Two 4 x 4 replicated Latin square studies, each containing 8 lactating Holstein cows, were conducted simultaneously in south Georgia during the summer. The effects of dietary cation source (Na or K) and increasing dietary cation-anion balance (milliequivalents of Na + K - Cl per kilogram of feed DM) within cation source (control = 120.4 meq/kg of feed DM; Na source = 219.7, 347.8, 464.1 meq/kg of feed DM; K source = 231.2, 352.6, 456.0 meq/kg of feed DM) were determined on performance and acid-base chemistry during hot, humid weather. Cow body temperatures were elevated by environmental conditions but were not affected by dietary cation-anion balance. Differences in body temperature from dietary cation source probably were related to differences in cow BW. Intake of DM increased linearly, but yields of milk and FCM did not change with increasing dietary cation-anion balance, and cation source had no effect. Milk fat and protein percentages were not altered by dietary cation-anion balance, and greater milk fat and protein percentages from cows offered the Na versus K source diets probably were due to differences between cows in the two Latin squares. Alterations in blood acid-base chemistry with increasing dietary cation-anion balance were as expected. Greater blood buffering capacity, indicated by blood base excess and bicarbonate content, may be responsible for the improved feed intake.

The objective of this experiment was to determine the effect of a beta-glucanase-protease enzyme blend product (EBP) on fecal digestibility (FD), apparent ileal digestibility (AID), standardized ileal digestibility, and digestibility in the hindgut of growing pigs. Twelve ileal-cannulated, growing barrows (38.2 +/- 0.5 kg) were housed in individual metabolism crates, blocked by previous feed intake into 3 groups with 4 pigs each, and randomly assigned to 1 of 4 treatments within a square (group) of 3 replications of 4 x 4 Latin square design. Treatments were basal diet (Basal), Basal + 0.05% of EBP (0.05% EBP), Basal + 0.10% of EBP (0.10% EBP), and hydrolyzed casein for measurement of endogenous amino acids. The Basal diet consisted of corn and soybean meal and was calculated to have 3.36 Mcal of ME/kg and 1.1% of total lysine, as-fed basis. Feed intake of each replicate of the Latin square during the first period was 85% of the minimum feed intake of the 4 pigs during the preliminary period and was equalized within each square. The feeding level was increased by 100 g/d in each subsequent period. Each of the experimental periods was 14 d, including 4 d of dietary adaptation, 5 d of fecal collection, 3 d of transition period, and 2 d of ileal collection. Ileal effluents were collected continuously for the same 12-h interval each day. Pigs fed the EBP demonstrated increased (P < 0.05) FD of DM, OM, energy, CP, nonfiber carbohydrate, total dietary fiber, insoluble dietary fiber, acid-hydrolyzed fat, ash, Ca, and P compared with pigs fed Basal. The AID of NDF and hemicellulose was increased (P < 0.05) by supplying the EBP either at 0.05 or 0.10% in the diets, but AID of DM and energy was not increased. The AID of acid-hydrolyzed fat tended to be greater (P = 0.051) for the pigs fed the EBP than for those fed Basal. Ileal digestibility of most amino acids was not affected by treatment, but the EBP reduced the apparent and standardized digestibility of methionine, alanine, and serine (P < 0.05). The difference between FD and AID of hemicellulose was lower (P < 0.05) for the pigs fed the EBP than for those fed Basal. These results demonstrated that the EBP fed to growing pigs improved the FD of DM, OM, energy, CP, nonfiber carbohydrate, total dietary fiber, acid-hydrolyzed fat, Ca, and P, and the AID of NDF and hemi-cellulose, but the standardized ileal digestibility of amino acids was not improved by supplying the EBP in corn-soybean meal-based diets of growing pigs.

A replicated trial of 3 X 3 Latin square design was conducted with growing pigs (about 29 kg initially) to determine the effects of different levels of feed intake on nutrient digestibilities determined near the end of the small intestine and over the total digestive tract. Pigs were fiftted with simple T-cannula. Feeding levels were ad libitum (AL) and limit-fed (4.5 or 3% of body weight/d). A 16% sorghum-soybean diet was used. Limit-fed pigs were fed at 12-h intervals and water was limited to 2 liters/kg of diet; AL pigs received water ad libitum. Consumption by pigs fed ad libitum averaged 6% of body weight/d. Neither feeding method nor level greatly affected nutrient digestibility measured at the end of the small intestine, but values tended to decrease as feeding level decreased. Comparisons of nutrient digestibility between AL and limit-fed pigs ranged from 2.9 to .7 percentage units, with only N (P less than .10) and methionine (P less than .05) reaching significance. Differences between 4.5 and 3% were slightly larger, ranging from 4.3 to -.2 percentage units, with differences for dry matter, N, gross energy and several amino acids reaching significance (P less than .10 or P less than .05). Measured over the total tract, observed differences among feeding levels were again small, but the trend was reversed, with digestibilities increasing as feeding level decreased. The estimated percentage of ingested nutrients that disappeared in the large intestine increased as feeding level decreased.(ABSTRACT TRUNCATED AT 250 WORDS)

The acceptibility of bacon produced from swine fed diets containing elevated levels of oleic acid was evaluated. Slicing yields and sensory scores for overall palatability and flavor quality were lower for bacon produced from swine fed canola oil (P < 0.05). A higher percentage of panelists detected off-flavors in canola oil bacon than in bacon produced from swine fed safflower oil, sunflower oil, animal fat or a typical corn-soybean meal diet (P < 0.05).