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Effect of shelter on the performance of Friesian cows during winter in a mediterranean climate
Abstract
The effect of different shelters that is, a shades tructure( 3.-5m high) in a dry lot and a tie-stallb arn in comparisont o a dry lot with no protection against climatic conditions (rain and wind), on the milk production and some physiologicalp arameterso f Dutch-typeF riesian S.Afi.TydskVre. ek.1, 995 ,25(2 ) cows was determinedo ver 53 days during winter in a temperatec limatez one.A completed iet ( l3.5VoC P and9 .6 MJ MElkg DM) was fed ad libitum daily to cows. Ambient temperaturesre cordedd uring the trial werew ithin the thermoneutrazlo nef or dairy cattle( 18.-5r 4.0 and 8.7 t 2.6"C for maximum and minimum temperatures respectively)T.o tal rainfalld uring the trial period was 180.6m m. Daily precipitationh ighert han 5.0 mm was recordedo n 12 days. Althoughd ry matteri ntaked iffered( P < 0.01) betweent reatmentsi,t wasn ot relatedt o treatment.D aily milk productiona nd milk composition did not differ (P > 0.05) betweent reatments.P lasmac ortisol and thyroxine levels of cows in the different housing systems also did not diff'er( P > 0.05),i ndicatingn o advantagein providing r:laborate housingf acilitiesf or dairyc owsu ndert hesec limaticc onditions.
Die invloedv an verskillendeb eskuttingsfasiliteitnea, amlik 'n skaduwee- afdak(3 .5 m hoog)i n 'n oop kamp en 'n intensieweb ehuisingstelseiln vergelykingm et 'n oop kamp waarin geen beskutting teen klimaatstoestand(er e6n en wind) verskaf is nie, op die melkproduksie en sekere fisiologiese maatstawwe van Hollandse tipe Frieskoeieis oor'n periodev an 53 dae gedurended ie winter in'n gebiedm et 'n gematigdek limaatb epaal.' n Vollediged ieet( l3.5Vo RP en 9.6 MJ ME/kg DM) is op 'n ad libitum-basis daagliks aan koeiev oorsienO. mgewingstemperatugred urended ie proefperiode wasb inned ie gemaklikheidsonveir melkkoeie( 18.-5+ 4.0 en 8.7 + 2.6"C vir maksimume n minimumt emperatureo nderskeidelik)D. ie totaleh oeveelheidre envalg edurended ie periodew as 180.6m m. 'n Daagliksen eerslagv an ho€r as 5.0 mm is op 12 dae aangeteken. Hoewel daagliksed roemateriaal-innametsu ssenb ehandelingsv erskil het (P < 0.01),k an dit nie aand ie behandelingtso egeskrywf ord nie. Melkproduksiee n melksamestellinvga n koeie binne die drie behuisingstelsehlse t nie verskil nie (P > 0.0-5)B. loedplasmapeile van kortisol en tiroksienh et ook nie tussend ie behandelingsv erskil nie (P > 0.05).R esultated ui op geenv oordelein die voorsieningv an uitgebreideb ehuisingsfasiliteitveir melkkoeieo nder hierdie klimaatstoestandneie
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Keywords: Milk production, dry lot, tie-stall barn, shade structure,
tyroxine, cortisol, temperate climate.