Use of a crush-reducing device to decrease crushing of suckling piglets by sows.
Weanling pigs tend to avoid wind, and suckling piglets are thought to be more sensitive to wind than weanlings, owing to their thinner s.c. fat layer. We developed a crush-reducing device based on the anticipated behavior of suckling piglets toward wind and evaluated the performance of the device through field testing. The crush-reducing device consisted of six photo sensors, a controller, six solenoid valves, and an air compressor. In this study, 206 sows and their suckling piglets (Landrace xYorkshire) were investigated to ascertain the individual effects of several factors. Some of the newborn piglets were cross-fostered before the crush-reducing device was implemented. Litter weights were measured on d 0 and 4 to determine the influence of the crush-reducing device on the weights of suckling piglets. The crushing of suckling piglets by sows was affected by season (P < 0.01) and litter size (P < 0.05), but not by the parity of the sows; however, the number of crushed piglets per litter was less (P < 0.01) in the crush-reducing device group (0.05 +/- 0.02 crushed piglets/litter) than in the control group (0.23 +/- 0.04 crushed piglets/litter), regardless of litter size or season. The BW gain of suckling piglets did not differ between the control and the crush-reducing device groups. Based on these results, the crush-reducing device is expected to decrease the number of crushed piglets per litter without influencing the BW gain of suckling piglets, thereby greatly contributing to the productivity of pig breeders.
Towards qualitative and quantitative prediction and detection of parturition onset in sows using light barriers
A single light barrier can be used for the prediction and detection of parturition.A validated classification performance close to 90% was achieved.Approaches for measuring the parturition related activity increase were compared.A method for a quantitative prediction of the duration until parturition was tested. Piglet mortality can be a large economic and animal welfare issue in breeding facilities. A system that predicts the parturition can help the breeder in economically organising staff assignments in order to achieve an optimal workload levelling. In the current study, light barriers at the head and torso region of a sow were used to measure and classify the activity increase of 34 sows related to their near parturition. Based on this data, 4 different activity frequency and activity duration based qualitative predictors for the near onset of parturition were developed retrospectively, utilising cumulative sum techniques and a global threshold approach. The threshold optimisation for the qualitative prediction was performed using a random set of 17 sows and validated with the remaining sows. The best performing qualitative prediction yielded a validated sensitivity of 88% at a precision of 88%. This prediction generated parturition alerts with a 25th percentile of 13h and a 75th percentile of 20h before the parturition started. Based on this indicator, a quantitative prediction of the time remaining until the onset of parturition could be developed. This prediction exhibited a mean prediction error of 0.5h?2.6h (SD) for 88% of the sows over a period of 13-24h before the onset of parturition. At the same time 12% of the predictions were unusable with a mean prediction error of 12.5h?6.9h (SD). In addition, a method for detecting the parturition onset with an accuracy of ?4h, a sensitivity of 88% and a precision of 97% for the head sensor could be obtained. With data from the torso sensor, the performance of the various indicators was generally lower and optimality was achieved with different thresholds. The present study follows other studies showing the general detectability of the parturition related increase in activity using video, light barriers and ultrasonic distance sensors. It is also closely based on earlier studies using accelerometers for individual qualitative parturition detection, with the explicit intent to reproduce these results using light barriers.
On the fractionation of β-lactoglobulin and α-lactalbumin
Abstract Existing methods for the preparation of α-lactalbumin and β-lactoglobulin are examined critically. It is proposed that the most satisfactory method for the preparation of the whey protein fraction from bovine milk is (NH 4 ) 2 SO 4 fractionation. A number of new gentle procedures for the fractionation of the whey proteins are compared with some existing methods. The distribution of total protein at various stages is determined by total Kjeldahl nitrogen and the kind of protein by starch-gel electrophoresis. The effect of variables, such as pH, salt concentration and temperature on the separation of α-lactalbumin and serum albumin from β-lactoglobulin is studied. Differences in the behavior ( e.g. solubility) of genetic variants of β-lactoglobulin are noted. The solubility of each of the major whey proteins, under similar conditions to those used in the fractionation, is compared with its solubility in the whey protein mixture. The understanding gained of factors important in the fractionation is used in recommending new procedures for α-lactalbumin and β-lactoglobulin isolation.