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1.
Colostrum intake is important for health and postnatal development of neonatal calves. We studied the effects of enhanced first colostrum feeding on growth, health status, and metabolic and endocrine traits in calves during their 1st wk of life. Calves of group CL (GrCL; n = 7) were fed colostrum of milkings 1 to 6 twice daily during the first 3 d of life, followed by milk replacer (MR) up to d 7. Calves of group CH (GrCH; n = 7) were fed colostrum of the first milking during the first 3 d and then colostrum (of the first milking) twice daily, which on d 4, 5, 6, and 7 was diluted with 25, 50, 75, and 75 parts of MR, respectively. Pre- and postprandial blood samples were taken on d 1, 2, 3, and 7 for the determination of various metabolic and endocrine traits, and on d 5 intestinal absorption capacity was measured using the xylose absorption test. Rectal temperatures and fecal scores were higher (P < .05) in GrCH than in GrCL. Plasma concentrations of total protein and albumin were higher (P < .05) on d 7, IgG on d 2 and 3, and urea on d 2, 3, and 7 in GrCH than in GrCL. Plasma concentrations of triglycerides were higher (P < .05) on d 2 and of phospholipids and cholesterol were higher (P < .01) on d 7 in GrCH than in GrCL. Plasma insulin and glucagon concentrations were higher (P < .05) in GrCH than in GrCL, whereas prolactin and growth hormone concentrations were higher (P < .05) in GrCL than in GrCH. Enhanced colostrum intake had no effects on xylose absorption on d 5. Higher plasma protein, urea, and lipid concentrations in GrCH partly mirrored higher protein and fat intake but additionally pointed to higher protein synthesis and lipid turnover.  相似文献   

2.
Introduction Newborn development is characterized by high protein synthesis and nitrogen (N) turnover rates in many tissues, especially in the gastrointestinal (GI) tract (G oldspink and K elly 1984; Y oung et al. 1988; S immen et al. 1990; X u 1996). Colostrum provides particularly large amounts of nutrients (especially proteins) and immunoglobulins as well as non-nutrient growth-promoting factors; it therefore plays a major role in the development of the neonatal gut, especially protein synthesis, and other organs, as shown in several species including cattle (B erseth et al. 1983; P atureau M irand et al. 1990; C ampana and B aumrucker 1995; O dle et al. 1996; X u 1996; B urrin et al. 1997). Rates of body protein synthesis and N turnover were greater during enteral than during parenteral feeding, indicating considerable involvement of the GI tract in protein metabolism (D uffy and P encharz 1986). Protein components in colostrum provided about 35% of amino acids (AA) in newborn lambs, suggesting that amounts of ingested protein with colostrum greatly influence the AA status of the neonate (Y von et al. 1993). Glutamine and glutamate are the most abundant AA in bovine milk protein (M eijer et al. 1993) and glutamine is of special interest for postnatal gut development (S ouba 1991; K imura 1996; H eird 1998). The glutamine:glutamate ratio was markedly changed in neonatal calves (D emign & eacute ; and R& eacute ; m & eacute ; sy 1979) after colostrum intake. Recently, we have demonstrated that gut growth and absorptive capacity of the intestine, as well as metabolic and endocrine changes in newborn calves, are greatly dependent on amounts of ingested colostrum (H ammon and B lum 1997, 1998; B& uuml ; hler et al. 1998). Based on that AA absorption, metabolism and status may be influenced by amounts of fed colostrum. Therefore in this study we have tested the hypothesis that feeding colostrum for different durations, or feeding only milk replacer, affects plasma protein and free AA concentrations during the first week of life in calves.  相似文献   

3.
Little knowledge on the digestive and metabolic utilization of solid feed in veal calves is available. The objectives of the study were to determine the effects of 2 solid feeds offered at 2 feeding levels (FL90 and FL105) in addition to a milk replacer on heat production (HP) and protein and fat deposition in veal calves. Sixteen calves (148.0 +/- 3.7 kg) received milk replacer (75% of a reference DE allowance) and solid feeds that consisted of corn grain and pelleted hydrolyzed wheat gluten without (CO) or with (CS) chopped wheat straw. The solid feed supply provided 15 or 30% of the reference DE allowance to achieve FL90 or FL105, resulting in 4 treatments: CO90, CS90, CO105, and CS105. A fifth treatment consisted of using the milk replacer alone at FL90 (treatment M90) and was measured in 4 other calves. All calves were kept individually for 7 d in a respiration chamber to estimate energy and N balances and fasting HP. The digestibility coefficients of DM, OM, GE, and major nutrients were at least 94% for M90 and decreased when solid feed was added (P < 0.05). Methane production was negligible in M90 calves and increased when solid feed was given (ranging 8 to 23 L/d between CO90 and CS105, P < 0.01), indicative of ruminal fermentation. The provision of increasing amounts of solid feed decreased urinary energy in connection with a tendency (P = 0.09) for a reduction of urinary glucose excretion. The metabolizability of DE was greater with the milk replacer (95.6%) and decreased when straw was added (P < 0.01). Neither CO90 or CS90 affected HP and total energy retention (P > 0.05). Dietary treatment had no effect (P > 0.05) on activity HP (53 kJ/kg of BW(0.85) daily) but did affect thermic effect of feeding; efficiency of utilizing ME for maintenance and growth was greatest for the M90 calves (84.5%, P = 0.02). Fasting HP tended (P = 0.09) to increase at the greatest FL (308 vs. 298 kJ/kg of BW(0.85) daily). Maintenance ME requirement increased (P = 0.04) from 364 to 382 kJ/kg of BW(0.85) daily when feeding level increased (P = 0.04) but was not affected by ingestion of solid feed. The provision of solid feed to veal calves was associated with a reduced efficiency of N retention (P = 0.04), and energy retained as protein tended to decrease (P = 0.08), probably as a result of an imbalanced AA supply of the solid feeds. The data were used to calculate the energy contents of solid feed. The utilization of energy from solid feed differed from that of milk replacer.  相似文献   

4.
This study compared the performance of female Holstein calves fed either whole milk (WM) or milk replacer (MR) having similar gross composition to WM. Calves (n = 20) were separated from their mothers within 2 h of birth, weighed, moved into individual pens, and fed colostrum (10% of their BW over 2 feedings daily) for the first 3 d. Calves were alternately assigned to either WM (n = 10) or MR (n = 10) and were fed using mobile plastic bottles. At each feeding, diluted MR was prepared in buckets by mixing 0.143 kg of MR powder (as-is basis) in 1 L of lukewarm water. Calves on both treatments were fed (1.8 L/feeding) for 4 times daily for the first 25 d of age. Feeding frequency was reduced to 3 times daily for next 5 d, then to 2 times daily for next 14 d, and then to once daily during the last 5 d of the preweaning period. Feed intake, growth, and health variables were monitored until calves were 70 d of age. Mean daily consumption of WM and MR was similar in both treatment groups (P = 0.74). Initial BW of calves fed either WM or MR was similar (42.1 +/- 3.3 vs. 41.9 +/- 2.9 kg, respectively; P = 0.83). Calves fed WM or MR daily consumed similar amounts of calf starter (1,019 vs. 1,056 g, respectively; P = 0.32), hay (121.5 vs. 126.3 g, respectively; P = 0.30), and water (5.2 vs. 5.0 kg, respectively; P = 0.54). At weaning (d 49) and postweaning (d 70), BW was greater (P = 0.03 and P = 0.02, respectively) in calves fed WM than in those fed MR. Mean DMI from both solid and liquid feeds was not affected by the treatments during the preweaning (P = 0.21) and postweaning (P = 0.16) periods. Body weight gain efficiency during preweaning and overall was improved (P = 0.001 and P = 0.002, respectively) in calves fed WM than in those fed MR. Health (days scoured, rectal temperature, respiratory score, and general appearance score) and serum chemistry variables (glucose, total protein, urea N, nonesterified fatty acids, and creatinine) in calves were not affected (P >or= 0.12 and P >or= 0.12, respectively) by the treatments. Even though gross composition of the MR and WM was similar, growth was greater in calves fed WM. Calves fed WM consumed similar amounts of DM and were heavier than those fed MR, probably because of better bioavailability (digestion and assimilation) of nutrients and availability of some unknown growth factors from WM.  相似文献   

5.
Polish Friesian male calves (n = 78) were used to investigate the effects of innovative feeding plans based on the provision of large amounts of solid feeds on growth performance, welfare, and carcass characteristics of veal calves. Groups of calves (initial BW 71.5 ± 3.7 kg) were fed 1 of 3 treatments (26 calves/treatment): 1) milk replacer plus corn grain (CG), 2) milk replacer plus an 80:20 mixture (as-fed basis) of corn grain and wheat straw (CGS), or 3) milk replacer plus a 72:20:8 mixture (as-fed basis) of corn grain, wheat straw, and extruded soybean, respectively (CGSES). All the treatments provided at least 170 kg DM/calf from solid feed throughout the 206 d of fattening. Type and concentration of milk replacer were the same for all calves throughout fattening. Calves fed CGSES received 96% of the daily amount of milk replacer delivered to CG and CGS to balance the dietary CP content. No differences (P ≥ 0.063) among treatments were observed for growth performance and DMI. Health status of CG calves was less than CGSES calves, as indicated by the greatest (P < 0.001) proportion of milk replacer refusal events and the greatest (P < 0.001) incidence of treatments for respiratory disorders. Inclusion of straw and soybean in the solid feeds increased (P < 0.001) the daily intake of iron in CGS and CGSES as compared with CG; however, blood hemoglobin concentrations measured at d 5 and 31 were greater (P < 0.05) than when measured on d 80, 122, and 206 of fattening. Feeding treatment did not (P ≥ 0.107) affect HCW, dressing percentage, or carcass color. Calves fed CG had heavier (P < 0.001) reticulorumens and more (P < 0.001) developed rumens than CGS and CGSES calves, but 84% and 68% of CG rumens (P < 0.001) showed overt signs of hyperkeratinization and plaques, respectively. These alterations of rumen mucosa were not detected in CGSES calves, and only 8% of CGS calves had rumen plaques. Regardless of feeding treatment, postmortem inspection recorded a prevalence of more than 84% abomasal lesions. When feeding veal calves with large amounts of solids, it is advisable to avoid the provision of corn grain alone and replace part of the cereal with a roughage source to improve calf health and prevent rumen mucosa alterations.  相似文献   

6.
In case of diarrhea calves are treated with oral rehydration solutions (ORS), which are known to increase abomasal pH and inhibit milk clotting in vitro. Nevertheless, recent studies have shown that ORS with HCO3 ≤ 62 mmol/L do not interfere with abomasal milk clotting in healthy calves. However, in diarrheic calves, feeding ORS and milk simultaneously may disturb abomasal curd formation and exacerbate diarrhea due to faster abomasal passage of ingesta. Therefore, the aim of the present study was to ultrasonographically examine abomasal milk clotting and diameter after feeding milk and milk replacer (MR) with and without ORS to healthy and diarrheic calves. Abomasal curd formation and diameter in healthy and diarrheic calves were ultrasonographically imaged before and after feeding milk, MR and ORS prepared in milk or MR. Feeding mixtures of milk or MR with ORS did not cause any remarkable differences in the ultrasonographic images of abomasal content. Moreover, abomasal milk clotting was not disturbed due to diarrhea. Statistically significant differences of abomasal diameter after feeding between healthy and diarrheic calves indicated that abomasal emptying is delayed in diarrheic calves. Hence, further studies are needed to determine reasons for decelerated abomasal passage in calves suffering from diarrhea.  相似文献   

7.
Cow colostrum is rich in insulin-like growth factors IGF-I and II, thus the dietary effects of recombinant human (rh) rhIGF-I on the newborn were of interest. The objective of this study was to examine the effects of dietary IGF-I upon selected blood components and gut absorptive development. Calves were blocked by birth weight and fed two times per d for a total of four times with the initial restricted diet. The initial feeding was 1.5 l and the remaining three feedings were at 2 1 with one of three experimental diets: 1) milk replacer plus isolated colostrum derived globulins (MR), 2) same as 1 above plus 750 ng/ml rhIGF-I (MR+), 3) pooled cow colostrum (COL). Thereafter, all animals received only milk replacer at 5% of body weight (BW)/feeding two times per d with only treatment 2 having continued addition of 750 ng/ml rhIGF-I until experimental completion at 6 to 7 d after birth. At feeding three, animals were fed D-xylose (0.5 g/kg BW) and 5,000 U of bovine kidney membrane γ-glutamyl transferase as indicators of gut absorptive capacity. Colostrum-fed animals received 5,000 U of natural occurring γ-glutamyl transferase activity in the 1.5 l first feeding. Blood samples taken over time were collected and saved as frozen plasma. All diets were analyzed for nutrient composition and endogenous levels of test hormones. Colostrum fed calves had greater globulin concentration (P < 0.01) than MR or MR+ fed calves. Recombinant hIGF-I feeding had no effect (MR vs. MR+) upon total protein, albumin or globulin blood levels. Absorption of colostrum γ-glutamyl transferase at first feeding resulted in a peak total blood U of 4.5% of that fed. Although enzyme absorption was greatly reduced by the third feeding (0.5% of total fed), MR+ fed calves exhibited no significant difference in enzyme absorption when compared with the controls (MR vs. MR+). However, pharmacokinetic analysis of D-xylose absorption at the third feeding showed diet effect upon absorption of D-xylose. Dietary rhIGF-I may change development or activity of sugar transporters and also may alter absorption of macromolecules (closure) in neonatal calves.  相似文献   

8.
Plasma glucose concentrations in neonates are influenced by colostrum feeding and by glucocorticoids. We have tested whether a high-glucocorticoid status after birth, as well as colostrum feeding, influences glucose metabolism in association with changes of hepatic expression and activities of gluconeogenic enzymes phosphoenolpyruvate carboxykinase (PEPCK; EC 4.1.1.32) and pyruvate carboxylase (PC; EC 6.4.1.1) in neonatal calves. Calves (n = 14 per group) were fed either colostrum or a milk-based formula with nutrient and energy contents similar to colostrum. Half the calves in each feeding group were treated with dexamethasone (DEXA; 30 microg/[kg BW x d]). Pre- and postprandial blood samples were taken on d 1, 2, 4, and 5 and liver samples were collected on d 5 of life. Dexamethasone treatment increased (P < or = 0.05) plasma concentrations of glucose, insulin, and glucagon more in colostrum-fed than in formula-fed calves but increased (P < or = 0.05) urea concentrations and decreased (P < or = 0.05) concentrations of NEFA, ACTH, and cortisol independent of colostrum vs. formula feeding. Colostrum feeding increased (P < 0.05) plasma glucose, but decreased (P < 0.05) plasma urea concentrations. Glucagon-to-insulin ratios in DEXA-treated and colostrum-fed calves were decreased (P < 0.05). Dexamethasone treatment decreased hepatic mRNA levels and activities of PC (P < 0.001 and P < 0.10) and activities of PEPCK (P < 0.001) but increased (P < 0.001) the glycogen content. Colostrum feeding increased (P < 0.05) mitochondrial PEPCK mRNA levels and PEPCK activities in calves not treated with DEXA but decreased (P < 0.1) amounts of PC mRNA. In conclusion, increased plasma glucose concentrations after DEXA treatment were not associated with a stimulation of hepatic gluconeogenic enzyme activities; however, colostrum feeding probably raised plasma glucose concentrations because of increased hepatic gluconeogenic activities.  相似文献   

9.
The incorporation of oral rehydration solutions (ORS) into ‘milk meals’ is potentially an effective, time-saving method of treating diarrhoeic calves. Although milk-based ORS are effective in improving the hydration and acid–base status of healthy calves, this effect remains to be confirmed in dehydrated/diarrhoeic animals. In this study, six experimentally-dehydrated calves were fed with either milk replacer (MR) or an ORS prepared in either water (WORS) or MR (MORS). In one experiment, calves were not treated and blood samples were taken before and after feeding. Parameters of hydration status were determined and blood gas analysis was performed.Plasma volumes increased significantly following the intake of a ‘fluid meal’ whereas they remained constant in the absence of treatment. The rate of plasma volume expansion was reduced by the feeding of MR relative to WORS or MORS. In dehydrated calves, the expansion of plasma volume was more pronounced following the intake of WORS but the increase was less and plasma osmolality increased significantly following the ingestion of MORS. The acid–base status of animals improved as a result of fluid absorption, but this effect was less obvious as the experimental protocol resulted in severe dehydration and moderate acidosis. Feeding hypertonic MORS raised the plasma osmolality in dehydrated calves, and may increase the risk of hypernatraemia in diarrhoeic calves, which should therefore have ad libitum access to water when undergoing treatment with hypertonic ORS. Further research is planned to assess whether feeding ORS reconstituted in milk or MR combined with ad libitum access to water offers a practical treatment for diarrhoeic calves.  相似文献   

10.
Eight male Holstein calves 7 to 10 d of age were fed a milk replacer containing a skim milk powder subjected to low-temperature drying either with or without addition of an oxalate-NaOH buffer known to prevent curd formation. The calves were used in a completely randomized design to study the effect of milk clotting on digestibility and blood parameters. Plasma glucose and plasma insulin were similar (P greater than .05) for the clotting and the nonclotting milk replacers. For both treatments, concentrations of glucose and insulin reached a peak 2 h postfeeding (P less than .01). Plasma triglycerides were higher (P less than .01) postfeeding for the nonclotting than for the clotting milk replacer. Plasma essential amino acids and plasma urea were higher, whereas plasma calcium was lower, for the nonclotting milk (P less than .01). Digestibility of dry matter, protein and fat was similar (P greater than .05) between clotting and nonclotting milk. The dry matter content of feces was not affected by clotting (P greater than .05). The data are interpreted to indicate that clotting of the milk replacer modifies blood concentrations of triglycerides, essential amino acids and urea without changing the digestibility of the diet.  相似文献   

11.
Female calves (n = 108) were assigned to 6 cold milk feeding treatments in two experiments for a 70-day period. Live-weight (LW) was measured weekly, with an additional LW taken at day 410 and post-calving for animals in experiment 1. In Experiment 1, the effect of feeding frequency and age of turnout to pasture on calf performance and 1st lactation milk yields were evaluated. The whole milk (WM) feeding treatments applied were (i) once daily feeding (OD), (ii) twice daily feeding (TD), (iii) OD feeding, outdoors at 38 days (ODO). In Experiment 2, the effects of feeding milk replacer (MR) as opposed to WM and age of turnout to pasture on calf performance were evaluated. The treatments applied were (i) OD feeding with WM (OD), (ii) OD feeding with milk replacer (MR) (ODMR), (iii) OD feeding with MR, outdoors at 38 days (ODMRO). Experiment 1: There were no differences (P > 0.05) in LW or average daily gain between TD and OD calves at day 80 or 410. ODO calves had lower LW at day 80 as compared to OD or TD (P < 0.001). Calf LW at day 80 was 86, 89 and 85 kg and at day 410 was 304, 309 and 316 kg for OD, TD and ODO, respectively. Milk feeding frequency or time of calf turnout had no effect on LW post calving, milk composition or 1st lactation milk yields. Experiment 2: Total LW at day 80 was higher (P < 0.05) for ODMR compared to OD or ODMRO calves. Calf LW was 87, 95, and 88 kg for OD, ODMR and ODMRO, respectively. However, LW at day 410 did not differ between treatments.This study showed that while some differences were observed in calf LW at day 80, these differences had no effect on LW at day 410 or 1st lactation milk yield. It can be concluded that calves can be successfully reared when fed OD with WM or MR, indoors and when turned out to pasture at 38 days of age.  相似文献   

12.
Six cannulated lactating cows were used in two replicated, concurrently run 3 x 3 Latin square experiment to study the interaction between level of feeding and diets differing in ruminally undegraded protein (RUP) on bacterial protein synthesis, ruminal escape of dietary protein, and flow of total and individual amino acids (AA) to the small intestine. Treatments consisted of three diets formulated to contain 69 g (HL), 53 g (HH), and 48 g (LL) of RUP per kilogram of DM, respectively. Measurements were made in early lactation, at high feeding level (19.3 kg DM/d), and repeated at late lactation (9.8 kg DM/d, low feeding level) with the same animals and diets. Decreasing feed intake increased (P < .05) the apparent digestibility of OM, NDF, and ADF in the rumen and the total tract, decreased (P < .05) ruminal liquid and particulate passage rate and total ruminal VFA concentration, and increased ruminal pH and ammonia concentration. Decreased level of intake reduced the (P < .05) efficiency of bacterial N synthesis (28.1 vs 23.7 g bacterial N/kg OM truly digested in the rumen) and decreased (P < .05) ruminal protein degradation rate measured with an in situ method. Duodenal flow of nonammonia nitrogen (NAN), and total AA were highest (P < .05) for the HL diet and lowest (P < .05) for the LL diet at the high feeding level. However, at the low feeding level, diet composition did not affect the amount of NAN or total AA passing to the small intestine. Diet HL increased the proportion of Met, His (P < .05), and Arg (P < .07) in the duodenal digesta at both feeding levels. When purines were used to calculate bacterial N synthesis, no differences between diets were detected. However, when diaminopimelic acid was used, highest bacterial N synthesis was detected for diet HH at the high feeding level. Diet HL supported the highest (P < .05) milk protein production at the high feeding level, and the highest (P < .05) milk protein content at the low feeding level. In conclusion, level of feeding and amount of RUP altered the amount and composition of AA presented to the cows.  相似文献   

13.
The objective was to evaluate effects of feeding level of milk replacer on body growth, plasma metabolite and insulin concentrations, and allometric growth of visceral organs in suckling calves. Holstein bull calves (n = 8; 3–4 days of age) were fed either a low amount (average 0.63 kgDM/day, LM) or high amount (average 1.15 kgDM/day, HM) of high protein milk replacer until they were slaughtered at 6 weeks of age. Body weight (BW) at 4, 5, and 6 weeks of age, feed intake, average daily gain, and feed efficiency were higher in the HM than LM calves. The HM group had higher plasma glucose at 3 and 4 weeks of age and insulin levels after the age of 4 weeks compared with LM calves whereas no effect was detected on plasma nonesterified fatty acid or urea nitrogen concentrations. The HM calves had greater empty body weight (EBW), viscera‐free BW and most of the organs dissected than LM calves. Relative weights (% of EBW) of liver, spleen, kidneys, and internal fat were higher, whereas head and large intestine was lower in HM than LM calves. The results suggest that increased milk feeding levels would accelerate the growth of the body and specific organs.  相似文献   

14.
This study examines milk production and the effect of milk production and sex of calf on body weights and gains of red deer calves and hinds of the Iberian subspecies (Cervus elaphus hispanicus). Milk production was assessed in 14 hinds by weighing calves before and after suckling and by adjusting these values to the Gamma function. Gamma estimates of total milk production up to d 105 were similar to the amounts computed directly from double weighing. Hinds showed two types of lactation curve: 1) the standard mammal lactation curve, with an asymmetrical peak at wk 2 to 4 (Type I) and 2) decreasing curves with no peak (Type II). Although there was great interindividual variability, hinds with Type I curves showed a trend to produce more milk than those with Type II. The type of curve did not seem to affect weight variables of the calf or those of the dam. Calves that gained more weight consumed greater amounts of milk (P<.05). Males were heavier than females at birth (P<.05), but males did not differ from females in their weight at 105 d, milk consumption, and gain. Gender did not affect hind weight, but dams of male calves showed a trend to be lighter (P = .063) at d 105 than dams of female calves. Our results suggest that suckling differences found in other studies between male and female calves may not involve differences in milk production, although other rearing costs seem to affect hind weight losses. They also suggest that the curve type may not depend only, as reported, on the nutrition plane.  相似文献   

15.
The objective of the present paper was to obtain haematological and biochemical parameters of calves during their milk feeding. Another goal was to compare a current feed ration containing the commercial feed mixture Biosan with two alternative rations comprising skimmed milk and fat supplement. The effect of milk drink acidification and the effect of the physical form of fat added to skimmed milk were investigated. the calves were divided into six groups, by 6 to 8 calves each (P1-Biosan, PP1-acid variant, P2-skimmed milk+fat concentrate powder KMKS, PP2-acid variant, P3-skimmed milk+fat paste, PP3-acid variant). The highest average daily liveweight gains were recorded in calves fed on unacidified skimmed milk with fat paste supplement (1.074 kg)-Tab. I. The highest average daily liveweight gains were observed in calves fed on fat paste enriched milk drink (P3) while the calves administered milk with fat concentrate powder (P2) had only slightly higher average daily weight gains than the calves on Biosan diet (group P1). The growth of daily weight gains as a result of diets containing acidified milk (PP1 and PP2) is also a positive finding; this growth is even statistically significant in the former case (P < 0.05). The calves showed hypohaemoglobinaemia from the beginning of the experiment (51.3-69.0 g/l) and the low haematocrit value (0.29-0.43 l/l), Tab. II, while the plasma iron level was paradoxically high (Tab. V).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

16.
As the dairy industry continues to grow, more dairy calves are available for dairy, beef, and veal purposes. Rearing systems must be highly efficient to make this industry cost efficient, making the evaluation of rearing methods important to establish the most practical method. A study was designed and conducted to evaluate effects of housing and feeding systems on performance of neonatal Holstein bull calves. Treatments (2 × 2 factorial arrangement) consisted of: 1) individually housed, bottle-fed (n = 5 bull calves); 2) individually housed, bucket-fed (n = 5 bull calves); 3) group-housed, bottle-fed (n = 5 pens; 4 bull calves/pen); and 4) group-housed, bucket- (trough) fed (n = 5 pens; 3 or 4 bull calves/pen). Feeding treatments began on d 7 when calves had been acclimated to their new environment. Body weight measurements were collected every 7 d and blood samples were collected on d 0, 28, 55, and 66 for β-hydroxybutyrate (BHBA) concentration as a gross indicator of ruminal development. No housing × feeding interactions or feeding treatment effects were observed (P > 0.10). Average DMI (dry feed plus milk replacer) was increased (P < 0.05) for group-housed vs. individual animals after d 41, and final BW was greater (P < 0.05) for group-housed calves compared with individually housed calves. Feed efficiency and ADG, however, remained similar (P > 0.10) for all treatments. Fecal scores (P > 0.26), CV for BW (P > 0.26), and BHBA concentrations (P > 0.14) showed no differences among treatments. Housing system had greater effect on calf performance compared with milk feeding regimen.  相似文献   

17.
The objective was to study the growth potential of Sahiwal calves given milk or milk replacer with or without concentrates. For this purpose, forty-eight Sahiwal calves were divided into four groups of 12 animals each with equal sex ratio. In each group, the calves were offered either milk or a milk replacer (MR) at a rate of 10% of their body weight adjusted weekly. In addition to this, calves were fed either a starter ration plus Egyptian clover hay (SR + H) or hay only (H) until the end of trial. The milk or MR was withdrawn gradually from day 56 until animals were weaned completely by day 84. Calves offered milk grew faster than those offered MR (357 ± 9 vs. 162 ± 9 g/day; p < 0.05) and displayed higher weaning weights (51.6 ± 0.8 vs. 35.2 ± 0.8 kg; p < 0.05). The calves offered SR + H grew faster (311 ± 9 vs. 208 ± 9 g/day; p < 0.05) and displayed higher weaning weights (48.7 ± 0.8 vs. 38.1 ± 0.8 kg; p < 0.05) than those fed H alone. Calves offered milk plus SR + H showed the highest growth rate and weaning weights (401 ± 13 g/day and 56.3 ± 1 kg, respectively). The lowest growth rate and weaning weights were observed in calves offered MR and H only (115 ± 13 g/day and 30.3 ± 1 kg, respectively). Calves offered the MR had higher number of scour days than those offered milk (13.5 vs. 3.3). The feeding of whole milk in combination with the starter ration and hay resulted in superior growth rates, higher weaning weights, and healthier calves than the other feeding regimens.  相似文献   

18.
Experiments were conducted to investigate the effects of the presence of a trainer cow on behavior, performance, health, and feeding patterns of newly weaned beef calves. In Exp. 1,252 weaned calves (270+/-18 kg) were allocated to 22 pens (11 to 15 calves per pen). A trainer cow was randomly assigned to each of 11 pens. Calves were weighed prior to feeding on d 0, 3, 7, 14, 21, and 28. Rectal temperatures were taken on each of these days (except d 28) and blood samples were collected on d 0, 3, and 7 and subsequently analyzed for serum haptoglobin and leukotoxin antibody titers. Instantaneous scan observations of calf behavior were made at 10-min intervals between 0730 and 1730 on d 1, 2, 4, 5, and 6. A similar protocol was used in Exp. 2, in which 297 calves (258+/-17 kg) were allocated to 24 pens. Blood analyses included haptoglobin, white blood cell counts (WBC), and neutrophil:lymphocyte (NL) ratios. In Exp. 3, the above protocol was followed and patterns of feed bunk attendance of individual calves were also monitored using radio frequency identification by passive transponder ear tags. Trainer cows did not influence (P > .10) calf rectal temperatures, requirements for antibiotic therapy, WBC, NL ratios, or leukotoxin antibody titers. Pooled across treatments, NL ratios were lower (P < .01) on d 0 (.31) than on d 3 (.36) or d 7 (.39). Although differences in weight gain were detected in some periods within the three experiments, there were no differences (P > .10) overall (d 0 to 28). Trainer cows did not affect (P > .05) frequency or duration of bunk visits by the calves. Averaged across treatments, frequency and duration of bunk visits increased (P < .001) from 9.6 visits/d and 56.7 min/d between d 0 and 3 to 12.3 visits/d and 108.9 min/d between d 15 and 21. The number of calves observed eating during scan sampling observations also increased from 16.4% on d 1 to 25% on d 4 (P < .10) and 29% on d 5 and 6 (P < .05). More (P < .05) calves were observed lying on d 1 (41.7%) and d 2 (45.3%) than on d 4 (37.5%), d 5 (34.8%), or d 6 (36.2%). With a trainer cow present, fewer (36.7% vs 41.5%; P < .001) calves were observed lying and more (11.7% vs 10.2%; P = .08) were observed walking than when no cow was present. Trainer cows did not improve calf health, time spent at the feed bunk, or performance of newly weaned calves.  相似文献   

19.
In two experiments, a total of 46 Finn Cross and Dorset lambs were artificially group-reared. Thirty eight were weaned abruptly at 14 d of age from a commercial milk replacer (MR) to a dry starter diet (SD). Lambs were self-fed cool (10 to 15 C) MR reconstituted to 25% dry matter (DM). The ground (2-mm screen) SD averaged 26.2% crude protein and 7.4% fat (DM basis). For both experiments, birth and weaning weights averaged 3.8 and 8.0 kg, respectively. Experiment 1 tested a strategy for encouraging postweaning DM intake. Fifteen lambs received MR reconstituted to 33% DM from d 11 to 14, and 15 lambs received standard 25% DM MR. Between d 14 and 15, intakes of DM, gross energy, crude protein and water dropped 86, 89, 85 and 64%, respectively. Lambs doubled their birth weights during the milk-feeding period and consumed 1.41 kg SD between d 14 and 25. The MR reconstitution rate did not affect weaning weight, postweaning SD or water intake, or growth check (GC, P greater than .10). Postweaning GC averaged 12.2 d and was not influenced (P greater than .10) by birth weight, sex or weaning weight. Mortality and disease rates under these conditions were negligible. Experiment 2 was designed to differentiate between the dual effects at weaning of altering the type of diet and of reducing the level of nutrient intake. Eight lambs were weaned to SD at 14 d, and eight lambs were bottle-fed isocaloric levels of MR from d 12 to 30. At weaning, plasma glucose concentration declined 1.4 mM from 6.7 mM due to fasting and an additional 1.0 mM due to the change of the type of diet (P less than .01). Plasma acetate and urea N concentrations rose steadily after d 16 in the SD-weaned lambs, but not in the MR-fed lambs (P less than .01), suggesting that the SD-weaned lambs absorbed ruminal fermentation products. These results indicate that artificially reared lambs may be routinely weaned to a dry diet at 14 d of age. The major alterations in plasma metabolites that occur within 6 to 8 d after abrupt weaning may define the period when these lambs become functional ruminants.  相似文献   

20.
The aim of this study was to evaluate the effects of the addition of two roughage sources (wheat straw and beet pulp) to the milk replacer diet of veal calves, in order to reduce stress and improve animal welfare. We allocated 138 Polish Friesian male calves to three different feeding plans: a milk replacer diet (Control), 250 g/d of wheat straw in addition to the milk replacer, or 250 g/d of dried beet pulp in addition to the milk replacer. Within each feeding treatment, 16 calves were individually housed and 30 were kept in group pens (five calves/pen). Several behavioral, physiological, and health welfare indicators were monitored throughout the fattening period, which lasted for 160 d. Abnormal oral behavior around the meals was higher in Control calves (P < 0.01), while its lowest level was observed in straw-fed calves. At the beginning of the trial, chewing was higher in calves receiving solid feeds (P < 0.001), but the difference from the Control gradually decreased and disappeared at wk 13 for calves fed beet pulp and at wk 17 for those fed wheat straw. At the end of the fattening period, no differences among treatments were found in the frequency of chewing. Regardless of the diet, self-grooming decreased with age and no relationship was observed between this behavior and the presence of rumen hairballs. Cross-sucking was performed with low frequencies (from 4.70% at wk 2 to 1.05% at wk 23 around the meals, and even lower far from the meals) and was not affected by the provision of roughage. The time in contact with the bucket during the whole day was higher in Controls, whereas calves fed wheat straw maintained a lower level of this activity until the end of the trial (P < 0.01). The calves fed wheat straw spent more time in contact with the feed trough (P < 0.001) than those fed beet pulp and Control calves. No differences were found in cortisol curves due to the feeding treatment. In calves fed beet pulp, most hematological measures statistically differed from the other treatments, possibly in response to the higher iron intake and(or) to the higher hemoconcentration, probably due to the administration of beet pulp as dried feed. The incidence of abomasal ulcers and erosions was increased by the provision of the solid feeds, particularly by a structured fiber source such as straw. A roughage source able to satisfy calves' behavioral needs and to improve digestive processes without damaging the digestive apparatus still has to be identified.  相似文献   

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