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Reproduction and milk production responses were compared between dairy cows offered a high (HPA; n=453 in 4 replicates) or low (LPA; n=317 in 3 replicates) pasture allowance for the first 14 d after the planned start of mating (d 0 of experiment) in 2 seasonal, pasture-based dairy herds. Estimated pasture dry matter intake (DMI) between d -1 and 13 were 14.3+/-2.8 and 8.0+/-1.7kg of DM/cow per day for HPA and LPA cows, respectively. The LPA cows produced 22% less energy-corrected milk during the 14-d feeding treatment period, and milk yield remained less in LPA cows at d 53 despite all cows receiving pasture allowances to support DMI of 16kg of dry matter/cow per day from d 14 onwards. The 3-wk submission rate (percentage of cows inseminated at least once from d 0 to 20) and the 3- and 6-wk pregnancy rates of LPA cows (88, 45, and 71%, respectively) were lower than those of HPA cows (94, 53, and 78%, respectively), but conception rates to first (50%) or second (47%) service and final pregnancy rates (93%) did not differ between treatments. These results quantify the immediate and subsequent responses in reproductive performance and milk production to a severe restriction in DMI at the onset of a seasonal breeding period in pasture-grazed dairy cows.

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Simple SummaryIn pig farming, weaning is abrupt, and occurs between the third and fourth week of age. Creep feed is commonly offered to reduce feed neophobia by creating a sensory link between suckling and post-weaning diets. However, low intake of creep feed is observed within and between litters. This experiment estimates the effect of prenatal flavor exposure on the performance of piglets when the same flavors are included into their creep feed. Gestational sows were fed either a flavored (garlic or aniseed; n24) or an unflavored diet (n24) from 90 to 114 days of gestation. Their litters were offered either garlic, aniseed or unflavored creep feed during the suckling period, and its intake was measured as well as the animal’s final body weight (BW) and average daily gain (ADG). No differences are found in any parameter analyzed according to prenatal flavor exposure (p > 0.05), observing a huge feed intake variability between litters. An unclear post-ingestive benefit of flavored creep feed intake, and the reward contrast between maternal milk and creep feed diets, may accelerate flavor learning extinction during the suckling period. Results of the present and previous experiments suggest that current flavor continuity strategies that are proposed for pig production systems need to be reconsidered.AbstractPiglets can prefer flavors that are presented to pregnant sows, hence this study intended to estimate the effect of prenatal exposure of piglets to flavors on the intake of flavored creep feed and performance. Gestational sows were fed either a flavored (garlic or aniseed; n24) or an unflavored diet (n24) from days 90 to 114 of gestation. Their litters were offered either garlic, aniseed, or unflavored creep feed during the suckling period, and its intake was measured as well as animal’s final body weight (BW) and average daily gain (ADG). Data was analyzed taking into account the diet offered to both sows and piglets, as well as the interaction between these variables. As previous experiments have shown, flavor learning did not affect a piglet’s performance during the suckling period, finding no differences for creep feed intake, ADG, or BW according to diets (p > 0.05). Repeated exposure of piglets to previously learned flavors without clear post-ingestive benefits could nullify the strategies proposed. Moreover, milk and creep feed diets show a great reward contrast that may accelerate learning extinction. Results of the present and previous experiments suggest that current flavor continuity strategies that are proposed for pig production systems need to be reconsidered.