86,578 research outputs found
Population structure of European sprat (Sprattus sprattus) in the Greater North Sea ecoregion revealed by otolith shape analysis
No full textA successful discrimination of fish populations is essential for sustainable management and assessment. Otolith shape analysis has been used on several species to reveal their population structure. Our aim was to use the otolith shape of European sprat (Sprattus sprattus) to investigate large- and small-scale geographical variability across the Greater North Sea ecoregion. The otolith shape was extracted from digitalised images and transformed into Wavelet coefficients to be analysed with multivariate statistics. Otolith shape was observed to follow the genetic population structure recently defined for the region, supporting the latest revision of the stock boundaries. Four main groups were identified based on phenotypic variability: (i) Norwegian fjords; (ii) North Sea and offshore Skagerrak–Kattegat; (iii) coastal Skagerrak–Kattegat; and (iv) Uddevalla fjord. However, 4-fold cross-validations based on Linear Discriminant Analysis resulted in low accuracy limiting at the moment the ability to use otolith shape analysis for population identification at an operational basis. Our results show the importance of coastal areas, which might be inhabited by distinct populations of sprat that are currently not acknowledged in the management and assessment
Chapter 8. Milking routines.
No full textSince the milk ejection reflex was described by Ely and Petersen (1941), several studies have been carried out in ruminants, in order to evaluate the optimal way of stimulating milk letdown. Proper premilking teat preparation is essential for the production of high quality milk. This chapter aims to clarify the mechanisms that are on the basis of the milk ejection reflex in buffalo species, taking into account teat sanitation and premilking stimulation
Assessment of human-animal relationship in cattle kept on slatted floor
No full textThe nature of human contacts toward cattle can affect their subsequent behavioural response. The aim of this study was to evaluate the test-retest reliability of some variables used to assess the quality of human–animal relationship. These variables were: time needed to isolate a subject from the group in a corner of the pen (TI), isolation time (IT) and number of flight attempts (FA). They were recorded in 1 farm on 30 Italian Freisian males aged 10 months. Observations were conducted in the home pens by two trained people: one always recording the variables (observer), the other always performing the test (handler). Three recordings were performed at 15 day intervals. Reliability was tested using the Kendall’s W coefficient. The three observations were significantly similar (P<0.05, P<0.001 and P<0.01 for TI, IT and FA, respectively), although the W coefficient was high for IT (0.81) but lower for TI (0.50) and FA (0.67). In addition, the Spearman coefficient showed a significant correlation between IT and FA (rs=-0.40, P<0.05). These results indicate that the time of isolation may be a reliable indicator of the animal responsiveness to the stockperson
Valutazione del benessere della bufala a livello aziendale: ripetibilità di alcuni indicatori biologici
No full textThe aim of this study was to evaluate the repeatability of some animal related variables. Recordings were performed in 3 dairy buffalo farms. For each farm 30-40 animals were selected. Observations were conducted by a team of 8 trained assessors. Animals were observed in 3 occasions at 3 week intervals. Each animal was always assessed by the same observer. The variables collected were the behaviour during milking (stepping and kicking), avoidance distance, lameness and cleanliness. For each farm and each variable repeatability was computed using the Kendall coefficient of concordance (W) and a ratio between the variance of the animal and the sum of the latter with the error variance. These two methods yielded similar results which indicated that avoidance distance, stepping and kicking were repeatable
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