Browsing by Author "Lindemann, M. D."
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- An assessment of the effects of dietary folic acid supplementation on serum folates status, conceptus development and reproductive performance in gilts and sowsHarper, Allen F. (Virginia Tech, 1992-04-05)The effects of dietary folic acid supplementation on serum folate status, conceptus development and reproductive performance in gilts and sows was investigated in a series of experiments. The specific objectives of the study were to: 1) to study the serum folates profile following rapid consumption of a single meal containing different levels of supplemental folic acid; 2) to study the effects of maternal folic acid supplementation on conceptus survival, growth and development prior to mid-gestation in gilts and sows; and 3) to study the effects of multiple levels of dietary folic acid supplementation on sow reproductive performance over four successive parities. In the first experiment (Chapter III), gilts fed a single, rapidly consumed meal, had a rapid increase in serum folates concentration during the first hour postprandial. Within eight hours after feeding, serum folates in the gilts had returned to near prefeeding levels. The results also suggest that supplementing the diet with increasing levels of folic acid over a range of 0 to 4 ppm results in more rapid postprandial uptake and elimination of folic acid from general circulation. In the second experiment (Chapter IV), supplementing the diet of first parity and third parity breeding sows with 2 ppm folic acid had no effect on litter size at day 45 of gestation. However, several measurements associated with placental and fetal growth were increased with folic acid supplementation. Results of a fifth parity trial with four levels of supplemental folic acid were variable and inconclusive. The implications of increased placental and fetal growth up to day 45 of gestation in the first and third parity sows is discussed. In the third experiment (Chapter V), a decline in serum folate concentration in pregnant sows from mating to mid- to late gestation was clearly demonstrated. Supplementing the sow's diet with folic acid over a range of 0 to 4 ppm resulted in a linear increase in serum folate concentration at mating, during gestation and at weaning. However, under the conditions of this experiment, folic acid supplementation had no significant effect on sow reproductive performance.
- An assessment of the effects of dietary oil supplementation on fetal survival in gilts at 40 days of gestationRigau, Alberto Pérez (Virginia Tech, 1993-06-15)Eighty-six crossbred (Duroc x Yorkshire) gilts were used in two trials (50 gilts in Trial 1 and 36 gilts in Trial 2) for an assessment of the effect of supplemental dietary fat during early gestation on fetal survival, fetal development, and fatty acid concentration in gilt plasma and fetal head and body. Three diets contained 4% (w/w) added fat either as coconut, soybean, or fish (menhaden) oils. A fourth diet was used as a control. On d 37 to 45 postbreeding, gilts were slaughtered and numerous fetal and ovarian measurements made. Two sets of four randomly selected fetuses per gilt from Trial 1 were prepared. Blood samples from each gilt were obtained on the day of slaughter for determination of the plasma fatty acid profile. Across both trials, percentage fetal survival did not differ according to treatment, but in Trial 2 fetal survival was higher (P < .06) for gilts fed fish oil, compared with the controls. The fatty acid profile of plasma of gilts and the conceptus tissues were similar; both were influenced by the fatty acid concentration of the diets. The ratio of n-3/n-6 fatty acids was higher in conceptus tissue than in maternal plasma and the ratio was higher (P < .05) for the fish oil diet compared with the other diets. The relatively high concentration of omega-3 fatty acids in fetal tissues supports the hypothesis that omega-3 fatty acids play a role in the development of the pig conceptus and contributes to improve fetal survival. However, the high percentage fetal survival observed in all the treatments may have masked benefits of supplemental oil.
- The effect of feeding varying levels of Bifidobacterium globsum a on the performance, scouring index, gastrointestinal measurements and immunity of weanling and growing-finishing pigsAgar, Gary A. (Virginia Tech, 1991-08-14)Four trials using 312 weanling pigs (average initial wt of 7.2 kg) were conducted to examine the effectiveness of Bifidobacterium globsum a (BGA) on the growth performance, scour scores, humoral and cell-mediated immune response and pH and chloride ion concentration (CIC) of feces and gastrointestinal section contents. The effect of continuous feeding of BGA from weaning to market weight on performance and carcass characteristics was evaluated using pigs from Trial 3 (n=80). Dietary treatments were 0, 5.0 x 104 , 6.7 x 106 and 7.5 x 108 colony forming units (CFU)/d in Trial 1 and 0, 6.0 x 104 , 5.0 x 105 and 5.0 x 106 CFU/d in Trials 2 through 4 and the grower-finisher trial. In Trial 1, ADG was effected quadratically at wk 1-2 and 1-5 (P < .05) and wk 3-5 (P < .01) with pigs fed the medium (6.7 x 106 ) BGA level having higher ADG than control pigs. Quadratic diet effects were also observed for average daily feed intake (ADFI) at wk 1-2, 1-5 (P < .10) and 3-5 (P < .05) with pigs fed the medium level of BGA having greater ADFI than control.
- Effects of group-size-floor space allowance during the nursery phase of production on future litter size and retention of sows through three paritiesCallahan, Stuart Russell; Cross, A. J.; DeDecker, A. E.; Lindemann, M. D.; Estienne, Mark J. (Oxford University Press, 2020-01-01)We previously reported that reduced floor space allowance caused by increasing the number of gilts per pen decreased growth and affected blood chemistry and immunology. The current objective was to determine effects of nursery group-size-floor space allowance on future litter sizes and retention in the breeding herd through three parities in sows. A 3 × 3 factorial arrangement of treatments was employed with 2,537 gilts classified as large (6.92 ± 0.06 kg), medium (5.60 ± 0.06 kg), or small (4.42 ± 0.06 kg), and placed in nursery pens of 14, 11, or 8 pigs to allow 0.15, 0.19, or 0.27 m2 floor space/pig, respectively. After the nursery and grow-finish periods, 1,453 gilts selected for breeding were relocated to one of 11 sow farms. Total litter size and pigs born alive increased (P < 0.01) with increasing parity and total litter size was 12.94, 13.28, and 13.99 (SE = 0.13) and pigs born alive was 12.21, 12.64, and 13.23 (SE = 0.11) for Parities 1, 2, and 3, respectively. There was a tendency (P = 0.08) for a quadratic relationship of group-size-floor space allowance and total litter size (13.39, 13.54, and 13.27 [SE = 0.13] for gilts allowed 0.15, 0.19, or 0.27 m2 floor space/pig, respectively). A linear effect of size of pig at weaning (P = 0.03) on pigs born dead was detected and was 0.64, 0.75, and 0.75, for small, medium, and large size pigs, respectively. There was no effect of group-size-floor space allowance on the percentages of gilts completing zero (P = 0.36), one (P = 0.35), two (P = 0.32), or three (P = 0.50) parities. In contrast, the percentage of small gilts that failed to complete one parity was greater (P < 0.05) and the percentage completing one parity (P < 0.05) was less than for either large or medium gilts. Abortion rate was greater (P < 0.01) in gilts classified as small (2.51%) or medium (1.36%) at weaning compared with those classified as large (0.20%). Size at weaning did not affect the proportion of gilts completing two (P = 0.88) or three (P = 0.72) parities. Group-size-floor space allowance during the nursery phase of production did not have remarkable effects on future litter sizes or retention in sows. Likewise, size of pig at weaning did not affect litter size and pigs born alive. Compared with larger pigs, however, more pigs classified as small at weaning and entering the breeding herd did not complete a parity and displayed a greater abortion rate.
- Evaluation of a copper lysine complex and copper sulfate in weanling and finishing pigs, and the effect of copper supplementation on circulating growth hormone and IGF-1 levelsApgar, Gary Allen (Virginia Tech, 1994-12-12)The objectives of this research were 1) to evaluate CuS0₄ and a CU lysine complex (CuLys) as growth promotants for weanling pigs, 2) to assess the effects of feeding growth stimulating levels of Cu from both sources on dry matter digestibility (DMO) and mineral balance of finishing pigs, and 3) to examine the effect of feeding elevated CU on serum growth hormone and IGF-1 levels. Two trials (176 pigs) were conducted in which pigs were fed 0, 100, 150, or 200 mg/kg Cu from CUS0₄ or CuLys. Elevated Cu increased daily gain and feed intake linearly, with no difference between the sources. Dietary CU linearly increased liver, kidney (P < .001), and brain (P < .05) Cu stores. In the liver, the linear response between the sources was different (P < .001); pigs fed 200 mg/kg Cu from CuLys had the highest CU concentration. Serum CU increased linearly with no difference between the two sources. Serum mitogenic activity increased linearly during wk 1 to 2 and 1 to 5 (P < .05), with no difference between the two sources. Twenty-four barrows were used to examine the effect of Cu additions from both Cu sources on digestibility and mineral balance. Pigs fed Cu from CuLys tended to have greater DMD when compared with controls (P < .10), but percentage of Cu absorbed was not different among the treatments. Pigs fed Cu from both sources absorbed more eu than controls (P < .01), with no difference between sources. Pigs fed CuS0₄ (P < .027) and CuLys (P < .101) absorbed more Fe than controls but Zn balance was not affected. Twelve pigs were cannulated after 7 wk of growth to quantify the effect of elevated dietary Cu on circulating growth hormone and IGF-1 levels. Growth performance was not improved by added Cu, but efficiency of gain was greater for pigs fed Cu when compared with controls (P < .101). Baseline growth hormone secretion was greater in pigs fed Cu (P < .06) for three of four days; however, average concentrations were not affected by diet. Concentrations of IGF-1 were higher in control pigs (P < .05).
- Methionine and glucose transport by isolated intestinal brush border membrane vesicles from pigs and lambs fed an Aspergillus productJang, Insurk (Virginia Tech, 1993-10-05)This study was designed to determine whether feeding an Aspergillus product would influence growth or feed utilization and intestinal mucosal cell function as indicated by uptake of methionine and glucose by isolated intestinal brush border membrane vesicles (BBMV). In Experiment 1, 24 weanling pigs were paired by sex, BW, and litter and were allotted, within pairs, to either an 18% CP corn-soy diet (control) or the same diet supplemented (.15%) with an Aspergillus product. There were no differences (P > .05) in ADG, daily feed intake, or feed/gain between the two groups. In Experiment 2, 24 weanling wether lambs were paired by BW and were randomly assigned within pair to a 14% CP diet containing 61.1 % cracked corn, 17.3% soybean meal, and 15% ground orchard grass hay (control) or the same diet fortified (.07%) with an Aspergillus product. There were no differences (P > .05) in ADG, daily feed intake, or feed/gain between the two groups. Enrichment of alkaline phosphatase in BBMV used in transport studies were 12.7-fold higher in pigs and 5.6-fold higher in lambs over the original homogenate.
- Response of early weaned pigs to an escherichia coli challege and their absorption to ovalbumin or xylose as influenced by creep feedingRisley, Chad Richard (Virginia Tech, 1987-06-05)The effect of exposure to creep feed at 10 d of age vs no exposure to creep feed or sow's feed on the ability of pigs weaned at 21 d of age to respond to an oral challenge of E. coll or to absorb ovalbumin or xylose was investigated. Eighty pigs (45 exposed, 35 control) were orally challenged 24 h after weaning with 3x1011 organisms of E. coli (0157 H88AC:H43); control pigs tended (P<.10) to scour more than the exposed pigs (46% vs 27%). Ovalbumin absorption was similar for both exposed and control pigs (P>.10), but absorption for both treatments increased (P<.001) from d 1 to d 4 and decreased to d 13 (P<.001). Xylose absorption was less (P<.02) at d 1 for exposed pigs compared with control pigs (0.781 vs .825 mmol) with no differences (P>.20) occurring thereafter. Lowest xylose absorption for both treatments occurred on d 7. Creep feeding conferred some protection to the E. coll challenge, but had little effect on intestinal absorption of ovalbumin and xylose.