Thermal insulation of young calves exposed to cold.

Tissue, external and whole animal insulation values were determined for 12 newborn male Holstein calves continuously housed for two weeks in hutches within environmental chambers in which temperature was maintained at a constant 17 degrees C (three calves) or cycled on a daily basis either between -20 degrees and -8 degrees C (three calves) or between -30 degrees and -18 degrees C (six calves). Three of the six calves at the coldest temperature were outfitted with an insulated coat. The insulated coat provided calves a 52% increase in total insulation. Tissue insulation of cold-housed calves increased 37.2% over the first two weeks of life. It was concluded that the capacity for vasoconstriction improved with age. External insulation did not change significantly except during the first week in cold-housed calves without insulated coats. External insulation values were five to eight times those of tissue insulation values for all treatment groups. This indicated that insulation of structures external to the skin (hair, bedding, ground, etc.) provided most of the insulation for calves.     

Some observations on the effects of age of calves on the phagocytosis and killing of Staphylococcus aureus by polymorphonuclear leucocytes

The effects of age on bovine polymorphonuclear (PMN) cell function were investigated by comparing the efficiencies of phagocytosis and killing of Staphylococcus aureus by peripheral blood leucocytes sequentially obtained from 15 calves between the ages of less than 1 and 84 days. One group of seven calves was kept in a controlled environmental chamber with air temperature of 5 degrees C and 58% relative humidity (RH) and another group of eight calves was kept at 16 degrees C and 58% RH. The calves were given a diet a liquid milk substitute and dry food, and were weaned abruptly from the liquid diet at 35 days of age. The in-vitro efficiencies of phagocytosis, and of killing, Staphylococcus aureus by peripheral blood leucocytes were similar for calves in air temperatures of 5 degrees C and 16 degrees C (P greater than 0.05). Peripheral blood leucocytes obtained from calves of less than 1 day of age were more efficient in phagocytosing S. aureus than those obtained when the same calves were 14-84 days of age (P less than 0.001). Peripheral blood leucocytes obtained when the calves were 42 and 56 days of age were significantly less efficient in phagocytosing and killing S. aureus than those obtained when the same calves were less than 1, 14, 28, 70 and 84 days of age (P less than 0.001).     

Growth and Survival of Holstein and Brown Swiss Calves Reared Outdoors in Individual Hutches

The effects of outdoor raising of Brown Swiss and Holstein replacement calves in individual hutches were studied on a farm having northern Mediterranean climatic conditions. A total of 240 female calves was used with 30 calves of each breed and born in each of the four seasons. The animals were kept for 3 months in individual hutches and then in groups of 10 until 6 months of age. The birth weights of the Brown Swiss and Holstein calves were 37.2±0.21 and 37.9±0.22, respectively. The average birth weights were highest in spring and lowest in winter. Breed and seasonal effects were evident at 6 months. The live weights for the two breeds at 6 months were 114.1±1.3 and 126.3±1.5 kg, respectively. The numbers of health disorders were significantly higher in the first month of life. Mortalities occurred in the following months, being 2.5% in Holsteins and 5% in Brown Swiss by 6 months of age. The results indicated that calves can be reared outdoors successfully.     

Health and metabolic responses of young calves housed at -30 degrees C to -8 degrees C.

Newborn, male, Holstein calves, were continuously housed for three weeks in calf hutches at 17 degrees C or in a thermal environment which varied rhythmically on a daily basis either between -20 degrees C and -8 degrees C (experiment A) or between -30 degrees C and -18 degrees C (experiment B). Compared to warm-housed calves, cold-housed calves in experiment A had metabolic rates which were significantly higher (p less than 0.001) in a standing position but which were not significantly different (p less than 0.05) in a recumbent position. Recumbent and standing cold-housed calves in experiment B had an increased (p less than 0.05) metabolic rate compared to warm-housed controls. Heat loss was less (p less than 0.05) for recumbent cold-housed calves in experiment B than for standing calves in a thermoneutral environment. Localized subcutaneous hemorrhages of hindlimbs were a consistent necropsy finding among all cold-housed calves. Average daily gains of cold-housed calves were not significantly different from warm-housed controls. Clinical, physiological and pathological findings indicated that cold treatments used in the present study did not cause serious harm to calves. It was concluded that calves housed in properly managed hutches are remarkably cold tolerant.     

The effect of extreme temperatures on hematologic and biochemical indicators in heifers

The study was aimed at finding the effect of low and high temperatures on some biochemical parameters in heifers. Thirty half-sister heifers were used as the experimental material. The animals were divided into two groups. The experimental group including 16 heifers was kept loose on deep litter in an open barn with no thermal insulation. The control heifers (n = 14) were kept in a thermally insulated house. Blood was collected at extreme temperatures: above 30 degrees C and below -5 degrees C. An insignificant decrease of haemoglobin and haematocrit was recorded in the blood collected at low and high temperatures from the heifers kept in the open barn; a reduction of cholesterolaemia and total lipaemia was recorded at high temperatures. High and low temperatures significantly increased the concentration of free amino acids; the differences between the experimental and control group being from 36 to 76 mumol per litre. The content of 3.5-cyclic adenosine monophosphate was increased insignificantly at extreme temperatures. Hyperglycaemia was recorded in the heifers at high temperatures and at the beginning of the winter season. At low temperatures the concentration of thyroxine was found to be increased in the blood of the experimental animals: 120 nmol per litre and 161 nmol per litre vs. 95 nmol and 116 nmol in the control group.     

初乳饲喂次数对娟姗犊牛生产性能的影响

为研究探讨初乳饲喂次数对娟姗犊牛生产性能的影响,试验选取初生重接近的健康娟姗犊牛20 头,随机分为4 组,分别为对照组、试验I组、II组和III组,每组5 头犊牛,试验期为60 天。4 组犊牛出生当日饲喂两次初乳,首次初乳量按照体重的10.0%进行灌服,第2次初乳于出生后6~8 h按照体重的5.0%进行饲喂。4 组犊牛出生当日在产房饲养,2日龄时均转为室外犊牛岛单栏饲养。2日龄后,对照组每天上午06:00和下午16:00时各饲喂常乳1次,2~6日龄每次饲喂1.50 L,7~20日龄每次饲喂1.80 L,21~35日龄每次饲喂2.50 L,36~60日龄每次饲喂3.00 L,自7日龄开始犊牛自由采食颗粒料。试验Ⅰ组、Ⅱ组、Ⅲ组分别继续饲喂初乳至犊牛2日龄、4日龄、6日龄后再饲喂常乳,饲喂时间和饲喂量与对照组一致。结果表明:(1)在饲喂初乳后48 h、72 h、96 h,试验组与对照组犊牛血清免疫球蛋白g(IgG)均差异显著(p<0.05),120 h、144 h、168 h,试验Ⅰ组与对照组比较,犊牛血清IgG含量差异不显著(p>0.05),试验Ⅱ组、Ⅲ组血清IgG含量与对照组相比,差异极显著(p<0.01)。(2)随着初乳饲喂次数的增加,可有效降低犊牛20日龄内腹泻发生率,试验Ⅰ组、Ⅱ组、Ⅲ组较对照组比较犊牛腹泻发生率分别降低9.5%、22.5%、36.5%,治疗犊牛腹泻总成本较对照组分别下降12.0 元、43.2 元、76.8 元,3 组试验组犊牛成活率为100.0%。(3)初乳饲喂次数的增加,使0~60日龄娟姗犊牛平均日增重(ADG)升高,试验组与对照组相比较,日增重均差异极显著(p<0.01),分别增加16.7 g、33.3 g、80.0 g。试验Ⅱ组、Ⅲ组较试验Ⅰ组ADG差异也极显著(p<0.01)。综合考虑,建议娟姗犊牛饲喂初乳至6日龄,可降低犊牛腹泻发生率、减少治疗费用,提高犊牛成活率及ADG。     

Consequences of short term fluctuations of the environmental temperatures in calves--Part 2: Effects on the health status of animals within three weeks after exposure

The aim of the present study was to examine consequences of sudden changes in ambient temperature over a 4-hour period (see part 1 [ELMER & REINHOLD, 2002]) on respiratory health in clinically healthy calves. Therefore, the relationship between short-term changes in ambient temperature and the occurrence of clinical respiratory disease was checked over a period of 3 weeks after exposure in 10 calves exposed to 5 degrees C, in 9 calves exposed to 35 degrees C and in 8 control calves (kept at 18-20 degrees C). Within the period beginning 3 days before exposure and lasting until up to 21 days after exposure, each calf was examined clinically. Rectal temperature and respiratory rate were measured daily. All calves were euthanised on day 21 after exposure. Macroscopically visible pneumonic lesions were evaluated using a semiquantitative system. Tissue samples from tonsils, bronchi, trachea, lung and mediastinal lymph nodes were examined bacteriologically. In contrast to non-exposed control calves, severe respiratory illness was observed in individual calves of both exposed groups (5 degrees C, 35 degrees C). Significant increases in body temperature, respiratory rate and animal losses (2 calves died in the group exposed to 5 degrees C, one calf died in the group exposed to 35 degrees C) were the main clinical findings. At necropsy (3 weeks after exposure), no pneumonic lesions were observed in control calves--despite the fact that this group had the highest microbiological colonisation rates in tonsils and in large airways, i.e. trachea and bronchi, within all groups. However, variable pneumonic lung lesions were seen in remaining calves exposed to cold or warm air (5 degrees C, 35 degrees C). The microbiological examination confirmed that mainly Mycoplasma spp. were identified in the lung tissue of calves exposed to 5 degrees C while Pasteurella multocida and/or Mannheimia haemolytica were the only germs found in the lung tissue of calves exposed to 35 degrees C. The results of parts 1 and 2 of the present study related to health issues of calves should be taken into account for future legislation on animal welfare.     

Effects of two different rearing protocols for Holstein bull calves in the first 3 weeks of life on health status,metabolism and subsequent performance

The aim of this study was to investigate the impact of weight gain of calves within the first 3 weeks of life on health status and subsequent performance. Holstein bull calves were reared either intensively (IR; individual hutches and ad libitum milk feeding for the first 3 weeks of life; n = 24), or according to the established protocol [ER; 4 l milk/day in hutches during week 1 and 720 g/day milk replacer (MR) from day 8 to 21 in a group pen; n = 24]. Water, hay and concentrates were freely available to all calves. From week 4, calves of both groups were housed together in a group pen and fed 720 g MR/day; step‐down weaning was performed between week 5 and 10. Key metabolic blood parameters were analysed on day 2, 12, 21 and 70 of life. After weaning, all animals were fed concentrates and corn silage until slaughter at an age of 8 months. Within the first 3 weeks, average daily weight gain was threefold higher in IR calves in relation to ER calves (1.28 vs. 0.38 kg/day, p < 0.001). Neither incidence nor duration of scouring differed significantly between groups. Starter intake (week 4–10) was higher in IR calves in relation to ER calves (49.7 vs. 38.0 kg/calf, p = 0.006). Serum glucose, urea, albumin and insulin were higher at an age of 21 days in IR calves in relation to ER calves; no differences were obvious at an age of 70 days. Plasma GH and IGF‐I concentrations revealed an uncoupling of the somatotropic axis in ER calves within the first 3 weeks of life. At slaughter, body weight of IR calves tended to be higher than that of the ER calves (320 vs. 309 kg, p = 0.07). In conclusion, intensive feeding and individual housing during the first 3 weeks of life had positive long‐term effects on subsequent performance.     

The effect of cellulase on calves fed an acidified milk diet]

The purpose of this research was to establish the influence of 3 j Cx cellulase applied per gram of COT concentrate mixture, fed in combination with a milk diet acidified by formic acid to the value of pH 4.6, on calf growth performance in one metabolism and two field experiments. In the metabolism experiment two groups of calves, with six animals in each, were fed acidified whole milk, which was diluted stage by stage till weaning at 60 days of age. The average live weight gain in the control at the end of the milk feeding period, i.e. from 14 to 60 days of age, was 29.90 kg. This corresponds to a daily live weight gain of 0.650 g. The total live weight gain of male calves in the experimental group was 29.30 kg, corresponding to a daily live weight gain of 0.638 g (Tab. I). Tab. II shows the average feed and nutrient intakes per kg live weight gain. The calves which received the enzyme supplement tend to have the higher feed conversion rate. During the forage feeding period, i.e. from 61 to 90 days of age, the average daily live weight gains were 1.10 kg and 0.980 kg in the control and experimental groups, respectively (Tab. III). The average live weight of 90 days old male calves was 107.70 kg and 103.90 kg in the control and experimental groups, respectively. The amount of consumed nutrients (digestible protein and starch units); in relation to the total feed intakes, is lower in the experimental groups, which proves the higher feed conversion rate (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of monensin on performance and selected biochemical and hematological parameters in the blood of calves]

The aim of this study was to find out the influence of monensin, a ionophore antibiotic, on calf performance and selected physiological parameters. Monensin is a product of Streptomyces cinnamonensis. It has effects on all Gram-negative microbes, such as Escherichia coli, salmonellas, pseudomonads and vibria. It has a small effect on Gram-positive microbes. At the beginning of the experiment eight young crossbred bulls (C x N) at the age of three weeks were weighted and divided into two groups, experimental and control ones. Calves were kept in individual boxes and fed acidified whole milk (2 ml of 85% formic acid per 1 litre of milk). They had a free access to concentrates (COT), hay and drinking water. The calves received 3 lt. of whole milk twice a day until the age of eight weeks. 0.5 mg of monensin per 1 kg live weight were served orally to calves of the experimental group every day. Monensin was made by the Spofa Corporation, Prague. Daily intake of feed was recorded and the calves were weighted once a week. Blood samples were taken from the jugular vein before the beginning of the experiment, and in the period from the fifth to the tenth week of age, always before morning feeding. The average daily live weight gain was 0.452 kg and 0.471 kg for the control and experimental group, respectively, during the milk feeding period, the index being 104.2 (Tab. I). Tab. II shows the average feed intake per 1 kg live weight gain.(ABSTRACT TRUNCATED AT 250 WORDS)     

A comparison of indoor and outdoor calf housing systems using automated and manual feeding methods and their effect on calf health,behavior, growth,and labor

Housing and feeding are integral to calf rearing, and must meet calf needs while remaining functional for the farmer. This study compared health, behavior, growth, and labor requirements of calves housed in groups indoors and fed via an automatic or manual milk feeding system compared to calves manually fed in individual or group hutches outdoors. Seventy-six (49 Holstein Friesian [HF] and 27 HF × Jersey) dairy heifer calves were balanced for birth weight (35.2 ± 4.95 kg), birth date (1 February ± 7.2 d) and breed. The experiment was a randomized block design with four treatments; 1) indoor group housing with automated feeding (IN_AUTO; 12 calves per pen), 2) indoor group housing with manual feeding (IN_MAN; 12 calves per pen), 3) outdoor group hutch with manual feeding (OUT_G_MAN; 8 calves per pen), and 4) outdoor individual hutch with manual feeding (OUT_I_MAN; 6 calves: 1 per pen). Calves in OUT_treatments moved outdoors at 18 d (± 5.9 d). Each treatment was replicated once. Milk allowance increased gradually from 6 to 8 L/day (15% reconstitution rate) with ad libitum fresh water, concentrates, and hay offered from 3 d old. Gradual weaning occurred at 8 wk old. Measurements were divided into period 1; before movement outdoors, and period 2; after movement outdoors. Health was similar among treatments, regardless of period, with the most frequent score being zero (i.e., healthy). Summarized, standing and lying were observed 24.3% and 29.8%, respectively, in OUT_I_MAN calves, compared to 8.0% and 49.1%, for the other systems, which were similar. No difference in bodyweight (BW) existed between treatments, except at weaning where BW was lower for OUT_I_MAN (67.4 ± 2.84 kg) compared to IN_MAN (74.2 ± 2.01 kg), and day 102 where OUT_I_MAN (94.1 ± 2.85 kg) were lighter than IN_AUTO (101.1 ± 2.10 kg) (P = 0.047). Total labor input was greatest for OUT_I_MAN (00:02:02 per calf per day; hh:mm:ss) and least for IN_AUTO (00:00:21 per calf per day) (P < 0.001). The labor for feeding (00:00:29 per calf per day), feeding inspection (00:00:10 per calf per day), and cleaning equipment (00:00:30 per calf per day) was greatest for OUT_I_MAN. All calves showed good health and growth patterns. Differences in behavior expressed by calves in the OUT_I_MAN, compared to other treatments may indicate compromised welfare. Thus, although outdoor group hutches do not negatively impact calves, indoor housing, particularly using automated feeders, can improve labor efficiency.     

The effect of group size on health and growth rate of Swedish dairy calves housed in pens with automatic milk-feeders

Group pens equipped with automatic milk-feeding systems are increasingly being used for young dairy calves in Sweden. The system is, however, associated with an increased risk of clinical respiratory-tract disease and a reduced growth rate. In an experimental study we compared the health and growth rate of two different group sizes of calves (6-9 versus 12-18) kept in pens with automatic milk-feeders. The experiment was performed from September 2002 to February 2004, in nine commercial dairy farms in south-west Sweden. Each farm was equipped with two pens with automatic milk-feeders and no possibility of direct contact between calves from different pens. The calves were housed individually until 3-35 (median, 12) days of age, and then were allocated to one of the two group pens by random-number lists. Altogether 892 calves were studied: 297 in the small- and 595 in the large-sized groups. The calves' heart girths were measured at birth and at 56 days of age. Blood samples for analysis of serum haptoglobin concentration (S-Hp) were collected once for each calf, at four to eight weeks of age. Diseases were recorded by the farmers and by a veterinarian, who visited the farms every third week and physically examined all the calves. The effects of group size on the risks of diarrhoea, clinical respiratory-tract disease and increased respiratory sounds, and on the growth rate and S-Hp were evaluated using multiple logistic- and linear-regression models with herd as fixed effect. Age at transfer to group pen, breed, immunoglobulin concentration of colostrum received, parity of the dam and presence of diarrhoea before transfer to the group pen, season, sex, year, and, in the analysis of growth rate, birth heart girth were extra explanatory variables. Calves in pens for 12-18 calves had a higher incidence of respiratory illness (OR: 1.4) and grew 0.022 cm/day less than calves housed in groups of 6-9 animals (equivalent to approximately 40 g/day). We detected no differences between calves kept in the small-sized versus the large-sized groups in terms of risk of diarrhoea or mean S-Hp. We concluded that housing calves in groups of under 10 calves is preferable from a health and growth perspective.     

Body weight and selected hematologic and biochemical parameters in calves fed various diets during milk feeding]

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)     

Peripheral circulating insulin-like growth factor-I and -II in cattle

Interrelationships between circulating concentrations of the insulin-like growth factors (IGF-I and IGF-II) were investigated in 235 blood samples taken from 145 healthy beef or dairy calves, bulls and cows of different breeds and ages. Autoradiography of Western ligand blots indicated different IGF binding protein (IGFBP) profiles between sera from different categories of cattle. Each IGF radioimmunoassay was validated by determining the effects of IGFBPs, ligand and contraligand, as well as serial dilution and comparison with results obtained after molecular sieve chromatography in acid. In female cattle mean values for IGF-I varied from 5.1 nmol/l in postparturient Holstein cows to 18.5-20.5 nmol/l in growing beef heifers, while mean IGF-II concentrations ranged from 30.0 nmol/l in the cows to 14.7-15.7 nmol/l in the beef heifer calves. In male cattle mean serum IGF-I ranged widely from 8.2 nmol/l in 1-day-old Holstein calves to 67.4 nmol/l in 16-month-old Simmental-type bulls. Mean IGF-II concentrations decreased from 22.9 nmol/l in 1-day-old Holstein bull calves to 11.9 nmol/l in 12-month-old beef bulls. Thus, total molar IGF concentrations were fairly stable in female cattle (24.7-35.1 nmol/l) but extended from 27.3 nmol/l to 81.8 nmol/l in the male cattle. The tendency for a reciprocal relationship between serum concentrations of these growth factors was most obvious in the periparturient cows.     

Relationships between counts of nasopharyngeal bacteria, temperature, humidity and lung lesions in veal calves

Nasopharyngeal swabs were taken from four groups of veal calves at intervals throughout their growth and the aerobic bacteria cultivated from the swabs counted. The calves were kept under three different husbandry systems; naturally ventilated straw-yards, fan-ventilated crates and crates with a controlled climate. The numbers of bacteria isolated varied in a complex manner; however, in one group of calves a significant proportion (P less than 0.01) of the variation in weekly bacterial counts was associated with the changes in vapour pressure and temperature which took place between two and four days previously. In calves kept at a constant temperature of 16 degrees C, the bacterial populations in the nasopharynx were at a minimum between 65 and 75 per cent relative humidity and tended to rise at humidities outside this range. There was a temporal relationship between nasopharyngeal bacteria and lung lesions. In three groups the numbers of bacteria in calves at nine weeks old were positively correlated (P less than 0.05) with lung damage observable at 16 to 18 weeks old.     

不同固液比例饲喂模式对断奶前后犊牛营养物质代谢及瘤胃发酵的影响

本试验旨在研究断奶前后犊牛在不同固液比例饲喂模式下营养物质代谢及其瘤胃发酵的异同,从而探索基于不同饲喂模式下的犊牛断奶方式。试验选用7日龄荷斯坦公犊牛36头,随机分成3组,每组12头,各组采用相同原料组成、相同营养成分的代乳粉和颗粒料。在总干物质饲喂量保持一致的情况下,改变固液饲料饲喂比例,形成3种饲喂模式组:高液体饲料比例(HL)组,28~56日龄内,颗粒料∶代乳粉保持在1∶2,56日龄断奶;对照(LS)组28~56日龄内,颗粒料∶代乳粉从1∶2逐步降低到1∶1,56日龄断奶;高固体饲料比例(HS)组,28~42日龄内,颗粒料∶代乳粉从1∶2逐步降低至1∶0,并于42日龄断奶。试验期77 d。分别于犊牛28、42、56和84日龄采集瘤胃液,35和63日龄进行断奶前后消化代谢试验。结果表明:断奶前,与HS组相比,HL、LS组犊牛总能代谢率相对较高,但差异不显著(P0.05);断奶后,HS组消化能代谢率、氮利用率及氮的生物学价值较HL组显著提高(P0.05)。与HL组相比,HS组84日龄瘤胃液微生物蛋白含量显著提高(P0.05)。3组间瘤胃液氨态氮浓度无显著差异(P0.05)。84日龄时,HS组犊牛瘤胃液总挥发性脂肪酸浓度和丁酸比例显著高于HL组(P0.05),各组间丙酸、戊酸比例无显著差异(P0.05)。综上可得,适量增加固体饲料饲喂比例有助于改善断奶前后犊牛瘤胃发酵环境,促进瘤胃微生物蛋白的合成,提高断奶后犊牛饲粮能量代谢率、氮的生物学价值及氮利用率;采用高固体饲料饲喂模式,犊牛在42日龄固体饲料采食量达到1.0 kg/d时实施断奶具有一定优势。     

Biologic quality of colostrum and calves from dairy cows injected with zinc during pregnancy]

The effects of an administration of the Zindep inj. preparation (Biotika) were evaluated in pregnant dairy cows as exerted on specific weight, total protein (TP) content, total immunoglobulin (IgC) and albumin (ALB) contents in colostrum. These parameters were also followed: calf's health, live weight, leucocyte (Lc) counts, T-lymphocyte (T-Ly) counts, contents of TPs, IgCs and ALBs in the blood serum of calves. Zinc concentrations were determined in colostrum, milk and calf blood serum. Our observations included 16 dairy cows in the seventh month of pregnancy in the second lactation and their calves in the winter feeding season. Eight experimental dairy cows were treated with the Zindep preparation in form of an injection to the neck muscles at a dose of 3 mg Zn/kg live weight in the mid-seventh month of pregnancy. Blood samples were taken from v. jugularis from all calves before their first drinking, on days 5, 15 and 30 of age. Colostrum, and/or milk samples were obtained by drawing of the colostrum or milk from the udder quarters within 60 minutes after parturition, on days 5 and 15 of lactation. Zn levels at birth were 16.48 +/- 2.67 mumol/l in experimental calves and 13.84 +/- 3.19 mumol/l in control calves. Zincaemia decreased slightly in both groups on days 5 and 15 of age, but it was insignificantly higher in calves coming from Zindep-treated dairy cows. Zn levels in the blood serum on the 30th day of age were 18.45 +/- 2.44 mumol/l in experimental animals and 15.73 +/- 3.11 mumol/l in control animals. Zn content in the colostrum of experimental cows was 2.40 +/- 0.42 mg/l and in the control it was 1088 +/- 0.52 mg/l (P < 0.05). On day 5 of lactation, Zn amounts in the milk of experimental dairy cows decreased to 0.95 +/- 0.12 mg/l and to 0.76 +/- 0.10 mg/l in the control (P < 0.01). Zn levels in the milk of experimental cows on day 15 of lactation were 0.95 +/- 0.13 mg/l and in the milk of control group they were 0.82 +/- 0.14 mg/l. Colostrum specific weight from zinc-treated cows was 1,067.86 +/- 0.75 g/cm3 and 1,056.8 +/- 13.53 g/cm3 in the control. TP and IgC concentrations were 137.81 +/- 38.11 g/l and 110.13 +/- 29.91 U ZST, respectively, in the colostrum of experimental group, and 105.98 +/- 32.02 g/l and 85.53 +/- 25.42 U ZST, resp., in control animals.(ABSTRACT TRUNCATED AT 400 WORDS)     

Changes in biochemical indicators in dairy cows induced by extremely low temperatures

The objective of the experiment was to find out the effect of extremely low temperatures on the biochemical characteristics of the cows. Twenty-one dairy cows were used as the experimental material. The experimental group (n = 12) was kept loose in an open barn without thermal insulation and the control group (n = 9) was kept in an insulated cow-house. The winter season included two periods of extremely low temperatures: from the 3rd to the 21st of January 1985 the average minimum temperature in the open barn was -12.6 degrees C and the lowest temperature was -19 degrees C, and in the period from the 8th to the 20th of February 1985 the average minimum temperature was -13.1 degrees C and the lowest recorded temperature was also -19 degrees C. At the beginning of hypothermic stress, the concentration of non-esterified acids and total proteins increased in the cows of the experimental group; potassiaemia was decreased in this group. Cholesterolaemia and glycaemia increased during the long-continued exposure to low temperatures. The activity of the thyroid gland was increased at all measurements.     

Bile acid concentrations in serum, bile and feces of healthy calves and calves with diarrhea

On 32 calves (age 3 to 14 days) with spontaneously occurring diarrhoea, the following investigations were carried out: Regular examination of serum bile acid concentrations, collection of the entire faeces with determination of bile acid concentrations, as well as microbiological examinations. Six clinically healthy calves served as control group. In addition, bile acids in bile were determined in 16 other calves of the same age group and in 6 beef bulls. There was no significant influence of daytime or feed intake on serum bile acid concentration in diarrhoeic or healthy calves. Possibly due to the low concentrations of bile acids in the bile of young calves (4.8 +/- 3.7 mmol/l, compared to 57 +/- 13 mmol/l in the bulls), the concentrations in faeces were also rather low (control group 623 +/- 92, calves with diarrhoea 318 +/- 277, after diarrhoea. 794 +/- 935 mumol/kg). Most of it was cholic acid, whereas only traces of desoxycholic acid were found. In spite of the comparatively low concentrations of fecal bile acids, the diarrhoeic calves excreted larger amounts of bile acids than the healthy calves (12.7 +/- 13.5 vs. 1.4 +/- 0.8 mumol/kg), but this was independent of the type of enteropathogen or pathogen combinations which were detected. There were no indications for a direct influence of the diarrhoea by bile acids. However, through enteral bile acid losses, profuse diarrhoea lasting several days can cause a reduction in the total bile acid pool.     

Experimental bovine pneumonic pasteurellosis. I. Prevention of the disease.

Fifteen three- to six-month old Hereford-cross calves were divided into three groups. The first group was inoculated with bovid herpersvirus 1 (Strain 108), the second with a commercial intranasal vaccine against bovid herpesvirus 1 and the third group acted as controls. At least three weeks after vaccination, all calves were weaned, placed in an environmental chamber at 25.0 degrees C (days) and -13.3 degrees C (nights) and challenged with an aerosol of bovid herpesvirus 1 followed four days later by an aerosol of Pasteurella haemolytica. All surviving calves were sacrificed four days after the second aerosol. None of the calves inoculated with bovid herpesvirus 1 virus or the commercial vaccine developed a generalized pneumonia, although there were one or two nodules (4--8 mm diameter) in two of the calves given the commercial vaccine. Four of the five control calves had extensive lobar pneumonia at necropsy, two of the five died from the disease. Details of the clinical, pathological, bacteriological, virological and some of the serological findings are reported.