Research-Article| Volume 72, ISSUE 10, P2712-2717, October 1989

Relationship Among Climatological Variables and Hourly Distribution of Calvings in Holsteins Fed during the Late Afternoon1

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      A survey of 924 calvings of Holstein cows and heifers in one large commercial herd during the fall of 1985 revealed a nonuniform pattern of calving over a 24-h period. Pregnant females were attended 24 h/d and fed daily a complete diet between 1500 and 1600 h during the dry period or the last 30 to 60 d of gestation. More calvings occurred from 0601 to 1800 h than from 1801 to 0600 h (56 versus 44%). Cows calving during the last 12 h of the day (1201 to 2400 h) had gestation periods that averaged 1.3 d longer than cows calving during the first 6 h of the day. Length of gestation was increased 1.3 d for every hour decrease in daylength from September to December but was unaffected by any other climatological measure (barometric pressure, precipitation, wind velocity, temperature, percentage sunshine, or relative humidity). The hour of calving was unrelated to any of the climatological measures during the week preceding parturition. However, partial regressions of climatological variables on days to calving revealed significant regressions for barometric pressure [quadratic; β = (60.1 ± 2.6) × 10−13 mm2 Hg/d], precipitation [β = (2.02 ± .8) × 10−1 mm/d], humidity [β = (1.2 ± .2) × 10−2%/d], and daylength [β = (−3.5 ± .5) × 10−1 h/d]. It was concluded that pregnant cows and heifers fed during the late afternoon calved in a nonrandom pattern during the 24-h day; more calvings occurred during daylight hours. Changes in various environmental measures may serve as biological cues to initiate parturition in the bovine.


        • Bazer F.W.
        • First N.L.
        Pregnancy and parturition.
        J. Anim. Sci. 1983; 57: 425
        • Bellows R.A.
        Some nutrition effects on birth weight and calving difficulty and relationships of feeding time and calving.
        in: Proc. 15th Annu. Conf. AI Beef Cattle. Natl. Assoc. Anim. Breeders, 1981
        • Bosc M.J.
        Influence de la photoperiode ou des conditions de milieu sur la parturition.
        in: Ortavant R. Reinberg A. Rhythmes et Reproduction. Masson, Paris1980: 179-183
        • Bosc M.
        • Guillemin P.
        • Bourgy G.
        • Pignon P.
        Hourly distribution of time of parturition in the domestic goat.
        Theriogenology. 1988; 30: 23
        • Dvorak R.A.
        A note on the relationship between barometric pressure and calving incidence.
        Anim. Reprod. Sci. 1978; 1: 3
        • Edwards S.A.
        The timing of parturition in dairy cattle.
        J. Agric. Sci. Camb. 1979; 93: 359
        • Erb H.N.
        • Grohn Y.T.
        Epidemiology of metabolic disorders in the periparturient dairy cow.
        J. Dairy Sci. 1988; 71: 2557
        • Freeman A.E.
        Secondary traits: sire evaluation and the reproductive complex.
        J. Dairy Sci. 1984; 67: 449
        • Hudgens R.E.
        • Albright J.L.
        • Pennington J.A.
        Influence of feeding time and diet on time of parturition in multiparous ewes.
        J. Anim. Sci. 1986; 63: 1036
        • Laster D.B.
        Factors affecting pelvic size and dystocia in beef cattle.
        J. Anim. Sci. 1974; 38: 496
        • Lickliter R.E.
        Behavior associated with parturition in the domestic goat.
        Appl. Anim. Behav. Sci. 1984/1985; 13: 335
        • Lowman B.G.
        • Hankey M.S.
        • Scott N.A.
        • Deas D.W.
        Influence of time of feeding on time of parturition in beef cows.
        Vet. Rec. 1981; 109: 557
        • Macmillan K.L.
        • Pearce M.G.
        • Copeman P.J.A.
        • Macdonald K.A.
        • Kilgour R.G.
        Effects of varying feeding time on diurnal calving patterns in dairy cows.
        Proc. N.Z. Anim. Prod. 1985; 45: 35
        • Mather E.C.
        • Melancon J.J.
        The periparturient cow–a pivotal entity in dairy production.
        J. Dairy Sci. 1981; 64: 1422
        • Price T.D.
        • Wiltbank J.N.
        Dystocia in cattle: a review and implications.
        Theriogenology. 1978; 9: 195
        • Rossdale P.D.
        • Short R.V.
        The time of foaling of thoroughbred mares.
        J. Reprod. Fertil. 1967; 13: 341
        • Selye H.
        The general adaptation syndrome and the diseases of adaptation.
        J. Clin. Endocrinol. 1946; 6: 117
        • Sommer H.
        Der einfluss des wetlers auf denzeifpunkt der geburt beim rind.
        Zuchtungskunde. 1965; 37: 290
        • Statistical Analysis System
        SAS User's guide.
        SAS Inst. Inc., Cary, NC1981
        • Stevenson J.S.
        • Call E.P.
        Reproductive disorders in the periparturient dairy cow.
        J. Dairy Sci. 1988; 71: 2572
        • Sumar J.
        Reproductive physiology in South American camelids.
        in: Land R.B. Robinson D.W. Genetics of reproduction in sheep. Butterworths, London1985: 61-95
        • Thompson J.R.
        • Pollak E.J.
        • Pelissier C.L.
        Interrelationships of parturition problems, production of subsequent lactation, reproduction, and age at first calving.
        J. Dairy Sci. 1983; 66: 1119
        • Yarney T.A.
        • Rahnefeld G.W.
        • Parker R.J.
        • Palmer W.M.
        Hourly distribution of time of parturition in beef cows.
        Can. J. Anim. Sci. 1982; 62: 597