The objective of the study was to determine the effects of feed delivery time and its interactions with dietary concentrate inclusion and parity on milk production and on 24-h averages and patterns of feed intake and blood metabolites. Four multiparous and 4 primiparous lactating Holstein cows were used in a 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments. Experimental periods included 14 d of adaptation and 7 d of sampling. A higher concentrate diet with a forage:concentrate ratio (dry matter basis) of 38:62 or a lower-concentrate diet with a forage:concentrate ratio of 51:49 was delivered at either 0900 or 2100 h. During sampling periods, daily feed intakes, as well as feed intakes during 3-h intervals relative to feed delivery, were determined. During 2 nonconsecutive days of the sampling period, jugular blood was sampled every 2 h. Average temperature and relative humidity in the experimental facility were 20.4 degrees C and 68.1%, and the maximum daily air temperature did not exceed 25 degrees C. This data does not suggest that cows were heat-stressed. Changing feed delivery time from 0900 to 2100 h increased the amount of feed consumed within 3 h after feeding from 27 to 37% of total daily intake but did not affect daily dry matter intake. The cows fed at 2100 h had lower blood glucose at 2 h after feeding but greater blood lactate and beta-hydroxybutyrate acid at 2 and 4 h after feeding than cows fed at 0900 h. These effects of feed delivery time on the 24-h patterns in blood metabolites may be caused by the greater feed intake during the 3 h after feed delivery of the cows fed at 2100 h. Daily averages of glucose, urea, lactate, and beta-hydroxybutyrate acid and nonesterified fatty acids in peripheral blood were not affected by time of feeding. The change in feed delivery time did not affect milk yield and milk protein but increased milk fat percentage from 2.5 to 2.9% and milk fat yield from 0.98 to 1.20 kg/d in multiparous cows, without affecting milk fat in primiparous cows. The interactions between diet and time of feeding on daily feed intake, milk production, and blood metabolites were not significant. The effects of the time of feed delivery on the 24-h patterns in blood metabolites suggest that this time may affect peripheral nutrient availability. Results of this study suggest beneficial effects of feeding at 2100 h instead of at 0900 h on milk fat production of lactating cows, but parity appears to mediate this effect.

Nikkhah, A., Furedi, C. J., Kennedy, A. D., Scott, S. L., Wittenberg, K. M. Crow, G. H. and Plaizier, J. C. 2011. Morning vs. evening feed delivery for lactating dairy cows. Can. J. Anim. Sci. 91: 113–122. A study was conducted to investigate the effects of changing feed delivery time from morning (0900) to evening (2100) on feed intake, diurnal feed intake patterns, digestion, rumen fermentation, milk production and composition, as well as on several blood metabolites. Eight (four ruminally cannulated) lactating Holstein cows, consisting of four primiparous and four multiparous cows, were used in the study. The change in the time of feed delivery increased the proportion of feed consumed within 3 h of feed delivery in all cows (54.7 vs. 46.3±4.1%, means±SE, P=0.05), but increased daily dry matter intake only in primiparous cows (18.5 vs. 20.4±0.7 kg d−1, P=0.05). Average daily concentrations of blood glucose, lactate, urea and β-hydroxybutyrate (BHBA) as well as rumen pH and concentrations of volatile fatty acids (VFA) were not affected by feed delivery time. However, rumen pH was lower (P<0.05), at 5 and 6 h after feed delivery, while total rumen VFA and acetate were higher (P<0.05) only at 6 h after feed delivery in cows fed in the evening. Also, compared with feed delivery at 0900, feeding cows at 2100 resulted in lower (P<0.05) blood glucose and urea at 2 h after feed delivery, and increased BHBA (P<0.05) at 4 and 6 h after feed delivery. Cows fed at 2100 tended to produce more milk fat than those fed at 0900 (1.11 vs. 0.97±0.07 kg d−1, P=0.08). Milk yield and milk protein were not affected by the time of feed delivery. Changing the feed delivery time from morning to evening increased apparent total tract digestibility of dry matter, nitrogen, and neutral detergent fibre. The results of this study suggest that changing time of feed delivery from 0900 to 2100 increases feed consumption within 3 h after this delivery and rumen fermentation within 6 h after this delivery, changes diurnal patterns of glucose, urea and BHBA in peripheral blood, tends to increase milk fat, and increases nutrient digestibilities.

Application of alternative feedstuffs in swine diets will be dependent on characterization of their nutritive value. In 2 experiments, we determined the AA and energy utilization of Manitoba-grown zero-tannin faba beans (ZTFB) and co-fermented wheat and corn dried distillers grains with solubles (wcDDGS). Corn dried distillers grains with solubles (cDDGS) was also included for comparison. In Exp. 1, 6 ileal cannulated barrows (29.3 ± 1.3 kg) were fed 3 diets in a replicated 3 × 3 Latin square design to determine the apparent (AID) and standardized (SID) ileal digestibility of AA. The 3 diets contained ZTFB, wcDDGS, or cDDGS as the sole source of AA. The SID of N and AA were calculated using published values for ileal endogenous N and AA losses from our laboratory. In Exp. 2, 12 intact barrows (22.5 ± 1.1 kg) were fed 4 diets in a two 15-d period crossover design to determine DE and ME contents of the test ingredients by difference method. The diets were a basal corn-based diet or the basal diet with corn replaced by 46% ZTFB, wcDDGS, or cDDGS. The concentrations (DM basis) of GE (kcal/kg), CP (%), and Lys (%) in ZTFB were 4,144, 27, and 1.6, respectively, and corresponding values for wcDDGS were 5,112, 31, and 0.8. The ZTFB had greater (P < 0.05) SID of Lys (87%) compared with wcDDGS (72%) and cDDGS (68%); as a result, the SID content (g/kg DM) of Lys in ZTFB (13.5) was greater (P < 0.05) than that of either wcDGGS (6.03) or cDDGS (6.68). The dried distillers grains with solubles (DDGS) samples had greater (P < 0.05) SID and contents of sulfur AA (Met and Cys) compared with ZTFB. The ME content (kcal/kg DM) of ZTFB (3,548) was less (P < 0.05) than that of cDDGS (3,851) whereas the ME content of wcDDGS (3,669) was similar to that of ZTFB or cDDGS. The results showed that ZTFB has greater digestible Lys whereas wcDDGS has greater digestible sulfur AA but both ingredients have comparable ME content. Therefore, a blend of these 2 ingredients can serve as an excellent source of AA and energy for swine.

The effects of delivery time (0900 or 2100) of a diet consisting of 45% of dry matter as chopped hay and 55% of dry matter as concentrates on milk production of dairy cows were determined in a 6-wk experiment consisting of 3 wk of adaptation and 3 wk of sampling. Feed delivery time did not affect feed intake and milk production. Average milk fat percentage decreased from 2.14% during week 4 to 1.73% during week 6. The low milk fat could was assumed to be caused by the short dietary particle lengths, and could have prohibited effects of feeding time on milk production. The decrease in milk fat over time might have been due to increased sorting against long and medium length feed particles. This increase in sorting was greater in 0900-fed cows than in 2100-fed cows. Key words: Time of feeding, dairy cows, milk production, sorting