Bacterial diversity in tree canopies of the Atlantic forest.

We found an extraordinary level of bacterial biodiversity in the tree leaf canopy of a tropical Atlantic forest by using culture-independent molecular methods. Our survey suggests that each tree species selects for a distinct microbial community. Analysis of the bacterial 16S ribosomal RNA gene sequences revealed that about 97% of the bacteria were unknown species and that the phyllosphere of any one tree species carries at least 95 to 671 bacterial species. The tree canopies of tropical forests likely represent a large reservoir of unexplored microbial diversity.

Effects of barley variety and processing methods on feedlot steer performance and carcass characteristics.

An experiment was conducted to evaluate ammoniation and temper processing of two barley varieties of diverse types on feedlot cattle performance and diet digestibility. Steptoe (feed variety) and Klages (malting variety) barleys were processed as dry-rolled (DR); tempered and rolled (TR); tempered, ammoniated, and rolled (AR); and tempered, ammoniated, and fed whole (AW). Crossbred steers (n = 240, initial weight 266 kg) were blocked by weight and randomly assigned to one of eight treatments in a 2 x 4 factorial arrangement. Diets contained 30% barley (DM basis) for the growing phase and 85% (DM basis) for the finishing phase. Growing phase ADG and gain to feed (G/F) were less (P < .05) for AW than for DR, TR, and AR. Average daily gain was less (P < .05) for AW than for TR and AR in the finishing phase. There were no differences (P > .05) in ADG or G/F between DR, TR, and AR during growing or finishing phases. Gain to feed was greater (P < .05) for TR and AR than for AW but not for DR for the total trial. Hot carcass weight, longissimus muscle area, and kidney-pelvic-heart fat were greater (P < .05) for TR and AR than for AW. Total finishing diet ADF digestibility was greater (P < .05) for Steptoe than for Klages (40.5 vs 31.4%, respectively). The DR treatment had the lowest ADF digestibility, whereas AR had the greatest (P < .05). Results suggest that there were no differences in feedlot steer performance due to barley varieties of the same bulk density and that barley grain must be mechanically processed for optimal performance response rather than ammoniated and fed as whole grain.

Dose-response effects of recombinant bovine somatotropin (Posilac) on growth performance and body composition of two-year-old rainbow trout (Oncorhynchus mykiss).

Two hundred rainbow trout (Oncorhynchus mykiss, mean weight 301.5 g) were allotted to four treatments with five replicates in a randomized block design to determine the dose-response effects of recombinant bovine somatotropin (rbST; Posilac) on growth performance and carcass composition. Treatments were sham-injected controls (S), 10 micrograms/g BW of rbST (L), 20 micrograms/g BW of rbST (M), and 30 micrograms/g BW of rbST (H). The tanks held 135 L; water flow = 15.1 L/min; temperature = 15 degrees C. The fish were maintained in a 12-h light:dark cycle and hand-fed twice daily. The fish received a single intraperitoneal (i.p.) injection on d 0 and were weighed on d 0, 14, 28, and 56. On d 56 the fish were killed. The whole body (WBW), eviscerated carcass (EC), viscera (VIS), and reproductive organ weights and the increase in average daily body length (ADL) were determined. Recombinant bST reduced (linear, P < .004) feed intake 17.6% from d 0 to 14 and improved ADG 44.8% from d 0 to 14 (linear, P < .001) and 8.1% from d 0 to 56 (linear, P < .022). Treated groups had improved (linear, P < .001) feed efficiencies for d 0 to 28. Treatment with rbST increased final weight (linear, P < .018) and length (linear, P < .001), decreased carcass dry matter (linear, P < .001) and fat (linear, P < .001), content, increased carcass ash (linear, P < .001) and tended to increase carcass protein (linear, P < .054) content. Recombinant bST increased WBW (linear, P < .018) and EC (linear, P < .003) but decreased (linear, P < .015) testes weight. Ovary weights, VIS and overall gonadosomatic index were unaffected (P > .05) by rbST. Recombinant bST was undetectable in serum samples taken on d 56 as determined by radioimmunoassay. Overall, the improved ADG, feed efficiency, body mass, and composition indicate that administration of rbST to rainbow trout may be an efficacious method of modulating growth in fish.

Classification of beef calves as protein-deficient or thermally stressed by discriminant analysis of blood constituents.

Linear discriminant functions hold promise for identifying either protein-deficient or cold-stressed calves based on blood constituents. For each of 2 yr 60 artificially bred Angus heifers were assigned randomly to a 2 x 2 factorial nutritional plan consisting of .32 or .96 kg/d of maternal CP and 8.7 or 12.2 Mcal/d of ME. The calves from these heifers were assigned randomly to environmental chambers set at either 0 or 21 degrees C in a repeated measures design. Linear discriminant functions were computed for 1 yr (training data) and then used to predict the classification of calves for the other year (validation data). Using the original data, the correct classifications of calves to the protein groups were 96, 80, 60, 59, 54, and 51% for blood samples obtained at 0, 12, 24, 36, 48, and 72 h of age, respectively. Using normalized data, corresponding correct classifications to protein groups were 94, 91, 80, 56, 54, and 52%. Results indicate that protein classification should use blood samples obtained within 12 h of age for reasonable success. For cold-stressed calves, correct classifications using original data were 47 (pre-exposure), 72, 54, 70, 67, and 66% for calves at 0, 12, 24, 36, 48, and 72 h of age, respectively. Corresponding correct classifications using normalized data were 54 (pre-exposure), 74, 70, 72, 69, and 77%. Cold stress could be detected after only 12 h of exposure; the time window for testing was much wider than for protein classification, but the classification generally was less discriminative.

Concentrations of serum constituents in cold-stressed calves from heifers fed inadequate protein and(or) energy.

A study with neonatal calves was conducted to determine the effects of maternal crude protein (CP) and(or) metabolizable energy (ME) malnutrition, cold stress (0 or 21 degrees C), and age on concentrations of selected serum constituents. For each of 2 yr, 60 artificially bred Angus heifers were assigned randomly to a 2 x 2 factorial nutritional plan 150 d before predicted parturition. The diets provided each heifer with either .32 or .96 kg/d of CP and 8.7 or 12.6 Mcal/d of ME. Blood samples were obtained from heifers at parturition and from their calves at birth and at 12, 24, 36, 48, and 72 h of age. Sera were analyzed for concentrations of blood urea nitrogen (BUN), creatinine (Creat), iron, total protein (TProt), alkaline phosphatase (AlkPhos), total bilirubin (TBil), and cholesterol (Chol). Mean correlations of these constituents in calf sera between 12-h adjacency intervals were high, but those between longer times (48 or 60 h) were low. Simple correlations of serum constituents between cows and calves at birth were low except for BUN (r = .578 and .295 for yr 1 and 2, respectively). There were significant main treatment effects for maternal CP consumption on BUN levels, for environmental temperature on BUN, Creat, and TBil levels, and for years on BUN, Creat, iron, and AlkPhos levels in calves. Significant polynomial relationships were found over hours of age for all variables. Blood urea N decreased in normal calves but remained relatively constant at a low level in deficient calves. Year x hour of age interactions occurred for iron, TProt, AlkPhos, TBil, and Chol. Protein x year x hour of age interactions were found for iron and Chol. These results suggest that random sampling times are not useful for decision making during the first 72 h after birth. Consideration must be given to multiple samples taken at specific calf ages, to environmental temperatures, and to maternal protein nutritional levels when interpreting calf blood sera data.

Postpartum reproductive performance in crude protein-restricted beef cows: return to estrus and conception.

A study was conducted to evaluate the effect of a deficiency in dietary crude protein intake on postpartum reproductive performance of first-calf beef cows. Forty primigravid Hereford heifers were randomly assigned to two groups that were fed isocaloric (100% NRC requirements) diets containing .96 (adequate) or .32 (deficient) kg crude protein per head daily. Animals were individually fed from 150 d prepartum to 40 d postpartum and then were group-fed until the end of the experiment at 110 d postpartum. Total nutrient intake was increased by 33% at time of parturition to meet lactation requirements. Animals were artificially inseminated between 45 and 110 d postpartum when they showed estrus. Eighty-nine percent of those fed adequate protein showed estrus, whereas only 63% of protein-restricted heifers exhibited estrus (P less than .05). First-service conception (P less than .05; 71 vs 25%) and overall pregnancy rates (P less than .05; 74 vs 32%) were lower in protein-restricted heifers. Compared with those fed adequately, protein-restricted heifers had a tendency for longer intervals to first estrus (P less than .08; 75 vs 86 d), to first service (P less than .09; 76 vs 87 d) and to conception (P less than .09; 81 vs 92 d). Regardless of diet, weight at first estrus, weight at first service and average daily gain to 40 d postpartum were negatively correlated (P less than .01) with length of intervals from parturition to first estrus and first service.(ABSTRACT TRUNCATED AT 250 WORDS)

Postpartum reproduction in protein restricted beef cows: effect on the hypothalamic-pituitary-ovarian axis.

The influence of dietary CP on circulating LH and anterior pituitary and hypothalamic function was examined. In Exp. 1, 28 cows were randomly assigned to four treatment groups: adequate CP (ADQ; .96 kg/d) or deficient CP (DEF; .32 kg/d) beginning at 90, 60 and 30 d before parturition and continued at a 33% increase in feed consumption after parturition. Cows were bled at 15-min intervals for 8 h on d 20, 40 and 60 after parturition. Pituitaries were collected on d 62 to analyze GnRH receptor numbers and gonadotropin content. Frequency of pulsatile LH release increased (P less than .05) from 20 to 60 d in ADQ cows. Basal and mean LH were not affected (P greater than .10) by CP restriction or by days after parturition. Crude protein did not affect pituitary GnRH receptors (P greater than .10), but it did affect pituitary LH content, FSH content and FSH concentration (P less than .05). In Exp. 2, 28 cows were assigned to treatment groups as in Exp. 1. All cows were challenged with GnRH (.22 micrograms/kg BW) at 20, 40 and 60 d after parturition and were bled every 30 min for 6 h. Responsiveness to GnRH increased with increased time after parturition (P less than .07). Deficient CP decreased GnRH-induced LH release (P less than .05). In Exp. 3, 12 cows were randomly assigned to ADQ or DEF CP beginning 120 d before parturition. All cows received 1 mg estradiol-17 beta (E2) on d 19, 39 and 59 after parturition and were bled every 30 min for 14 h beginning 14 h following E2. Response to E2 was unaffected by CP restriction (P greater than .10), whereas time to E2-induced LH peak decreased as time after parturition increased in ADQ cows (P less than .05). Results suggest that delayed return to estrus in CP-deficient postpartum beef cows might be due to reduced gonadotropin release from the anterior pituitary and decreased anterior pituitary responsiveness to GnRH.

First aid for acute sports injuries.

This article deals with management of acute sports injuries on the field or on the ice and in the dressing room or in the arena's first-aid room. Its most vital message is "Be prepared". A team approach and suitable ambulance and hospital back-up are mandatory. Individual management of a specific acute injury should be approached with a practice plan. Collars, splints, back board, doctor's bag, ambu bag, suture tray and emergency medications should be at hand. Care must be taken that no long-term harm befalls the player. The attending physician must be knowledgeable about preventive equipment and immediate institution of rehabilitation procedures, and must try to inform the coach or trainer and parent as to when the athlete can safely return to play. It is important that the athlete not return to play until he/she is 100% fit.

Antibody responses in protein-energy restricted beef cows and their cold stressed progeny.

Antibody titers were measured in serum and colostral whey of pregnant beef cows immunized with tetanus toxoid and chicken red blood cells while being fed diets either restricted or nonrestricted in protein and/or metabolizable energy during the last 150 days of gestation. Serum antibody titers were also measured in the colostrum-fed, cold and noncold stressed progeny that were actively immunized with dinitrophenol conjugated to keyhole limpet hemocyanin. In general, there were no major or sustained differences in humoral immune responses to injection of tetanus toxoid or chicken red blood cells between cows fed diets that were adequate or restricted in protein or metabolizable energy. In the few cases where serum antibody titers to tetanus toxoid or chicken red blood cells differed (P less than 0.05) between adequately fed or restricted cows, the differences were no greater than twofold. Anti-chicken red blood cell titers were uniformly low (P less than 0.05) by a magnitude of two to threefold in colostral whey of cows restricted in protein and/or metabolizable energy when compared to titers in cows fed adequate amounts of protein and metabolizable energy. With one exception, neither maternal dietary restriction nor cold exposure had a major effect on the ability of the calves to absorb antitetanus toxoid and chicken red blood cell antibodies from colostrum. The humoral immune responses of all calves to injection of keyhole limpet hemocyanin and dinitrophenol were similar in magnitude.

Estimation of repeatability of blood constituents in gestating beef cattle on protein- and energy-restricted diets.

Repeatabilities of blood constituents were calculated for 104 Angus heifers on two separate experiments fed adequate, protein-deficient, energy-deficient, or both protein- and energy-deficient diets. Four statistical methodologies were compared including analysis of variance, principal component (structural) analysis based on the sample covariance and sample correlation matrix, and maximum likelihood. Of 12 blood constituents tested only seven were considered sufficiently important to be included in the analysis. These blood constituents included blood urea nitrogen (BUN), creatinine (Creat), alkaline phosphatase (Alk Phos), total protein (T Prot), total bilirubin (T Bil), cholesterol (Chol) and Iron (Fe). If the standard linear model assumptions were met for heifers on the adequate diet, the estimators appeared to be quite similar for both years except when the correlation coefficient was relatively small. If the assumption of homogeneity of the variance-covariance matrix (compound symmetry) was relaxed, the structural analysis method based on the sample correlation matrix appeared preferable. However, when combining all diets, the maximum likelihood methodology was preferred. Among the specific blood constituents, Alk Phos had the highest repeatability, not only for the heifers on the adequate diet, but also for heifers on other treatments in both years. Repeatabilities for T Prot appeared to be the most consistent over all rations in both years. Repeatability estimates for Fe were high and relative rankings were consistent for both years, while repeatabilities for the other variables were either low and(or) inconsistent.

Variation of virus replication in primary bovine kidney cell cultures derived from 68 three-day-old calves.

Primary kidney cell cultures were prepared from 68 three-day-old calves. Complete monolayers of these cultures were infected separately with viral diarrhea, infectious bovine rhinotracheitis, parainfluenza, and adenovirus 7 viruses. The yield of virus from all infected cultures was calculated by plaque titer assay after 2 to 4 days' incubation. The variation of virus yield was substantial between individual cultures.

Effects of prepartum protein restriction in the beef cow on immunoglobin content in blood and colostral whey and subsequent immunoglobin absorption by the neonatal calf.

Protein intake of first-calf beef heifers was restricted during the last 100 days of gestation, and the effects on passive transfer of colostral immunoglobins from the cow to the neonatal calf were examined. There were no significant correlations between concentration of immunoglobins (IgM, IgG1 and IgG2) in the sera or colostrum of the cow and prenatal crude protein consumption (.52 to .98 kg crude protein/day). Absorption of certain colostral immunoglobins (IgG1, and IgG2) by the calf were positively correlated (P less than .01) at 12, 18, 24 and 36 hr after birth to the maternal crude protein consumption. Colostrum was collected from the first milkings of pluriparous dairy cows, and then freeze-dried, mixed and reconstituted to be equivalent to 1 liter of colostrum. Mean IgG1 concentrations for the high and low protein groups were 6.02 +/- .90 and .78 +/- .15 mg . ml-1 (P less than .01), respectively. No relationship (P greater than .05) was found between the concentration of IgM in calf sera and daily crude protein intake of the dam. These data indicate that there was a selective decrease in absorption of IgG1 and IgG2 in calves from heifers fed low protein prenatal diets.

Effects of maternal nutritional restriction and cold stress on young calves: absorption of colostral immunoglobulins.

Fifty-seven newborn calves delivered from heifers fed rations either adequate or restricted in protein or metabolizable energy were housed in cold (1 C) or normothermic (21 C) environmental chambers for 3 days to determine the effects of maternal nutritional stress and cold exposure on ability of the animals to absorb colostral immunoglobulins (Ig). In general, the serum Ig concentrations in the newborn calves from dams fed rations restricted in protein or metabolizable energy and the concentrations in sera of the respective calves from dams fed adequate protein or metabolizable energy were similar throughout the 3-day period of observation. Likewise, the serum Ig concentrations in the cold-exposed calves were similar to those in the calves kept at normothermic temperature. An exponential increase in mean serum concentrations of IgM, IgG1, and IgG2 occurred between 3 and 6 hours of age; the values continued to increase, but at a slower rate after 6 hours and reached a peak by 12 hours of age. Then, IgM and IgG2 decreased until 48 hours, after which time they increased, but IgG1 varied only slightly from the peak at 12 hours and then increased. With one exception, data indicated that neither the maternal dietary restrictions or the cold exposure imposed on the calves caused significant (P greater than 0.05) differences in absorption of colostral Ig when compared with that of the respective calves from dams fed adequate diet or the calves kept at normothermic temperature.

Immunoglobulin levels in serum and colostral whey or protein-metabolisable energy restricted beef cows.

Aberdeen Angus cows were fed adequate diets or diets restricted in protein and, or metabolisable energy for the last 156 days of gestation to determine effects of nutritional restriction on concentrations of immunoglobulins in serum and colostral whey. There were no significant interactions between the effects of low protein and metabolisable energy on immunoglobulin concentrations. Thus, observed differences in immunoglobulin concentrations between the restricted and adequate dietary groups were attributed to the main effects of treatment. Low protein or metabolisable energy had little overall effect on serum IgM concentrations although levels began to decrease sooner in gestation in restricted animals than in those fed adequate diets. Concentrations of IgG1 in serum of all animals were similar and a precipitous decrease in concentration was noted at about 240 days of gestation and this decrease continued until parturition. Serum IgG2 concentrations increased in all animals as parturition approached. Immunoglobulin concentrations in colostral whey were either similar to or tended to be slightly higher in dietary restricted animals than in animals fed adequate diets although the differences were not significant.

Serum complement activity of protein-energy malnourished beef cows.

Beef heifers were fed protein- or energy-deficient rations (or both) for approximately the last 5 months of pregnancy. Serum samples were periodically collected and were analyzed for amounts of total complement (C) hemolytic activity. After being fed the rations for approximately 2 months, heifers given low-energy rations had significantly lower (P < 0.01) amounts of C than did those fed adequate energy rations, This decrease in C was observed regardless of the amount of dietary protein, although low protein intake seemed to exaggerate the effect of low energy consumption. Reduced protein in the rations had no effect on C titers when caloric intake was adequate. Also, the depressive effect of low dietary energy on C values was no longer apparent after approximately 4 months of feeding the rations. Amounts of C dropped by 20 to 40 U for all groups at or near the time of parturition. The C values averaged over all test dates were significantly lower (P < 0.05) for those heifers given low energy in their rations as compared with values for heifers fed adequate energy rations (146.9 vs 160.8 U).

Effects of maternal protein-energy malnutrition and cold stress on neutrophil function of bovine neonates.

The effects of maternal protein or calorie deprivation (or both) on the bactericidal activity of neutrophils and sera from newborn calves subjected to cold stress were studied. Nutritional deficiencies in the dam had little effect on in vitro bactericidal activity of neutrophils and base-line sera taken at birth. Neutrophils obtained at birth destroyed Staphylococcus aureus but not Escherichia coli when incubated with either unheated or heated autologous base-line sera. Heat treatment of base-line sera to inactivate complement did not alter bacterial growth. When incubated in the presence of autologous base-line sera, neutrophils from 3-day-old calves were no more active in the destruction of either bacterium than were neutrophils from newborn calves. However, addition of day 3 (immunoglobulin-containing) sera enabled day 3 neutrophils to destroy E coli (P < 0.0001). The increased destruction of E coli by day 3 neutrophils and day 3 sera was not affected by heat treatment of the sera. Maternal protein deficiency significantly increased (P < 0.05) destruction of E coli by day 3 neutrophils and sera. This effect was independent of energy levels. There were no differences observed in the bactericidal activity of neutrophils and sera taken from calves exposed to 1 C or 21 C environmental chambers for 3 days. Also, cold stress-nutritional stress interactions were not detected.

Hemolytic complement levels of neonatal calves delivered from protein-energy malnourished dams and subjected to cold stress.

Beef cows were placed on protein-deficient and/or energy deficient rations for the last 150 days of pregnancy. After birth their calves were placed on 1 or 21 C environmental chambers for 3 days, and sera were collected for determination of complement (C) levels. At birth, the mean complement hemolytic (CH50) titer of all calves was 46.0 +/- 1.7 units, but the titer rapidly dropped (P < 0.01) to 31.6 +/- 1.2 by 12 hours after birth. Levels of C activity then began to rise and reached a mean titer of 76.3 +/- 3.0 by 3 days of age. A quadratic curve of predicted CH50 values was constructed from the data. Differences between principal and control groups of calves were not detected. These results suggest that maternal protein-calorie deprivation and limited cold stresses have little effect on levels of C activity in the bovine neonate. Possible explanations for the decrease in CH50 levels after birth are discussed.