中草药饲料添加剂在奶牛生产中的应用

本文针对中草药对奶牛泌乳性能、抗热应激、免疫机能及繁殖等方面的影响作一综述。     

饲料中添加烟酸对夏季奶牛产奶性能的影响

试验选取9头泌乳早期处于热应激的荷斯坦牛,采用3×3拉丁方设计,分别饲喂基础日粮(对照组)和在基础日粮中添加5g/d和10g/d烟酸日粮,研究添加烟酸对奶牛生产性能影响。结果表明:添加5g/d和10g/d烟酸可使奶牛产奶量分别提高13.20%和9.39%(P<0.05);而4%标准乳量无显著差异(P>0.05);添加烟酸对乳蛋白和乳脂率无显著影响(P>0.05)。     

Organic dairy farming in Norway under the 100% organically produced feed requirement

The derogation to use a percentage of cheaper non-organic feeds in organic livestock diets for herbivores expired from January 2008. (In Norway, a maximum of 15% conventional feedstuffs per year was allowed until 24 August 2005, 5% in the interim.) This study aimed to assess changes in resource use and financial impacts for organic dairy herds of the 100% organic feeding rule (compared with 85% organic feeds) using a two-stage stochastic programming modelling framework. In this study, the objective function was to maximise expected net income. Two organic dairy farms in the lowlands of southern Norway, both having a milk quota of 100,000 l but with varying farmland availability (37 ha vs. 20 ha), were examined. Furthermore, situations with and without possibilities to buy organic silage were studied. Milk production per cow was highest on the farm with the most strict land constraint. For farmers that fully utilise the non-organic feed allowance, the more expensive organic feeds determine the marginal feed cost. Hence, a removal of the non-organic feed allowance will not influence optimal farm practice (provided that marginal milk production is still profitable). A switch from conventional to organic concentrates as the only adjustment was found on the 37 ha farm and also on the 20 ha farm if there was no possibility to buy some organic silage. On the 20 ha farm with possibilities to buy organic silage, it turned out to be unprofitable to keep all the cows. Fewer cows resulted in several other changes in the model solution such as a lower milk yield per cow, less milk produced in total and more work off-farm. The financial gain from carrying out the optimal management changes was, however, very small. In all cases studied, the introduction of 100% organic feeds resulted in an economic loss of NOK 19,200–23,600 (or 7–12% of the expected net income with 85% organic feeds). The economic losses were due to the price premium of organic concentrates.     

The effect of feed barrier design on displacements during feeding of dairy cows in small herds

The aim of this study was to investigate the effect of feed barrier design on displacements in dairy cows fed only roughage diets in the bunk in small commercial dairy herds. Six Norwegian dairy herds with open barriers (OB) and six herds with individual headspace barriers (IHB) were randomly selected. Number of displacements and withdrawals without physical contact was somewhat higher, but not significantly higher, in the IHB herds than in the OB herds but the variation between herds within the type of barrier were very large. The number of pushes and buttings directed towards the front part of the body of cows was significantly higher in the OB herds than in the IHB herds whereas pushes and butts directed towards the side of cows were significantly higher in the IHB herds than in the OB herds.     

Environmental impacts of a Japanese dairy farming system using whole‐crop rice silage as evaluated by life cycle assessment

The objectives of this study were to assess and compare the environmental impacts of two types of dairy farming systems, one of which makes use of whole‐crop rice silage and the other of which is conventional, using life cycle assessment (LCA). The functional unit was defined as 1 kg of 4% fat‐corrected milk (FCM). The processes associated with the dairy farming life cycle, such as feed production, feed transport, animal management including biological activity of the animal, and waste treatment were included within the system's boundaries. Environmental impacts of the rice silage‐using and conventional dairy farming systems were 987 and 972 g CO₂ equivalents for global warming, 6.87 and 7.13 g SO₂ equivalents for acidification, 1.19 and 1.23 g PO₄ equivalents for eutrophication, and 5.53 and 5.81 MJ for energy consumption, respectively. Our results suggest that the dairy farming system using rice silage in Japan has smaller environmental impacts for acidification, eutrophication, and energy consumption, and a larger impact for global warming compared with conventional farming. Further interpretation integrating these impact categories suggested 1.1% lower environmental impact of the rice silage‐using dairy farming system as a whole.     

Participatory Livestock Farmer Training for improvement of animal health in rural and peri-urban smallholder dairy herds in Jinja,Uganda

Within the framework of a research project investigating methods to decrease mastitis incidence, farmer groups for participatory training in a modified Farmer Field School approach were initiated in order to improve animal health and farmer knowledge in mastitis control technologies in smallholder dairy farms in the Jinja district of Uganda. Two peri-urban groups and one rural group met for common learning and training two hours per fortnight during a 12-month period, facilitated by two local extension agents together with one or two scientists from Makerere University. Farmers rotated each time between farms owned by group participants, which demanded mutual trust, openness and respect. From their own assessment the farmers felt they had improved their milk production and reduced mastitis incidence on their farms. In an evaluation workshop, they articulated how they had built up common knowledge and experience from training in systematic clinical examination of animals, evaluation of the farm environments, and identification of improvements. Much of the acquired new knowledge was about basic dairy cow management and husbandry practices. In addition, they gave examples of how they were now used as resource persons in their local communities. Principles of learning and empowerment are discussed.     

Effect of using Acacia mearnsii tannin extract as a feed additive on nutritional variables and productive performance in dairy cows grazing a temperate pasture

This study was carried out to evaluate the impact of including Acacia mearnsii tannin extract (TA) as a feed additive on nutrition and productive performance of dairy cows grazing a high‐quality temperate pasture and receiving supplementation with a concentrate feedstuff. Fourteen multiparous Holstein cows were assigned to either of the following treatments: concentrate without or with 20 g TA/kg dry matter (DM). Concentrate intake accounted for 32% of the total DM intake. Tannin addition increased the herbage DM intake by 22% (p < .05). There was no effect of TA inclusion on milk yield, milk composition, milk nitrogen (N) excretion, milk and plasma urea‐N concentration, urinary excretion of total N, urea‐N, and purine derivatives. However, TA inclusion increased the N intake and retention, total N excretion in manure, fecal N to urine N ratio, and decreased the dietary N efficiency for milk production and the percentage of ingested N excreted in urine (p < .05). In conclusion, supplementing dairy cows grazing a high‐quality temperate pasture with a concentrate containing 20 g TA/kg DM showed the potential of decreasing the proportion of ingested N excreted in urine without affecting the productive performance.     

甜菜碱对奶牛采食量、泌乳性能和血液指标的影响

选用20头体重(597±11.8)kg、泌乳天数(88±4.5)d、日产奶(26.3±0.5)kg的经产奶牛,随机分为4组,采用4×4拉丁方设计,研究甜菜碱(0、50、100和150g/d)对泌乳早期奶牛采食量、泌乳性能和血液指标的影响。结果表明:日粮添加甜菜碱对奶牛的采食量、乳蛋白率、乳糖率和血糖浓度无显著影响,100g/d组和150g/d组鲜奶产量显著高于对照组和50g/d组(P<0.05);100g/d组和150g/d组4%乳脂校正乳、能量校正乳和乳脂产量显著高于对照组(P<0.05);100g/d组乳脂率显著高于对照组(P<0.05);100g/d组和150g/d组血浆游离脂肪酸和β-羟丁酸浓度显著低于对照组(P<0.05)。根据以上结果推断,甜菜碱的适宜添加水平为100g/d。     

Farming strategies in organic dairy farming: Effects on breeding goal and choice of breed. An explorative study

Organic farming principles give rise to multifunctionality: different activities are combined at farm level to create ecological and economic synergies. These principles do however allow for different operationalisations and different farm development strategies, for example with regard to the use of external inputs or the decision whether or not to use advanced breeding technologies such as artificial insemination. Maintaining and improving diversity are therefore characteristic to organic farming. Since organic farming took off in the early 1990 s, many specialised dairy farms which tend to be more mono-functional in nature, have converted to organic, adding a new farming strategy to the diverse collection of farming strategies in organic dairy farming. All these farming strategies actually create different organic production environments for cows, which might result in different demands on selective breeding and breeding technology. This differential demand was explored in a survey, among 151 organic dairy farmers, on general farm strategy, milk production, breeding goal, choice of breed and approach to reproduction. Farmers were divided into one of two groups on each of three strategic options: a) diversification in farm business—Specialised Dairy Farming vs. Multifunctional Farming; b) intensity of milk production—Low Input vs. High Input Farming and c) naturalness of breeding—Farming with Artificial Insemination vs. Farming with Natural Service.A pair-wise comparison within each strategic option showed that each pair differed significantly with regard to farm characteristics, farm goal and animal production goals. However, there were only minor or no significant differences within each pair with regard to overall breeding goal. For each strategic option, big differences were found within each pair as regards preferred cattle breeds and crossbreeds. Farmers in the Specialised Dairy Farming and High Input Farming groups preferred milk-type cattle (Holstein and Holstein crossbreeds), while farmers in the Multifunctional Farming and Low Input Farming groups preferred various native Dutch breeds. But even farmers with a similar strategy (within one group) differed strongly in their choice of breeds and crossbreeds. These results indicate that organic farmers are going through process of learning by doing, experimenting as they search for breeds or crossbreeds that are optimally suited to their farm environment and that best agree with their farm development strategy. In this, the growing preference for keeping bulls on the farm for natural service is remarkable.     

围产期饲粮中添加外源能量饲料对奶牛泌乳性能的影响

试验研究围产期奶牛日粮中添加瘤胃脂肪粉、葡萄糖及丙二醇外源能量饲料对奶牛泌乳性能的影响.试验选取40头处于围产前期、体况相近的中国荷斯坦奶牛,随机分成4组,每组5个重复,每个重复2头牛,处理组日粮在对照组基础日粮中分别添加200 g/d的过瘤胃脂肪粉(脂肪组)、葡萄糖(葡萄糖组)和丙二醇(丙二醇组),试验期30 d.结...     

Glycerine as a feed supplement for beef and dairy cattle: A meta-analysis on performance,rumen fermentation,blood metabolites and product characteristics

This study aimed to comprehensively evaluate the effects of glycerine supplementation at various concentrations on performance, rumen fermentation, blood metabolites and product characteristics of beef and dairy cattle in vivo by using a quantitative meta-analysis approach. Meta-analysis was performed by integrating a total of 52 studies from 39 articles and 182 treatments into a database. Data were constructed into an intact database and did not distinguish between beef and dairy cattle, except for the parameters of production performance and product characteristics. Data summarized were analysed by using a statistical meta-analysis that employed a fixed effect of glycerine supplementation level and a random effect of various studies for both beef and dairy cattle. Significance of an effect was stated at the probability level of p < .05, and p < .1 was considered as a tendency of significant. Results revealed that there was a linear decrease on dry matter intake (p < .01) and daily gain (p < .05) of beef cattle with the increasing levels of glycerine supplementation. Glycerine supplementation did not decrease milk production of lactating dairy cows. Molar proportion of acetate in the rumen was decreased (p < .001), whereas propionate and butyrate proportions were increased (both at p < .001) by glycerine supplementation. Generally, glycerine did not change nutrient digestibility except that it reduced fibre digestibility (p < .001). Glycerine supplementation linearly lowered triglyceride and NEFA concentrations (both at p < .05) in the blood serum, but not other blood metabolites. Glycerine tended to linearly increase (p < .1) carcass percentage in beef cattle. Increasing dietary glycerine levels decreased milk fat (p < .01) but elevated milk protein (p < .001). Glycerine tended to increase milk lactose (p < .1) by following a quadratic pattern. The proportion of MUFA was increased quadratically by glycerine supplementation (p < .05), whereas glycerine tended to decrease SFA by following a quadratic pattern (p < .1).     

Physically effectiveness of beet pulp‐based diets in dairy cows as assessed by responses of feed intake,digestibility, chewing activity and milk production

Nine multiparous Holstein cows (DIM = 56 ± 5 day) were randomly assigned to three experimental diets containing fine‐dried (T1), normal‐dried (T2) and pelleted (T3) beet pulp (BP) at 12% on a dry matter basis in a 3 × 3 change over design in three 21 day periods to evaluate the effects of three types of BP. Bulk density, functional specific gravity and water‐holding capacity of ration and intake were similar, but intake of physically effective fibre was different among treatments. Without significant differences, nutrients' digestibility in T1 trended to be higher than T2 and T3. Ruminal liquid pH and N‐NH3 concentration were lower in T1 and higher in T3 than T2. Grinding and pelleting of BP increased and decreased volatile fatty acid concentration respectively. Grinding decreased acetate and propionate and increased butyrate and lactic acid. In contrary to pelleting, grinding of BP increased the particulate ruminal passage rate, but decreased ruminal mean retention time and lower compartment mean retention time. Pelleting of BP decreased ruminal passage rate, but increased ruminal mean retention time and lower compartment mean retention time. Grinding increased 5.64, 5.9 and 5.8% eating time, rumination and total chewing activity in comparison with normal BP respectively. Pelleting increased 2.7%, 16.3% and 10.0% eating time, rumination and total chewing activity in comparison with T2 respectively. Milk yield had no significant difference, but milk yield adjusted to 4% fat, and milk fat (kg/day), fat, protein, casein and total solid of milk (%) were affected by the treatments. Results from this experiment show that based on milk fat assay, grinding did not reduce effectiveness of BP, but pelleting significantly increased effectiveness of BP. In addition, based on total chewing activity, grinding did not reduce physically effectiveness of BP, but pelleting of BP increased its physically effectiveness.     

Plasma cholesterol levels and short-term adaptations of metabolism and milk production during feed restriction in early lactating dairy cows on pasture

Low plasma total cholesterol (TC) concentrations are characteristic during the negative energy balance in early lactating dairy cows. The objective was to investigate short-term effects of different TC concentrations during an aggravated energy deficiency through a 1-week concentrate withdrawal on adaptations of metabolism and milk production. Multiparous Holstein cows (n = 15) were investigated during 3 week beginning at 24 ± 7 DIM (mean ± SD). Cows were kept on pasture and received additional concentrate in experimental week 1 and 3, while in week 2, concentrate was withdrawn. Blood was sampled once and milk twice daily. Based on their average TC concentration during week 1 (prior to concentrate withdrawal), cows were retrospectively assigned into a high (H-Chol; n = 8, TC ≥ 3.36 mmol/L) and a low TC groups (L-Chol; n = 7, TC < 3.36 mmol/L). Concentrations of phospholipids and lipoproteins were higher in H-Chol compared to L-Chol throughout the study (p < 0.05). During concentrate withdrawal, milk yield, glucose and insulin concentrations decreased similarly in both groups, while milk fat, milk acetone and plasma BHB were higher in H-Chol compared to L-Chol (p < 0.05). Compared to initial values, plasma NEFA, TAG and VLDL increased in both groups within 2 days after concentrate withdrawal (p < 0.05). Concentrations of NEFA during week 2 were greater in L-Chol compared to H-Chol (p < 0.05). Despite reintroduction of concentrate, milk yield in H-Chol remained lower for two more days compared to week 1 (p < .05), whereas milk yield recovered immediately in L-Chol. Activity of aspartate aminotransferase was higher in H-Chol compared to L-Chol in week 2 (p < 0.05). Greater plasma TC concentrations were associated with a reduced increase of NEFA. Further research is warranted if TC concentrations are related to adipose tissue mobilization and fatty acid turnover.     

不同水平的青贮饲料对饲喂稻草秸秆奶牛瘤胃微生物数量和微生物蛋白合成的影响

本试验的目的是确定饲粮中青贮银合欢添加水平对奶牛瘤胃微生物种群、氮平衡和微生物蛋白合成的影响。试验采用4×4拉丁方设计,选择12头初始体重为163±16 kg、带有瘤胃瘘管的奶牛,随机分为4个组,每组3个重复,每个重复1头牛。基础日粮以100%的水稻秸秆为原料,处理组分别用30%、60%和100%的青贮银合欢替代水稻秸秆,奶牛自由采食水稻秸秆和青贮银合欢,每天按照体重的0.2%补充浓缩料。结果表明,用60%青贮银合欢替代水稻秸秆组奶牛瘤胃微生物群,尤其是纤维素分解菌、蛋白分解菌和厌氧真菌的数量显著增加(P<0.05),各组对淀粉分解菌群无显著影响(P>0.05)。原生动物种群数量随日粮青贮银合欢添加水平的增加呈线性下降(P<0.05)(P<0.05)。此外,氮平衡和微生物蛋白合成均随着日粮青贮银合欢添加水平的升高而升高(P<0.05),其中以60%青贮银合欢组最高。结论:在本试验基础上,用60%青贮银合欢替代水稻秸秆可以显著提高奶牛体内的微生物数量和微生物蛋白的合成。     

Effect of several doses of zeolite A on feed intake,energy metabolism and on mineral metabolism in dairy cows around calving

The object of the present study was to determine the influence of different zeolite A doses on dry matter intake (DMI) and mineral metabolism, and to evaluate an optimum dosage for preventing hypocalcaemia. Eighty pregnant dry cows were assigned to four groups (I–IV). They were fed a total mixed ration (TMR) ad libitum. Groups II, III and IV received an average daily dose of 12, 23 and 43 g zeolite A/kg DM for the last 2 weeks prepartum. Individually DMI was recorded daily. Blood and urine samples were taken before, during and after zeolite A supplementation. Serum was analysed for Ca, Mg, P_i, K, non‐esterified fatty acids and β‐hydroxybutyrate (BHB). Urine was analysed for Ca, Mg, P_i, K and net acid‐base excretion (NABE). After calving, milk yield (fat corrected milk) and milk composition were determined. During zeolite A supplementation, mean DMI of Group IV (7.3 ± 1.3 kg/cow/day) was significantly lower compared to Groups I–III (10.1, 10.9, 9.5 kg/cow/day). The reduced feed intake of Group IV resulted in significantly increased BHB as well as decreased NABE after calving. Zeolite A supplementation in higher doses (III and IV) had a stabilizing effect on Ca metabolism around calving for older cows, whereas cows in Groups I and II showed a subclinical hypocalcaemia. The mean serum Mg concentration decreased significantly in older cows in Group IV at calving. The mean P_i concentration in cows of Group IV decreased into ranges of hypophosphataemia already 1 week after beginning of zeolite A feeding. The mean DMI postpartum as well as the milk yield was not affected by zeolite A supplementation. Feeding of 23 g zeolite A/kg DM TMR prepartum proved to be an adequate dosage for reducing subclinical hypocalcaemia frequency without significant effects on feed intake and P_i concentration in serum.     

Cubicle refusal and rearing accommodation as possible mastitis risk factors in cubicle-housed dairy heifers.

Fifty-nine of the 65 dairy farms with cubicle sheds in the Norwegian county of Oppland in 1990 were included in a study of rearing accommodation, cubicle refusal and mastitis incidence. The farmers recorded the favoured resting location of the individual cows and heifers throughout the final week of pregnancy as well as during calving. The observations were matched with individual records of mastitis cases during the first 30 days after calving. Mastitis incidence in the heifers was analysed by logistic regression using rearing accommodation and cubicle refusal as independent variables, controlling for herd as a clustering factor. Cubicle refusal was found in 29% of the heifers, but in only 3% of older cows. The results of the analysis indicated a tendency for cubicle refusal to be associated with an increased mastitis incidence among the heifers (OR = 2.2, c.i.95%OR = 0.9-5.4, P = 0.08). Cubicle refusal accounted for 21% (0-32%) of the mastitis cases in the study population (PAF = 0.21).     

Radioimmunoassay of milk progesterone as a tool for fertility control in smallholder dairy farms

This study focused on the use of radioimmunoassay of progesterone in milk for the diagnosis of post-partum ovarian cyclicity and accurate detection of oestrus and non-pregnancy in cows in the artificial insemination (AI) programme in Bangladesh. In Investigation 1, milk samples were collected on day 0 (day of AI), day 9–13 and day 21–24 from 444 milking cows of various breeds presented for the first post-partum insemination by 413 farmers living at 182 villages/regions in Mymensingh District from 6 AI centres and sub-centres. Each cow was then examined three times after each AI until it stopped returning to oestrus. Sixty to 90 days after the last AI, the cows were examined per rectum to confirm the pregnancy. Milk progesterone data on day 21–24 contributed to a clear diagnosis with respect to non-pregnancy in 100% cows, indicating a possible use of this progesterone assay for identifying non-pregnant cows in AI programmes. In Investigation 2, milk progesterone was monitored two times in a month with a 10-day interval in 88 cows. The samples were taken between 10 days after calving and the first detected oestrus, followed by two more samples 10 days apart. The proportion of cows accurately detected in oestrus was 30%. Another 30% were stated to be in oestrus when they were not (false positive) and 40% were not detected when they were in oestrus (false negative). The mean intervals between calving and oestrus and between calving luteal activity were 40 to 362 days (median = 120, n = 82) and 34 to 398 (median = 111, n = 64) days, respectively. The body condition scores at calving and at the initiation of luteal activity influenced the interval between calving and luteal activity (p < 0.05). Cows suckled twice daily initiated luteal activity earlier than their counterparts suckled several times daily (p < 0.05). Determination of progesterone in milk on day 21–24 is a good means for detecting non-pregnant cows.     

Effects of soybean meal supplementation on ruminal kinetics of feed particle size reduction and passage in dairy cows fed rice straw

Six ruminal-cannulated nonlactating Holstein Friesian cows (mean body weight:660 ± 42.9 kg) were used to investigate the effect of soybean meal (SBM) supplementation on voluntary rice straw (RS) intake, feed particle size reduction, and passage kinetics in the rumen. They were allocated to two dietary treatments: RS alone or RS supplemented with SBM. Voluntary dry matter intake of RS and total tract fiber digestibility was increased by SBM supplementation (p < 0.05). Supplementation with SBM decreased rumination time per dietary dry matter (DM) and neutral detergent fiber (NDFom) intake (p < 0.01). Particle size distribution in the rumen and total ruminal NDFom digesta weights were not affected by SBM supplementation. However, the disappearance rates of total digesta and large and small particles from the rumen were increased by SBM supplementation (p < 0.01). Moreover, SBM supplementation increased the rate of size reduction in ruminal particles (p < 0.05). In situ disappearance of DM and NDFom of RS in the rumen was greater in SBM-supplemented cows than in nonsupplemented cows (p < 0.05). This study clearly showed that increased ruminal RS particle size reduction, passage, and fermentation due to SBM supplementation accelerated the RS particle clearance from the rumen and resulted in increased voluntary RS intake of dairy cows.