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Three loose housing systems for lactating cows (compost bedded pack, CBP; conventional bedded pack, BP; and freestalls, FS) were assessed on one farm in terms of cow behavior and welfare. An on-farm welfare assessment based on the Welfare Quality protocols was used four times every three months on 757 cows. Video recordings taken twice over four days were used to assess behavior patterns at resting areas. Cows in CBP and BP were dirtier than those in FS (p < 0.0001). Fewer integument alterations were recorded for CBP and BP than FS (p < 0.001). Cows in BP were quicker to lie down and stand up compared to those in CBP or FS (p < 0.001). Percentages of cows needing more attempts before rising were higher for FS (p < 0.01). However, a higher frequency of kneeling was observed in CBP (p = 0.033). A lower percentage of cows lying in the resting area was recorded for FS (56%) than CBP or BP (97 or 84%, respectively, p < 0.05). Overall, in this study, cows kept in bedded pack barns were dirtier but had fewer integument alterations and spent more time lying down in the resting area than cows housed in freestalls.

The ban on the use of antibiotics as growth promoters in animal feeds in the European Union has stimulated research on potential alternatives. Recently, propyl-propane thiosulfonate (PTSO), a stable organosulfurate compound of garlic, was purified. The objectives of the current study were to investigate the potential effects of PTSO on rumen microbial fermentation and to define effective doses. Two experiments were conducted using dual-flow continuous culture fermenters in 2 replicated periods. Each experimental period consisted of 5 d for adaptation of the ruminal fluid and 3 d for sampling. Temperature (39°C), pH (6.4), and liquid (0.10 h(-1)) and solid (0.05 h(-1)) dilution rates were maintained constant. Samples were taken 2 h after feeding and from the 24-h effluent. Samples were analyzed for volatile fatty acids (VFA) and nitrogen fractions, and degradation of nutrients was calculated. In addition, 24-h effluents from experiment 2 were analyzed for their fatty acid (FA) profile. Treatments in experiment 1 included a negative control without additive, a positive control with monensin (12mg/L), and PTSO at 30 and 300mg/L. The addition of 30mg/L did not affect any of the measurements tested. The addition of 300mg/L reduced microbial fermentation, as suggested by the decreased total VFA concentration, true degradation of organic matter and acid detergent fiber, and a tendency to decrease neutral detergent fiber degradation. Experiment 2 was conducted to test increasing doses of PTSO (0, 50, 100, and 150mg/L) on rumen microbial fermentation. At 2 h postfeeding, total VFA and molar proportion of propionate responded quadratically, with higher values in the intermediate doses. Molar proportions of butyrate increased and branched-chain VFA decreased linearly as the dose of PTSO increased. In the 24-h effluents, total VFA, acetate, and branched-chain VFA concentrations decreased linearly and those of propionate responded cubically with the highest value at 100mg/L. Saturated FA decreased and unsaturated FA increased linearly with increasing dose of PTSO. The concentration of trans-10,cis-12 conjugated linoleic acid decreased by 78.5% with addition of PTSO at the highest dose (150mg/L). Results suggest the potential of PTSO to modify ruminal fermentation in a direction consistent with higher propionate molar proportion, higher outflow of unsaturated FA, and low trans-10,cis-12 conjugated linoleic acid in an effective dose between 50 and 100mg/L.

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Essential oils may affect rumen fermentation, nutrient digestion, and milk production and composition. The objective of this study was to test the effects of capsicum oleoresin (CAP) and propyl-propane thiosulfonate (PTSO) on rumen fermentation, total tract digestibility, and milk yield and composition in lactating dairy cattle. Six lactating Holstein cows (averaging (mean ± SD) 130 ± 40 days in milk and 723 ± 55 kg of body weight) fitted with rumen cannulae were used in a duplicated 3 × 3 Latin square design. Treatments were: a control diet (CTR), the CTR diet with the addition of 500 mg/d/cow of CAP, and the CTR diet with the addition of 250 mg/d/cow of PTSO. Dry matter intake (DMI) averaged 20.7 kg/d with a tendency towards higher intake in cows fed CAP and lower in those fed PTSO (p = 0.08). Milk yield averaged 31.8 kg/d with no difference among treatments. However, feed efficiency was higher in PTSO supplemented cows compared with CTR (1.65 and 1.41 kg of milk yield/kg of DMI, respectively; p < 0.01). At the doses used in this experiment, CAP and PTSO failed to demonstrate any effects on rumen fermentation, but PTSO increased the efficiency of feed utilization to produce milk.