Relationships among intramammary health,udder and teat characteristics,and productivity of extensively managed ewes

Mastitis is an economically important disease and its subclinical state is difficult to diagnose, which makes mitigation more challenging. The objectives of this study were to screen clinically healthy ewes in order to 1) identify cultivable microbial species in milk, 2) evaluate somatic cell count (SCC) thresholds associated with intramammary infection, and 3) estimate relationships between udder and teat morphometric traits, SCC, and ewe productivity. Milk was collected from two flocks in early (<5 d) and peak (30 to 45 d) lactation to quantify SCC (n = 530) and numerate cultivable microbial species by culture-based isolation followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS; n = 243) identification. Within flock and lactation stage, 11% to 74% (mean = 36%) of samples were culture positive. More than 50 unique identifications were classified by MALDI-TOF MS analysis, and Bacillus licheniformis (18% to 27%), Micrococcus flavus (25%), Bacillus amyloliquefaciens (7% to 18%), and Staphylococcus epidermidis (26%) were among the most common within flock and across lactation stage. Optimum SCC thresholds to identify culture-positive samples ranged from 175 × 10³ to 1,675 × 10³ cells/mL. Ewe productivity was assessed as total 120-d adjusted litter weight (LW120) and analyzed within flock with breed, parity, year, and the linear covariate of log₁₀ SCC (LSCC) at early or peak lactation. Although dependent on lactation stage and year, each 1-unit increase in LSCC (e.g., an increase in SCC from 100 × 10³ to 1,000 × 10³ cells/mL) was predicted to decrease LW120 between 9.5 and 16.1 kg when significant. Udder and teat traits included udder circumference, teat length, teat placement, and degree of separation of the udder halves. Correlations between traits were generally low to moderate within and across lactation stage and most were not consistently predictive of ewe LSCC. Overall, the frequencies of bacteria-positive milk samples indicated that subclinical mastitis (SCM) is common in these flocks and can impact ewe productivity. Therefore, future research is warranted to investigate pathways and timing of microbial invasion, genomic regions associated with susceptibility, and husbandry to mitigate the impact of SCM in extensively managed ewes.     

Effect of calf weaning age and cow supplementation on cow productivity

Five years of data were collected on 124 Brangus-type cows to evaluate weaning calves at 8.5 or 10.5 mo of age and winter supplementation of the brood cow with 2.25 kg of molasses daily. Cows with calves weaned at 10.5 mg of age gained 14 kg less weight (P less than .01) during the late nursing period than did cows from which calves were earlier weaned. Age of calf at weaning had no effect on cow reproduction, but calves weaned at 10.5 mo were 2 to 3 d younger (P less than .06) and 5.3 kg lighter (P less than .05) at 8.5 mo of age. During the last 2 mo of nursing, calves weaned at 10.5 mo of age gained 37.2 kg and had a 31.9-kg heavier weaning weight than calves weaned at 8.5 mo of age. Molasses supplementation resulted in differences (P less than .01) in cow weight changes. Cows fed molasses had calving percentages 5 to 7 units higher (P less than .30) than cows not fed molasses. Feeding cows molasses for 145 d throughout the calving and breeding season increased calf weaning weight 7.7 (P less than .02) and 11.2 (P less than .03) kg, respectively, at 8.5 and 10.5 mo of age over the nonsupplemented controls.     

Inflammatory reactions in the teat and udder of the dry cow

The inflammatory reactions in the teat and udder of the dry cow were studied by total and differential somatic cell counts (SCC) and by measuring bovine serum albumin, N-acetyl-beta-D-glucosaminidase (NAGase), plasminogen and plasmin. The teat and udder cisterns were surgically separated from each other in two udder quarters of each cow. Salmonella endotoxin was infused in one teat cistern and one udder quarter, and saline was infused in one teat cistern and one udder quarter. The inflammatory response was followed by several samplings post infusion. The reactions in the dry udder quarters were mainly in line with the results of similar studies in lactating glands. The differential SCC and the NAGase results were, however, somewhat different. The teats were capable of a strong inflammatory response. Reactions different from those seen in the glands were observed with regard to permeability changes and NAGase. The experimental model used showed promising results and is suitable for further studies of the inflammatory process.     

奶牛产奶性能与乳房性状的相关分析

本文对南京市栖霞区个体农户饲养的 40 0头荷斯坦奶牛的悬韧带、后乳房宽度、后乳房高度、乳头长与奶牛的产奶量和乳脂率进行了相关分析 ,数据应用MicrosoftExcel进行计算分析。结果表明 :后乳房宽度和悬韧带均与产奶量呈强正相关 ,与乳脂率呈中等强度的负相关 ;后乳房高度与产奶量呈中等强度的负相关 ,与乳脂率呈弱正相关 ;乳头长与产奶量呈弱正相关 ,与乳脂率呈弱负相关     

Twinning in cattle: III. Effects of twinning on dystocia, reproductive traits, calf survival, calf growth and cow productivity

An evaluation of natural twinning in beef cattle revealed that cows birthing twins had shorter (P less than .01) gestation lengths, more (P less than .01) retained placentas, more (P less than .01) dystocia, more (P less than .01) days to estrus, lower (P less than .01) conception rates and more (P less than .01) days to pregnancy than cows birthing singles. Days to estrus, conception rate and days to pregnancy were not affected by number of calves reared (1 vs 2) in cows birthing twins. Survival at birth was greater (P less than .01) for single- than for twin-born calves, but twins and singles did not differ (P greater than .05) in postnatal survival. When dystocia was experienced, calf survival at birth was 95% vs 73% for singles vs twins compared with 99% vs 92% when no dystocia was experienced. Calves born twins were lighter (P less than .01) at birth, 100 d and 200 d, but twins and singles did not differ in postweaning gains. Total calf weights at 100 d per cow calving were 12% greater (P less than .01) in cows birthing twins vs singles when twin calves reared by foster dams were excluded. The potential increase in cow productivity for total calf weight at 100 d is 40% if calf survival rates of twins with dystocia relative to survival rates of twins without dystocia were comparable to survival rates of singles with and without dystocia, and if cows birthing twins were fed and managed to obtain conception rates equal to those of cows birthing singles. Identification of cows gestating twins to provide for their higher prepartum nutritive requirements and calving assistance at parturition is necessary to make twinning in cattle an economically viable technology.     

新疆褐牛导入美国瑞士褐牛后代犊牛放牧补饲试验

[目的]研究新疆褐牛导入杂交后代在不同生产方式下的生产性能与适应性.[方法]选择美新褐杂交F1代、F2代犊牛68头,并按品种类型、性别随机分为2组,试验组为放牧补饲生产,对照组为天然放牧生产.[结果]表明:美新褐牛F1代、F2代犊牛试验组与对照组相比日增重显著(P＜0.05),试验组F1代较F2代公牛日增重提高10％,...     

Immunoglobulins, lysozyme and lactoferrin in the teat and udder of the dry cow during endotoxin-induced inflammation.

Immunoglobulins (Ig) and antibacterial proteins like lysozyme and lactoferrin are components of the humoral defence against infections. Changes in Ig, lysozyme and lactoferrin concentrations during endotoxin-induced inflammation in the test cistern and udder quarter of the dry cow were studied. Surgical closure of the passage between teat and udder cisterns enabled studies of reactions in the teat cistern without interference of the mammary gland. After endotoxin infusion, IgG1, IgG2, lysozyme, and to some extent IgM, increased in the teats and udder quarters, and were positively correlated with changes in somatic cell counts. No significant changes were observed in IgA or lactoferrin. The origin and significance of Ig, lysozyme and lactoferrin in the bovine teat and udder are discussed. Ig probably originated both from serum and from local plasma cells, while leukocytes appeared to be the source of lysozyme during inflammation. Secretory epithelium appeared to be the source of lactoferrin. Support for this theory was the almost total absence of lactoferrin in teat cistern samples.     

Creep grazing and early weaning effects on cow and calf productivity

One hundred fifty Simmental-Hereford cows and calves were used in a 3-yr study to evaluate three creep grazing treatments and an early weaning treatment on cow and calf performance during midsummer (July to September). Calves were approximately 150 d of age and averaged 178.6 kg when treatments were initiated. Tifleaf pearl millet (Pennisetum Americanum L. Leeke) was used as the forage for two of the creep treatments, representing two cow stocking intensities of .466 (TLM1) and .239 (TLM2) ha of base hill land pasture/cow, and as pasture for early weaned calves. A red clover (Trifolium pratense L.)-Kentucky bluegrass (Poa pratensis L.) mixture was used as the other creep forage. Hill land pastures were similar for the mature cow units in all creep treatments. Calf average daily gains ranged from .93 to 1.10 kg and were not influenced (P greater than .05) by treatment. Calf gains per hectare were similar for the control, red clover and TLM1 treatments. The TLM2 and early weaning treatments resulted in increases of 105.4 and 39.1 kg of calf gain/ha (P less than .05) compared with the control. When calves were allowed to creep graze millet, decreasing the forage area from .466 to .239 ha per cow-calf unit resulted in an increase of 97.7 kg of calf gain/ha with no reduction in calf gain. Cows on the more intensively grazed millet creep treatment (TLM2) lost more weight (P less than .05) during midsummer than those on the TLM1 treatment, but they gained 18.5 kg more (P less than .10) weight than TLM1 cows between weaning and the start of winter feeding.     

Effects of a two-year dairy herd health management programme on udder health, use of antibiotics and longevity

Since 2003, the Research Institute of Organic Agriculture (FiBL) is realizing a herd health management programme ("pro-Q" project) focussing on udder health. The objectives of the project are: (1) to reduce antibiotic mastitis treatments, (2) to optimise udder health and (3) to improve longevity, measured as averaged number of herd lactations. The farms get expert advice in prevention and treatment on herd- and animal-level. After 2 years, treatment recordings of the 65 investigated farms showed that antibiotic mastitis therapies were reduced from 38 to 26 treatments per 100 cows and year (equals a reduction of 32%). Lactation numbers of the herds increased significantly by 0.2 lactations from 3.3 to 3.5 lactations per cow. Udder health remained constant over all farms during 2 years: theoretical bulk milk cell counts averaged constantly at around 180000 cells/ml. Improvement of udder health on farm level was significantly influenced by higher somatic cell count when the project started and enhanced by farmer's motivation and farm-veterinarians' commitment to the project.     

反刍动物母犊体系中营养与免疫的关系

现代营养学研究表明营养与免疫有着密切联系。营养物质不但为动物维持正常的生长发育所必需,而且是维持免疫系统的功能使免疫活性得到充分表达的决定性因素。现代畜牧业除从品种、饲料、管理等方面作研究改进外,应用免疫技术提高动物生产性能、改善胴体品质、提高饲料转化效率,     

Farmer awareness of cow longevity and implications for decision-making at farm level

The aim of this study was to investigate if farmer awareness of longevity can explain why the longevity of dairy cows does not increase in Sweden, despite the fact that the genetic trend for longevity in Swedish dairy cattle is positive. In this study, farmers’ decisions were put in the forefront through a qualitative study with semi-structured interviews. The results showed that farmers seemed well aware of biological factors related to cow longevity, that they think the demands on dairy cows have increased over time and that they correlate the higher demands to shorter longevity. However, the farmers had not worked explicitly with longevity of their own herd. There are subjective management decisions behind a culling of a dairy cow, and the reporting of culling reasons does not mirror the farmer’s reasoning behind the decisions, which is a key factor determining longevity.     

Productivity of different cow genotypes: culling rates and early calf performance

Records of Jersey-sired (Jx), Santa Gertrudis-sired (Sx), Charolais-sired (Cx) and straightbred Hereford (H) cows were examined to determine culling rates, birth dates, weaning weights and average daily gains of their first, second and third calves. Culling categories were defined on the basis of number of calves weaned before removal from the herd. Calf performance data were analyzed by cow breed group and cow culling category. A second-degree polynomial model fit the data of all breeds, and accounted for a greater proportion of variation in percentage culled than did the linear model (P less than .05). Total percentage culled through the study were 71, 67, 54 and 53 for the H, Sx, Cx and Jx cows, respectively. Culling rates in the H and Sx cows tended to be higher at earlier ages than in the Cx and Jx cows. Cow-culling category was a significant source of variation only on birth date of first calves. Cows culled after one calf had calves that were born later than cows in the other two categories (P less than .05). Birth date, weaning weight and average daily gain of first calves varied with cow breed in that Jx cows had calves that were born earlier, gained faster and weaned heavier than first calves from the other breed groups (P less than .05). First calves from Sx and Cx cows gained faster (P less than .05) than calves from H cows.(ABSTRACT TRUNCATED AT 250 WORDS)     

Relationship between stress levels of the antepartum cow and her newborn calf

We investigated the relationship of the stress levels of the dam before and after delivery to that of her offspring soon after birth. Eight pregnant cows were penned 7 days before calving. Blood was taken from the jugular vein of cows at ?7, 1, 2 and 3 days from calving. Blood was also taken from newborn calves at 6 h and 1 and 2 days after birth. Concentrations of cortisol and immunoglobulin G in blood and colostrum were examined. Pearson's correlation coefficient showed that the higher the plasma cortisol concentration of a cow before calving, the higher that of its calf after birth (all P < 0.01). In addition, path analysis demonstrated that the direct effect of the plasma cortisol concentration of the dam before calving on the plasma cortisol concentration of her calf after birth was 0.971 (P < 0.01). However, the colostrum cortisol concentration correlated with neither plasma cortisol concentrations of cows before calving nor that of calves after birth. Unlike cortisol, a clear correlation of immunoglobulin G concentrations in plasma and colostrum was not observed between cows and calves. The results indicate stress is transferred from a cow to her newborn calf not by way of the colostrum but through the placenta.     

Age of calf at weaning of spring-calving beef cows and the effect on cow and calf performance and production economics

Over a 5-yr period, spring-calving cows were used in a carry-over design experiment to evaluate effects of calf age at weaning on cow and calf performance and production economics. Weaning management groups were early (n = 60, calf age 150 d, EW), traditional (n = 60, calf age 210 d, NW), and late (n = 60, calf age 270 d, LW). Cow body condition score (BCS) and weights at the last weaning date were different (P < .05) for EW (5.8, 583 kg), NW (5.5, 560 kg), and LW (5.2, 541 kg) management groups. Pregnancy rates among groups were similar. Days on feed for groups differed (P = .001) and was 247 for EW, 204 for NW, and 164 d for LW steers. Average daily gain in the feedlot differed (P = .01) among groups and averaged 1.5 kg for LW, 1.4 kg for NW, and 1.3 kg for EW steers. Dry matter intake while steers were in the feedlot was greater (P = .001) for LW than for NW and EW calves. Hot carcass weight was greater (P = .01) for EW (328 kg) and NW (332 kg) calves than for LW (321 kg) steers, and fat depth was greater (P = .05) for EW and NW steers than for LW steers. When carcass data for the NW and LW steers were adjusted to the fat depth of EW steers, carcass characteristics among groups were similar. Net income per steer at slaughter for the feedlot phase was greater (P < .001) for the EW ($75.36) and NW ($62.16) steers than for the LW ($10.09) steers. Again, when carcass data for the NW and LW steers were adjusted to the same fat depth of the EW steers, net income differences among groups were reduced. Replacement heifers were developed in a drylot and costs were higher (P < .001) for the EW than for NW and LW heifers. Annual cow costs were greater (P < .10) for the LW ($443.45) than for the EW ($410.09) and NW ($421.35) groups. Break-even for each system on a steer financial basis was not different between the NW and LW groups, and both the NW and LW groups had lower (P = .08) break-evens than the EW group. Age of the calf at weaning affects cow weight and BCS. Net income in each system is influenced by cow costs, month of the year that steer calves are purchased into the feedlot and finished steers are sold, month of the year cull cows are marketed, and replacement heifer development costs.     

Relationships between longevity,lifetime productivity,carcass traits and conformation in Polish maternal pig breeds

The objective of this study was to obtain heritability estimates for longevity (length of life, length of productive life, number of litters) and lifetime productivity traits (lifetime pig production, lifetime pig efficiency, lifetime litter efficiency) and genetic correlation between them and litter size at first farrowing, growth (ADG), backfat thickness (BF), loin depth, lean meat percentage (LMP), phenotypic selection index (PSI), and exterior in 19423 Polish Landrace (L) and 16049 Polish Large White (LW) sows. Heritabilities for longevity and lifetime productivity traits were 0.10–0.13 for L sows and 0.09–0.11 for LW sows depending on the trait definition. The genetic correlations among these traits were all high and positive, ranging from 0.76 to 0.99. Antagonistic genetic correlations (?0.21 to ?0.26) were found between longevity traits and PSI and LMP in LW sows, while in L sows the respective parameters were lower and not significant for length of productive life. The number of live‐born piglets in the first litter was positively correlated with lifetime pig production and lifetime pig efficiency in both breeds. The genetic correlations of longevity and lifetime pig production with ADG, BF, loin depth and exterior were small, and in most cases, not significant.     

Relationships between N'Dama cow body condition score and production performance under an extensive range management system in Southern Senegal: calf weight gain, milk production, probability of pregnancy, and juvenile mortality

This study aimed to determine the relationships between N'Dama cows body condition score (BCS) and (i) calf growth and the milk collected; and (ii) the probabilities of pregnancy and juvenile mortality. Animals from 10 herds ranging from 20 to 210 animals in herd size were followed monthly in an extensive range management system in Southern Senegal between 1993 and 1998. For daily weight gains and milk collected, linear mixed-effects models were fitted between calving and 6 months postpartum. Cow lactation was included as random effect, with an unstructured variance-covariance matrix. Calving season, parity, herd size, and calving BCS were the fixed effects. For the probabilities of pregnancy and juvenile mortality, survival models for grouped data were fitted on a monthly scale. The model selection was based on the Akaike information criteria. In large herds, calving BCS had little effect on milk production. In small herds, calves born to cows scoring ≥2.5 points at calving grew quicker and their dam were more milked. The relative difference in milk production between thin and fat cows averaged 23%. The relative gain was higher in the cool dry season than in the other seasons, and for primiparous than for multiparous cows. Except during the hot dry season, the probability of pregnancy was twice as high for cows scoring ≥2.5 points the two previous months than for other cows. The BCS had no effect on calf survival until 1 year of age in large herds. In small herds, calves born to thin cows at calving showed a survival at 1 year more than five points lower than calves born to fatter cows. The threshold of 2.5 points on a five-point scale is pertinent to describe the production performance of N'Dama cows in such a breeding context.     

Relationships between dairy cow mastitis and fertility management and farm performance

A field study was carried out on 38 dairy farms in the Netherlands to determine the relationship between mastitis and fertility management with 305-day milk production and gross margin. Questionnaires were used to get insight into the farmers' management. Out of 150 variables related to mastitis and fertility management, and technical and economic results, 44 variables were selected based on correlation of ≥0.25 or ≤−0.25 with milk production and/or gross margin. These variables were used in two separate partial least-squares (PLS) analyses. PLS has the advantage that it can handle a large number of variables in relation to the number of cases. The PLS-model of 305-day milk production had R² = 0.54 and showed a positive relation between 305-day milk production and awareness of the farmer regarding bulk somatic-cell count (BSCC), the goal level of the farmer for BSCC, and hygiene of the milking parlour. Fertility was negatively related to 305-day milk production, in spite of a relatively good fertility management on high-producing farms. R² = 0.46 for gross margin. The aspiration level of fertility did not seem to affect gross margin, but awareness of BSCC and calving interval (CI) had positive effects. Such awareness seemed a general parameter for good economic results, because it was correlated with different aspects of gross margin.