during the growing season. In the years 2005 and 2006, four 2-ha plots were used of which two were divided into four 0.5 ha paddocks each for rotational grazing, where sheep were moved each 10 days to the next paddock. The dOM was estimated from faecal crude protein concentration and OMI by oral administration of titanium dioxide. Herbage mass was similar in both grazing systems and dOM and OMI were higher (p < 0.05) at continuous grazing than at rotational grazing, but LWG did not differ probably because of extra energy expenditure for grazing and walking in a larger area. The dOM and OMI decreased (p < 0.05) with progress of the growing season and differed between years. Since precipitation during the growing season in both years was lower than the 30 years average which was probably the reason that positive effects of non-grazing periods on herbage regrowth and quality at rotational grazing could not occur, further studies are required in years with average precipitations before a final evaluation of these grazing systems can be made. Moreover, it seems necessary to quantify energy expenditure for physical activity of animals in grazing studies.  相似文献   

2.
Effects of grazing management systems (GS) on biomass production and nutritional quality of rangeland vegetation in semiarid regions are extensively studied; however, limited information is available regarding their effects on diet digestibility and feed intake of grazing livestock. We therefore analyzed digestibility of ingested organic matter (dOM), organic matter intake (OMI), and live weight gain (LWG) of sheep in a grazing experiment established in the Inner Mongolian steppe of China, where two GS were tested for six different grazing intensities (GI) from very light to heavy grazing. For the continuous grazing system, sheep grazed the same plots each year, and for the alternating system, grazing and hay making were alternated annually between two adjacent plots. In July, August, and September 2009 and 2010, feed intake and live weight of sheep were determined. The GS did not affect dOM (P = 0.101), OMI (P = 0.381), and LWG of sheep (P = 0.701). Across both GS LWG decreased from 98 g · d-1 for GI1 to 62 g · d-1 for GI6 (P &spilt; 0.001; R2 = 0.42). There were no interactions between GS and GI for all measured parameters (P ≥ 0.061), indicating that alternating grazing did not compensate for negative effects of heavy grazing even after 4 yr of grassland use. In summary, our study showed that irrespective of GI, alternating grassland use does not improve dOM, OMI, and hence, LWG of sheep. However, it might enhance revenues and ecological sustainability in the long term when compared to the common practice of continuous grazing at very high stocking rates.  相似文献   

3.
The concentration of condensed tannins (CT) in sulla (Hedysarum coronarium L.) is moderate and overall regarded as beneficial. However, the intake of this forage can reduce diet digestibility, particularly during flowering phase. An experiment was run to assess the effect of CT on feeding behaviour, intake, diet digestibility and performance of dairy sheep rotationally grazing sulla at flowering phase. Twenty-four late-lactating sheep were blocked in two homogeneous groups and submitted to the following treatments: i) twice daily drenching with 200 g/day of a 50% w/v water solution of an anti-tannic substance, polyethylene glycol, group PEG; ii) twice daily drenching with 200 g/day of water, group CON (Control group). All the sheep rotationally grazed as a flock two sulla plots from April to June (8 weeks in total). Sward height, herbage mass, botanical and chemical composition of the herbage were measured at the beginning and the end of each grazing period. The feeding behaviour (3 sheep per group) was continuously monitored for 24 h in 6 weeks using the IGER behaviour recorders. Herbage DM intake (DMI), dietary DM digestibility (DMD) and apparent CP digestibility (CPD) were estimated on 8 sheep per group by the n-alkane method. On average, PEG group had longer total grazing (503 ± 12 vs 460 ± 12 min, P < 0.05) and eating time (425 ± 13 vs 391 ± 13 min, P < 0.07) than CON group. Moreover PEG group showed shorter inter-meal intervals (41 ± 3 vs 52 ± 3, min, P < 0.05) and higher number of daily meals than CT-exposed group (24 ± 1 vs 19 ± 1 min, P < 0.01). The herbage DMI was not affected by the treatment whereas DMD (74.60 ± 3.48 vs 58.30 ± 3.01%), and CPD (60.14 ± 4.83 vs 38.21 ± 4.83%) were both increased by PEG administration (P < 0.05) confirming the negative effect of sulla CT on these variables. Milk yield tended to be higher in PEG than CON (1331 ± 45 vs 1205 ± 59 ml, P < 0.11). Milk protein content was similar between groups while milk fat content was higher in CON than PEG ewes (6.61 ± 0.15 vs 6.11 ± 0.15%, P < 0.05), being the reverse true for milk urea (46.04 ± 1.27 vs 53.04 ± 0.76%, P < 0.001). To conclude, this experiment shows that when sulla is grazed at flowering as monoculture, dietary CT can exert negative effects on DM and CP apparent digestibility, in this study partially counterbalanced by a better metabolic utilisation of the nutrients up-taken.  相似文献   

4.
The aim of the current study was to investigate the associative effects of a cornstalk-based diet supplemented with alfalfa (Medicago sativa) hay on intake, digestibility, nitrogen (N) metabolisation, rumen environment and hematological parameters in Xiaoweihan sheep. We also investigated the optimal range of alfalfa hay to achieve positive associative effects and avoid negative effects. Xiaoweihan sheep (n = 5; fitted with rumen T-cannula) were fed five cornstalk-based diets in a 5 × 5 Latin square design. Diets contained 0, 50, 150, 300, 450 g alfalfa, and were supplemented with 100 g concentrate, respectively. Our results suggested that supplementation of 300 g alfalfa hay reduced (P < 0.05) cornstalk intake, but significantly increased dry matter (DM) intake (P < 0.05). Additionally, DM digestibility of 150 g alfalfa hay supplementation was slightly higher than that noted in other diets. Metabolism studies showed 50–150 g alfalfa hay supplementation had a positive associative effect (P < 0.05) on N utilization, with the greatest benefit noted with 150 g per day (P < 0.05) compared to unsupplemented diets. Alfalfa supplementation (50–450 g per day) resulted in an elevated trend of ammonia nitrogen (NH3–N) with 50 or 150 g of alfalfa hay more likely to promote sheep rumen environment, with a noticeable increase (P < 0.05) in serum urea nitrogen (UREAN) concentrations observed with 300 g alfalfa hay per day. Our data suggested that the optimal range to achieve beneficial effects and avoid negative effects was 150–300 g per day for cornstalk-based diets for sheep.  相似文献   

5.
To clarify the effect of digesta weight in the reticulorumen on diurnal and seasonal fluctuations in herbage intake, six ruminally cannulated, non‐lactating dairy cows were grazed on perennial ryegrass/white clover pasture during morning and evening sessions in spring and autumn. The digesta weight of fresh matter, dry matter (DM) and fiber in the reticulorumen at the beginning and the end of each grazing session was lower in spring than in autumn (P < 0.01). Although the digesta weight was similar between the sessions at the beginning of grazing, it was greater for the evening than for the morning at the end of grazing (P < 0.01). The large particles proportion in the digesta was lower for the morning than the evening (P < 0.01), and it was lower in spring than in autumn (P < 0.01). The concentrations of volatile fatty acids in rumen fluid were generally higher in spring compared with autumn. The herbage DM intake during the evening was greater compared with the morning in both seasons (P < 0.01). However, there was no difference in herbage DM intake between seasons. The results showed that the rumen digesta fill was not the sole factor explaining diurnal and seasonal variation of herbage intake in grazing dairy cows.  相似文献   

6.
The nutritional status of cows grazing on a 120‐ha public alpine forestland pasture dominated by the dwarf bamboo Sasa senanensis located in central Japan was evaluated over the course of 2 years. Data were collected during grazing seasons in three periods: early (June), mid‐ (August) and late (late September–early October) periods. During these periods, the number of experimental Japanese Black cows varied between three and six. With the exception of the dry matter (DM) intake in 2005 and the crude protein (CP) digestibility in 2006, the DM and CP intake and digestibility were lower in the mid‐ and late periods than in the early period for both years (P < 0.05). Metabolizable energy intake was slightly insufficient for the requirement of the cows in the late period of 2005; in the mid‐ and late periods of 2006, the metabolizable energy intake was 0.4 to 0.5 times the requirement. These results suggest that the energy intake of cows grazing on forestland pasture dominated by S. senanensis would not satisfy their requirements starting in the mid‐period (August) grazing, even though the pasture had abundant herbage resources during these periods.  相似文献   

7.
Whole pod and seeds of velvet bean (Mucuna pruriens) were included in diets for growing sheep used to validate previously estimated ME values of 9.7 MJ and 12.6 MJ for whole pod and seed respectively. Twenty-four lambs, 15 females and nine males of 18.7 ± 2.4 kg average weight, were allocated in three treatments using a completely randomized block design with eight replicates per treatment. Each group was given a diet with a ratio of 60% of Napier grass (Pennisetum purpureum) and 40% of a supplement with the addition of 0%, 50% whole pod or 66% of M. pruriens seeds, for TI, TII and TIII respectively. Diets were formulated to meet the requirements for 100-g daily live weight gain (LWG). The total dry matter intake (836 g a−1 d−1, forage + supplement), LWG (90 g a−1 d−1) and feed conversion (9.66 kg DM/kg LWG) of lambs from TIII were lower (P < 0.05) compared to 941 g, 121 g, and 7.78 kg DM/kg LWG from TII and 976 g, 132 g and 7.50 kg DM/kg LWG from TI respectively. No difference was found (P > 0.05) between TI and TII in the three evaluated variables. The ME values of whole pod and seeds of M. pruriens used in this work were validated. It was concluded that M. pruriens can be included as a component in diets for growing sheep, as a partial replacement of conventional feedstuffs.  相似文献   

8.
A study which included growth and digestibility experiments was conducted to evaluate the feeding value of a) enset pseudostem, b) enset corm or c) enset mixture (containing equal amounts of pseudostem, corm and enset leaf on a DM basis) as a supplement to a basal diet of wheat straw fed ad libitum and restricted amounts of Desmodium intortum (Desmodium) hay to sheep. During the 71-day growth experiment, 18 one-year-old male sheep of indigenous breed with mean body weight (BW) of 20.2 (± 0.43) kg were randomly assigned to the three treatments. In the digestibility experiment, three male sheep with mean BW of 19.5 (± 1.06) kg were assigned to each treatment. Sheep supplemented with enset mixture consumed more (P < 0.001) wheat straw DM (335 g/day) than those supplemented with pseudostem (295 g/day). No differences were found in total dry matter (DM) and organic matter (OM) intake between diets supplemented with pseudostem, corm and enset mixture. Total nitrogen (N) intake (g/day) was higher (P = 0.0073) in sheep fed the diet with enset mixture (12.2) followed by corm (11.3) and pseudostem (10.7). The apparent digestibility of DM was higher (P < 0.001) in pseudostem (0.53) followed by corm (0.46) and enset mixture (0.41) supplemented sheep. Organic matter, neutral detergent fiber and N digestibility were similar among treatments. The amount of N lost in urine and faeces and the N-retention was similar among treatments. There were no differences in gain/day in sheep fed diets with pseudostem (29.3 g), corm (27.0 g) and enset mixture (36.5 g). It is concluded that supplementation of a wheat straw/Desmodium diet with enset fractions could be used equally at least to maintain body weight during the dry season.  相似文献   

9.
The study was carried out to evaluate the effect of supplementing leaves of enset (Ensete ventricosum) to straw-based diets on the performance of sheep. In a growth experiment, which lasted for 76 days, 36 male sheep (average body weight of 17.3 ± 0.58 kg) were allotted to six treatments. A digestibility trial was conducted using three of the six sheep from each treatment. The treatments were untreated or 2% urea- and 3% calcium oxide-treated wheat straw as a basal diet supplemented with three levels of chopped fresh enset leaf: low (215 g), medium (417 g) and high (594 g dry matter [DM] per day). The mean total DM intake tended to be higher (p < 0.1) at medium and high levels of supplementation than at the low level. The intake of total DM and nitrogen (N) was higher in treated than untreated straw. There was no significant difference in organic matter (OM) intake among treatments. Sheep fed medium and high levels of enset leaf supplements had similar weight gain but higher than those supplemented at low level. The digestibility of DM was not significantly different among treatments whereas the digestibility of OM tended to be higher at medium than other levels of supplementation. The digestibility of N was lower (p < 0.001) for treated than untreated straw whereas the digestibility of neutral detergent fibre was higher (p < 0.001) in treated straw. The highest mean N retention was at medium level of supplementation. There were no significant differences in total purine derivatives excretion, absorbed microbial purines and microbial N supply among treatments. It could be concluded that there is no major beneficial effect beyond medium level of enset leaf supplementation in both treated and untreated straw. For efficient utilization of enset leaf, sources of fermentable energy are necessary.  相似文献   

10.
The experiment was conducted at Dilla Agricultural Technical Vocational Education and Training (ATVET) College in Ethiopia using twenty-four yearling intact male Sidama goats with a mean body weight (BW) of 16.8 ± 1.14 kg (mean ± SD). The objective of the experiment was to examine the effect of different levels of cottonseed meal (CSM) supplementation on the feed intake, digestibility, BW gain, and carcass parameters of Sidama goats. The experiment consisted of 90 days of feeding trial and 10 days of digestibility trial followed by evaluation of carcass parameters at the end of the experiment. The treatments included ad libitum feeding of hay (T1, control) and daily supplementation of CSM at 200 g (T2), 300 g (T3) and 400 g (T4) per head on dry matter (DM) basis. The experimental design was a completely randomized block design. The experimental goats were blocked on initial BW and six goats were randomly assigned to each treatment. Hay DM, crude protein (CP) and neutral detergent fiber (NDF) intake were higher (P < 0.001) in the non-supplemented than in the supplemented goats, however, the contrary was true for total CP intake. Total DM intake was higher (P < 0.001) for goats supplemented with the high level of CSM than those on the control treatment. Among CSM supplemented goats, the intake of CSM DM, CP, NDF (P < 0.001) and total CP (P < 0.01) were higher in the order of T4 > T3 > T2. The high level of supplementation with CSM resulted in better (P < 0.05) apparent digestibility coefficient (DC) of DM and organic matter (OM) compared to the non-supplemented goats. The apparent DC of CP was higher (P < 0.01) for supplemented than non-supplemented goats. The non-supplemented goats had lower daily BW gain, empty BW, dressing percentage on slaughter weight base, rib-eye muscle area (P < 0.01), BW change (P < 0.001), final BW (P < 0.05) and higher feed conversion ratio (P < 0.01) than the supplemented ones. The medium level of supplementation resulted in higher daily BW gain (P < 0.01), BW change (P < 0.001), final BW (P < 0.05) and lower feed conversion ratio (P < 0.01) than the lower level of supplementation, but with no differences (P > 0.05) in these parameters with the high level of supplementation. Therefore, it is concluded that supplementation of CSM at 300 g DM per head per day resulted in better animal performance parameters in Sidama goats.  相似文献   

11.
Variability in aboveground herbaceous biomass and its quality were studied in response to three different stocking densities during a 2-yr grazing experiment with sheep on a montane summer pasture in the Chinese Altay. We determined herbaceous cover and aboveground biomass in 16 paddocks of 0.25 ha each. Vegetation cover showed high spatial variation, prompting us to implement a randomized block design. Forage intake of one male sheep per paddock was quantified four times per grazing season by collection of total feces and estimation of diet digestibility. Sheep weight was recorded every 3 wk. Aboveground herbaceous dry mass (DM) was characterized by pronounced annual variation. Biomass quality declined with progressing season and increasing sheep density. Daily organic matter intake per sheep ranged from 0.7 to 1.4 kg, which was paralleled by a biomass removal of 710 ? 1 560 kg DM/ha at densities of 8 ? 24 sheep/ha. At 8 sheep/ha, animals gained weight throughout each grazing period, whereas weight losses of 40 ? 100 g/d occurred at higher densities. These results challenge the presently followed concept of a fixed stocking density for summer pastures in Altay Prefecture, Xinjian, China. Such practice may result in low herbage allowances and thus deficient sheep nutrition in one year, as well as underutilization of forage resources in another. Flexible adjustment of stocking densities is also advisable for montane pastures where spatiotemporal variability, although less pronounced than in desert steppes of the Altay foothills, is nonetheless highly relevant.  相似文献   

12.
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   

13.
The objective of this study was to investigate the effect of daily herbage allowance and concentrate supplementation level offered at approximately 40 and 80 days in milk (DIM) and the carryover effects at 120 DIM on the production performance of spring calving dairy cows. Sixty-six (30 primiparous and 36 multiparous) Holstein–Friesian dairy cows (mean calving date — 7 Feb ± 9.9 days) were randomly assigned to a 6 treatment (n = 11) grazing study. The experiment was a randomised block design with a 3 × 2 factorial arrangement of treatments (3 daily herbage allowances (DHA's; approximately 13, 16 and 19 kg DM/cow/day; > 4 cm) and 2 concentrate allowances (0 and 4 kg DM/day). Treatments were imposed from 21 February to 8 May. Following this period (subsequent 4-weeks) animals were offered a daily herbage allowance of 20 kg DM/cow/day and no concentrate. Milk production, total dry matter intake (TDMI), energy balance (EB) and blood metabolites were measured on three occasions — at approximately 40, 80 and 120 days in milk, R1, R2 and the carryover period, respectively. Cows offered a low DHA had a lower post-grazing sward height but increased sward utilisation (> 4 cm) during R1 and R2, there was no difference during the carryover period. Concentrate supplementation increased post-grazing sward height by 11% during R2 but had no effect during R1 and the carryover period. Daily herbage allowance had no effect on milk yield or composition during R1 however a low DHA tended to reduce milk yield in R2. Concentrate supplementation increased milk and solids corrected milk (SCM) yield by 4.1 and 2.8 kg/cow/day, respectively during R1 and also increased R2 milk production performance, this effect extended into the carryover period. Offering a low DHA restricted grass dry matter intake (DMI) during R1 and R2 yet concentrate supplementation significantly increased total DMI (2.3 (R1) and 3.0 (R2) kg DM/cow). Animals offered a low DHA had a significantly lower bodyweight (BW) than those offered a medium or high DHA during P1 and P2. Concentrate supplementation increased BW during P1 and P2 (+ 9 and + 14 kg/cow, respectively). There was no effect of treatment on BW during P3. There was no effect of DHA on EB in R1; during R2 animals offered a low DHA had the lowest EB. Concentrate significantly increased EB in R1 and R2 and increased plasma glucose concentration while it decreased plasma NEFA and BHB concentrations. The results of this study indicate that animals should be offered a low DHA up to 80 DIM after which DHA should be increased however animals should also be supplemented with concentrate during the early post-partum period.  相似文献   

14.
The botanical composition, intake and digestibility of the diet selected by Inner Mongolian Cashmere goats grazing on a native Leymus chinensis plant community were measured in two grazing periods (June and August) using the n-alkane markers. In each grazing period, 48 Inner Mongolian Cashmere goats (24 wethers and 24 does with an average live weight of 22.1 ± 1.2 kg and 19.6 ± 0.8 kg, respectively) were divided in two groups (G1: grazing group; G2: cage-fed group) of 24 animals each. Based on the observation of G1 grazing behaviour, G2 goats were fed on herbage obtained by a simulative method and were housed in metabolism cages to determine the alkane faecal recoveries. Diet composition was estimated by comparing the odd-chain n-alkane pattern (C25–C35) of the selected plant species with the n-alkane faecal concentrations, corrected for their incomplete faecal recovery. The alkane pair C32:C33 and C36 alkane were used to estimate intake and diet digestibility, respectively. The results showed that the increase of herbage availability from June to August, resulted in higher (P < 0.05) DM, CP, ME, ADF and NDF intake of both wethers and does, with no evident changes in ADF and NDF intake in does., The intake of nutrients differed significantly between wethers and does in both experimental periods, except for NDF in EP1 and ME in EP2. Differences between grazing seasons and goats' sex in nutrients digestibility were not observed. Diet composition indicated seasonal differences, being Sonchus brachyotus, Artemisia frigida and Phragmites communis the main components of the diet in June. However, Suaeda corniculata, Chloris virgata, Xanthium sibiricum and Echinochloa crusgalli became the main diet components in August. Moreover, the sex affected significantly the diet choices in both grazing periods.  相似文献   

15.
N utilization at cow and field level was examined over two grazing periods of 30 days with 64 Holstein dairy cows. At cow and field level the effect of sward type (diploid vs. tetraploid perennial ryegrass, both mixed with white clover) and compressed sward height (6 vs. 10 cm) was examined. At dairy cow level the effect of urea supplementation (0 vs. 145 g/day) and energy supplementation strategy (soy hulls(am)/barley(pm) vs. barley(am)/soy hulls(pm)) was also examined. Cows grazed grass/clover swards for 7.5 h/day and were restrictively fed in the barn (3.2 kg dry matter (DM) in maize silage, 3.6 kg ground barley, 3.6 kg soy hulls per day). In none of the two periods were yield of milk (Period 1: 30.9 kg, Period 2: 25.4 kg), fat, protein and lactose significantly affected by sward type, sward height, urea supplementation or energy supplementation strategy. Urea supplementation increased the urea concentration in milk. Also low sward height and feeding soy hulls(am)/barley(pm) increased the urea concentration, probably due to a higher protein content in the sward and a higher grass intake, respectively. N utilization at cow level was highest with high sward height and no urea supplementation. Feeding soy hulls(am)/barley(pm) increased milk yield numerically but was counterbalanced by an equivalent increase in estimated grass intake, and supplementation strategy seemed therefore not to affect N utilization. At field level the N surplus was higher on diploid than on tetraploid swards (50 and 21 kg N/ha) due to a higher clover content in the diploid swards, whereas the difference in N surplus between sward heights was minimal (32 and 38 kg N/ha). Estimated N removal from the pasture in the grazing periods (intake minus excretion) increased by 5.2 kg N/ha when feeding soy hulls(am)/barley(pm), whereas with no urea supplementation the net N removal increased by only 2.5 kg N/ha. It was concluded that N utilization in dairy cows can be improved by decreasing N intake from both herbage and supplementary concentrate without compromising milk yield, and that N balance at field level could be improved by strategic barn feeding.  相似文献   

16.
The objective of this experiment was to study the effects of interactions between medium quality grass silage (GS1) and maize silage (MS) as well as between low-quality grass silage (GS2) and MS on ad libitum intake, digestibility and N retention in wether sheep. Two grass silages (GS1 and GS2) were ensiled in round bales, without additives, from the primary growth of orchard grass (Dactylis glomerata L.) harvested at two different maturity stages. The study consisted of seven feeding treatments incorporating GS1, GS2 and MS fed alone and forage mixtures of GS1 and MS as well as GS2 and MS (67:33% and 33:67%, respectively, DM (dry matter) basis).Delayed harvesting lowered (P < 0.05) the crude protein (CP) concentration in GS2 compared to GS1. The DM content (g kg− 1 fresh sample) and starch concentration (g kg− 1 DM) of MS were 264 and 211, respectively.Inclusion of MS in the GS1-based ration had positive linear effects on CP and starch digestibility (P < 0.05 and P < 0.01, respectively) and N intake (P < 0.01) while a negative effect on neutral detergent fibre (NDF) and acid detergent fibre (ADF) digestibility (P < 0.05 and P < 0.01, respectively). A positive associative response of GS1 and MS was observed for DM ad libitum intake (g kg− 1 M0.75 day− 1) (quadratic, P < 0.05), CP digestibility (quadratic, P < 0.01), N intake (quadratic, P < 0.01) and N balance (quadratic, P < 0.05). Inclusion of MS into the GS2-based ration had a positive linear effect on the ration fresh matter ad libitum intake (kg day− 1 and g kg− 1 M0.75 day− 1) (P < 0.01 and P < 0.001, respectively), NDF ad libitum intake (kg day− 1 and g kg− 1 M0.75 day− 1) (P < 0.01), digestibility of DM (P < 0.01), organic matter (OM) (P < 0.01), ADF (P < 0.05), starch (P < 0.001), digestibility of OM in DM (D-value) (P < 0.001), and N intake (P < 0.01). Positive associative effects of GS2 and MS were observed on all the intake and digestibility parameters measured, N intake (quadratic, P < 0.001) and N balance (quadratic, P < 0.05). It was concluded that, as expected, a positive associative response of GS2 and MS was recorded for all the measured parameters while that of GS1 and MS for a limited number of parameters, probably due to lower quality of MS (lower starch concentration) than required for improved utilization of the GS1-based ration.  相似文献   

17.
In vivo digestibility (eight animals) and solid particles passage rate measured by faecal Cr (four animals fistulated at the rumen) were determined on riverine buffalo bulls and Delle Langhe rams, given four diets at maintenance level (50 g/kg M0.75 per day of dry matter), according to a Latin square design, composed of a factorial combination of high and low NDF and of high and low protein undegradability. The diets were: L-30 = low NDF (530.0 g/kg DM), low undegradability of protein (29.6%, CP = 138.0 g/kg DM); L-40 = low NDF (537.0 g/kg DM), high undegradability of protein (41.0%, CP = 139.0 g/kg DM); H-30 = high NDF (583.0 g/kg DM), low undegradability of protein (28.3%, CP = 128.0 g/kg DM); H-40 = high NDF (NDF = 580.0 g/kg DM), high undegradability of protein (40.0%, CP = 128.0 g/kg DM). The digestibility of organic matter (66.68% vs. 64.32%, P < 0.05) and of the other analytical fractions (NSC, NDF, cellulose and hemicelluloses) was significantly higher in buffaloes with the exception of that of crude protein which was similar for the two species. Considering the diets within the species, the increased undegradable protein in the small intestine produces different effects: in the buffalo, it does not positively influence the digestibility of NSC but does increase that of cellulose, on the other hand in sheep it influences the digestibility of NSC. The post-ruminal digestibility of the undegraded protein, both in buffalo and sheep, is higher than that from protein of microbial origin. The passage rate of the marker of the solid particles, through the first compartment, k1 (2.86% h− 1 and 2.54% h− 1 for the buffalo and the sheep) and through the entire intestinal tract, MRT (57.50 and 58.88 h for the buffalo and the sheep) does not show significant differences in the two species. The passage rate of the marker of the solid particles in buffalo rumen, at variance with the structural carbohydrates of the diet, is more variable compared with that of the sheep.  相似文献   

18.
A 3 × 2 factorial design with growing dairy-breed bulls was used to study the effects on animal performance of (1) proportion of concentrate (rolled barley) in the diet, and (2) inclusion of rapeseed meal (RSM) in the barley-based concentrate in a total mixed ration (TMR). The interactions between concentrate proportion and RSM supplement were also examined.Three feeding experiments comprised in total of 84 Finnish Ayrshire bulls and 6 Friesian bulls. The bulls were fed TMR ad libitum. The three concentrate proportions were 300 (L), 500 (M) and 700 (H) g/kg dry matter (DM), fed without RSM (RSM−) or with RSM (RSM+). Rapeseed meal was given so that the crude protein (CP) content of the concentrate was raised to 160 g/kg DM in the RSM+ diets. In the RSM− diets the CP content of the concentrate was 128 g/kg DM, so the CP content increased 25% with RSM supplementation. Increasing the proportion of concentrate led to a linear improvement in daily live weight gain (LWG) (P < 0.05), but there were no significant treatment differences in the DM intake (kg/d). Increasing the proportion of concentrate also led to significantly higher CP (P < 0.001) and phosphorus (P) (P < 0.001) supply and significantly improved DM and organic matter (OM) digestibility (P < 0.001). However, the digestibility of neutral detergent fibre (NDF) decreased (P < 0.001) as the proportion of concentrate increased. The feed conversion rate (kg DM/kg LWG) decreased significantly with increasing concentrate proportion (P < 0.001). Rapeseed meal supplement had no effect on animal performance, but the supply of CP (P < 0.01) and P (P < 0.001) was higher when RSM was included in the diet. The CP (P < 0.001) and NDF (P < 0.05) digestibilities were also higher for the RSM+ diets than for the RSM− diets. Because RSM at the concentration used did not affect animal performance, there is no reason to use RSM supplementation for finishing dairy bulls when there is good quality grass silage and barley-based concentrate in the TMR ration. This study also shows that there is a need to update the Finnish feeding recommendations for dairy-breed growing bulls, and extra calculations are needed for the energy and protein supply of growing dairy bulls.  相似文献   

19.
The effects of (i) frequency of herbage allocation and (ii) herbage allowance on ewe and subsequent lamb performance, when autumn-saved (extended grazed, deferred grazed) pasture is grazed (between 28 Nov and 30 Jan) by spring lambing ewes during mid gestation, were studied in Experiment 1. This involved 72 crossbred ewes from days 41 to 104 of gestation allocated to one of four treatments; two herbage dry matter (DM) allowances (1.0 and 1.8 kg per ewe) by two frequencies of herbage allocation (daily or twice weekly). From day 105 of gestation to parturition all ewes were housed and offered grass silage (ad libitum) plus a total of 19 kg concentrate. Increasing herbage allowance improved ewe body condition score (P < 0.01) and live weight (P < 0.01) at the end of deferred grazing, and tended to increase herbage intake (P = 0.08) during deferred grazing. Reducing the frequency of herbage allocation increased lamb birth weight (P < 0.05). Otherwise frequency of herbage allocation did not alter (P > 0.05) forage intake or utilization, or ewe or subsequent lamb performance. In Experiment 2, the effects of herbage allowance (1.0 or 1.8 kg DM per ewe), frequency of allocation (daily, twice weekly) and grazing date (28 Nov. to 4 Dec., 12 to 18 Dec., 2 to 8 Jan. and 23 to 29 Jan.) during deferred grazing on herbage yield and composition at four subsequent harvest dates (4, 18 and 25 Apr., and 25 May) were evaluated in a split-plot design consisting of 128 plots. Delaying grazing date reduced herbage yield (P < 0.05) and the concentrations of neutral detergent fibre (NDF; P < 0.01) and acid detergent fibre (ADF; P < 0.01). Delaying harvest date increased herbage yield (P < 0.001) and reduced (P < 0.001) the concentrations of NDF, ADF and metabolisable energy. Increasing herbage allowance at grazing increased (P < 0.05) subsequent herbage yield. Frequency of herbage allocation during deferred grazing did not affect (P > 0.05) subsequent herbage yield. There was a significant interaction (P < 0.001) between grazing date and harvest date for herbage yield. It is concluded that to maximise stock carrying capacity and reduce labour requirement a herbage DM allowance of 1 kg per ewe per day, allocated twice weekly, is sufficient for ewes on deferred grazed pasture in mid pregnancy.  相似文献   

20.
The study investigated rumen dry matter (DM) degradability characteristics in a completely randomized design and the effects of milk, sweet potato foliage (SPF) from three cultivars (A = TIS-87/0087; B = TIS-8164; C = TIS-2532.OP.1.13), dried brewers' grains (DBG) and cottonseed meal (CSM) as supplements to Panicum maximum (Panicum) for pre-weaned calves in randomized complete block designs. Diet 1 = milk + SPF-A foliage + Panicum, Diet 2 = milk + SPF-B foliage + Panicum, Diet 3 = milk + SPF-C foliage + Panicum, and Diet 4 = milk + DBG & CSM + Panicum (as control). Dry matter (130 ± 0.4 to 864 ± 3.9 g kg− 1), ash (54 ± 4.2 to 173 ± 2.8 g kg− 1 DM), OM (827 ± 4.2 to 946 ± 5.7 g kg− 1 DM), N (7.4 ± 0.6 to 38.6 ± 1.4 g kg− 1 DM), and NDF (439 ± 1.4 to 774 ± 8.5 g kg− 1 DM) contents were highly significant (P < 0.01). In Trial I, 16 pre-weaned calves were used over 70 d with milk intake (34.8 ± 4.4 ml kg W− 0.75 d− 1), Panicum DMI (22.3 ± 2.77 g kg W− 0.75 d− 1), total DMI (35.7 ± 2.83 g kg W− 0.75 d− 1), and LWG (198 ± 44.6 g d− 1) not significantly different (P > 0.05). Supplement DMI varied (P < 0.05) from 11.6 g kg W− 0.75 d− 1 in Diet 3 to 16.6 g kg W− 0.75 d− 1 in Diet 4. In Trial II, 16 pre-weaned local and crossbred calves were involved over 77 d with initial age of calves, Panicum intake, metabolic DMI, and LWG similar (P > 0.05) among crosses. Birthweight varied (P < 0.05) from 17.3 kg for N'Dama × Jersey crosses to 21.2 kg for White Fulani × Brown Swiss crosses. Supplement and total DMI ranged (P < 0.05) from 172 to 483 g d− 1 for N'Dama × Jersey crosses to 233 and 674 g d− 1 for non-inseminate or purebred calves, respectively. The LWG in the White Fulani × Brown Swiss and the N'Dama × Jersey calves were respectively 30% and 24% better, though not significantly, than purebred calves. In Trial III, rumen DM degradability characteristics of feeds in three N'Dama steers showed no significant differences (P > 0.05) in slowly degradable fraction (b) and rate of degradation of b (c). Soluble fraction (a), 48-h degradation, potential degradability (PD) and effective degradability (ED) varied significantly (P < 0.05) and were lowest in Panicum, but similar for foliage among the three sweet potato cultivars. Panicum fodder showed improvements in degradation characteristics with supplementation.  相似文献   

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