Cows housed indoors with cubicles are probably more restricted in their choice of lying posture and orientation compared with cows housed on pasture. We therefore compared lying postures on pasture in Uruguay and the Netherlands with lying postures in cubicles in the Netherlands, also recording orientation on pasture in Uruguay and divider and bedding type in Dutch cubicles. We visited one farm with four herds in Uruguay, doing live observations, and 25 Dutch farms, taking pictures of cows. Observations of 205 cows on pasture in Uruguay showed more long postures, lying on their belly with their neck stretched. Two herds preferred lying towards north and south, while one herd preferred west and east. Pictures of 217 cows on pasture in the Netherlands showed more wide postures (lying on the side with three or four legs stretched out). Pictures of 527 cows in cubicles in the Netherlands showed more narrow postures (lying on the side with hind legs folded). More long postures (lying on the belly with a stretched neck) and less short postures (lying with the head folded back) were seen in cubicles with soft floors and English dividers; more narrow postures were seen in cubicles with concrete floors. Wide postures were seen more in cubicles with mattresses and free-hanging dividers. We conclude that since cows in cubicles show more narrow postures than on pasture and cannot choose their orientation, their choice in showing preferred behavior is restricted. More research is needed to study the consequences of restricted choice in lying behavior on the health and welfare of dairy cows.

Inclusion of fish oil (FO) in the diet of dairy cows could improve the energy status and milk yield and reduce the interval from calving to first postpartum ovulation, but the effects may differ depending on the specific period of supplementation. To test these hypotheses, 28 pregnant Holstein heifers were randomly assigned to four treatments in a 2 × 2 factorial design: prepartum oral drench of FO (0 or 140 g/cow.day) for 21 days before calving, and/or postpartum oral drench of FO (0 or 190 g/cow.day) for 21 days after calving. Prepartum, heifers grazed in native pastures with supplements of wheat silage and wheat bran, while postpartum, cows grazed on improved pastures with addition of concentrates and corn silage. No interaction between prepartum and postpartum FO was detected for any variable analysed. Prepartum and postpartum total DM intake, milk yield, protein yield and percentage were not different among treatments. Milk fat percentage (3.83 versus 3.34 ± 0.10%) and yield (0.88 versus 0.73 ± 0.04 kg/day) decreased with postpartum FO but were not affected by prepartum FO. Prepartum and postpartum body condition score and plasma concentration of non-esterified fatty acids and cholesterol were not different among treatments, but urea concentration was higher in cows drenched with FO during prepartum (5.91 versus 4.64 ± 0.35 mM). Proportion of cows that ovulated the dominant follicle of the first postpartum wave and days to first postpartum ovulation, as determined by ovarian ultrasonography, were not affected by drenching with FO, but size of the dominant follicle in the first wave was decreased when FO was drenched only during the pre- or postpartum period compared with drenching in both periods. Dietary supplementation with FO during the postpartum period affected milk fat synthesis but more research is needed to establish its effects on resumption of ovarian activity in grazing dairy cows.

To compare an injectable progesterone (MAD-4) with an intravaginal device (IPD), and natural O17 with synthetic oestradiol (OB) in a synchronisation protocol, 51 cows were divided into four groups. Each group was treated with one of the two sources of progesterone and one of the two oestradiol formulations. Oestrus behaviour, follicle diameter, and pregnancy rates were evaluated. Oestrus behaviour (p = 0.902), numbers of cows in oestrus (p = 0.917), follicle diameter (p = 0.416), and pregnancy rates (p = 0.873) were similar among the four groups. More cows in the group treated with the IPD and OB scored > 200 oestrus behaviour points compared to the other groups (p = 0.038). A longer interval between the end of treatment and oestrus was observed among cows treated with MAD-4 than cows given the IPD (p = 0.030), but no differences were found between animals receiving the two oestradiol formulations (OB and O17). While the use of MAD-4 requires further testing, similar responses to natural oestradiol observed in the present study could allow the use of this formulation in reproductive protocols because it is not associated with the potential human health risks of OB.