Effect of adding fat and(or) milk products to the weanling pig diet on performance in the nursery and subsequent grow-finish stages.

Six experiments were conducted to evaluate the use of fat in diets containing a high level of milk products for weanling pigs. In Exp. 1, 192 pigs (6.6 kg and 23 d) were used to determine whether milk products (0 or 40%) in the diet influenced the utilization of fat (0 or 10%). No fat x milk product interactions were found. Adding milk products to the diet improved (P < .01) ADG, ADFI, and gain/feed (G/F). Adding fat to the diet did not influence performance. In Exp. 2, 3, and 4, 576 pigs (6.0 kg and 20 d) were used to determine the influence of fat level on performance. Adding soybean oil (0, 3, 6, or 9%) to the diet from d 0 to 14 after weaning had no influence on growth performance. Increasing soybean oil (0, 2, 4, or 6%) in the diet from d 14 to 35 had no influence on ADG; however, G/F improved linearly (P < .001). In Exp. 5, 196 pigs (7.5 kg and 26 d) were used to determine the influence of fat source (soybean oil, corn oil, or tallow) on performance. Pig performance was not different among fat sources. In Exp. 6, 240 pigs (5.4 kg and 21 d) were used to determine the influence of fat and(or) milk product inclusion in the nursery diet on subsequent grow-finish performance. Adding milk products, but not fat, to the nursery diet improved (P < .08) overall performance to market weight. These results indicate adding fat to the diet from d 0 to 14 after weaning had no influence on performance. Adding fat to the diet from d 14 to 35 improved G/F; however, it did not improve ADG or overall performance to market. Diet composition during the nursery period can affect subsequent performance.

Lecithin in swine diets: I. Weanling pigs.

One digestibility experiment (Exp. 1) and two growth experiments (Exp. 2 and 3) were conducted to evaluate the use of lecithin as an emulsifier of soy oil and(or) an energy source in a two-phase starter diet program. Phase 1 consisted of d 0 to 14 postweaning, and Phase 2 consisted of d 14 to 35 postweaning. Diets were based on corn, soybean meal, and 20% dried whey and contained a constant ME:lysine level. In Exp. 1 and 2, two levels of lecithin (0 and 2%) at two levels of soy oil (0 and 6%) were investigated. In both experiments, there was no interaction between lecithin and soy oil for any traits measured. In Exp. 1, the apparent digestibility of fat increased significantly with increased fat level in the diets. Addition of lecithin to diets improved (P < .05) nitrogen retention, and the addition of soy oil significantly improved apparent digestibility of DM, GE, fat, and CP. In Exp. 2, there was no significant effect of lecithin or soy oil on ADG. In Phase 2 and overall, the inclusion of lecithin and soy oil to diets significantly increased gain/feed but did not significantly improve gain/ME intake. In Exp. 3, pigs were fed diets containing 0, 1, 2, or 3% lecithin. The addition of lecithin to diets did not affect ADG, ADFI, gain/feed, or gain/ME intake during Phases 1, 2, or overall. These results fail to demonstrate that the addition of lecithin to diets for young pigs improves utilization of soy oil or growth performance.

Lecithin in swine diets: II. Growing-finishing pigs.

Lecithin was investigated in diets for growing-finishing pigs. Diets were based on corn and soybean meal and contained a constant ME:lysine level. The use of lecithin as an emulsifier on utilization of soy oil by the pig was investigated in Exp. 1. Diets were arranged in a 2 x 2 factorial structure with two levels of lecithin (0 and 2%) and two levels of soy oil (0 and 6%). There were no interactions between lecithin and soy oil for any measurements of growth performance. In general, the inclusion of lecithin or soy oil did not affect (P > .1) ADG but did improve (P < .01) gain/feed during the finishing period and during the entire experiment. During the finishing period, gain/ME intake was improved (P < .01) by both lecithin and soy oil. The use of lecithin as an energy source for pigs was investigated in Exp. 2. Dietary treatments were corn and soybean meal diets with 0, 1, 2, or 3% lecithin. There were no significant differences in performance of pigs as measured by ADG, ADFI, gain/feed, and gain/ME intake among the four lecithin levels. Lecithin did not improve utilization of soy oil by growing-finishing pigs. Furthermore, lecithin was not an efficacious source of supplemental dietary fat for growing-finishing pigs in this study.

Antimicrobial supplementation of growing pigs: the effect of porcine sera fractions on in vitro muscle cell proliferation.

Sera obtained from pigs before and after subtherapeutic levels of ASP250 supplementation (pre and post serum pools) have been subjected to comparative fractionation by using gel filtration and affinity chromatography on immobilized Cibacron Blue F3G-A. Comparable serum fractions obtained from pre- and post-ASP250 blood sera were assayed in muscle cell culture bioassays designed to measure their effect on proliferation. Pre- and post-ASP250 sera were subjected to gel filtration and divided into the following fractions: fraction 1, Kav less than .17; fraction 2, Kav = .17 to .41; fraction 3, Kav = .41 to .59. Post-ASP250 fractions 2 and 3 increased proliferation rate in cultured muscle cells to a greater extent than comparable pre-ASP250 fractions (P less than .001). Chromatography of fraction 3 on immobilized Cibacron Blue F3G-A showed that both pre- and post-ASP250 fraction 3 contained a putative inhibitor of myogenic cell proliferation as well as mitogenic factors. However, negative growth factor activity was greater in pre-ASP250 fraction 3 than in post-ASP250 fraction 3 (P less than .05). Additionally, positive growth factor activity was lower in pre-ASP250 fraction 3 than in post-ASP250 fraction 3 (P less than .05). These data suggest that levels and(or) activities of both positive and negative muscle growth factors in serum may be altered by the addition of antimicrobials to the diets of growing pigs.

In vitro muscle cell proliferation and protein turnover as affected by serum from pigs fed antimicrobials.

The effect of antimicrobial supplementation of pigs on the capacity of their sera to influence proliferation and protein turnover in cultured muscle cells was evaluated. Mitogenic activity of sera increased when pigs were fed ASP250 (P less than .005) or carbadox (P less than .001), whereas the mitogenic activity of serum from pigs receiving the basal diet remained unchanged (P = .5). Additionally, sera from ASP250-fed pigs significantly decreased (P less than .001) total cellular protein degradation compared with sera obtained from the same pigs prior to supplementation. Neither ASP250 nor carbadox stimulated proliferation of myogenic cells when added to the culture media. Inclusion of ASP250 in swine diets altered the composition of their sera in a way that stimulated muscle cell proliferation and reduced the rate of protein degradation in cultured myogenic cells. Likewise, the inclusion of carbadox in swine diets increased the ability of their sera to stimulate cultured muscle cell proliferation.

Limits of medium-chain and long-chain triacylglycerol utilization by neonatal piglets.

Fifteen unsuckled neonatal piglets from three litters were fasted for 2 h after birth then allotted within litter to a 2 x 3 factorial arrangement of treatments and given by stomach tube 2.36, 4.91 or 11.32 g of either (1-14C)-triolein or (1-14C)-trioctanoin/BW (kg).75. The hourly 14CO2 production was measured for 12 h for estimating the oxidation rate of dosed triacylglycerols. The contents of each segment of the digestive tract were collected for 14C and lipid analyses for calculating absorption of the dosed triacylglycerols. Grams of trioctanoin absorbed (P less than .01) and oxidized (P less than .001) by piglets were higher than grams of triolein. The maximum amounts of trioctanoin and triolein absorbed in 12 h were 2.77 +/- .29 and 1.83 +/- .36 g/BW (kg).75, respectively. The maximum amounts of trioctanoin and triolein oxidized in 12 h were 1.60 +/- .14 and .33 +/- .17 g/BW (kg).75, respectively. The maximum amounts of trioctanoin and triolein oxidization during 1-h periods were .231 +/- .017 and .049 +/- .021 g/BW (kg).75, respectively. The calculated maximum percentage of piglets' daily maintenance energy needs supplied by trioctanoin oxidation was 42.0%, compared with 10.6% from triolein. The maximum utilization of trioctanoin occurred at the intermediate dose. Results indicated that trioctanoin was used more effectively than triolein; it may be useful as a source of supplemental energy to improve the survival of piglets. A single dose should provide about 6 g/body wt (kg).75.

Effects of oral doses of corn oil and other factors on preweaning survival and growth of piglets.

Piglets were provided supplemental energy as oral doses of corn oil to find whether such treatment might improve survival or weight gains. A total of 1,840 piglets from 182 litters was used. Piglets were allotted to dosed and control treatments within litter on the basis of body weight. Dosed piglets received a total of 8 ml of corn oil in four doses during the first 48 h postpartum. The survival rate to weaning was high and not affected (P greater than .10) by the corn oil doses. Deaths of piglets low in birth weight were delayed by the fat doses, suggesting some utilization. The fat doses did not affect piglet weight gain. Factors affecting preweaning survival and growth of piglets were also evaluated using data from the same piglets. Specific factors investigated were sex, parity of dam, birth weight, litter size and the mean and standard deviation of piglet birth weights within litters. Male piglets were heavier at birth than females, but there was no sex effect on weight at 7 d or at weaning. Small males were less likely to survive to 3 d than were small females. Litters from primiparous sows were smaller at birth and weaning, but had lower percentages of stillbirths and of preweaning deaths than did those from multiparous sows. Piglets from primiparous sows were more uniform in birth weight. Piglets that were heavier at birth grew faster and were more likely to survive. Litter size affected growth but not survival of piglets. A heavier average birth weight in the litter reduced slightly the growth rate of individual piglets. An increase in variability of piglet birth weight within a litter was associated with an increase of the percentages of stillbirths and of preweaning mortality. A few litters accounted for a major portion of the mortality. Much of the variation in piglet mortality and growth was not explained by factors considered.

Nutritional availability of spray dried lard water protein.

Four growth trials were conducted with rats and chicks to investigate the nutritional value of Spray Dried Lard Water (SDLW--a by-product from the rendering process of animal lard) as a source of protein in a semipurified diet. Weanling rats lost weight when fed a diet containing 10% of SDLW as sole source of protein. Responses of rats to amino acid(s) supplementation indicated tryptophan as the first-limiting amino acid, then threonine, methionine and lysine. One-week-old chicks fed diets containing SDLW to provide 20% crude protein responded to dietary amino acid supplementation. The results suggested that the limiting amino acid sequence of spray dried lard water for chicks was methionine, tryptophan, threonine and lysine, respectively. Results from this study also showed that biological availability of the amino acids in SDLW protein was rather low.

Efficacy of different phosphorus supplements for sows during gestation and lactation.

PIP: This study was undertaken to compare dicalcium, Curacao, and soft ph sophates as supplemental feeding during gestation and lactation. In Exp eriment 1, 37 crossbred sows at 11 months of age were mated and each of 4 groups given an experimental diet. The basal diet was a 16% crude pro tein-fortified corn-soybean meal containing .34% of phosphorus and .72% of calcium. The test diets were fortified with either dicalcium, Curaca o, or soft phosphate to provide .52% of phosphorus. Limestone was given to maintain .72% of calcium. Animals were confined in a concrete feedin g area and fed 1.8 kg of diet per head per day until Day 94 of gestation . At that time the diet was increased to 2.3 kg/day. On Day 109 of gestation animals were moved to farrowing crates until 10 days postpartu m and then to wooden units until weening at 8 weeks. Sows were sacrific ed after 8 weeks lactation, or if they developed posterior paralysis. In this experiment, the different phosphate sources were without observed influence on the livability or performance of pigs up to 8 weeks of age (p less than .05). Gilts receiving no supplemental phosphorus had significantly lower bone ash and phosphorus than did those receiving either of the supplements. Posterior paralysis was observed in 5 of 9 sows fed the unsupplemented diet, in 3 of 9 fed the soft supplemented diet, and in 2 of 10 fed the Curacao phosphate supplement. None fed dicalcium phosphate developed paralysis. The paralysis usually occurred after 6 weeks of lactation and was often accompanied by a fractured femur. In Experiment 2, 70 sows were bred at 10 months of age and fed 1.8 kg of the experimental diets. During 36 days of lactation, phosphorus digestibility, retention, and balance were shown to be lower for those fed only the basal diet. Bone ash, bone phosphorus, and bone strength were lower in those fed the unsupplemented diet. Results of these studies indicate the need for supplemental phosphorus in sow feeding. When feeding dicalcium phosphate or Curacao phosphate the use of over .5% phosphorus in the sow's diet is unnecessary during gestation and lactation.^ieng