Distributional uptake of gamma-globulin in small intestine of neonatal calves.

Newborn calves deprived of colostrum were used to determine distribution of uptake of gamma-globulin labeled with iodine-125 in small intestine. Ten calves less than 12.5 h of age (average 7 h) were anesthetized, and intestines were exteriorized through an abdominal incision. Intestine was ligated into 10-cm segments, 70 cm apart, beginning at the ileocecal junction and progressing anteriorally, then each segment injected with 100 mg (appoximately 1 microCi) labeled gamma-globulin in 5 ml electrolyte solution, and incubated for 1.5 h. One additional segment was formed adjacent to segments 1, 5, and 10 to assess uptake after .5 h incubation with [iodine-125] gamma-globulin. After prescribed gamma-globulin exposure, segments were excised; then volume of lumen contents, segment weight, and tissue activity were measured. The location of each segment was the percentage of distance from cecum to abomasum. Uptake was milligrams gamma-globulin per gram of segment tissue. Distribution of gamma-globulin uptake after 1.5 h incubation was a cubic function of segment position. Uptake was greatest in a region 15% of the cecum-abomasum distance and declined progressively toward the abomasum. After .5-h incubation with gamma-globulin, regression of uptake on segment position was a quadratic function with greatest uptake at 30% of cecum-abomasum distance. Uptake was greater in segments exposed to gamma-globulin for 1.5 h than .5 h.     

Hypoxia in neonatal calves: effect on intestinal transport of immunoglobulins

The effect of reduced oxygen tension in arterial blood (hypoxic hypoxia) for 24 h postpartum on the absorption of colostral Ig was studied in 12 neonatal calves. During this period, inspired air for hypoxic calves contained 10.5% O2, whereas that for normoxic calves contained 21% O2. After 24 h, inspired air for all calves contained 21% O2. Three dietary regimens also were imposed during the initial 24-h period: colostrum at 0 and 12 h, whole milk at 0 and 12 h, or fasting. Colostrum was fed to all calves at 24, 36, and 48 h. During the initial 24-h period, means for arterial partial pressure of oxygen were 26 and 73 mm Hg for hypoxic and normoxic calves, respectively. In those fed colostrum at 0 and 12 h, hypoxia extended the period of Ig absorption from 20 to 40.5 h. In calves fed whole milk or those that were fasted, no such effect was noted. These observations suggest that the effect of hypoxia on the cessation of Ig absorption by the small intestine is mediated through a secondary and as yet undetermined mechanism.     

Effect of orally administered duodenal fluid on serum proteins in neonatal calves.

This study was to determine if orally administered duodenal fluid, as a source of intestinal microorganisms, would influence absorption of gamma-globulin of colostrum in newborn calves. Duodenal fluid was obtained 2 h postfeeding from a cannulated milk-fed calf. Twenty-seven male and female Holstein calves obtained within 6 h of birth were assigned randomly to one of three treatments: 1) colostrum alone, 2) 200 ml duodenal fluid immediately followed by colostrum, and 3) 200 ml duodenal fluid followed 3 h later by colostrum. Pooled colostrum was fed at 10% of body weight in two daily feedings. Total protein, albumin, alpha-globulin, beta-globulin, and gamma-globulin of blood serum were determined prior to colostrum consumption, and again 24 and 48 h after administration of duodenal fluid. Total proteins, beta-globulin, and gamma-globulin of serum increased with age in all calves. Inocula interference with absorption was indicated by depressed values of serum in calves of treatment 3 as compared to treatment 1 calves for protein (5.28 to 6.28 g/dl), beta-globulin (.67 to .87 g/dl), and gamma-globulin (.76 to 1.33 g/dl). Protein was also lower in calves of treatment 3 (6.05 g/dl) compared to uninoculated calves (6.28 g/dl). Malabsorption of colostral proteins may be related to early establishment of large numbers of intestinal microorganisms in the newborn calf.     

In vivo breakdown of dietary [methyl−14C] and [uronate-6−14C]pectin-labelled spinach cell walls by rat intestinal microorganisms and incorporation of 14C into host tissues

The metabolism of dietary plant cell wall (PCW) pectin was followed in the rat using PCW isolated from spinach cell cultures ¹⁴C-labelled in the galacturonic acid residues or pectic methyl ester groups. ¹⁴C-PCW were rapidly broken down in the caecum and colon of the rat and generated several groups of soluble products. [¹⁴C]Methanol was released from [methyl^?14C]pectin-labelled PCW and some of the methanol was converted to ¹⁴C-labelled volatile acids. ¹⁴C-Labelled volatile acids were also generated from [uronate-6-¹⁴C]pectin-labelled PCW along with soluble but non-volatile material. ¹⁴C derived from both cell wall types was taken up by the caecal and colonic mucosa and transported to the liver, pelt and other body tissues. Some ¹⁴C was excreted as ¹⁴CO₂ and in urine.     

Influence of decoquinate fed to neonatal dairy calves on early and conventional weaning systems

Forty-four Holstein calves were assigned randomly to treatments in a 2 x 2 factorial arrangement of weaning age (4 or 7 wk) and coccidiostat (treatment or control). The objective of this study was to compare the effectiveness of a coccidiostat, decoquinate, on health parameters and growth of neonatal dairy calves on early and conventional weaning systems. Calves weaned at 4 wk had greater intakes of grain in wk 5 to 7 than did calves weaned at 7 wk. Differences in intakes between weaning groups were not apparent from wk 8 to 24. Fecal coccidia oocyst counts were not affected by age at weaning but were affected by coccidiostat feeding at the rate of .5 mg/kg BW/d offered from 3 d of age and throughout the trial. No effects due to age at weaning or coccidiostat treatment were found in plasma glucose, urea N, and minerals (Ca, P, Na, Cl, K, Mg). Growth parameters were significantly increased in treated animals. Total BW was increased (wk 9 to 24) in treated over control calves (127.3 versus 118.5 kg). Height at withers was also increased in treated calves (95.0 vs. 92.8 cm). Coccidiosis treatment increased growth of dairy calves from 9 to 24 wk, but no interactions were found between coccidiosis treatment and age at weaning.     

Effect of nitazoxanide on cryptosporidiosis in experimentally infected neonatal dairy calves

Cryptosporidium is a zoonotic protozoan that is most often diagnosed in association with diarrhea in 1- to 3-wk-old dairy calves. There are neither consistently effective nor approved antimicrobial drugs for treatment in animals. The objective of this study was to test nitazoxanide (NTZ) as a treatment for cryptosporidiosis in experimentally infected dairy calves. A randomized, controlled, and blinded trial was performed using Holstein bull calves obtained from a large commercial dairy. All births were attended by study personnel and calves were fed 4 L of heat-treated colostrum within 1 h of birth. Calves were randomly assigned to treatment or placebo group and maintained for a 32-feeding (16 d) study period. Twenty-three calves were enrolled with 3 lost to follow up. Thirteen calves were assigned to the treatment group and 7 calves to the placebo group. All calves were inoculated with 1 × 10⁶ viable Cryptosporidium parvum oocysts at feeding 3. Treatment was a commercially available NTZ product and the placebo was the carrier of the same product. Nitazoxanide was administered at 1.5 g twice per day for 5 d. Nitazoxanide or placebo treatment began after feeding 10 and when the fecal score was greater than 1 out of 3. Outcome measurements included twice-daily fecal and health scores and a once-daily oocyst count by an immunofluorescent antibody assay. Data were analyzed by nonparametric and time-to-event methods. Measures of passive transfer of antibodies, initial body weight, and onset of oocyst shedding were not different between treatment and control calves. Eighty-five percent of the NTZ-treated calves stopped shedding oocysts by the end of the observation period whereas only 15% of the placebo group stopped shedding. The median number of feedings with a fecal score equal to 3 was 2 in the NTZ group while it was 6 in the placebo group. Calves receiving NTZ were 0.13 times as likely to have severe and sustained diarrhea than control calves (95% confidence interval, 0.02-0.98). Treating calves with NTZ reduced the duration of oocyst shedding and improved fecal consistency.     

Influence of bovine antiserum (Bo-Bac 2X) injection on colostral immunoglobulin G absorption in neonatal dairy calves

On the background of positive survival data from farms in Mississippi, treating calves with antiserum injection in addition to normal colostrum administration, the objective of the present study was to evaluate the influence of a single subcutaneously administered bovine antiserum injection (0.031 g of IgG/kg of body weight) and pooled colostrum administration on efficiency of Ig absorption and on 24-h plasma IgG concentration in neonatal bull calves. Twenty-nine male dairy calves (21 Holsteins and 8 Jerseys) were assigned randomly at parturition to receive one of four treatments: 1) colostrum (n = 9), 2) colostrum and bovine antiserum injection (n = 7), 3) milk replacer (n = 5), or 4) milk replacer and bovine antiserum injection (n = 8). At birth, calves either did or did not receive an injection of bovine antiserum and were fed pooled colostrum or milk replacer (Holsteins, 3.8 L; Jerseys, 1.9 L) via an esophageal feeder. Blood was collected immediately before administration of the colostrum or milk replacer, then again at 24 and 48 h postpartum. Immunoglobulin G concentrations of colostrum, milk replacer, antiserum, and plasma were monitored by single radial immunodiffusion. Colostrum administration and injection of bovine antiserum each increased plasma Ig concentration at 24 h posttreatment. In addition, antiserum injection increased the apparent efficiency of absorption of colostral Ig by 42% over that for calves fed colostrum alone. The increase in plasma IgG for antiserum-treated calves exceeded the total amount of IgG administered in the antiserum injection; hence, this increase appeared to be the result of an increase in total absorption of colostral IgG, or possibly antiserum injection somehow triggered active synthesis of IgG. Injection of antiserum might possibly serve as a beneficial adjunct to a colostrum management program by enhancing the acquisition of passive immunity from colostral sources.     

Influence of microorganisms on retinol isomerization in milk

In order to have a deeper insight into the retinol isomerization phenomenon, in this work different milk samples have been analysed for their content of trans retinol and its cis-isomers, by means of reliable HPLC techniques. Levels of the different isomers and the degree of retinol isomerization (13-cis/all-trans ratio, %) have been monitored during milk storage at different temperatures and after addition of specific microorganisms. In raw milk stored at 4 degrees C for 96 h the degree of retinol isomerization shifted from 1.1 to 2.3%, while in raw milk stored at 22 degrees C for 24 h it increased from 1.1 to 12.7%. Among microorganisms tested in pasteurized milk, the most active in causing an increment in the 13-cis/all-trans ratio (%), from 3.4 to 33.4% in 8 h, was Streptococcus thermophilus. The results obtained demonstrated a relationship between microbial evolution and retinol isomerization. Therefore, the determination of retinol isomers is of importance not only for a more precise evaluation of vitamin A activity but also for the evaluation of the microbiological quality of milk.     

In vitro studies on microbial incorporation of nitrogen from [15N2] urea and [15N]ammonium chloride by human intestinal flora

6 typical bacteria species of the human intestinal flora (E. coli, Klebsiella pneumoniae, Proteus vulgaris, Streptococcus faecalis, Bacteroides fragilis, Bifidobacterium sp.) were incubated in a liquid medium for 48 h with [15N2]-urea and [15N]-ammonium chloride. The rates of [15N]-incorporation were calculated. They depend reproducible on the species examined, on the kind of the offered NPN-substance and on the amount of NPN-substance in the medium. With [15N2]-urea the minimal rate of incorporation was 3.8% (E coli) and the maximal one 95.6% (Bifidobacterium sp.). With [15N]-ammonium chloride the corresponding figures were 31.0 (Proteus vulg.) and 98.0% (Bifidobacterium sp.). The findings are discussed with regard to a possible enteral detoxification in uremic patients by bacterial utilization and elimination of urea and ammonia.     

Effect of soy protein on intestinal absorptive ability of calves by the xylose absorption test

Five calves per group were fed whole milk (control) or one of three milk replacers with one-thrid of the total protein provided by a soy product. Soy products were Promocaf (a commercial soy protein concentrate), an experimental soy flour. After a 24-h fast, calves were fed xylose solution. Urine was collected for 5 h. Jugular blood was sampled at 0, .5, 1, 1.5, 2, 2.5, 3, 4, and 5 h after xylose administration. Xylose tests were weekly on each calf through 5 wk of age. Urinary xylose excretion, as a percentage of xylose fed, was higher in the control group during the last 4 wk than in groups fed milk replacers. Mean urinary xylose excretions during 5 wk from calves sampled 5 h after xylose administration were 12.4, 4.2, 4.2, and 4.3% of xylose administered for calves fed milk, soy flour, soy protein concentrate, and Promocaf, respectively. Mean increases in peak of xylose concentration in plasma were 55.7, 44.4, 42.8, and 45.3 mg/100 ml. Peak values for control calves were higher than those for calves fed soy products at wk 4 and 5. Times required to reach peak value did not differ significantly. Neither xylose concentration of plasma nor urinary xylose excretion differed among the groups fed soy products.     

挤奶阶段对羊乳中微生物的影响

对奶山羊挤奶过程中不同挤奶阶段的乳样中微生物变化规律进行了研究.结果表明,不同挤奶阶段乳中微生物数量有明显变化,挤出的前期乳样中微生物数量最高,中期乳样次之,末期乳样最低.前期乳样的菌落总数、大肠菌群、嗜冷菌、嗜热菌、蛋白分解菌和脂肪分解菌的数量分别高达3×106、1.4×104、3.3×104、1.3 x 103、1.5×105和1.3×105cfu/mL,明显高于中期乳样和末期乳样(P＜0.05),尤其是前期乳样中的菌落总数已高出GB19301-2010中收购生鲜乳的微生物指标(2×106cfu/mL).因此在挤奶过程中,应尽可能的弃去前期乳样,以提高原料羊乳的卫生质量.     

Short communication: effect of pH on absorption of immunoglobulin G in neonatal calves

We fed newborn calves (n = 60) maternal colostrum (n = 12) or a colostral supplement product derived from edible bovine serum (n = 48). Sodium citrate was added to supplements to achieve a final pH of 7.5, 7.0, 6.0, and 5.0. Calves were fed colostrum (2 L/feeding) or supplement (454 g reconstituted in 2 L of water) at 1.2 and 12.6 h of age, which provided a total of 156 (colostrum) or 90 (supplement) g of IgG. We sampled jugular blood at 0 and 24 h of age to determine plasma IgG. Mean plasma IgG concentrations at 0 and 24 h of age were 0 and 6.7 g/L and were markedly higher in calves fed maternal colostrum compared with supplements (10.7 vs. 6.5 g/L) and were higher in Jersey vs. Holstein calves (8.5 vs. 6.1 g/L). Estimated apparent efficiency of IgG absorption was unaffected by treatment and averaged 20%. These data indicate that pH of colostral supplements between 7.5 and 5.0 do not markedly influence the efficiency of IgG absorption.     

Diet effects on glucose absorption in the small intestine of neonatal calves: Importance of intestinal mucosal growth,lactase activity,and glucose transporters

Colostrum (C) feeding in neonatal calves improves glucose status and stimulates intestinal absorptive capacity, leading to greater glucose absorption when compared with milk-based formula feeding. In this study, diet effects on gut growth, lactase activity, and glucose transporters were investigated in several gut segments of the small intestine. Fourteen male German Holstein calves received either C of milkings 1, 3, and 5 (d 1, 2, and 3 in milk) or respective formulas (F) twice daily from d 1 to d 3 after birth. Nutrient content, and especially lactose content, of C and respective F were the same. On d 4, calves were fed C of milking 5 or respective F and calves were slaughtered 2 h after feeding. Tissue samples from duodenum and proximal, mid-, and distal jejunum were taken to measure villus size and crypt depth, mucosa and brush border membrane vesicles (BBMV) were taken to determine protein content, and mRNA expression and activity of lactase and mRNA expression of sodium-dependent glucose co-transporter-1 (SGLT1) and facilitative glucose transporter (GLUT2) were determined from mucosal tissue. Additionally, protein expression of SGLT1 in BBMV and GLUT2 in crude mucosal membranes and BBMV were determined, as well as immunochemically localized GLUT2 in the intestinal mucosa. Villus circumference, area, and height were greater, whereas crypt depth was smaller in C than in F. Lactase activity tended to be greater in C than in F. Protein expression of SGLT1 was greater in F than in C. Parameters of villus size, lactase activity, SGLT1 protein expression, as well as apical and basolateral GLUT2 localization in the enterocytes differed among gut segments. In conclusion, C feeding, when compared with F feeding, enhances glucose absorption in neonatal calves primarily by stimulating mucosal growth and increasing absorptive capacity in the small intestine, but not by stimulating abundance of intestinal glucose transporters.     

西瓜清汁的动力杀菌效果研究

采用超高压纳米破碎机,对西瓜清汁进行了动力杀菌实验,考察了动力处理对西瓜清汁中微生物的杀灭效果。实验结果表明,常温下150MPa经3次动力处理,西瓜清汁中的菌落总数降至60cfu/mL,霉菌及酵母菌数降至17cfu/mL,均可达到《果、蔬汁饮料卫生标准——GB19297-2003》的微生物指标要求。实验还发现,制备的西瓜清汁中,微生物主要来自加工环境的外源微生物,新鲜西瓜果实中的内源微生物量很少。     

生产贮藏条件对原料奶中微生物的影响

以手工挤奶条件下不同来源的原料奶为研究对象,在冷藏(4℃)、室温(19℃)条件下,分别贮藏0,3,6,9 h后检测原料奶中菌落总数(TBC)、芽孢总数(TSC)、耐热芽孢数、嗜冷菌总数。结果表明,随着贮藏温度增加、时间延长,原料奶中微生物增幅加快(P<0.05),冷链条件下(4℃)贮运原料奶对控制微生物生长繁殖具有重要作用。手工挤奶条件下室温(19℃)贮奶3h、冷藏(4℃)贮奶6h后原料奶中菌落总数超过5×105 mL-1的国家标准,原料奶的芽孢总数、耐热芽孢数和嗜冷菌数均超出液态奶的生产要求,特别不利于长效奶(保质期30 d以上)的生产。改善牛奶生产环境对提高原料奶品质具有重要的作用。     

Analysis of methane production by microorganisms indigenous to a depleted oil reservoir for application in Microbial Enhanced Oil Recovery

We examined methane production by microorganisms collected from a depleted oilfield. Our results indicated that microorganisms indigenous to the petroleum reservoir could effectively utilize yeast extract, suggesting that the indigenous microorganisms and proteinaceous nutrients could be recruitable for Microbially Enhanced Oil Recovery.     

Influence of high dietary lead on selenium metabolism in dairy calves

Metabolism of orally dosed 75Se was studied in 10 intact male Holstein calves that were fed ad libitum a control diet containing no added Pb or supplemented with 1000 ppm Pb as PbSO4 for 4 wk. Lead-supplemented calves did not exhibit any clinical signs of Pb toxicity. Voluntary feed intake was reduced by 9.5% and average daily gain by 23%. Lead content of rib, liver, and kidney increased. Serum glutamic oxaloacetate transaminase activity was increased during the last 2 wk of the experiment in calves fed Pb. In calves receiving supplemental Pb, 75Se absorption, blood concentration, and urine concentration were reduced by 26, 21, and 42%, respectively. Tissue 75Se concentrations were significantly lower in kidney, liver, testicle, pancreas, small intestine, heart, spinal cord, and muscle in calves fed Pb. There was a significant negative correlation (r = -.78) between 75Se and stable Pb concentrations in the liver. It is not clear whether the ingestion of subclinical amounts of Pb could affect the absorption and utilization of Se in dairy calves to the extent of Se deficiency when dairy calves are kept in areas known to be low in Se.     

Addition of sodium bicarbonate to either 1 or 2 feedings of colostrum replacer: effect on uptake and rate of absorption of immunoglobulin G in neonatal calves

Forty Holstein dairy calves were blocked by birth date and sex, and randomly assigned to 1 of 4 treatments within each block to elucidate the effect of feeding regimen and sodium bicarbonate (NaHCO?) supplementation on absorption of IgG from colostrum replacer (CR). Calves received CR containing 191.4 g of IgG fed either in 1 feeding at 0 h (within 45 min of birth), with or without 30 g of NaHCO?, or in 2 feedings (127.6 g of IgG at 0 h, with or without 20 g of NaHCO?, and 63.8 g of IgG at 6 h, with or without 10 g of NaHCO?). The treatments were (1) 1 feeding of CR+0 g of NaHCO?; (2) 1 feeding of CR+30 g of NaHCO?; (3) 2 feedings of CR+0 g of NaHCO?; and (4) 2 feedings of CR+30 g total of NaHCO?. Only calves born with no dystocia were used on this study. Blood samples were taken at 0, 6, 12, 18, and 24h postpartum and were analyzed for IgG using a radial immunoassay. Results indicated that, individually, feeding regimen and NaHCO? treatments had no effect. However, the interaction was significant for 24-h IgG and area under the curve, and showed a trend for apparent efficiency of absorption. Absorption rate data indicated that, for calves fed within 45 min of birth, most IgG absorption occurred in the first 6 h after birth. From 6 to 12 h postpartum, IgG absorption started to decrease; however, IgG absorption remained higher for calves fed in a single feeding than in 2 feedings. These data indicated that NaHCO? may increase IgG absorption when calves are fed colostrum in a single feeding but is not beneficial when colostrum is fed in 2 feedings.     

Effects of nucleotide supplementation in milk replacer on small intestinal absorptive capacity in dairy calves

Milk replacer was supplemented with nucleotides and fed to dairy calves from birth through weaning to examine the potential for enhancing recovery of small intestinal function after enteric infection. Three treatments of 23 calves each were fed milk replacer (10% body weight/d) supplemented with no nucleotides (C), purified nucleotides (N), or nucleotides from an extract of Saccharomyces cerevisiae (S). Average daily gain, health scores, fecal dry matter, and fecal bacteria were monitored, and blood was analyzed for packed cell volume, glucose, blood urea nitrogen (BUN), and creatinine. Calves were monitored twice daily for fecal score, and 48 h after increased fecal fluidity was recorded, intestinal function was evaluated by measuring absorption of orally administered xylose (0.5 g/kg of body weight). Packed cell volume of blood was greater for treatment N for wk 2 and 5 compared with other treatment groups. Four calves per treatment were killed, and intestinal tissue was evaluated for morphology, enzyme activities, and nucleoside transporter mRNA expression. Treatment S calves had increased abundance of nucleoside transporter mRNA, numerically longer villi, and lower alkaline phosphatase than other groups. Growth measurements and plasma concentrations of glucose, BUN, creatinine, and IgG were not different between treatments; however, BUN-to-creatinine ratio was higher for treatment N, possibly indicating decreased kidney function. There were also no treatment effects on fecal dry matter and fecal bacteria population. However, N-treated calves had the highest detrimental and lowest beneficial bacteria overall, indicating an unfavorable intestinal environment. Supplementation of purified nucleotides did not improve intestinal morphology or function and resulted in higher fecal water loss and calf dehydration. Supplementation of nucleotides derived from yeast tended to increase calf intestinal function, provide a more beneficial intestinal environment, and improve intestinal morphology.