Copper toxicosis in lambs fed milk replacer

Thirty-four hysterectomy derived, crossbred lambs were fed a commercial, lamb milk replacer, containing added copper from birth. Twenty-five lambs died, four were killed and five survived. At necropsy, generalized icterus, enlarged kidneys and enlarged or small livers were found.     

Digestibility of a complete ration in horses fed once or three times a day and correlation with key blood parameters

To determine the influence of feeding frequency on apparent digestibility and blood metabolites in horses, four geldings were fed a complete ration either once (at 08:00 h) or three times a day (at 08:00, 13:00 and 18:00 h). Horses were provided with a mixture of cereals and chopped alfalfa hay at maintenance level for energy supply, 344 kJ/kg BW(0.75) on a daily basis. After three weeks' adaptation, total amounts of faeces and urine were collected for five days, using collection harnesses. Serial blood samples were taken at -30, -15, 0, 5, 15, 30, 45, 60, 90, 120, 180, 240, 300, 360, 480 and 600 min after feeding and analysed for glucose, L-lactate, triglycerides (TG), non-esterified free fatty acids (NEFA) and triiodothyronine (T(3)). Apparent digestibility coefficients of dry matter (DM), crude protein (CP), ether extract (EE), crude fibre (CF), ash and nitrogen-free extract (NFE) were not significantly different (P>0.05) between the two feeding frequencies. Basal plasma glucose, plasma glucose curves and other plasma blood metabolites were not affected by meal frequency. The horses fed the whole ration in one morning feeding did not consume the entire meal at once, but spared feed for ingestion throughout the day, which may explain the lack of effect. Feeding frequency did not affect plasma glucose response (area under curve :AUC) (P=0.705), but AUC (glucose) was negatively correlated with CP (R(2)=0.76; P=0.005) and CF digestibility (R(2)=0.61; P=0.022). Further research is needed to clarify whether different endocrine responses or differences in passage rate can explain these correlations.     

No abomasal curd formation in pre-ruminant calves after ingestion of a clotting milk replacer

The aim of this study was to ultrasonographically evaluate curd formation in 29 pre-ruminant calves that were fed a clotting milk replacer. Abomasal curd was absent in 8/29 calves at 2 h after feeding. In these eight calves, abomasal contents were observed as an anechoic image with small echogenic spots (five calves), or as an echogenic image with an unclear outline (three calves), but there was no echogenic image with a clear outline corresponding to curd that was visualised in the other 21 calves. The curd was not observed until 7 h after feeding in the eight calves. Our analysis also indicated that the absence of curd formation in the pre-ruminant calves did not have a significant impact on the appearance, appetite and vigour of pre-ruminant calves or on their blood parameters, including serum triglyceride, blood urea nitrogen and glucose concentrations. The study provided the first evidence that the abomasum of some calves does not form curd despite ingestion of a clotting milk replacer.     

Growth of rearing calves in relation to lysine contents of milk replacer and calf starter and feeding frequency of milk replacer

In two factorial feeding experiments with 90 and 102 rearing calves the effect of addition of extra lysine to the milk replacer in combination with a low and high lysine content of the calf starter on dry matter intake and weight gain was studied. Once or twice daily milk feeding was also compared. The calves received milk replacer up to the age of 8 weeks and calf starter and hay ad libitum from the 3rd week on. The experiments lasted to the age of 12 respectively 10 weeks. In the first experiment increasing the lysine content of the milk replacer from 14.5 g/kg to 18.5 g/kg had no effect on dry matter intake and weight gain. In the second experiment increasing the content of lysine to 17 g/kg resulted in higher intake of dry matter and higher weight gain, but only in combination with a calf starter with a low lysine content (6 g/kg). In the first experiment twice daily milk feeding resulted in higher intake of concentrate and higher weight gain as compared to once daily. In the second experiment this was only so if the starter had the lower lysine content. Increasing the lysine content of calf starter from 7 to 8.5 g/kg had no effect on dry matter intake and weight gain in the preweaning period in the first experiment. In the second experiment increasing the lysine content from 6 to 8.5 g/kg led to higher intake of concentrate and higher weight gain. This effect was only seen if the milk replacer had no extra lysine added. In the postweaning period there was no effect of increasing the lysine content from 7 to 8.5 g/kg (Exp. I). Increasing the lysine content from 6 to 8.5 g/kg led to higher dry matter intake and higher weight gain (Exp. II). These results are discussed in the light of the partial degradability of the concentrate protein in the rumen and the effect of duodenally available lysine on feed intake and weight gain.     

Effects of dexamethasone on lymphoid tissue in the gut and thymus of neonatal calves fed with colostrum or milk replacer

An increased susceptibility to disease in neonatal calves may be attributable to high glucocorticoid levels that influence immune reactions. We tested whether dexamethasone (DEXA) administration influences the proliferation, apoptosis, and number of B- and T-lymphocytes in Peyer's patches (PP) and thymus in calves fed colostrum (C) or a milk-derived formula. All calves were subcutaneously administered bovine colostrum-derived immunoglobulin G and fed chicken-egg derived immunoglobulins that protected against rotavirus and pathogenic Escherichia coli. The DEXA (30 microg/kg of BW daily) was injected for 4 d into groups fed colostrum on the first 3 d (CD+) and those fed the formula that contained nutrients in amounts as in colostrum but no immunoglubulin G (FD+). Groups CD- and FD were fed the same as the other two groups, but did not receive DEXA. Immunohistochemical methods were used to evaluate cell proliferation rates (by labeling of 5-bromo-2'-deoxyuridine), apoptosis rates (by terminal deoxynucleotidyl transferase-mediated X-dUTP nick end labeling). Numbers of T- and B-lymphocytes were determined with antibodies specific for CD3 and CD79 surface proteins. There were significant effects (P < 0.05) of DEXA treatment (decrease of cell proliferation rates in follicles of PP and thymus, increase of apoptotic rate in follicles of PP and thymus, decrease of B-lymphocyte numbers in follicles of PP, increase of B-lymphocyte numbers in domes of PP, increase of T-lymphocyte numbers in follicles of PP, and a decrease of intraepithelial T-lymphocyte numbers). There were significant effects (P < 0.05) of C feeding (decrease of cell proliferation rates in follicles of PP and of B-lymphocyte numbers in interfollicular areas, domes, and follicular-associated epithelium of PP, and an increase of cell proliferation rate in the thymus). A DEXA x feeding interaction (P < 0.001) was found for cell proliferation rate in the thymus. In conclusion, DEXA treatment decreased cell proliferation rates in follicles of PP and thymus and enhanced apoptotic rates in follicles of PP. Colostrum feeding decreased cell proliferation rates, likely of B-lymphocytes, in follicles of PP and numbers of B-lymphocytes in domes, follicular-associated epithelium, and interfollicular areas of PP and enhanced cell proliferation rates and selectively modified DEXA effects in the thymus.     

Consequences of failure of the reticular groove reflex in veal calves fed milk replacer

Summary

A number of problems seen in veal calves are associated with insufficient adaptation to the changes in husbandry connected with the fattening system. These problems include chronic tympanitis, chronic vomiting, cachexia, unthriftiness, abomasal erosions and ulcers.

Some of these problems are associated with failure of the reticular groove reflex, and result in ruminal drinking.

Persistent ruminal drinking causes a syndrome characterised by a variety of symptoms such as unthriftiness, severe growth retardation, inappetence, recurrent tympany, abdomal distension, a long dry haircoat and clay‐like faeces.

Clinical studies performed to investigate the pathogenesis of the syndrome are described. It was found that the milk was stored in the rumen and was partly broken down. The presence of milk in the rumen induced typical changes in the ruminal mucosa (hyper/parakeratosis) and also inhibited casein clot formation in the abdomasum. The small intestinal mucosa showed villous atrophy. After training, the reticular groove reflex was re‐established in a number of patients but the growth rate of these calves did not return to normal.     

Consequences of failure of the reticular groove reflex in veal calves fed milk replacer

A number of problems seen in veal calves are associated with insufficient adaptation to the changes in husbandry connected with the fattening system. These problems include chronic tympanitis, chronic vomiting, cachexia, unthriftiness, abomasal erosions and ulcers. Some of these problems are associated with failure of the reticular groove reflex, and result in ruminal drinking. Persistent ruminal drinking causes a syndrome characterised by a variety of symptoms such as unthriftiness, severe growth retardation, inappetence, recurrent tympany, abdominal distension, a long dry haircoat and clay-like faeces. Clinical studies performed to investigate the pathogenesis of the syndrome are described. It was found that the milk was stored in the rumen and was partly broken down. The presence of milk in the rumen induced typical changes in the ruminal mucosa (hyper/parakeratosis) and also inhibited casein clot formation in the abdomasum. The small intestinal mucosa showed villous atrophy. After training, the reticular groove reflex was re-established in a number of patients but the growth rate of these calves did not return to normal.     

Tributyrin administration improves intestinal development and health in pre-weaned dairy calves fed milk replacer

Butyrate and its derivatives possess various nutritional and biological benefits for mammals,whereas its effects on dairy calves have not been well characterized.This study evaluated the effects of tributyrin administration on blood immune,intestinal immune and barrier functions,and microbial composition of pre-weaned dairy calves.Twenty newborn Holstein bull calves were randomly assigned into a control group (no tributyrin supplementation,CON;n=10) or a treatment group (supplemented with tribut...     

Exocrine pancreatic secretion in pigs fed sow's milk and milk replacer, and its relationship to growth performance

The objective of this study was to quantify and compare the effects of sow's milk and 2 milk replacer diets (containing clotting or non-clotting protein sources) on exocrine pancreatic secretion, plasma cholecystokinin, and immunoreactive cationic trypsin in pigs. In addition, the relationship between exocrine pancreatic secretion and growth in milk-fed pigs was studied. In a changeover experiment, 9 chronically catheterized pigs of 6.6 +/- 0.19 kg of BW were studied for 3 wk. Pigs were assigned to each of 3 diets. Exocrine pancreatic secretion was measured from the third to the seventh day on each diet. The protein content and trypsin activity of the pancreatic juice were measured. Blood samples were taken at 10 min before and after milk ingestion and were analyzed for cholecystokinin and immunoreactive cationic trypsin. Pancreatic protein and trypsin secretion did not differ between pigs fed sow's milk and those fed milk replacer, but the volume secreted was less for the pigs fed sow's milk (0.75 vs. 1.03 mL x kg(-1) x h(-1); P < 0.01). A postprandial response to milk intake was not observed. The 2 milk replacer diets did not affect exocrine pancreatic secretion differently. The average exocrine pancreatic secretion (volume, 0.94 mL x kg(-1) x h(-1); protein, 4.28 mg x kg(-1) x h(-1); trypsin, 1.65 U x kg(-1) x h(-1)) was intermediate between literature values for suckling and weaned pigs. Plasma cholecystokinin was elevated (approximately 18 pmol x L(-1)) and showed low correlations with the pancreatic secretion traits. Plasma immunoreactive cationic trypsin was not significantly related to any of the pancreatic secretion traits and should therefore not be used as an indicator for exocrine pancreatic function in milk-fed pigs. Exocrine pancreatic secretion varied substantially among individual pigs (protein, 0.22 to 13.98 mg x kg(-1) x h(-1)). Pancreatic protein and trypsin secretion showed a positive, nonlinear relationship with performance traits. It was concluded that neither specific sow's milk ingredients nor the protein source are responsible for a low pancreatic protein secretion in suckling pigs. Exocrine pancreatic secretion was positively correlated with ADG in pigs at an identical milk intake.     

Effect of suckling cow's milk or milk replacer on abomasal luminal pH in dairy calves

Abomasal ulceration occurs commonly in suckling calves, and the cause for the high prevalence of abomasal ulceration is unknown. We hypothesized that diet may play a role in the etiopathogenesis of abomasal ulceration. Six male dairy calves with an abomasal body cannula suckled fresh Holstein cow's milk, all milk-protein milk replacer, or combined milk- and soy-protein milk replacer twice daily at 12% of body weight/d. Abomasal luminal pH was measured every second for 24 hours by using a miniature glass pH electrode. Mean 24-hour abomasal luminal pH for all milk-protein milk replacer (3.22) and combined milk- and soy-protein milk replacer (3.27) were similar but significantly (P < .05) higher than that for cow's milk (2.77; standard error = 0.08). Both milk-replacer formulations failed to clot after the addition of chymosin, whereas cow's milk clotted within 2 minutes. The in vitro titration curve of cow's milk and all milk-protein milk replacer were similar, but different to that of combined milk- and soy-protein milk replacer. The osmolalities of all milk-protein milk replacer (375 mOsm/kg) and combined milk- and soy-protein milk replacer (410 mOsm/kg) were greater than that of cow's milk (278 mOsm/kg). The slightly lower mean abomasal luminal pH in calves suckling cow's milk, compared to milk replacer, was probably due to clotting of cow's milk, with extrusion of low pH whey, and a slower rate of abomasal emptying caused by the hyperosmolality of milk replacer. Examination of our results suggests that suckling cow's milk may increase the prevalence of abomasal ulceration by decreasing mean luminal pH, although this remains to be determined.     

Effect of orally administered omeprazole on abomasal luminal pH in dairy calves fed milk replacer

The objective of this study was to determine whether oral administration of omeprazole, a proton-pump inhibitor, increased abomasal luminal pH in calves fed milk replacer. Four male dairy calves with cannulae in the abomasal body suckled milk replacer (60 ml/kg body weight every 12 h) and were administered a non-enteric-coated omeprazole (4 mg/kg body weight every 24 h) in a paste formulation for five successive days. Abomasal luminal pH was continuously measured using miniature glass pH electrodes. On the first day of omeprazole administration, there was a significant (P<0.05) increase in mean 24-h pH from 2.89 to 4.17. The mean 24-h pH on days 2, 3, 4 and 5 of omeprazole administration were 3.85, 4.02, 3.97 and 3.39 respectively. We conclude that oral administration of non-enteric-coated omeprazole increased abomasal luminal pH in calves fed milk replacer, but that the effect may decrease over time.     

饲喂代乳粉对羔羊生长性能和体组织参数的影响

研究饲喂代乳粉和母羊哺乳对羔羊生长性能和体组织参数的影响。选取18只日龄和体重相近、健康的杂交F1羔羊,随机分成试验组和对照组,每组9只。试验组饲喂代乳粉,对照组随母羊哺乳,饲养时间为90d。称取20、90日龄空腹体重,并于90日龄时每组随机选取4只屠宰,称量胴体、各胃室、小肠各段、内脏器官鲜重。结果表明:与对照组相比,试验组羔羊平均日增重提高18.61%(P0.05);宰前活体重、胴体重分别提高22.28%、32.44%(P0.05),屠宰率提高6.67%(P0.05);复胃总重增加13.25%(P0.05),其中瘤胃鲜重增加25.92%(P0.05),皱胃鲜重提高6.74%(P0.05),网胃和瓣胃鲜重则有降低的趋势;回肠鲜重和长度分别增长75.28%(P0.05)和35.50%(P0.05);肺、肾脏、肝脏和脾脏鲜重提高22.29%、30.10%、28.86%和38.22%(P0.05)。结论:饲喂代乳粉后可提高羔羊生长性能,但对屠宰率无显著影响,可促进其瘤胃的发育,并影响部分内脏器官发育。     

酸度调控剂的体外评价及其在犊牛代乳粉中的应用

以体外法评定酸度调控剂,并将筛选出的酸应用在犊牛代乳粉中,以动物饲养试验研究其对犊牛生长性能的影响,从而验证体外评价方法的可行性。体外评价试验采用1%酸溶液pH值及其缓冲性能、降低代乳粉pH值至5.0所需体积、加酸后代乳粉缓冲性能、体外抑菌率5个指标评价甲酸、乙酸、柠檬酸、富马酸、乳酸、盐酸的作用;动物饲养试验分两期进行,试验一设A1、A2、A3组,后两组分别以盐酸调整代乳粉pH值至5.5和5.0;试验二设B1、B2组,B2组以甲酸调整代乳粉pH值至5.0。每个处理6个重复,每重复1头牛。各试验期均为56d,测定犊牛体增重、饲料转化率和腹泻率。1%酸溶液的pH值以盐酸最低;加酸后代乳粉缓冲性能则以乙酸最高;将代乳粉乳液pH值从6.3调整至5.0时,甲酸溶液用量最低;而体外大肠杆菌抑菌率则以盐酸和甲酸效率最高。动物饲养试验表明,与A1组相比,A2、A3组犊牛全期平均日增重分别提高了5.2%、12.1%,A2组的腹泻率降低了29.7%,但差异都不显著(P0.05)。B2组犊牛的平均日增重在第14～28d显著高于B1组(P0.05),全期平均日增重提高了10.9%,腹泻率降低了37.5%。在犊牛代乳粉中添加盐酸或甲酸,可改善犊牛生长情况;本研究所采用的体外评价酸度调控剂方法可行。     

Growth performance, metabolic and endocrine traits, and absorptive capacity in neonatal calves fed either colostrum or milk replacer at two levels

Colostrum (CO) contains high amounts, whereas whole milk and milk replacer (MR) contain small amounts, of bioactive and growth-promoting substances, such as IGF-I. An experiment was designed to study the effects of feeding CO or MR on the first 3 d to neonatal calves, followed by whole milk up to d 7, at low and high density. Intestinal absorptive capacity, plasma metabolite and hormone concentrations, and growth performance were measured during the 1st wk of life. Body weight increased (P < .05) similarly in calves fed low or high amounts of CO but did not rise in MR-fed calves. Loose feces were more frequent (P < .05) and absorption of xylose on d 5 was lower (P < .01) in MR- than in CO-fed calves, but there were no effects of feeding density within CO-fed or within MR-fed groups. However, high feeding density within CO-fed groups enhanced (P < .05) total protein, globulin, triglyceride, cholesterol, and insulin concentrations, whereas in the initially high and low MR-fed groups only plasma glucose and insulin after the first meal and plasma NEFA on d 2 were modified (P < .05) by different feeding density. Thus, feeding different amounts of CO partly influenced protein and fat metabolism in calves during the 1st wk of life, but it did not measurably affect intestinal function. However, feeding different amounts of MR, in the absence of CO, barely affected metabolic and endocrine traits and absorptive capacity. Thus, high density CO feeding, and therefore a high supply of nutrients, together with greater amounts of bioactive and growth-promoting substances influenced neonatal metabolism and growth more than a high density of MR feeding containing only small amounts of bioactive and growth-promoting substances. Factors in addition to nutrient density seem to be important for the development of neonatal calves.     

Economic losses from an episode of zinc toxicosis on a California veal calf operation using a zinc sulfate-supplemented milk replacer

An episode of zinc toxicosis in 95 veal calves caused $29,602 in losses to the producer ($315/affected calf), most of them direct, out-of-pocket losses. Increased calf mortality and increased veterinary service costs accounted for a majority (70%) of the losses. Reduction of losses may have been accomplished by removing the source and increasing the roughage content in the diet, or by shipping the animals for immediate slaughter. Given the magnitude of the financial loss, especially those associated with calf mortality, it was concluded that producers should refrain from using large amounts of mineral supplements unless a deficiency has been diagnosed.     

Effect of level of milk replacer fed to Holstein calves on performance during the preweaning period and starter digestibility at weaning

Calves following an enhanced-growth feeding program usually show lower starter intakes during the preweaning period compared with conventionally-fed calves. To assess whether this low intake in calves following an enhanced-growth feeding program affects calf capacity to digest starter after weaning, 19 Holstein male calves were used to measure apparent nutrient digestibility at weaning. Calves were divided in two groups: calves on a conventional feeding program (CF) and calves on an enhanced-growth feeding program (EF). After one week of adaptation to milk replacer (25% CP and 19% fat), the CF calves were fed 4 l/d of milk replacer (MR) at 12.5% DM dilution rate from d 1–28, and 2 l/d from d 29 to weaning day at d 35, and the EF calves were offered MR at 18% DM dilution rate: 4 l/d from d 1–6, 6 l/d from d 7–13, 7 l/d from d 14–20, 6 l/d from d 21–28, and 3 l/d from d 29 to 35. Calf starter (20% CP) was offered ad libitum from the beginning to the end of study at d 42, and its consumption was recorded daily. Calves were weighed at d 3, 17, 24, 31, 38 and 42. Daily total faeces collection was conducted for the last 5 d of study. Final BW was numerically greater in EF than in CF calves (88.6 vs 81.2 ± 3.36 kg, respectively). Starter DMI was greater (P < 0.05) in CF compared with EF calves during the preweaning (0.68 vs 0.36 ± 0.078 kg/d, respectively) and postweaning (2.52 vs 1.90 ± 0.102 kg/d, respectively) periods, but there were no differences in total DMI (1.12 and 1.26 ± 0.078 kg/d, in CF and EF calves, respectively) during the preweaning period. However, apparent DM, OM, NDF, CP, and GE digestibility coefficients were greater (P < 0.05) in CF compared with EF calves (77.4 vs 71.8 ± 1.23%, 78.7 vs 73.2 ± 1.18%, 34.7 vs 20.3 ± 3.79%, 77.1 vs 71.6 ± 1.29%, and 75.6 vs 69.8 ± 1.25%, respectively) the week after weaning. It is concluded that calves in the EF treatment presented lower nutrient digestibility coefficients compared with CF calves the week after weaning.