Skin Injuries on the Body and Thigh of Dairy Cows: Associations with Season,Claw Health,Disease Treatment,and other Cow Characteristics

An epidemiological study was conducted in 18 dairy herds with the objective to characterize those groups of cows where skin injuries to the body and thighs occurred most frequently. Data were analyzed with multivariable logistic regression. The epidemiologic patterns were different in first and later lactations. In first lactation some degree of injury occurred among 7.7% of 1793 cows. For most cows occurrence of sole ulcer was positively associated with injury while occurrence of heel horn erosion was negatively associated with injury. The association between injury and body weight differed depending on month of calving (significant interaction). Injuries occurred most frequently among high yielding cows. Severe reproductive, metabolic, and/or infectious diseases were associated with injuries. In later lactations some degree of injury occurred among 13.4% of 832 cows in lactations 2 to 9 where severity of injury increased with lactation number. Injuries occurred least frequently at examinations made in the January to March. They occurred most frequently among cows with sole ulcers. Calving in March through October was associated with injuries especially if the cows were treated for limb disorders. Most cases of injuries occurred early or late in lactation or among high or very low yielding cows in lactations 2 to 9.     

Investigations of barley stripe mosaic virus as a gene silencing vector in barley roots and in <Emphasis Type="Italic">Brachypodium distachyon</Emphasis> and oat

Background  

Gene silencing vectors based on Barley stripe mosaic virus (BSMV) are used extensively in cereals to study gene function, but nearly all studies have been limited to genes expressed in leaves of barley and wheat. However since many important aspects of plant biology are based on root-expressed genes we wanted to explore the potential of BSMV for silencing genes in root tissues. Furthermore, the newly completed genome sequence of the emerging cereal model species Brachypodium distachyon as well as the increasing amount of EST sequence information available for oat (Avena species) have created a need for tools to study gene function in these species.     

Protocol: using virus-induced gene silencing to study the arbuscular mycorrhizal symbiosis in <Emphasis Type="Italic">Pisum sativum</Emphasis>

Virus-induced gene silencing (VIGS) is an alternative reverse genetics tool for silencing of genes in some plants, which are difficult to transform. The pea early-browning virus (PEBV) has been developed as a VIGS vector and used in pea for functional analysis of several genes. However, the available PEBV-VIGS protocols are inadequate for studying genes involved in the symbiosis with arbuscular mycorrhizal fungi (AMF).     

Cofeeding of phospholipids to turbot Scophthalmus maximus L. larvae as a tool to reduce live food consumption

The possible benefits of feeding a formulated diet, together with Artemia , to first-feeding turbot larvae were investigated. Five dietary regimes were used: control ( Artemia only), cofeeding with a diet rich in phospholipid (PL) from bovine brain, cofeeding with a diet rich in free fatty acids (FFA) from the same source, cofeeding with a commercial diet (Lansy A2), and a formulated feed only (PL-rich diet). All treatments with artificial diets and the control treatment that received Artemia exclusively gave a similar survival rate of the fish at day 29. Cofeeding with artificial diets resulted in a lower growth rate than the control treatment. Cofeeding the larvae with PL-rich or FFA-rich diets did not affect the pigmentation or resistance to salt stress of the larvae. Complete substitution of Artemia by the phosholipid diets from day 20, however, resulted in severe stress and pigmentation problems. Cofeeding might have interesting features for application since it may reduce the amount and cost of live food and also offer to the fish larvae essential nutrients that are not contained in sufficient amounts in the (enriched) live food.     

Visual monitoring of reproduction in dairy herds

Two complementary approaches to produce visual information from reproduction records are described and exemplified. The Event Display shows all reproductive events, over a year, for all cows in a herd, by symbols placed in an array with columns representing calendar weeks and rows representing individual cows. The Reproduction Monitor consists of graphs of insemination and pregnancy rates evaluated weekly with a Bayesian technique. These visual monitoring tools are well suited to explore temporal variation in reproductive performance, they provide a quick overview of herd performance, and they provide information about individual animals.     

Crossbreeding experiment with beef and dual-purpose sire breeds on Danish dairy cows

The experimental design and objectives are outlined for a crossbreeding experiment with European beef breeds as sire breeds and RDM (Danish Red), SDM (Black Pied Danish) and Danish Jersey as dam breeds.Results from a calving survey of 1006 single calvings are presented. Gestation length, birth weight and calving performance were strongly influenced by breed of sire, breed of dam and sex of calf. The variation in gestation length seemed to have only a slight effect on birth weight. The variation in birth weight had a strong effect on calving performance.The ranking of the sire breeds in descending order according to the frequency of unasisted calvings (which varied from 70 to 26 percent) was as follows: Hereford, Limousin, Danish Red and White Cattle, Simmental, Blonde d'Aquitaine, Chianina, Charolais and Romagnola.     

Application of event time analysis to replacement, health and reproduction data in dairy cattle research

Life data statistical methods are proposed for the analysis of dairy cattle production data representing the time from one event to another. The Kaplan-Meier estimator of survival is described and its applications to dairy cattle data are exemplified with data sets of replacement times, time from calving to first case of mastitis and time from calving to first insemination. All data sets include censored data from cows for which the event had not been observed at the end of lactation or data collection period. A method for modifying replacement times to a standard calving interval is presented. A simple non-parametric test of homogeneity in two samples is described.     

Sugar beet waste and its component ferulic acid inhibits external mycelium of arbuscular mycorrhizal fungus

External arbuscular mycorrhiza (AM) mycelium plays an important role in soil while interacting with a range of biotic and abiotic factors. One example is the soil organic amendment sugar beet waste. The fermented Aspergillus niger-sugar beet waste (ASB) increases growth and P uptake by the AM mycelium in soil whereas non-fermented waste (SB) had a strong inhibitory effect. The underlying mechanisms are not understood.We used gas chromatography-mass spectrometry to identify differences in composition of water extracts of ASB and SB. The chromatograms showed that ferulic acid was present in SB and absent in ASB. We compared the effects of the water extracts of SB and ASB and ferulic acid upon the growth of Glomus intraradices in in vitro monoxenic cultures.Hyphal growth of the AM fungus G. intraradices was extremely reduced in ferulic acid and SB treatments. Moreover, AM hyphae appeared disorganized, undulated and tangled. In contrast, ASB increased hyphal length and numbers of branched absorbing structures and of spores. We conclude that ferulic acid is one compound in SB which is responsible for its inhibition of AM extraradical growth. The relevance of these findings is discussed.     

Hyphal growth from spores of the mycorrhizal fungus Glomus caledonius: Effect of amino acids

Hyphal growth from spores of Glomus caledonius (Nicol. and Gerd.) Trappe and Gerdemann was stimulated by cystine, glycine and lysine at optimum concentrations of 4.6, 556 and 825 mg l^?1 respectively. When all three amino acids were supplied together in water agar, five times more growth was obtained than in the controls.