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1.
Replacement of skim milk proteins by solubilized wheat protein (SWP) in milk replacers for veal calves would contribute to the reduction in feeding costs. The occurrence of metabolic disorders has, however, been reported. Forty-two male calves received one of three treatments over 140 days: a control diet, a diet containing SWP without or with branched-chain amino acid supplementation. Liveweight gain, carcass yield, color and conformation did not show any significant differences. No metabolic disorders were noted. Supplementation with branched-chain amino acids reduced the marginal Val deficiency but did not modify the growth performances. With the SWP containing diets, the plasma metabolite profile was characteristic of those observed with non-clotting diets. It was statistically correlated to the changes in the orientation of the Semitendinosus muscle energy metabolism towards a more oxidative type and to indications of a lower efficiency of amino acid utilisation for protein deposition. At the present levels of inclusion, SWP proved to be an interesting alternative to the sole use of whey as the protein source in milk replacers for veal calves.  相似文献   

2.
Four experiments comprising 86 calves have been carried out in order to examine the influence of ground barley, coarse and fine hay, when raising young calves on a high lactose milk replacer causing diarrhoea. The frequency of diarrhoea decreased when feeding barley (P < 0.01) or fine hay (P < 0.001), but increased when feeding coarse hay (P<0.01). Barley increased (P < 0.01) live weight gain and carcass weight, reduced (P < 0.001) rumen pH, favoured gram-positive cocci and rods in the rumen, caused hyperkeratosis and gave increased (P < 0.01) empty reticulo-rumen weights, the latter being supposed to be enhanced by hyperkeratosis. The calves ate more (P < 0.001) fine than coarse hay, fine hay being superior (P < 0.01) in promoting growth of the rumen. All hay maintained a predominantly gram-negative rumen flora, but somewhat different from that on the milk replacer, and counteracted (P < 0.01) low pH in the rumen and apparently also hyperkeratosis due to barley. The results with barley indicated no relationship between diarrhoea and hyperkeratosis.  相似文献   

3.
In two experiments, the performance and health of calves fed on diets containing dried microbial cells (DMC) was monitored. In the first experiment 32 seven-day-old British Friesian bull calves, reared on a conventional early weaning system to 8 weeks of age, were given milk replacers in which 5, 10 and 20% spray-dried DMC and whey replaced 14–55% of skim milk protein. All DMC diets contained 36 g/kg of non-nucleic acid nitrogen. In Experiment 2, 38 two-day-old Ayrshire bull calves were fed for 63 days solely on one of two milk diets containing 0 or 10% DMC at 5 levels of intake designed to produce body gains of 0–1 kg/day. While the inclusion of up to 10% DMC in both experiments had little effect on performance or health, 20% DMC was associated with severe diarrhoea, loss of appetite and growth retardation, and impaired clotting of the milk in vitro. In Experiment 2 the response, in gain, by calves given increasing intakes of milk dry matter was linear and was unaffected by the type of diet offered.It was concluded that when levels of DMC in excess of 10% inclusion are used in association with maize starch, deleterious effects on performance are likely.  相似文献   

4.
Fiftysix calves, in 2 similar experiments, were given 1 of 4 diets including a high lactose milk replacer: ground barley (GB), ground barley plus coarse hay (GB + GH), coarse hay (CH) and the liquid diet only (NS) ; the 2 last diets were held as controls. The calves were on the experimental diet from 1–2 weeks of age until slaughtered at 7-8 weeks of age. As observed by stereo-microscopy, the ruminai papillae in calves fed on GB were thickened, mostly finger- or club-shaped and sometimes nodular; nodular papillae were always arranged on prominent mucosal folds. Scattered nodular papillae had white coats. For calves fed on GB + CH the papillae were mostly finger- or tongue-shaped. Histologically papillae in calves fed on GB had hyperplasia of secondary papillae and epithelial layers. Microabscesses associated with penetrating hairs were frequent, and some calves had dyskeratosis with infiltration of polymorphonuclear leucocytes at the apex of papillae, identified as the white coats. For calves given GB+CH, abscesses and apical dyskeratosis were absent and the hyperplasia of epithelial layers milder than in the case of the GB diet. An ameliorative effect of hay on papillary changes caused by barley is indicated.  相似文献   

5.
Fish protein hydrolysate (FPH) has been used as the sole source of protein in milk replacers for lambs in several experiments. In comparison with casein, diets containing FPH gave slightly inferior growth rates during the first 2 weeks of a 5-week rearing period. The lower growth rate was generally compensated for in the following 3 weeks so that overall growth rate and food utilization were similar with milk replacers containing casein or FPH. Diets based on FPH, lard and hydrolysed starch were found to give results similar to a milk replacer based on casein, butterfat and lactose. The use of fat fish to provide both the source of fat and protein has received some attention and needs to be further investigated.  相似文献   

6.
Milk substitutes for calves are based upon dried skim milk and added fats of vegetable or animal origin. Many attempts have been made to replace part of the skim milk in these feeds by cheaper sources of protein.A milk product coagulates in the calf's abomasum and has a high digestibility. Milk replacers based on fish protein hydrolysate (FPH) do not coagulate in the abomasum, but have a high apparent digestibility coefficient (0.92) and the amino acid balance is similar to that of skim milk.Calves were fed on milk replacers prepared from FPH made from various materials. In general, FPH prepared from white fish (cod, blue whiting, white fish offal) was satisfactory although calf performance until weaning was poorer than for calves fed on milk replacers with dried skim milk (SMP). Some ways are suggested by which the quality of the product (FPH) could be maintained. FPH preparations from fatty fish, like sprats and mackerel, were also used. An antioxidant was added in the preparation of sprats and mackerel because of the unsaturated nature of fish fats. Milk replacers containing sprats prepared without an antioxidant and mackerel (31% body fat) with antioxidant were unsatisfactory and further development work is required on FPH materials from fatty fish.FPH from white fish can be dried without any appreciable loss in calf performance. The daily gain to weaning was 0.25 and 0.29 kg per day for calves fed on the dried and undried material, respectively. On the basis of present knowledge it is suggested that FPH can replace one third of skim milk in milk replacers for early weaned calves; the proportion recommended may rapidly increase with further technical development of the product.  相似文献   

7.
Three milk-substitutes (control, pea and soya-bean)were given to 6 preruminant calves. In the control diet protein was almost entirely provided by skim milk powder. In the pea diet a pregelatinized dehulled pea flour provided 33.5% of the protein, the remainder being supplied by skim milk powder. In the soya-bean diet, 73.2% of the protein were provided by a soya-bean isolate and the remainder by whey powder. The concentrations of plasma triglycerides and the free alpha-amino nitrogen in the peripheral blood were lower with the pea and soya-bean diets than with the control diet before the morning meal, but became higher after feeding. That suggested a faster abomasal emptying of fat and protein with the pea and especially the soya-bean diet. Systemic antibody responses were induced against pea protein but not against soya-bean protein. No effect of the diet on the plasma concentration of immunoreactive beta-lactoglobulin was apparent after 6 days, suggesting there was no important change in gut permeability at least at that time.  相似文献   

8.
The present study aimed the detection of fraudulent manipulation of milk powder with a low cost component--whey powder, by applying the immunochromatographic assay to identify glycomacropeptide. Five commercial milk powder samples of various brands from the national market were analyzed: lactose enriched milk powder type 26, two whole milk powders, vitamin enriched milk powder and full cream milk powder. Our results showed additional whey (1-2%) in 60% of the selected samples after casein removal by precipitation with 20% trichloracetic acid. Another investigated sample--the enriched UHT milk for children aged 4-12 years--proved addition of whey. Other two commercial toddler formula milk powder samples of different brands were used for comparison for the presence of glycomacropeptide. The first sample which was regularly labeled as containing whey protein concentrate was found positive for glycomacropeptide in accordance with the label information, while the second one not containing whey proteins as specified by the product label, was found negative for glycomacropeptide, these two samples being in accordance with the actual legislation.  相似文献   

9.
In an experiment with 4 × 12 male veal calves, the influence of 0, 2.5, 5.0 and 7.5% ICI protein and sweet whey powder in a milk replacer on growth; feed efficiency; blood concentrations of urea, uric acid and allantoin; and on the iron status, colour of the meat and carcass grade of the animals was investigated. The proportion of skimmed milk powder in the milk replacer was thus reduced in protein equivalence by 5, 10 and 15% (groups II–IV).Feeding with 2.5, 5 and 7.5% ICI protein in the milk replacer gave, over the whole fattening period (60–150 kg), about the same rates of growth and feed efficiency as the exclusive use of milk protein. While the urea content in the serum was not significantly influenced by the protein sources used, the uric acid and allantoin levels of the groups given ICI protein had risen greatly at 5 weeks and at the end of fattening experiment. Despite the higher total iron supply to groups II, III and IV, the criteria indicating iron supply such as haemoglobin, haematocrit and myoglobin levels did not show any increase compared to group I. Similarly, no significant differences in meat colour and carcass grade were found among the experimental groups.For veal calves the level of ICI protein in the milk replacer can be up to 7.5% during the entire feeding period.  相似文献   

10.
Twenty Norwegian Landrace pigs were divided into 5 groups and fed a basal diet consisting of a mixture of dried skim milk and whey powder together with ground barley. The diet was supplemented with 0, 0.2, 0.8, 1.2 and 2.2 μg selenium as sodium selenite and was fed for 12 weeks. The muscle selenium level was increased by a factor of about 4 and the liver selenium by a factor of about 12 when the dietary selenium supplement was increased from zero to 2.2 μg/g. There was a significant linear correlation between dietary selenium and selenium concentrations in tissues. Possible benefit for humans consuming meat from animals having received the selenium doses used in this experiment are discussed. dietary selenium; tissue levels; pigs.  相似文献   

11.
Dairy foods and dietary calcium (Ca) are potential regulators of body weight and insulin sensitivity. The specific components of dairy responsible for these actions are not known but may include leucine. Our objective was to determine the effect of dietary protein (casein, skim milk or leucine) and Ca level [low, 0.67% (LC) or high, 2.4% (HC)] on adiposity and insulin sensitivity. Obesity was induced in Sprague–Dawley rats with a 6-week period of high-fat/high-sucrose (HFHS) diet intake. Rats were randomly assigned to one of six HFHS diets for 8 weeks where dietary protein was provided as casein, skim milk or casein enriched with leucine, and contained either LC or HC. Body composition via dual-energy x-ray absorptiometry and insulin sensitivity via euglycemic–hyperinsulinemic clamp were measured. Microarray was used to assess gene expression in liver and skeletal muscle. Rats fed leucine had greater insulin sensitivity than those fed casein or skim milk (P<.05). Dietary protein differentially regulated hepatic and skeletal muscle genes associated with insulin, peroxisome proliferator-activated receptor and mammalian target of rapamycin pathways. Specifically, two key genes responsible for insulin sensitivity, hepatic insulin receptor substrate (IRS) and protein kinase B (Akt), were altered in hepatic tissue in response to leucine. Rats fed skim milk and leucine diets had lower body weight compared to those fed casein (P<.05). HC reduced fat mass compared to LC (P<.05). While skim milk and leucine both reduced fat mass, only leucine improved insulin sensitivity compared to casein. Differential expression of genes such as IRS and Akt may be responsible for changes in insulin sensitivity in obese rats.  相似文献   

12.
The storage modulus of various concentrations of highly cross-linked waxy maize starch was measured in water, a salt solution, a salt solution with lactose, whey, and skim milk. The influence of the skim milk components was deduced from the differences in moduli between these systems. Salts appeared to have no direct influence on the modulus of the starch. Lactose increased the storage modulus, probably due to an increase in the particle rigidity of the swollen starch granules. The whey proteins had only a small effect on the modulus of the starch. However, the concentration of these proteins was very low. Casein micelles increased the modulus of the starch because the swollen starch granules are not accessible to the casein. A model based on the mutual exclusion of swollen starch granules and milk proteins was applied to predict the storage modulus of starch-milk systems as a weighed sum of the moduli of the starch and protein phases. Weight factors were derived from the hydration capacity of starch granules and casein micelles. Although the behaviour of aqueous starch-skim milk systems fell within the boundaries imposed by the model, the predictive power of this model was rather poor.  相似文献   

13.
The effect of calf milk replacers as substitutes for nonfat dry milk in the larval diet of the screwworm, Cochliomyia hominivorax (Coquerel), was determined in the laboratory. Pupal weight and fecundity of females were significantly greater than the control with some of the formulations tested. Larval crawl-off patterns for all diets were similar. Pupal weights were significantly affected only on day 1 of the 4-d crawl-off period. Among the formulations of calf milk replacer, Gold Label brand products showed the most promise as substitutes for the nonfat dry milk presently used in the screwworm production facility. Use of calf milk replacers would lead to a yearly savings of 39.3% in the cost of the dietary milk component. At a production level of 250 million flies weekly, this substitution would save approximately $338,000 dollars yearly.  相似文献   

14.
The research field for applications for lactose hydrolysis has been investigated for some decades. Lactose intolerance, improvement for technical processing of solutions containing lactose and utilisation of lactose in whey are main topics in development of biotechnological processes. In this article, the establishment of a hollow fiber membrane reactor process for enzymatic lactose hydrolysis is reported. Mesophilic beta-galactosidases were circulated abluminally during luminal flow of skim milk. The main problem, microorganisms growth in the enzyme solution, was minimised by sterile filtration and UV irradiation. In order to characterise the process parameters, such as skim milk concentration, enzyme activity and flow rates were varied. In comparison to a batch process, enzyme activity could be used longer and enzyme rest into the product should not occur. Furthermore, the three-dimensional separation of the substrate from the enzyme solution minimise blocking and washing out effects, which restrict processes with immobilised enzymes. A conversion rate of 78.11% was achieved at a skim milk flow rate of 9.9l h(-1), enzyme activity of 120 Uml(-1) and a temperature of 23+/-2 degrees C in a hollow fiber reactor with a membrane area of 4.9 m2.  相似文献   

15.
Twenty-four growing Assaf lambs, divided into four groups of six animals, were used to study the effect of the undegradable protein content of the post-weaning diet on feed intake, body growth and reproductive development. From week 1 to week 21, the four groups were fed ad libitum as follows: group LL was given barley straw and low protein concentrate (LP); group HH was given barley straw and high protein concentrate (HP); group LH was given barley straw and LP concentrate from week 1 to 11 (period 1) and barley straw and HP concentrate from week 12 to 21 (period 2); group HL was given barley straw and HP concentrate in period 1 and barley straw and LP concentrate in period 2. From week 22 to week 26 (period 3), all animals received the same amount of hay and LP concentrate. Barley straw intake was not significantly (P>0.05) affected by dietary treatments. In the 1st period, average concentrate intake and live body weight gain (LWG) were greater in lambs fed HP than LP supplement. In the 2nd period, concentrate intake was not significantly (P>0.05) affected by type of supplement, but LWG was greater for lambs fed HP than LP supplement. Scrotal circumference in week 11 was significantly (P<0.05) lower in lambs fed LP supplement than in lambs fed HP supplement. No significant differences (P>0.05) due to dietary treatments were observed on scrotal circumference in weeks 21 and 25. Dietary treatments had no significant (P>0.05) effect on either circulating concentration of testosterone or ejaculate characteristics. In conclusion, results from this study suggest that supplementing diets with undegradable protein enhanced performance throughout the breeding period and accelerated testis growth. Nevertheless, final testis size, pattern of circulating testosterone and sperm output were unaffected by dietary treatments.  相似文献   

16.
The objective of the study was to assess the post-weaning growth response of Sahiwal calves reared on four different pre-weaning dietary regimens. The four diets were: (a) whole cow's milk, starter ration (SR; CP = 20%, total digestible nutrients (TDN) = 72%) and Berseem hay (H; Egyptian clover; CP = 21%, TDN = 63%); (b) whole cow's milk + H; (c) milk replacer (MR; reconstituted to supplier specification; Sprayfo®) + SR + H; and (d) MR + H. The protein and fat percentages of reconstituted MR were 2.22 and 1.84, respectively. Milk or MR were fed at the rate of 10% of the calves’ body weight (BW) until 56 days of age, and then withdrawn gradually until weaned completely by 84 days of age. The average initial BW of calves in groups A, B, C and D were 56.3 ± 1.0, 47.5 ± 1.0, 40.4 ± 1.0 and 30.3 ± 1.0 kg, respectively. Initially, there were 12 calves in each group with six of each sex; however, one male calf died from each of groups B and C and were not replaced. During the post-weaning period, 13 to 24 weeks, the calves were fed a single total mixed ration ad libitum based on maize, canola meal, wheat straw and molasses containing 16% CP and 70% TDN. Daily feed intake and weekly BW gains were recorded. The data were analyzed by MIXED model analysis procedures using the statistical program SAS. The intake of calves as percent of their BW, feed conversion ratio and cost per kg of BW gain were not different (P > 0.05) across treatments. The daily gain at 24 weeks of age for the pre-weaning treatments A, B, C and D were 746 ± 33, 660 ± 33, 654 ± 33 and 527 ± 33 g/day and the final liveweights of calves were 119 ± 4.2, 102 ± 4.2, 95 ± 4.2 and 75 ± 4.2 kg, respectively. Gains were influenced significantly (P < 0.05) by pre-weaning treatments. The calves fed MR and H only during the pre-weaning period were unable to catch up post weaning with calves on other dietary treatments. The calves fed whole milk from birth at the rate of 10% of liveweight together with concentrates had higher weaning weight and superior growth rate post weaning as well. Thus, pre-weaning feeding was important for higher weaning weights and superior growth rates post weaning.  相似文献   

17.
Optimum growth conditions for mixed species starter FDs 0172 in skim milk, whey medium, and tryptone medium at 25 C in a “pH-stat” continuous fermentor were investigated. Specific growth rate and productivity were found to be influenced both by the medium and the pH value. Highest productivity was found in skim milk medium between pH 5.5 and 5.9. Lactic acid-producing activity of harvested cells decreased by continuous cultivation at pH values lower than 5.9 to 6.1, especially in tryptone and whey medium. Bacterial balance, CO2 production, and aroma formation were comparable to the control in skim milk and whey medium at any pH, but differed significantly for cells grown in tryptone medium.  相似文献   

18.
The objective was to study the effect of type of concentrate with varying starch and fibre content on growth and gastrointestinal development in preweaned dairy calves. Thirty-two newborn Danish Holstein male calves were allocated to four treatment groups in eight blocks of four calves. An experimental low-starch, high-molasses, high-fibre (EXP) concentrate or a traditional high-starch (TRA) concentrate were fed either at a high (HIGH; 2 × 3.2 kg/day) or a low (LOW; 2 × 1.6 kg/day) whole milk allowance in a 2 × 2 factorial design. TRA contained 350 and EXP 107 g starch/kg dry matter (DM), whereas the NDF content was 136 and 296 g/kg DM, respectively. Metabolizable energy (ME) was 11.2 and 12.2 MJ ME/kg DM in EXP and TRA, respectively. All calves had free access to artificially dried grass hay (9.8 MJ ME/kg DM). Four calves were culled during the experiment. The calves were euthanized either at 38 (12 calves) or 56 days (16 calves) of age. Evaluated across both slaughter ages, there was no difference between TRA and EXP in concentrate and hay intake, rumen weight and papillation. EXP resulted in increased villi number in duodenum and jejunum compared with TRA. Concentrate intake and reticulo-rumen weight was higher for LOW compared with HIGH milk allowance, whereas live weight gain was 20% lower. The results show that a low-starch, high-molasses, high-fibre concentrate with 8% lower ME content tended to reduce daily gain compared with a traditional calf starter concentrate, but resulted in similar ruminal development in preweaned calves both on a high and a low milk allowance fed along with grass hay. Furthermore, the results suggest that the experimental concentrate stimulated intestinal villi growth over that of the traditional concentrate.  相似文献   

19.
An effective colostrum management programme is the most important factor in determining the health and survival of the neonatal calf. Commercially available colostrum replacers (CR) and colostrum supplements (CS) are an alternative to colostrum on farms that do not have an adequate, high-quality colostrum supply, or those farms that want to prevent transmission of disease from cow to calf. The present study aimed to obtain a high immunoglobulin (Ig), dried bovine colostrum product that could be used as a CR or CS for dairy calves. Dried whey was made from 6 batches of colostrum and an additional 6 batches were used to produce dried whey and curds. Dried whey had higher IgG concentration (P<0.05) and lactose (P<0.05), and less fat (P<0.05) compared to curds or the original colostrum. There was a strong linear relationship between initial colostrum IgG concentration and whey (R2 = 0.86) with approximately 0.45 of the initial colostral IgG residing in curd. The high IgG and the composition of colostrum whey powder suggests it could be an effective CS product for use with dairy calves. The high fat and IgG content of the curd by-product indicate that it might be a potential weaning supplement in piglets or even a product for human consumption.  相似文献   

20.
Aim:  To determine the critical component(s) of skim milk for biofilm formation of Cronobacter species.
Methods and Results:  Biofilm forming ability of 72 Cronobacter strains in skim milk preparation was assayed by crystal violet staining. The results revealed that whey protein and casein are more important determinants of skim milk for biofilm formation than lactose, although there was a wide variation in biofilm forming ability. Biofilm structure and capsular material of six strains exhibiting different biofilm forming ability was investigated via electron microscopes. Scanning electron microscopy showed visually that while the strong biofilm formers (E27B, FSM 30 and 2·82) resulted in almost complete coagulation of skim milk, the weak biofilm formers (55, FSM 290 and 2·84) caused less coagulation. No capsule was clearly delineated in transmission electron micrographs of either strong or weak biofilm formers.
Conclusion:  These results indicate that, for biofilm formation of Cronobacter species in skim milk, nitrogen source is probably a more important determinant than carbohydrate, and that strong biofilm formers are responsible for substantial coagulation of skim milk.
Significance and Impact of the Study:  This study provides information for better understanding of the underlying mechanisms by which Cronobacter species form biofilm in infant formula milk.  相似文献   

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