Longevity of breeding sows in relation to leg weakness symptoms at six months of age

The objective of this study was to evaluate the influence of leg weakness symptoms measured early in life (at 6 months of age) on the longevity of the sows, i.e. the age at culling due to locomotory problems in a Danish pig herd. One hundred and eighty-seven gilts at 6 months of age were selected according to different leg weakness symptoms and were followed until culling and judged for leg weakness once in every gestation using a scale from 1 (normal) to 4 (severe changes). Age at culling, and the main and secondary reasons for culling were recorded. The influence of leg weakness symptoms on longevity was evaluated by survival analysis. Though only 12% of the gilts showed a stiff locomotion half of the sows had suffered from this and nearly one third had been distinctly lame at some time in their life. Buck-kneed forelegs, upright pasterns, legs turned out, standing under position and swaying hindquarters were associated with stiff locomotion or lameness, whereas weak pasterns on hind legs and splayed digits on forelegs were associated with brisk movement (freedom from locomotor problems). The following leg weakness symptoms at the gilt stage were found to have significant negative effects on longevity: buck-kneed forelegs, swaying hindquarters, and standing under position on hind legs.     

Nitrogenous constituents in plasma of foals weaned at three, four or six months of age

A study was conducted to measure the nitrogenous constituents in the blood of foals weaned at 3, 4 or 6 months of age (four foals per weaning age).Jugular blood was sampled from one week prior to weaning until one month post-weaning, and was analyzed for total protein, albumin, creatinine, urea Nitrogen and free amino acid content. Results indicated that the concentrations of most of the constituents in the blood of foals were not altered by the age of weaning, however, free amino acids decreased as age at weaning increased and creatinine was significantly higher in foals weaned at 6 months of age. Plasma creatinine, lysine and methionine levels generally decreased between pre-weaning and one month post-weaning. These data establish baseline values for blood nitrogenous constituents in foals at weaning.     

Comparison of biochemical parameters in the blood of healthy and diseased calves in a large barn

In a high-capacity calf-house, twenty-one calves were subjected to repeated clinical and biochemical examination until they were 22 weeks old. For evaluating the health condition of the animals, the calves were divided into two groups, one including healthy animals and the other including those suffering from bronchopneumonia and diarrhoea as the most frequent disorders in high-capacity calf-houses. From four to eight weeks of age, both groups of calves showed low levels of plasma magnesium and iron. The levels of plasma zinc and copper showed a continuous decrease with age. Compared with the healthy calves, the animals affected by a disease had statistically significantly lower levels of plasma vitamins (A, E, C). Further, the diseased animals also showed statistically significantly decreased levels of plasma glucose, serum albumins, and a lower activity of alkaline phosphatase in plasma. In addition to this, the diseased animals also had significantly higher levels of plasma gamma-globulins and urea. These clinico-biochemical parameters can be used for determining the subclinical forms of disease, for objective diagnosis and for the introduction of preventive measures in high-capacity calf-house.     

Phagocytic activity of blood leukocytes in calves from birth to 3 months of age

Forty-three calves of various age from the day of birth to the age of three months were subjected to the 2-hydroxyethylmethacrylate (HEMA) particle phagocytosis test. Significant differences in the phagocytic activity of blood leucocytes were recorded, all depending on age. New-born calves had very low phagocytic activity: only 16.5% of the leucocytes were found to be phagocytic, the phagocytic index being 0.39. A rapid increase in phagocytic activity was recorded during the subsequent days. At the age of three days 43% of the leucocytes of the calves were phagocytic. A decrease in phagocytic activity was found on the sixth to seventh day, and another increase was recorded only from the age of three to four weeks of age. No such changes in the development of phagocytic activity were observed in the calves reared without colostrum administration. Low values were maintained for a longer time after birth without the typical increase on the third to fifth day. Phagocytic activity increased in the zero-colostrum calves experimentally infected with rotavirus.     

Factors associated with morbidity,mortality, and growth of dairy heifer calves up to 3 months of age

Calfhood disease is an important problem on many dairy operations that can have substantial effects on heifer survival and productivity, and has economic and welfare impacts. Neonatal calf diarrhea (NCD) and bovine respiratory disease (BRD) are the most common causes of morbidity and mortality in young dairy cattle. The objective of this observational study was to investigate factors associated with the risks of morbidity and mortality, and with growth, in commercial dairy heifers calves. A total of 2874 heifer calves from 19 commercial dairy farms in Minnesota and Ontario were enrolled at 1–7 days of age and followed for approximately 3 months. Using cut-points of serum total protein of 5.2 and 5.7 g/dl, the incidences of failure of transfer of passive immunity (FTPI) were 11 and 32%, respectively. A cut-point of 5.7 g/dl was the most predictive of BRD before 5 weeks of age (sensitivity = 40%, specificity = 69%). The positive predictive value was poor (PPV = 18%), but the negative predictive value was good (NPV = 87%). A cut-point of 5.2 g/dl was most predictive of death before 5 weeks of age (sensitivity = 27%, specificity = 89%, PPV = 5%, NPV = 98%). Serum total protein during the first week of life was a poor predictor of NCD. Over 23% of calves were treated for diarrhea. Risk factors were weight at enrollment, other diseases before 2 weeks of age, and an interaction between season of birth and herd-level incidence of NCD. Almost 22% of calves were treated at least once for BRD. Factors associated with an increased risk of BRD included herd-level incidence of BRD, season of birth, navel dipping, other diseases before 2 weeks of age, failure of transfer of passive immunity, and manual control of temperature in pre-weaning housing. Administration of supplemental antibody products at birth was associated with a reduced incidence of BRD. Overall mortality was 3.5%. Risk of mortality was increased by treatment for BRD and other diseases. The mean average weight gain was 0.95 kg/day (range: 0.11–1.62 kg/day; SD = 0.2). Twinning status, FTP, treatment for NCD or other diseases, and month of birth influenced body weight. This study illustrated relationships among various diseases, mortality, and growth. Furthermore, it demonstrated the importance of colostrum for protection against BRD and improved growth performance, while bringing into question the optimal method of determining failure of transfer of passive immunity.     

不同生理阶段犊牛赖、蛋、苏氨酸平衡模式研究

应用部分扣除饲粮氨基酸(AA)的氮平衡试验法研究了中国荷斯坦犊牛不同生理阶段(2～3周龄和5～6周龄)赖(Lys)、蛋(Met)、苏氨酸(Thr)平衡模式。每个阶段各用12头犊牛进行N平衡试验。每个N平衡试验均设4个处理组,即氨基酸相对平衡的代乳品(PC)组(赖氨酸、蛋氨酸、苏氨酸含量依次为2.34%、0.72%、1.80%)、在PC基础上轮流将赖、蛋、苏氨酸扣除30%的其它3种代乳品(分别为PC-Lys、PC-Met、PC-Thr)组。每个处理设3个重复,每个重复1头牛。所有代乳品等能(17.8MJ/kg)等蛋白(22%)。试验结果表明,按单位代谢体重的N沉积与氨基酸摄入量计算,中国荷斯坦犊牛2～3周龄日粮模式为代乳品时,Lys、Met、Thr的平衡比例100:29:70;5～6周龄日粮模式为代乳品、开食料和羊草时,平衡比例为100:30:60;两阶段3种氨基酸的限制性顺序均为Lys、Met、Thr。     

Occurrence of mammary neoplasms in bitches in relation to breed, age, tumour type, and geographical region from which reported

Of 2075 mammary neoplasms in bitches reported by 14 veterinary schools in the United States and Canada, 1187 were histologically malignant, 557 were benign, and 331 were in the 'malignancy not determined' category. There were 12 breeds at significantly high risk for one or more of the major mammary tumour types; 7 of the 12 were hunting breeds. Mixed breeds were at low risk for all tumour types and categories, and collies were at low risk for benign neoplasms. Neutered bitches were only one-third as likely to have neoplasms as were entire bitches. There was no clear difference in distribution of the various tumour types in relation to age at first diagnosis. Among the four geographical regions studied separately, there were more similarities than differences in the rates of mammary neoplasms, especially when adenocarcinomas and malignant mixed mammary tumours were combined for analyses. There was, however, a marked excess of benign neoplasms in the south and west of North America.     

Absence of limiting amino acids in calves fed a corn and soybean meal diet past three months of age

We conducted three nitrogen balance trials using Holstein bull calves older than 16 wk (Trial 1; n = 8), 13 wk (Trial 2; n = 6), and 15 wk of age (Trial 3; n = 9) in a 4 x 4 (Trial 1) or 3 x 3 Latin square design (Trials 2 and 3) to identify limiting amino acids for a corn and soybean meal diet. All calves were trained to maintain reflex closure of the reticular groove after weaning at 5 wk of age. The basal diet was fed daily at 20 or 27 g/kg BW (Trial 1) and at 20 g/kg BW (Trials 2 and 3). The lower feeding level resulted in reduced urinary excretion of purine derivatives, suggesting reduced synthesis of ruminal microbial protein (Trial 1). In Trials 1 and 2, administration of DL-methionine plus L-lysine monohydrochloride through the reticular groove did not increase N retention compared with the supplement of isonitrogenous L-glutamine at either level of intake. In Trial 3, administration of either casein or isonitrogenous monosodium glutamate increased N retention to a similar extent above that observed with a N-free supplement. Results suggested that no specific amino acids were limiting for the corn-soybean meal diet. Administration of methionine plus lysine resulted in a remarkable increase in plasma methionine (Trials 1 and 2), especially at the lower intake level (Trial 1), and a decrease in plasma branched-chain amino acids at either intake level. Glutamine supplementation did not increase plasma branched-chain amino acids compared with the supplementation of diammonium citrate (Trial 2).     

Vaccine immune response and interference of colostral antibodies in calves vaccinated against rabies at 2, 4 and 6 months of age born from antirabies revaccinated females

Considering the high prevalence of rabies in cattle, we aimed to evaluate the interference of colostral antibodies transferred to calves after birth and the benefit of administering an antirabies vaccination in two-month-old calves compared to vaccinating at 4 and 6 months of age. Calves born from females revaccinated against rabies during the third trimester of pregnancy were studied. Forty-eight hours after parturition, blood samples from dams and offspring were collected, and antirabies neutralizing antibody titers were analyzed using the Rapid Focus Fluorescent Inhibition Test. We found that all calves had similar titers of antibodies transferred through the colostrum. Furthermore, none of the calves presented a satisfactory serological response after the first vaccination, but all had an appropriate response after revaccination. This study demonstrates that antirabies vaccination should be recommended for calves at two months of age in endemic and epizootic situations.     

The ontogeny of the somatotropic axis in male and female Hereford calves from birth to one year of age

Insulin-like growth factor-binding proteins-2 and -3 may play a role in age-dependent growth response to bovine ST (bST) treatment in cattle; however, samples have been collected at infrequent intervals and at limited time points. Therefore, the objective of this experiment was to examine the ontogeny of components of the somatotropic axis in Hereford calves from birth to 1 yr of age at weekly intervals to determine whether there is a certain age or time frame when the somatotropic axis may change and/or potentially become more responsive to exogenous bST administration. Blood samples and body weight measurements were collected from eight male and eight female Hereford calves once per week from birth to 1 yr of age. Serum concentrations of ST, IGF-I, IGFBP-2, and IGFBP-3 were determined. Males began to grow faster than females at approximately 16 wk of age (P < 0.05). Average concentrations of ST, IGF-I, and IGFBP-3 were greater in males than females (P < 0.01). Average concentrations of IGFBP-2 were greater in females than in males (P = 0.05). Concentrations of ST decrease with age (P < 0.01); however, the decrease occurred earlier in female calves. Concentrations of IGF-I and IGFBP-3 increased in males and females (P < 0.01), and concentrations of IGF-I began to plateau at approximately the same time as growth rate differences were observed (16 wk of age). Following an initial increase (birth to approximately 16 wk of age), concentrations of IGFBP-3 remained constant until approximately 43 wk of age. Concentrations of IGFBP-2 increased to approximately 10 wk of age (P < 0.05), followed by a decrease, and then, similar to IGFBP-3, remained constant until 43 wk of age. Correlations between average daily gain, ST, IGF-I, IGFBP-2, and IGFBP-3 were determined. Average daily gain was negatively (P < 0.01) correlated with ST and positively (P < 0.1) correlated with IGF-I. In females, ST was negatively (P < 0.01) correlated with IGF-I. Concentrations of ST were positively correlated (P < 0.01) with IGFBP-2 and IGFBP-3. Concentrations of IGFBP-2 were negatively correlated (P < 0.01) with IGF-I and positively correlated (P < 0.01) with IGFBP-3. In conclusion, serum concentrations of ST, IGF-I, IGFBP-2, and IGFBP-3 differed between male and fe-male calves. In addition, changes in components of the somatotropic axis occurred around the same time as males began to grow faster than females.     

The effect of age at weaning on the health status of bull calves in a feedlot

Incidence of morbidity and mortality in a feedlot were compared among 381 bull calves weaned one month apart (October 3 and November 1). The calves were 156 and 192 days old at weaning in the earlier and later weaned groups, respectively. Following an adjustment period, the calves were fed a mixed finishing diet containing 90% concentrate ad lib for 140 days in a feedlot. The rate of morbidity did not differ significantly between the two weaning groups. Sick calves in the earlier weaned group had a longer treatment period than those in the later weaned group (3.2 vs 1.4 days, p<0.05). Infections of the respiratory tract were the major cause of sickness and most of the respiratory infections occurred in the early stages of the feedlot period. The frequency of respiratory infections was higher among the earlier weaned calves compared with that in the later weaned group (p<0.01) indicating a higher susceptibility to these infections when calves were weaned at younger ages. Bloat was the second most common health problem among the bulls; however, its incidence did not differ between the two groups (p>0.05). The rate of mortality did not differ significantly between the two groups.     

Attempt to estimate the share of human Salmonella infections, which are attributable to Salmonella originating from swine]

On the basis of the data obtained in 1996 and 1997 in Germany on the frequency of detection of Salmonella and also of single Salmonella serovars in foods and infected humans, attempts were made to assess the relevance of Salmonella from swine as a source of human infection. Four assumptions considered as reasonable were made concerning the development of human salmonellosis. On the basis of these assumptions, a model for the estimation of the share of human Salmonella infections attributable to the swine population is proposed. According to this, ca. 20% of human cases of salmonellosis have been caused by Salmonella originating from swine.     

Utilization of bioelectrical impedance to predict carcass composition of Holstein steers at 3, 6, 9, and 12 months of age

The objective of this experiment was to study the usefulness of bioelectrical impedance analysis (BIA) in determining soft tissue composition (STC) and carcass fat-free mass (CFFM) of Holstein steers at different ages. Growth data and prediction of STC and CFFM were determined for four groups of Holstein steers: 12 of 3 mo, 12 of 6 mo, 15 of 9 mo, and 16 of 12 mo of age. Average weight for animals at 3, 6, 9, and 12 mo were 96.6, 204.7, 354.1, and 465.9 kg, respectively. Average fat content of carcass soft tissue at 3, 6, 9, and 12 mo were 2.6, 9.8, 18.2, and 24.6%, respectively. Average protein content of the carcass soft tissue was 20.7% at 3 mo, 20% at 6 mo, 18.30% at 9 mo, and 16.9% at 12 mo of age. Feed and water were withheld for 20 h before the BIA was applied. Steers were sedated and forced to recumbency in a lateral position on their right sides over a nonconductive surface. Two electrodes were placed on each limb of the right side (metatarsal and metacarpal regions on back and front foot, respectively). Resistance (Rs) and reactance (Xc) were obtained by attaching four terminals to the electrodes. Impedance and other predictors such as Vol1 (L/Rs), Vol2 (L2/(RS2+Xc2).5, Vol3 (geometrical animal volume), L (2 x height + body length), and L2 were calculated from Rs and Xc, and body measurements and were used to generate prediction equations for CFFM and carcass soft tissue composition. Carcass fat-free mass was predicted accurately for all age groups and the pooled data (r2 = .99 at 3 mo, .99 at 6 mo, .97 at 9 mo, .77 at 12 mo, and .98 for the pooled data). Correlation coefficients between impedance readings and CFFM and carcass composition were calculated. Carcass CFFM and kilograms of H2O for the pooled data (across age groups) were both correlated highly to Vol1 (.97), Vol2 (.95), L (.97), and L2 (.97).     

Relationships between body weight and bone length at one day and at six weeks of age in male turkeys fed on adequate and low protein starter diets

Male turkey poults were fed on diets containing either adequate (29%) or inadequate (20%) amounts of crude protein from 1 d to 6 weeks of age. Each bird was weighed and the length of its lower‐leg measured at 1 d and at 6 weeks of age.

The initial body weight of adequately‐fed turkeys bore little or no relationship to 6‐week body weight. Length of lower‐leg at 1 d gave a more reliable prediction of body weight ranking at 6 weeks. In contrast initial body weight was more reliable than initial bone length in predicting body weight ranking at 6 weeks when the low‐protein diet was fed.     

The proportion of beef bulls in western Canada with mature spermiograms at 11 to 15 months of age

A study was conducted to determine the proportion of yearling beef bulls that have mature spermiograms at 11 to 15 months of age, and to evaluate the relationship between semen quality traits, age, and scrotal circumference. Semen samples and data on sperm motility and scrotal circumference measurements were obtained from 1641 bulls of 14 breeds. Criteria for a satisfactory spermiogram included sperm concentration > or = 400 x 10(6)/mL, > or = 60% progressively motile sperm, and > or = 70% morphologically normal sperm. The mean scrotal circumference measurements for all bulls combined were 33.4, 34.4, 35.2, 35.8, and 35.3 cm at 11, 12, 13, 14, and 15 months of age, respectively. The percentage of bulls with matures spermiograms at 11, 12, 13, 14, and 15 months of age were 20%, 30%, 51%, 52%, and 61%, respectively. There was a high positive correlation (r = 0.9) between the number of bulls with > or = 70% normal sperm and scrotal circumference measurement. The main types of morphologic defects observed in immature bulls were proximal droplets and midpiece defects.     

Microcytosis, hypoferremia, hypoferritemia, and hypertransferrinemia in standardbred foals from birth to 4 months of age

At birth, 24 Standardbred foals were assigned at random to 1 of 2 groups and were given a placebo supplement (group 1) or an iron supplement (248 mg of iron/treatment; group 2). Foals were given iron supplement or placebo 4 times during the second and third weeks after birth. Hematologic variables and general health were monitored until foals were 4 months old. Mean PCV in foals of both groups decreased during the first 2 weeks after birth, but values remained within adult horse reference ranges. During the first 6 weeks after birth, foal erythrocytes were smaller than adult horse erythrocytes, but foal erythrocyte glucose-6-phosphate dehydrogenase activity was greater than that in adult horses. At every measurement, indices of anisocytosis were lower in foals, compared with adult horse reference values, suggesting that foals have a homogeneous population of microcytic erythrocytes during early foalhood. In 2-week-old foals of both groups and in 4-week-old placebo-treated foals, mean serum iron concentration was lower than that in adult horses. In foals at birth and during the first 4 months, total iron-binding capacity values were above the adult reference range. In newborn foals, transferrin saturation percentage values decreased to below the reference range in foals from 2 weeks to 4 months after birth. When foals were born, serum ferritin concentration values were above the adult horse reference range, but decreased to within the reference range by the time foals were 1 day old. From 2 through 6 weeks after birth, foal ferritin concentration values were below the adult reference range.(ABSTRACT TRUNCATED AT 250 WORDS)     

The ontogeny of the somatotropic axis in Hereford calves from birth to one year of age and its response to administration of exogenous bovine somatotropin

Administration of exogenous bovine ST (bST) increases growth rate, feed efficiency, and carcass quality in beef cattle. The magnitude of response to bST in beef cattle is variable and related to the age of the animal. Our objective was to determine the response of the somatotropic axis, in particular IGF-I, IGFBP-2, and IGFBP-3, to bST treatment from birth to 1 yr of age. Blood samples were collected before and after a single injection of bST (500 mg) every 50 d from birth to 1 yr of age in male and female Hereford calves. Body weights and serum concentrations of ST, IGF-I, IGFBP-2, and IGFBP-3 were determined. At birth, serum concentrations of ST, IGF-I, and IGFBP-3 increased (P < 0.05) following bST treatment. From 50 to 350 d of age, average concentrations of ST and IGF-I were greater (P < 0.05) in males, whereas IGFBP-2 concentrations were greater (P < 0.05) in females. No gender differences in IGFBP-3 concentrations were observed. Following bST treatment, IGF-I increased (P < 0.05) from 50 to 350 d of age, IGFBP-2 decreased (P < 0.05) from 50 to 200 d of age, and IGFBP-3 increased (P < 0.05) at 250 d of age. At 250 d of age, baseline concentrations of IGFBP-2 decreased (P < 0.05). Due to the positive response of IGFBP-3 and decreased baseline IGFBP-2 at 250 d of age, we conclude that this is an age at which the somatotropic axis is most responsive to exogenous bST, and it therefore may be an appropriate age to begin bST treatment in beef calves to realize the positive influence of bST on BW gain, feed efficiency, and carcass composition.