Managing the lactating sow for optimal weaning and rebreeding performance.

Management of the lactating sow influences milk production and subsequent reproduction through changes in nutrient intake. The management goal during lactation is to maximize feed intake. Decreasing the effective environmental temperature, increasing the nutrient density of the lactation diet, maintaining fresh adequate supplies of feed and water, and preventing excess weight gain during the prior gestation period will increase nutrient intake during lactation. Effective environmental temperature of the lactating sow can be maintained in the thermoneutral zone by using drip cooling, increased ventilation rates and flooring materials with superior conductive properties. Sow parity, genetics, litter size, and disease level will also influence feed intake. Management practices must account for these factors and, thus, should be tailored to individual farm situations to ensure adequate nutrient intake and prevent aberrations in subsequent reproductive performance.     

Analysis of a Long-term Experiment with Repeated-measurement Models

Long‐term experiments are a classical case of repeated measurements. Traits are measured on the same experimental unit over many years so that correlations arise between the observations made on the same plot in consecutive years. This paper describes the analysis of a three‐crop‐rotation long‐term experiment. We analysed the yields of the crops and the organic carbon content in the topsoil over 30 consecutive years. Several variance–covariance approaches are discussed and the trait‐specific best fit is interpreted. Mixed models are used to describe the structure of the experiment. Both yields and soil organic carbon show a more or less pronounced variance heterogeneity. Especially for yields, the heterogeneity of cycles and years is dominant. The consideration of correlations results in a better model fit in all cases.     

Marketing dairy practice

Marketing to veterinarians is the process of synchronizing the business aspects of his or her goods and services so that they are understood and desired by animal owners. The basic components of a successful marketing program are in four categories: the individual, the situation, the needs, and the implementation. Each category is important and all are interrelated; however, the implementation of a program should not begin until a self-analysis has been done and the situation and its needs are thoroughly researched. Programs that have been used by successful practitioners can be copied. No program can be effective unless the economic status of the client's enterprise is known and understood.     

Effect of folic acid supplements on homocysteine concentration in plasma of gestating sows.

An experiment comprising 19 German Landrace sows was established to evaluate the effect of folic acid supplements (10 mg/kg concentrate) on homocysteine and folic acid concentration in plasma and serum, respectively, of highly pregnant sows as compared to an unsupplemented control (basal diet contained 0.62 mg folic acid/kg concentrate). Blood samples were taken between day 75 and 110 of gestation for homocysteine analysis and on day 100 of gestation for folic acid determination. Due to the folic acid supplements serum folic acid concentration increased significantly (104 nmol/l in controls and 140 nmol/l in supplemented sows). In contrast, homocysteine concentration in the plasma was not significantly influenced by folic acid supplements (16.6 mumol/l in controls and 15.2 mumol/l in supplemented sows). Further investigations seem to be necessary to clarify the physiology of homocysteine metabolism in swine.     

Host serum proteins in Taenia saginata metacestode fluid

Taenia saginata cyst fluid was examined for host proteins; IgG1 and IgG2 as well as haemolytic complement activity were detected. Polyacrylamide gel electrophoresis revealed differences in proteinograms among the samples taken from 1-, 4-, and 10-month old cysts. Fluid from older cysts had fewer protein components and showed a weaker antigenic reaction with sera of bovines infected with T. saginata than that of younger cysts. The roles of antibody and complement in initiating degeneration of the parasite are discussed.     

Patterns of silver eel (Anguilla anguilla L.) sex ratio in a catchment

Abstract –  Changes in the numbers and size-class structure of European silver eels, Anguilla anguilla , in the River Frémur (France) were examined over a 9-year period after installation of downstream eel passes. The number of silver eels migrating downstream peaked in 1999, then decreased strongly and steadily after 2000, reaching relatively low levels. At the same time, a gradual shift in the silver eel sex ratio from a dominance of males (size from 270 to 442 mm, age from 3 to 6 years) to females (size from 366 to 1112 mm, age from 4 to 9 years) was recorded. Possible explanations for the escapement patterns observed are environmental sex determination and the installation of eel passes on the main hydraulic engineering structures in 1992 and 1996.