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1.
Copper poisoning in a dairy herd fed a mineral supplement   总被引：3，自引：1，他引：2       下载免费PDF全文
Copper poisoning in a dairy herd resulted in the death of 9 of 63 (14%) adult Holstein cows. Clinical signs were acute anorexia, weakness, mental dullness, poor pupillary light reflexes, and scant nasal discharge. These were followed by recumbency, chocolate-colored blood, jaundice, and death. Four animals exhibited signs of hyperesthesia and/or rumen stasis prior to death. At necropsy there was generalized icterus of body tissues, with the liver appearing orange and the kidneys dark blue. Histologically, there was accumulation of hemosiderin in Kupffer cells, and severe to moderate hepatocellular necrosis in all cases. Ammonium molybdate added to the ration, combined with the cessation of mineral supplementation, arrested the outbreak.

These cases illustrate significant mortality, due to copper poisoning, in adult cattle fed a low-dose mineral dietary supplement for over two years. Dietary copper intake of the herd (on a dry matter basis) was 37.5 mg/kg for lactating cows and 22.6 mg/kg for dry cows.

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2.
The objectives of this study were to quantify the effect of 16 ppm of dietary monensin on milk production and composition of dairy cows, and to investigate factors having a potential impact on this effect. Data were generated from a total of 3577 Holstein dairy cows (47 herds) in Quebec enrolled in a herd-level, randomized clinical trial investigating the effects of monensin supplementation. Milk production and composition data were collected from monthly dairy herd improvement (DHI) testing. Monensin increased milk production by 0.9 kg/cow/d in cows under 150 days in milk (DIM) (P < 0.05). Monensin decreased milk fat percentage by 0.18 percentage points during the whole lactation (P < 0.05). This decreasing effect was larger for component-fed cows (P < 0.05) and for cows being fed low levels of dietary physically effective particles (P < 0.05) when compared respectively to cows fed total mixed ration and cows fed high levels of dietary physically effective particles. The results of this study suggest that monensin influences milk production and milk composition of dairy cows, and that diet composition and feeding system influence those effects.  相似文献   

3.
Poloxalene, a nonionic surfactant, was fed to beef cattle on a legume ration or a high grain ration to observe its effect on bloat. It was also fed to lactating dairy cows to note any effect on yield or composition of milk.

Poloxalene was beneficial in the prevention of bloat with both legume and grain rations. It had no effect on per cent fat, protein, solids-not-fat, or yield of milk.

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4.
The aim of this study was to determine the effect of different levels of fibrolytic enzyme on nutrient utilization and milk production in dairy cows. Four multiparous early-to-mid-lactation Holstein–Friesian crossbred cows were randomly allocated in a 4 × 4 Latin square design. Cows were fed a balanced total mixed ration (TMR) on a dry matter (DM) basis containing 0, 1.2, 2.4, and 3.6 g/kg DM of fibrolytic enzyme in TMR, where the TMR comprises 60% concentrate supplemented with a fibrolytic enzyme at 0, 2, 4, and 6 g/kg DM of concentrate, and 40% urea-molasses-treated sugarcane bagasse (UMSB) was used as a roughage source. Fibrolytic enzyme supplementation in TMR containing UMSB did not affect dry matter intake (DMI) of dairy cows (p > 0.05). There was a quadratic effect of fibrolytic enzyme levels on the digestibility of DM, organic matter (OM), neutral detergent fiber (NDF), and acid detergent fiber (ADF) (p < 0.05), and the maximal response was reached at 1.2–2.4 g/kg DM of fibrolytic enzyme added in the TMR. Furthermore, 3.5% fat-corrected milk, milk fat, total volatile fatty acids, and propionic acid were greater in a cow fed with 1.2–2.4 g/kg DM of fibrolytic enzyme, resulting in a lower ratio of acetic acid to propionic acid (p < 0.05). In conclusion, adding a fibrolytic enzyme in TMR containing UMSB improved nutrient utilization, rumen fermentation, and milk production of lactating dairy cows.  相似文献   

5.
研究全混合日粮与非全混合日粮饲喂产奶牛,选择200头荷斯坦奶牛随机分为试验组和对照组,试验组饲喂全混合日粮,对照组饲喂相同配方和数量的草料,经30 d饲喂对比试验,结果表明：试验组日平均产奶量为23.52 kg,对照组日平均产奶量为21.78 kg,试验组比对照组日平均产奶量增加1.74 kg,日平均产奶量提高7.99%,差异极显著（P〈0.01）。饲喂全混合日粮组比饲喂非全混合日粮组奶牛增收17 760元,经济效益明显。  相似文献   

6.

This study was performed with the main objective of evaluating the effect of the combination of pelleting and monensin on fatty acids (FA) composition, the concentration of total polyphenols and flavonoids, and the oxidative stability of milk in cows fed a concentrate containing soybean seeds. Eight Holstein multiparous cows were distributed in a replicated Latin square design. The four supplement treatments consisted of the combination of two factors (pelleting and monensin) and one concentrate as follows: (1) unpelleted concentrate with no monensin (CO); (2) pelleted concentrate with no monensin (PE); (3) unpelleted concentrate with 96 mg of monensin/kg of dry matter, DM (MO); and (4) pelleted concentrate with 96 mg of monensin/kg of DM (PM). There was no interaction between pelleting and monensin for milk production and concentration of milk protein, lactose, total polyphenols, flavonoids, conjugated dienes (CD), and reducing power. Fat and total solids concentration in milk were decreased when cows were fed pelleted (PE and PM) concentrates. Feeding cows with PE and PM concentrates increased the CD concentration in milk. Regarding milk FA concentration, there was no difference among treatments for total saturated, monounsaturated, and polyunsaturated FA. The most prominent result was that pelleting increased the milk concentration of omega-3 FA. Altogether, the present study suggests that the pelleting process can improve the milk fat quality by increasing the omega-3 FA, while the combination of pelleting and monensin in the diet of grazing dairy cows fed soybean-based concentrate adds no further improvements to FA profiles and oxidative stability of milk.

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7.
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   

8.
苹果发酵物对奶牛产奶性能和疾病的影响   总被引：4，自引：0，他引：4  
将有益微生物接种到以苹果渣为主的培养基中进行有氧和无氧培养,制成颗粒状苹果培养物。对高产奶牛进行饲喂试验表明,用苹果发酵物代替等量的甜菜或苹果发酵物和甜菜粕同时使用,奶牛分别增产鲜奶1.89和1.90千克/头·日,同时乳脂、乳蛋白质、乳固体物都有上升趋势,奶牛发病率明显下降。苹果发酵物是一种新型反刍动物饲料。  相似文献   

9.
In this study, the effect of increasing the proportion of concentrate in the diet, on efficiency of feed utilisation, was determined when Holstein–Friesian cows grazed short-rotation ryegrass (Lolium multiflorum) or kikuyu (Pennisetum clandestinum) pastures. The concentrates were energy-dense dairy pellets fed twice-a-day at milking and the roughage component was lucerne hay and the pasture.When cows grazed ryegrass, there was no effect on animal performance as the proportion of concentrate in the diet increased from 0.23 to 0.35 (4.75 to 7.50 kg concentrate/cow/day). The substitution rate of concentrates for pasture for the first 1.57 kg concentrate/cow/day fed was 0.58 but rose to 1.18 for the next 1.28 kg concentrate/cow/day.When cows grazed kikuyu, there was also no effect of increasing the proportion of concentrate in the diet on total dry matter intake (DMI) or milk production. However, there was a substantial increase in the in vivo digestibility of whole diet, pasture and acid detergent fibre (ADF) was observed when the proportion of concentrate in the diet increased from 0.08 to 0.25. However, there was a marked decline in pasture digestibility (72% to 64%), and more so in ADF digestibility (61.3% to 48.4%), as the proportion of concentrate in the diet increased further to 0.29 (5.52 kg/cow/day). The intake of kikuyu, when determined by difference between pre- and post-grazing pasture mass, was substantially underestimated compared to the use of the n-alkane technique, and this discrepancy increased as the pasture on offer increased.On both pasture types, the neutral detergent fibre intake, as a % of bodyweight varying from 1.6% to 2.2% for kikuyu and 1.5% to 1.6% for ryegrass was far above the values claimed of 1.2% to restrict intake.The results of this study highlight the limits to the amount of concentrate that can be fed on a typical Australian dairy farm where concentrates can only be fed twice-a-day at milking. The results also provide a more appropriate benchmark for fibre limitation in the ration when cows graze pasture, particularly poorer quality tropical grasses, and this value is well above that found in more intense feeding situations.  相似文献   

10.
多花黑麦草饲喂奶牛效果研究   总被引：4，自引：3，他引：4  
设4种不同梯度多花黑麦草Lolium multiflorum和配合饲料的日粮组成对24头黑白花奶牛进行饲喂试验,以期探讨最佳经济效益的日粮组成,为推广饲用玉米Zea mays-多花黑麦草种植系统提供理论依据.结果表明,随配合饲料饲喂量的减少,多花黑麦草采食量增加,青贮玉米的采食量不断减少.以每头饲喂6 kg配合饲料 30 kg多花黑麦草 自由采食青贮玉米试验组(2组)奶牛每天平均产奶量最高,达到11.59kg/头.以每头饲喂5 kg配合饲料 40 kg多花黑麦草 自由采食青贮玉米试验组(3组)奶品质最好,经济效益最高.  相似文献   

11.
In order to study the main effects of particle size, three ruminally fistulated cows (550 to 580 kg BW) were fed a constant low concentrate level (3.56 kg DM/d, 20% of total DMI) and a fibre-rich hay (approximately 60% NDF in DM) in long (28.7 mm), chopped (9.2 mm) and fine ground (2.9 mm) form in a 3 x 3 Latin square design. In another three factorial experiment with 8 wethers (4 animals were ruminally fistulated, mean BW = 68 kg) the main effects and interactions of the above mentioned hay particle sizes at two concentrate levels (10.4 to 13.3% and 29.5 to 40.1% of DMI, resp.) and two intake levels (restricted and ad libitum) were investigated. In comparison to long hay (28.7 mm), feeding of chopped hay (9.2 mm) at low concentrate levels, increased not only the hay intake (7% in dairy cows and 13% in sheep) but also the intake of digestible organic matter (12% in dairy cows and 32% in sheep), due to an increase in the apparent digestibility of OM by 3.8% in dairy cows and 8.2% in sheep. Ad libitum feeding of fine ground hay in combination with low concentrate amount in the ration increased the passage rate in the hindgut and consequently the hay intake, but not the intake of DOM, due to a significant depression of digestibility, especially of fibre fractions (4 to 7% in dairy cows and 4.5 to 14% in sheep), in comparison to 28.7 and 9.2 mm hay particle sizes. The digestibility decreased significantly with restricted feeding of fine ground hay in sheep only in comparison to 9.2 mm particle size. A threefold increase of concentrate amount leveled out all effects of the particle size reduction. The effect of particle size was more pronounced in sheep than in dairy cows.  相似文献   

12.
The aims of this study were to examine the effects of and possible interactions between dry matter (DM) intake and feeding Fusarium toxin-contaminated wheat on ruminal fermentation, serum chemical parameters and milk yield of dairy cows. Fourteen dairy cows equipped with ruminal and duodenal cannulas were analysed. All animals were fed the same ration, the daily feed amounts being adjusted to current performance. On DM basis, the ration consisted of 60% concentrate including 55% wheat [Fusarium-contaminated wheat (mycotoxin period) or control wheat (control period)] and was completed with 40% maize and grass silage. Each cow was fed the contaminated wheat [deoxynivalenol (DON), 8.21 mg/kg DM and zearalenone (ZON), 0.09 mg/kg DM] and the control wheat (0.25 mg DON/kg DM and 51 microg ZON/kg DM). As expected, a higher organic matter (OM) intake decreased the amounts of fermented crude nutrients related to the respective intakes. An increased amount of crude protein degraded (p < 0.05) and a lower molar percentage of propionate in the rumen fluid were observed when feeding the Fusarium toxin-contaminated wheat at increased OM intakes in comparison with the control wheat. The activities of serum aspartate aminotransferase (ASAT; p < 0.001), glutamate dehydrogenase (GLDH; p < 0.01) and gamma glutamyl transferase (gamma-GT; p < 0.01) increased with increasing OM intake and were not related to the mycotoxin contamination of the wheat.  相似文献   

13.
Cattle from 2 herds developed copper toxicosis after the ingestion of chicken litter. The affected animals were adult Holstein cows and crossbred steers that ate 9 to 16 kg of litter/day. These cattle developed a sudden onset of weakness, depression, anorexia, icteric mucous membranes, and dark reddish brown urine. Liver copper concentrations in 2 cattle (1 from each herd) were 436 and 730 ppm. Results of copper analyses of chicken litter ranged from 620 to 920 ppm. Sodium molybdate and sodium thiosulfate were added to the ration of the dairy herd. Two cows with clinical signs of copper toxicosis recovered after being given additional sodium molybdate and thiosulfate supplements, orally.  相似文献   

14.
An understanding of carbohydrate nutrition is essential to optimize production of dairy cattle. Two rations, both of which appear to be balanced, may have dramatically different results when fed to high-producing dairy cattle. Carbohydrates directly affect microbial protein production and therefore protein nutrition of dairy cattle. Energy intake can be maximized by considering the amount and type of carbohydrate in the ration: 1. The fiber level of the ration should be evaluated. NDF levels should be between 25 and 30% for high-producing cows in early lactation. Within this range, less fiber is required with adequate forage particle length and high frequency of grain feeding, and when buffers are fed and slowly fermented NSC sources are included in the ratio. For mid- and late-lactation cows, fiber levels are higher, ranging between 30 and 36% NDF depending upon the energy required to support milk production and restoration of body condition. 2. Provide adequate effective fiber. There should be some forage particles 1.5 in long in the ration. Limit most high-fiber byproducts to 25% of fiber requirements. 3. Feed highly digestible fiber sources. Differences in fiber digestibility of 30% will result in over 4 Mcal of NEL per day with 15 lb NDF intake. In addition, highly digestible fiber has less gut fill effect, possibly increasing dry matter intake. 4. Consider site of starch digestion. Slowly degraded starch sources such as sorghum may require steam flaking to increase ruminal fermentation. Other situations may require the addition of a slowly degraded starch source. 5. Increase frequency of concentrate feeding. Feed grain at least four times per day or include in a total mixed ration. 6. Include buffers. Under some situations (corn silage, early lactation) buffers allow more grain to be fed. 7. Add fat. Fat supplementation to milking cows has become a common practice in high-producing herds. Fat has about three times the energy of cracked corn and is often used to replace a portion of the grain to increase the energy density of the ration. It is important to realize that fat can cost up to two to three times more per megacalorie of energy than grain. Before fat is added to the ration, less expensive ways to increase energy density (listed previously) should be thoroughly explored.  相似文献   

15.
Two on-farm experiments and one on-station observation were conducted between July 1994 and September 1995 to study the effect of supplementation with fresh fodder of Calliandra calothyrsus on milk production from grade Friesian and Ayrshire cows in the second trimester of their lactations. The cattle were kept under zero-grazing systems on small farms in the coffee-based land use system at altitudes of 1500 to 1800 m on the slopes of Mt Kenya. These cows form a pivotal part of the farming system since they produce both milk for sale and manure for crop production. Milk production is normally in the region of 10 kg/cow per day when the animals are fed on a diet based on Napier grass and crop residues, together with 2–4 kg/day of commercial concentrate. In terms of milk production, 3 kg of fresh calliandra had the same effect on yield as 1 kg of additional dairy meal and, at normal production levels, the effects of the two supplements were strictly additive. Calliandra had a marked positive effect (about a 10% increase) on the butterfat content of the milk, a factor that was highly valued by farmers, even though institutional buyers as yet offer no premium price for milk quality. The average small farm can produce enough calliandra fodder to supplement two dairy cows and some additional small stock from relatively underutilized niches along the farm perimeter and terrace risers, without any adverse effect on current levels of crop production.  相似文献   

16.
It was hypothesized that long‐term intake of a diet contaminated with deoxynivalenol (DON) and differing in the proportion of concentrate might affect hepatocellular integrity and function as well as biomarkers of systemic inflammation in lactating dairy cows. In Period 1 (11 weeks), 26 lactating German Holstein cows (13 primiparous and 13 pluriparous, 31 days in milk, 522 kg body weight, on average) were divided into two groups and fed diets (50% concentrate) with (MYC, n = 12; on average 5.3 mg DON/kg DM) or without (CON, n = 14) DON contaminations. In Period 2 (16 weeks), each group was further divided into two groups to test whether elevated concentrate proportion as additional burden might enhance the toxicity of DON. The cows in MYC60 (n = 6; 4.6 mg DON/kg DM) and CON60 (n = 7) received the diet with 60% concentrate, while cows in MYC30 (n = 6; 4.4 mg DON/kg DM) and CON30 (n = 7) received the diet with 30% concentrate. Blood samples were taken in biweekly intervals for activities of aspartate amino transferase (AST), glutamate dehydrogenase (GLDH) and gamma‐glutamyl transferase as well as for concentration of total bilirubin and haptoglobin. Biopsies from liver were collected in week 27 for morphological analyses. No DON effect was found for the variables assessed in blood. The diet with 60% concentrate led to higher activities of AST and GLDH in Period 2. No morphological change was found by both light and electron microscopic analyses of liver samples. Results indicated that long‐term intake of DON‐contaminated diet over 27 weeks led to neither relevant damages of hepatocytes nor systemic inflammatory responses in lactating dairy cows, even if the dietary concentrate proportion was increased to 60%.  相似文献   

17.
Abstract

The objective of this study was to evaluate the feed intake models in the Nordic feed evaluation system NorFor. Data from 196 feeding experiments with dairy cows, and 17 experiments of periodical data, and 135 experiments of complete data with growing cattle were used in the evaluation by mixed model regression. The feed intake by both dairy cows and growing cattle were overestimated by the models. A linear bias indicated that over prediction increased with level of intake both by dairy cows and growing cattle. Most animal and diet factors were significantly related to the residuals, which indicated that those factors did not act independently in the predictions of feed intake. This kind of errors can restrict future ration formulation and animal performance, since animal production parameters included in the prediction models will be a consequence of the diet fed at the time they were measured.  相似文献   

18.
The aim of the present trials was to determine the effect of an experimental Brown‐midrib (Bm) corn hybrid in relation to a commercial corn hybrid (Con) on digestibility in wethers and on dry matter intake (DMI), milk yield and milk composition in dairy cows. Digestibility of crude fibre (CF), neutral detergent fibre (NDFom) and acid detergent fibre (ADFom) were higher for Bm (CF Con: 57.8%; Bm: 67.2%; NDFom Con: 56.8%; Bm: 64.8%; ADFom Con: 52.0%; Bm: 63.9%), but concentration of net energy for lactation did not differ (Con: 6.4 MJ/kg DM; Bm: 6.3 MJ/kg DM). A total of 64 lactating German Holstein cows were assigned to one of the two dietary treatments Con or Bm according to milk yield, lactation number, days in milk and live weight. In Trial 1, cows were fed a total mixed ration consisting of 50% corn silage (Con or Bm) and 50% concentrate on dry matter (DM) basis. In Trial 2, the same animals were fed the respective silage for ad libitum intake and 5.3 kg of concentrate DM per animal per day. In Trial 1, DMI and milk‐fat content were decreased significantly for the Bm‐treatment (DMI Con: 22.5 kg/day; Bm: 21.5 kg/day; milk fat Con: 3.8%; Bm: 3.3%). In Trial 2, milk yield and fat‐corrected milk (FCM) were increased significantly, whereas milk‐fat% was decreased significantly (milk yield Con: 25.8 kg/day; Bm: 29.4 kg/day; FCM Con: 27.2 kg/day; Bm: 29.6 kg/day; fat Con: 4.4%; Bm: 4.0%). Diets did not influence ruminal pH or temperature. Diets, furthermore, did not influence rumination in either trial. Additional research on digestibility and rumen fermentation should, however, be carried out using dairy cows at respective intake levels as trials with wethers cannot be transferred to high‐yielding ad libitum fed cows.  相似文献   

19.
CASE DESCRIPTION: The owner of a herd of 74 Holstein-Friesian cattle reported decreased milk production, weight loss, and coughing among lactating cows. Owner-initiated antimicrobial treatment was unsuccessful; 1 lactating cow died, and 50% of the lactating cows had clinical signs of respiratory distress, such as tachypnea and coughing. CLINICAL FINDINGS: On the basis of history, physical examination findings, and fecal examination results, affected animals were determined to have Dictyocaulus viviparus (lungworm) infestation. The disease history suggested that the herd contained cows with subclinical patent lungworm infestations; after introduction of susceptible heifers, the pastures had become heavily infested with D viviparus and clinical problems subsequently developed in both newly introduced and resident cows. TREATMENT AND OUTCOME: Affected and unaffected heifers and adult cows were treated with a pour-on formulation of eprinomectin (0.5 mg/kg [0.23 mg/lb]). One animal died, but 2 weeks after treatment, clinical signs among affected cattle were markedly improved. Ten weeks after treatment, milk production improved from 23 kg/cow/d (51 lb/cow/d) to 28 kg/cow/d (62 lb/cow/d). CLINICAL RELEVANCE: The outbreak provides additional evidence that dictyocaulosis is becoming more common among adult dairy cattle, rather than almost exclusively affecting young stock. This may be attributable to anthelmintic use and management practices on dairy farms. Combined with anecdotal reports of an increase in the incidence of dictyocaulosis among adult cattle in North America, D viviparus infestation should be included as a differential diagnosis for decreased milk production, weight loss, and coughing among adult dairy cattle.  相似文献   

20.
Chronic copper toxicity in a dairy cow   总被引：2，自引：2，他引：0       下载免费PDF全文
A three year old Holstein dairy cow fed a ration containing a copper supplement died of chronic copper poisoning. The concentration of copper in the liver was 331 ppm (wet weight). The typical lesions of chronic copper toxicity including icterus, hepatic fibrosis and hemoglobinemic nephrosis were found at necropsy. The chronic copper toxicity was not considered to be a herd problem since the liver copper concentration in a slaughtered cull animal and blood samples taken from five animals in the same herd were within normal limits.  相似文献   

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