Age-related changes of selected blood biochemical indicators in dairy calves during their first week of life

The aim of this study was to determine the influence of age and ingested food (colostrum and mature milk) on the concentrations of selected blood biochemical components connected with nitrogen and mineral metabolism in dairy calves during their first week of life. The experiment was carried out on 13 Polish Black and White breed dairy calves. The animals were fed colostrum within the first 3 days of postnatal life and thereafter the mature milk of their dams until the end ofthe experiment (7 days). The obtained results showed that intensive catabolic and anabolic changes in nitrogen occur in the first week of life. These changes were particularly intense during the first 24-48 hours of life and may reflect dynamic tissue remodelling. The results of this experiment also show that healthy calves efficiently regulate water and electrolyte homeostasis.     

Occurrence of bifidobacteria in faeces of calves fed milk or a combined diet

The development of faecal bacteria composition in calves fed milk or a combined diet was investigated from 4 to 21 days of age. On day 7, bifidobacteria in faeces of milk-fed calves already increased from about 7.6 to 9.2 log CFU/g and did not change until the end of the study, whereas in calves fed the combined diet bifidobacteria only moderately increased to 7.9 log CFU/g and decreased slowly until day 21. The counts of bifidobacteria in calves on a combined diet were significantly (p < 0.01) lower compared to those in milk-fed calves. Bifidobacterial counts determined by cultivation or by fluorescence in situ hybridisation (FISH) did not differ significantly. Our results showed that the occurrence of bifidobacteria in calf faeces is highly dependent on the diet composition. Faecal bacteria flora of calves fed exclusively by milk is rich in bifidobacteria, but in calves on a combined diet coliforms dominated.     

Sucking behaviour of dairy calves fed milk ad libitum by bucket or teat

The milk intake and sucking behaviour of Dutch and Holstein-Friesian crossbred calves fed milk replacer ad libitum by either the bucket method (n=8) or an artificial teat (n=6) were compared. The animals were observed for 3 weeks from the age of 2 weeks, penned individually and all provided with a “dummy” (artificial) teat near the milk source within the pen.

The teat-fed calves ingested significantly more milk than the bucket-fed calves (11.9 vs. 8.0 kg/day; P<0.05), and this intake took much longer (44.2 vs. 17.7 min/day; P<0.05). In both treatment groups, milk intake was organized in “meals”. The meal criterion, separating the withinmeal and between-meal non-feeding intervals, was set at 5 min. Frequency of meals and daily total meal duration did not differ significantly. Meals occurred rather randomly throughout a 24-h period.

On average, the dummy teat was used for 13 min per day by bucket-fed calves, but for only 1 min by teat-fed calves (P<0.05). Sucking of the dummy teat was largely clustered within the meal periods.

It is concluded that in the young calf a need for sucking exists independently of milk satiation. However, the level of satiation depends on whether the calf drinks or sucks the milk. Nutritive sucking is clearly more reinforcing than non-nutritive sucking.     

Gastrointestinal development of dairy calves fed low- or high-starch concentrate at two milk allowances

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.     

Methemoglobinemia and acidosis during the first week of life

Recently attention has been called on the possible role of acidosis in the increased methemoglobin formation in the erythrocyte of newborn infant. In the present paper the relations between acidosis and methemoglobin content in the red cells of newborns has been investigated. No significant differences between the percent of methemoglobin in the normal newborns and percent of methemoglobin in the newborns with acidosis has been found. In addition, no correlations between the base excess and percent of methemoglobin has been observed. On the contrary, two newborns with low glucose-6-phosphate dehydrogenase activity demonstrated a significantly increased methemoglobin content in their red cells. The results of our study do not confirm a key role of acidosis in the mechanism of methemoglobin formation in the neonate. It is likely than impairment of red cell metabolism should be the main factor in the formation of methemoglobin in the first days of life.     

Comparative study of some haematological and biochemical blood parameters in fishes from the Skagerrak

Marine fishes caught in the Skagerrak, 27 different species representing various groups of fishes (Cyclostomi, Holocephali, Elasmobranchii and Teleostei), were examined for the following haematological and biochemical blood parameters: haematocrit, haemoglobin, mean corpuscle haemoglobin concentration, total plasma protein, blood glucose and blood lactate. Interspecies variations as well as variations within some species were observed. The haemoglobin values for all species showed a positive correlation to the corresponding haematocrit values. Relatively low values for haematocrit and haemoglobin were found in cyclostomes, holocephaleans and elasmobranchii compared to the majority of teleosts. Within the teleost group, the haematocrit and haemoglobin levels were positively correlated with the activity of the fish species. The cyclostome Myxine glutimsa L. had a total plasma protein content in the same range as most teleosts, whereas holocephaleans, elasmobranchii and the deep-water teleost Coryphaenoides rupestris Gunnerus showed comparatively low values. Among teleosts some relationship seemed to exist between the total plasma protein level and the activity of the fish species. In addition, a correlation between plasma protein content and levels of blood lipids were noted. Values for blood glucose and blood lactate were found to be lower in cyclostomes, holocephaleans and elasmobranchii than in most teleosts. Higher blood glucose levels were observed in the more active teleost species.     

Serum and milk concentrations of leptin in gilts fed a high- or low-energy diet during gestation

Concentrations of leptin in serum and milk were assessed in gilts fed diets during gestation that differed in energy level. Beginning at day 45 and continuing throughout pregnancy, gilts received either a high-energy (6882 kcal metabolizable energy (ME) per day) or low-energy (5221 kcal ME per day) diet (n = 9 per group). All gilts had ad libitum access to a standard lactation diet throughout a 21 day lactation. During gestation, gilts consuming the high-energy diet gained more body weight (P < 0.01) and backfat thickness (P = 0.03) than gilts fed the low-energy diet; however, serum concentrations of leptin remained similar between groups (P = 0.35). Within 24 h after farrowing, gilts fed the high-energy diet had greater levels of leptin in serum and milk than gilts that consumed the low-energy diet during gestation (P < 0.07); Across treatments, backfat thickness and leptin levels in serum were positively correlated (r(2) = 0.51; P = 0.03). At weaning, backfat thickness (P < 0.07), but not body weights or serum and milk levels of leptin (P > 0.1), were greater for gilts fed the high-energy, versus the low-energy, diet during gestation. Gilts that were fed the low-energy diet during gestation consumed more feed during week 2 of lactation (P = 0.06). Our results suggest that altering the level of energy in the diets of gestating swine can influence circulating and milk concentrations of leptin, as well as feed consumption, during lactation.     

Studies on blood biochemical constituents and rumen fermentation in growing buffalo calves fed ammoniated straw-based rations supplemented with different protein sources

Studies were done on blood biochemical constituents and rumen fermentation pattern of growing buffalo calves fed ammoniated wheat straw (UAS)-based rations supplemented with three different protein supplements. Eighteen buffalo calves (140 kg) were divided into three groups of six calves each and were fed on UAS supplemented with a concentrate mixture (roughage:concentrate ratio 58:42) containing 8% (or 3.5% of total ration) untreated groundnut cake (GNC) (group I), 8% formaldehyde treated GNC (group II) and 8% fish meal (group III), respectively, for 19 weeks. During this growth study, blood biochemistry was studied. Rumen fermentation study was done on three fistulated growing buffalo calves using a 3×3 Latin square switch over design. Blood glucose and ammonia-N did not differ significantly among the treatments. However, blood urea-N of calves in group III was higher (P<0.05) than in groups I and II, but the latter two did not differ from each other in this respect. Total protein in group I was comparable to group II and group III which were significantly different from each other. The rumen pH, total volatile fatty acids, ammonia-N and total protozoal count were similar, however, total N and TCA insoluble N in group II and group III were higher (P<0.01) than in group I. Fish meal containing diet favoured holotrichs, whereas, protected GNC containing diet favoured spirotrichs as indicated by significantly higher count. It was concluded that the beneficial effects of supplementing formaldehyde protected GNC at 8% in the concentrate mixture to the UAS-based diets were greater than supplementation of unprotected GNC or low quality fish meal in ration of buffalo calves growing at 400 g because of improved rumen fermentation, absorption and metabolism of nutrients as observed in blood biochemistry.     

Renal regulation of potassium homeostasis in calves in the first week of life including the role of atrial natriuretic peptide

The experiment was carried out on 10 clinically healthy Polish-Friesian var. Black-and-White cow calves, during the first seven days of postnatal life. The results indicate that renal removal of potassium depends primarily on the quantity reabsorbed in the tubules, whereas clearance of the electrolyte, due to stable levels in the blood plasma, depends on the amount excreted in the urine. With stable tubular reabsorption of potassium, a relatively unchanging amount of excreted potassium was observed in the urine. However, reduced tubular reabsorption caused a significant increase in excretion and clearance of the electrolyte. Changes in the amount of filtered potassium play a minor role in the regulation of excretion. Small changes in the blood plasma potassium concentration observed primarily resulted from changes in glomerular filtration rate and tubular reabsorption, since the concentration of electrolyte in the blood after birth remained within the physiological range. The results ofthis study suggest that neonate calf kidneys are sufficiently prepared to regulate kalemia. Atrial natriuretic peptide is not directly involved in the regulation of tubular reabsorption of potassium in calves in the first week of life, although it is highly likely that the peptide is involved in the excretion of potassium in the urine in calves during the first seven days of life.     

A reappraisal of protein turnover values in neonates fed human milk or formula

We investigated the effect of human milk feeding on the nitrogen metabolism of appropriate-for-gestational age infants of birth weight 1.5-2.0 kg. Eight infants received pooled mature human milk. The remaining 20 were divided into two equal groups, who received one of two low-protein, milk-based formulae. The formulae were identical in composition except for the protein source, which was either casein- or whey-predominant. The three diet groups received similar total nitrogen (390 mg N.kg-1.d-1) and energy (500 kJ.kg-1.d-1) intakes. The human-milk-fed group, however, received a significantly higher intake of nonprotein and urea nitrogen and a significantly lower true protein nitrogen. Nitrogen metabolism was studied using a modified constant infusion of [15N]glycine, mixed with the feeding every 2-3 h. Urine was collected in approximately 3-h aliquots and analysed for total ammonia and urea nitrogen. Excretion of the 15N label was measured in urinary urea and ammonia. No differences were seen between the three diet groups in total [15N]urea or [15N]ammonia urinary excretion. However, the concentration of 15N in urinary urea in the human-milk-fed group was lower than in the two formula-fed groups. This reduction in concentration appeared due to a higher dietary intake of urea among the human-milk-fed group, and the consequent dilution of the label in the urine. As a result, protein turnover rates calculated from the [15N]urea end product were artificially raised in the milk-fed group, and were significantly higher than those in the formula groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparative biochemical study of brain phospholipids in insects

Studies have been made on the content of total phospholipids (PL) and their separate families in the brain of larvae and imago of the insect species Blaberus giganteus, Periplaneta americana, Tenebrio molitor and Barathra brassicae. It was shown that during larval-pupal-imaginal transformation in T. molitor and B. brassicae the content of total PL increases by 17 and 14% respectively, whereas in B. giganteus and P. americana PL concentration undergoes only insignificant changes. With respect to total PL content the species investigated form the following sequence: B. brassicae greater than T. molitor greater than P. americana greater than B. giganteus. In larval and imago forms of these insects phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, sphingomyelin and polyglycerophosphatide were found in the brain. Besides, in the brain of B. giganteus and P. americana lysophosphatidylethanolamine and in the brain of T. molitor -- phosphatidic acid are present. Qualitative PL composition in larval and imago forms is identical, while quantitative ratio of separate fractions differs insignificantly. In all the species investigated, phosphatidylethanolamine and phosphatidylcholine are the most abundant phospholipids.     

Performance of Holstein calves receiving equal quantities of milk at fixed or variable amounts per day during milk-feeding period

Two experiments were conducted to determine the effects of feeding equal quantities of milk during the pre-weaning period through different milk-feeding regimes on calf growth, starter intake and selected blood metabolites. In experiment 1, 44 female Holstein calves (3 days of age and 39.2±4.3 kg of BW) were distributed randomly to one of two milk-feeding programs (1 calf per pen; 22 pens per treatment group): (1) consistent (CONS; 6 l/day of milk from days 3 to 60 and 3 l/day from days 61 to 65 of age) or (2) step-up/step-down (SUSD; 5 l/day of milk from days 3 to 15, 8 l/day from days 16 to 40, 6 l/day from days 41 to 50, 3 l/day from days 51 to 60 and then 2 l/day from days 61 to 65 of age). No difference between treatments was observed in starter consumption, feed efficiency, hip width and heart girth. However, pre-weaning average daily gain (ADG) tended to be greater in CONS than in SUSD calves (0.78 v. 0.70 kg/day; P=0.07). Blood β-hydroxybutyrate at day 45 (pre-weaning) was lower in SUSD than in CONS calves (0.14 v. 0.21±0.013 mmol/l). In experiment 2, 26 male Holstein calves (3 days of age and 39.4±4.1 kg of BW) were assigned at random to one of two milk-feeding protocols (1 calf per pen; 13 pens per treatment group): (1) consistent (CONS; (7 l/day of milk from days 3 to 40 and 2 l/day from days 41 to 45 of age) or (2) step-down (STD; 8 l/day of milk from days 3 to 30, 4 l/day from days 31 to 40 and 2 l/day from days 41 to 45 of age). The milk-feeding program had no effect on the performance measurements, with the exception that ADG (days 15 to 30), starter intake (days 30 to 45) and heart girth (day 45) were greater in STD than in CONS calves. In conclusion, it appears that if the total amount of milk intake is held constant over the course of milk-feeding period, the method of milk feeding would have negligible effects on calf performance.     

The utilization of glucose for the synthesis of milk components in the fed and starved lactating goat in vivo.

1. [U-14C]Glucose and [3-3H]glucose were infused into fed and starved lactating goats in order to study glucose metabolism in the mammary gland. 2. Glucose carbon was oxidized and metabolizet to milk lactose, citrate and triacylglycerol in the lactating goat udder. 3. Recycling of glucose carbon in the lactating animal accounted for 10-20% of the total glucose turnover in the whole animal. Recycling of glucose 6-phosphate in the udder accounted for about 25% of the glucose 6-phosphate metabolized. 4. Flux of glucose 6-phosphate through the pentose phosphate pathway was sufficient to account for 34% of the NADPH required for fatty acid synthesis in the gland in the fed animal. 5. Net metabolism of glucose 6-phosphate via the pentose phosphate pathway accounted for 17.8 and 1.2% of the glucose phosphorylated by the mammary gland in the fed and starved animal respectively. Metabolism of glucose 6-phosphate via the pentose phosphate pathway was sufficient to account for all the CO2 produced from glucose in the fed animal, but only 17% of the CO2 produced from glucose in the starved animal.