Feed Intake Pattern Research Articles

Adaptation to High Concentrate Diets by Beef Cattle. II. Effect of Ruminal pH Alteration on Rumen Ferementation and Voluntary Intake of Wheat Diets

An in vivo and in vitro fermentation study was conducted in conjunction with a feed intake trial to study the effect of controlling rumen pH on feed intake and rumen microbial fermentation patterns in steers fed a 90% concentrate wheat diet. Rumen pH was supported by direct rumen infusion of an equal molar mixture of sodium and potassium hydroxide. Total feed intake was greater (P<.1) for hydroxide (9.87 kg) infused than for the control steers (8.39 kg). Higher period intakes were observed for the infused steers at all times with the exception of hour 2. Rumen pH values were significantly lower (P<.01) for the control steers (5.39 vs 5.88). These data indicate a possible relationship between low rumen pH and cessation of voluntary feed intake. Small differences in in vivo lactate occurred between these two treatments, possibly because of rumen microbial adaptation to a high concentrate diet at the time the study was conducted. However, higher (P<.01) in vitro lactate concentrations were observed in incubations where ruminal fluid source was from the hydroxide infused steers. Differences in volatile fatty acids (VFA) concentrations due to treatment were not large with the exception of valerate, which was appreciably higher (P<.05) in the control animals. Moles/100 moles of acetate and isovalerate were significantly greater and valerate lower in the hydroxide infused versus control steers.

Effect of Excess Methionine on Growth, Feed Intake, Energy Utilization and Plasma Amino Acid Pattern in Chicks

In order to investigate the effects of dietary excess methionine on growth, feed intake, energy utilization and plasma amino acid pattern in chicks, 7-day-old single-comb White Leghorn chicks were fed diets adequate and excess in methionine for 14 days, and then body composition and plasma amino acid pattern were determined.Excess methionine markedly decreased body weight gain, feed intake, and efficiency of feed utilization. Body composition was not affected by feeding excess methionine, but the chicks fed the methionine excess diet retained significantly less fat, protein and energy than those fed the methionine adequate diet. Metabolizability of dietary energy was not altered by excess methionine, wheress utilization of nitrogen and energy was decreased.Excess methionine drastically increased plasma methionine level, and levels of some other amino acids in plasma were also changed by excess methionine.

Calcium Metabolism in the Laying Hen: 3. Pattern of Feed (Calcium) Intake as Influenced by Time of Day and Oviposition

Seventy-five Kimber K-137 hens (65 weeks of age) with an average egg production of 50 percent were kept in individual cages and fed a 3.0 percent calcium diet. Individual feed consumption and egg production values were determined at two hour intervals from 6 a.m. to 6 p.m. Natural daylight was approximately 11 hours and 30 minutes. The birds were on a 15 hour day with lights supplied only during the morning hours. The experiment was repeated for five days giving a total of 2,250 individual feed intake determinations.Definite daily feed intake patterns were established in relation to time of day. The same general feed intake pattern was observed regardless of whether the hen did or did not lay that day or was out of production. Two percent more feed was consumed by layers on non-oviposition days than on oviposition days. The results also suggest that oviposition has an influence on the pattern of feed intake. However, this effect could be almost completely masked depending upon time of oviposition. Because of this making effect a true 24 hour pattern of feed intake in relation to oviposition could not be established.

Diurnal Variations in Blood and Rumen Metabolites and Feeding Activity of Dairy Steers Under Controlled Lighting

Photographic evidence of diurnal eating patterns of five steers allowed free access to hay in an environment free of natural light were recorded during 37, 24-hour periods preceded by a 14-day preliminary period. Four replicate collections of rumen liquor, jugular blood, and carotid blood were obtained at 2-hour intervals. Rumen liquor samples were analyzed for acetic, propionie, and butyric acid concentrations as well as for pH. Blood samples were analyzed for volatile fatty acids, reducing substances, and ketones. The greatest concentration of eating activity occurred during two periods peaking at 0600 and 1630 hours. Smaller peaks were noted at 0930 and 1430 hours. Only rumen pH and jugular β-hydroxybutyrate were significantly correlated (.476 and −.243) with eating activity. Generally, the steers stopped eating before detectable rises in metabolite concentration. However, periods of maximum metabolite concentration were associated with periods of relatively little eating. These data do not preclude metabolite Concentration as a factor in the regulation of ruminant feed intake patterns.

The effect of pattern of food intake in pregnancy upon sow productivity

SUMMARYSeven research and teaching centres have co-operated in an experiment involving 154 sows. The experiment compared the effect of feeding four different patterns of feed intake during pregnancy upon reproductive performance of sows. In each case approximately 220 kg of feed were given during each gestation according to four patterns of intake designated Constant (C), Low-High (L-H), High-Low (H-L) and High-Low-High (H-L-H). During lactation all animals were given a daily ration of 3·7 kg of feed for litters of five pigs or less, and 0·4 kg for each additional piglet. Wherever possible the sows remained on the same nutritional regimes for three parities.Although the pattern of feed intake slightly affected the live-weight changes of the sows during the course of pregnancy, the treatments had no significant effects on overall change in weight of the sows in pregnancy or in lactation in any of the three parities. The live weights of the sows at the end of the third parity were very similar for all treatment groups.The patterns of feed intake had no appreciable or significant effect on the numbers of pigs born, their average weight at birth or upon the numbers of pigs which survived to weaning at 6 weeks or their live weight. The health and breeding regularity of the sows were also unaffected by the treatments.There were differences between the centres in many of the variables which were compared, but there was no evidence of any important centre × treatment interactions.It is concluded that, at the levels of intake given in pregnancy and lactation in this experiment, there are no beneficial or detrimental effects of changing the pattern of intake during pregnancy.

Relationship of various blood metabolites to voluntary feed intake in lactating ewes.

Two-day trials were conducted with ewes in early lactation. A pelleted ration (45% conc-55% roughage) was fed for a period of three hours at 8 AM and 3:30 PM. On day 1 sufficient feed was offered to insure ad libitum consumption at both periods. On day 2 the AMfeed was limited to one-half the amount consumed dur ing the pre-experimental AMperiod, and the PM feed was ad libitum. Carotid and jugu lar blood samples were taken at 0, 0.5, 1.5, 3 and 7 hours after the AMmeal. Correlations were calculated between AMand PM feeding periods on days 1 and 2. Interval feed con sumption was measured after 0.5, 1.5 and 3 hours in the AMand 0.5 and 3 hours in the PM. Seventy percent of the feed was consumed in the first 20 to 30 minutes. Blood vola tile fatty acids (VFA) and ketones increased markedly and peaked at 3 hours (day 1) and 1.5 hours (day 2). Blood glucose levels dropped sharply by 0.5 hour but increased significantly by 1.5 hours on both days. Plasma free fatty acids (FFA) decreased on both days, but rose markedly on day 2 by 7 hours. Acetate, propionate and glucose levels were poorly correlated to feed intake patterns. Ketone correlations, although low, had a pattern similar to butyrate correlations. Butyrate and FFA levels were the most highly correlated to subsequent VFI. FFA concentration at 7 hours was the best single predictor of subsequent feed intake, accounting for 50% of the variation (fi2 = 0.496).