Jim L. Nelssen

Conjugated linoleic acid

Conjugated linoleic acid (CLA), first positively identified in 1987 (Ha et al.), is a collective term describing the positional and geometric conjugated dienoic isomers of linoleic acid. Linoleic acid (C18:2) has double bonds located on carbons 9 and 12, both in the cis (c) configuration, whereas CLA has either the cis or trans (t) configuration or both located along the carbon chain. Sources of CLA have been shown to elicit many favorable biological responses including: (i) increased rate and (or) efficiency of gain in growing rats (Chin et al., 1994) and pigs (Dugan et al., 1997; Thiel et al., 1998; O’Quinn PR, Waylan AT, Nelssen JL et al., submitted for publication); (ii) reduced fat deposition and increased lean in mice (Park et al., 1997) and pigs (Dugan et al., 1997; Thiel et al., 1998; O’Quinn et al., 2000a); (iii) improved immune function in rats and chicks (Cook et al., 1993; Sugano et al., 1998); and (iv) reduced atherosclerosis in rabbits (Lee et al., 1994) and hamsters (Nicolosi et al., 1997). Conjugated linoleic acid is also a potent anticarcinogen in vivo and in vitro (Ha et al., 1990; Ip et al., 1991; Durgam and Fernandes, 1997) and may exhibit some antioxidant properties (Decker, 1995), possibly as a result of its involvement in the metabolism of a-tocopherol (O’Quinn et al., 1999). Additionally, CLA increases adipocyte insulin sensitivity (Houseknecht et al., 1998b) and, therefore, has become a highly studied factor for the management of type I (Collier et al., 1988) and type II (Hendra et al., 1991; Singh et al., 1992) diabetes mellitus, a disease affecting over 100 million people in the United States alone (Pickup and Crook (1998).

Effects of dried distillers grains with solubles on growing and finishing pig performance in a commercial environment

Three experiments were conducted to determine the optimal level of dried distiller grains with solubles (DDGS) from a common ethanol manufacturing facility and to determine the potential interactions between dietary DDGS and added fat on performance and carcass characteristics of growing and finishing pigs. All experiments were conducted at the same commercial facility and used DDGS from the same ethanol manufacturing facility. In Exp. 1, a total of 1,050 pigs (average initial BW 47.6 kg), with 24 to 26 pigs per pen and 7 pens per treatment, were fed diets containing 0 or 15% DDGS and 0, 3, or 6% added choice white grease in a 2 x 3 factorial arrangement in a 28-d growth study. Overall, there were no DDGS x added fat interactions (P >/= 0.14). There was an improvement (linear, P < 0.01) in ADG and G:F as the percentage of added fat increased. There was no difference (P = 0.74) in growth performance between pigs fed 0 or 15% DDGS. In Exp. 2, a total of 1,038 pigs (average initial BW 46.3 kg), with 24 to 26 pigs per pen and 10 pens per treatment, were fed diets containing 0, 10, 20, or 30% DDGS in a 56-d growth study. Pigs fed diets containing DDGS had a tendency for decreased ADG and ADFI (both linear, P = 0.09 and 0.05, respectively), but the greatest reduction seemed to occur between pigs fed 10 and 20% DDGS. In Exp. 3, a total of 1,112 pigs (average initial BW 49.7 kg), with 25 to 28 pigs per pen and 9 pens per treatment, were used in a 78-d growth study to evaluate the effects of increasing DDGS (0, 5, 10, 15, or 20%) in the diet on pig growth performance and carcass characteristics. From d 0 to 78, ADG and ADFI decreased linearly (P </= 0.04) with DDGS level, but the greatest reduction seemed to occur between pigs fed 15 and 20% DDGS. Efficiency of gain tended to improve (P = 0.06) when DDGS were included in the diet. There was no effect of DDGS (P = 0.22) on loin depth. Carcass weight and percentage yield decreased (linear, P </= 0.04) with increasing levels of DDGS in the diet. Backfat and fat-free lean index tended to decrease (linear, P </= 0.09) with increasing levels of DDGS in the diet. In conclusion, finishing pigs raised under commercial production conditions can be fed 10 to 15% DDGS from the source evaluated in this study before growth rate is compromised.

Effect of crude glycerol on pellet mill production and nursery pig growth performance

The objective of this study was to determine the effects of diets containing crude glycerol on pellet mill production efficiency and nursery pig growth performance. In a pilot study, increasing crude glycerol (0, 3, 6, 9, 12, and 15%) in a corn-soybean meal diet was evaluated for pellet mill production efficiency. All diets were steam conditioned to 65.5 degrees C and pelleted through a pellet mill equipped with a die that had an effective thickness of 31.8 mm and holes 3.96 mm in diameter. Each diet was replicated by manufacturing a new batch of feed 3 times. Increasing crude glycerol increased both the standard (linear and quadratic, P < 0.01) and modified (linear, P < 0.01; quadratic, P </= 0.02) pellet durability indexes up to 9% with no further benefit thereafter. The addition of crude glycerol decreased (linear; P < 0.01) production rate (t/h) and production efficiency (kWh/t). In a 26-d growth assay, 182 pigs (initial BW, 11.0 +/- 1.3 kg; 5 or 6 pigs/pen) were fed 1 of 7 corn-soybean meal-based diets with no added soy oil or crude glycerol (control), the control diet with 3 or 6% added soy oil, 3 or 6% added crude glycerol, and 6 or 12% addition of a 50:50 (wt/wt) soy oil/crude glycerol blend with 5 pens/diet. The addition of crude glycerol lowered (P < 0. 01) delta temperature, amperage, motor load, and production efficiency. The addition of crude glycerol improved (P < 0.01) pellet durability compared with soy oil and the soy oil/crude glycerol blend treatments. Pigs fed increasing crude glycerol had increased (linear, P = 0.03) ADG. Average daily gain tended to increase with increasing soy oil (quadratic; P = 0.07) or the soy oil/crude glycerol blend (linear, P = 0.06). Adding crude glycerol to the diet did not affect G:F compared with the control. Gain:feed tended to increase with increasing soy oil (linear, P < 0.01; quadratic, P = 0.06) or the soy oil/crude glycerol blend (linear, P < 0.01; quadratic, P = 0.09). Nitrogen digestibility tended (P = 0.07) to decrease in pigs fed crude glycerol compared with pigs fed the soy oil treatments. Apparent digestibility of GE tended (P = 0.08) to be greater in the pigs fed soy oil compared with pigs fed the soy oil/crude glycerol blends. In conclusion, adding crude glycerol to the diet before pelleting increased pellet durability and improved feed mill production efficiency. The addition of 3 or 6% crude glycerol, soy oil, or a blend of soy oil and glycerol in diets for 11- to 27-kg pigs tended to increase ADG. For pigs fed crude glycerol, this was a result of increased ADFI, whereas, for pigs fed soy oil or the soy oil/crude glycerol, the response was a result of increased G:F.

Effects of dried distillers grains with solubles on carcass fat quality of finishing pigs.

A total of 1,112 pigs (initial BW of 49.8 kg) were used in a 78-d study to evaluate the effects of 0, 5, 10, 15, or 20% dried distillers grains with solubles (DDGS) and sex on carcass fat quality of finishing pigs. All diets contained 6% choice white grease and were fed in 4 finishing phases (50 to 59, 59 to 82, 82 to 105, and 105 to 123 kg, respectively). The experiment was conducted in a commercial research finishing barn in southwestern Minnesota. There were 9 replicates of each dietary treatment, with 25 to 28 pigs per pen, and barrows and gilts were distributed equally in each pen. On d 57, the 3 heaviest barrows from each pen were visually selected, removed, and marketed, and a total of 6 pigs per treatment were selected randomly for fatty acid analysis. On d 78, the remaining pigs from each pen were individually tattooed and shipped to a pork processing plant. Jowl fat, backfat, and belly fat samples were collected from 1 barrow and 1 gilt chosen randomly from each pen and analyzed for fatty acid composition. Iodine value (IV) was calculated for diets and fat samples. Fat quality data were analyzed as a split plot with DDGS treatment as the whole plot and sex as the subplot. Concentrations of C18:2n-6, PUFA, and IV increased (linear, P = 0.02) with increasing DDGS in backfat, jowl fat, and belly fat in pigs marketed on d 57 and 78. In contrast, C18:1 cis-9 and MUFA concentrations decreased linearly (P = 0.05) in all 3 fat depots with increasing DDGS. For every 10% DDGS included in the diet, IV of backfat, jowl fat, and belly fat increased by 2.3, 1.6, and 2.2 g/100 g, respectively. In pigs slaughtered on d 78, there were no (P ≥ 0.10) sex × dietary DDGS interactions observed. Compared with barrows, gilts had greater (P < 0.05) C18:2n-6, PUFA, and PUFA:SFA ratio and lesser (P < 0.03) C14:0 concentrations in backfat and belly fat but not jowl fat. Gilts had greater (P = 0.03) belly fat IV than barrows, but there were no (P > 0.25) differences between gilts and barrows in backfat and jowl fat IV. In summary, feeding increasing amounts of DDGS linearly increased the IV of backfat, jowl fat, and belly fat in pigs. Although jowl fat was less responsive to increased DDGS than backfat and belly fat, pigs fed diets with 20% DDGS and 6% choice white grease exceeded the maximum jowl IV of 73 g/100 g set by some packing plants.

Effects of fermented soybean meal and specialty animal protein sources on nursery pig performance.

In 2 experiments, 602 pigs were used to evaluate the effects of fish meal, fermented soybean meal, or dried porcine solubles on phase 2 nursery pig performance. In Exp. 1, nursery pigs (n = 252; PIC TR4 x 1050; 6.8 kg initial BW and 7 d after weaning) were fed: 1) a control diet containing no specialty protein sources and the control diet with 2) 5% fish meal, 3) 3.5% dried porcine solubles, 4) 6.0% fermented soybean meal, 5) a combination of 1.75% fermented soybean meal and 1.75% dried porcine solubles, or 6) a combination of 3.0% fermented soybean meal and 2.5% fish meal. There were 7 replications with 6 pigs per pen. Experimental diets were fed for 14 d, and then all pigs were fed a common diet without specialty protein sources for 14 d. From d 0 to 14, pigs fed dried porcine solubles alone or with fermented soybean meal had improved (P < 0.05) ADG and G:F compared with pigs fed all other diets. Overall (d 0 to 28), pigs fed dried porcine solubles had improved (P = 0.01) ADG (421 vs. 383 g) and G:F (0.77 vs. 0.73) compared with pigs fed the control diet and had improved (P = 0.03) G:F (0.77 vs. 0.74) compared with pigs fed the combination of fermented soybean meal and fish meal. In Exp. 2, nursery pigs (n = 350; PIC C22 x 1050; 6.1 kg initial BW and 7 d after weaning) were fed 1) a control diet containing no specialty protein sources and the control diet with 2) 3% fish meal, 3) 6% fish meal, 4) 3.75% fermented soybean meal, 5) 7.50% fermented soybean meal, 6) a combination of 1.88% fermented soybean meal and 1.88% dried porcine solubles, or 7) a combination of 3.75% fermented soybean meal and 3.75% dried porcine solubles. There were 10 replications with 5 pigs per pen. Experimental diets were fed from d 0 to 14, and then all pigs were fed a common diet without specialty protein sources for 21 d. From d 0 to 14, pigs fed increasing fish meal had increased (quadratic, P = 0.05) ADFI. Pigs fed increasing fermented soybean meal had improved (quadratic, P = 0.01) G:F. Pigs fed the combination of fermented soybean meal and dried porcine solubles had improved (P < 0.05) ADG and G:F compared with pigs fed diets containing fish meal and had improved (P < 0.05) ADG and ADFI compared with pigs fed diets containing fermented soybean meal. Overall (d 0 to 35), pigs fed diets with increasing amounts of fermented soybean meal had improved (quadratic, P = 0.03) G:F. Feeding nursery pigs diets containing dried porcine solubles, either alone or in combination with fermented soybean meal, can improve growth performance compared with those fed high concentrations of soybean meal or fish meal.

Influence of weaning weight and growth during the first week postweaning on subsequent pig performance

This report is brought to you for free and open access by New Prairie Press. It has been accepted for inclusion in Kansas Agricultural Experiment Station Research Reports by an authorized administrator of New Prairie Press. Copyright 1992 Kansas State University Agricultural Experiment Station and Cooperative Extension Service.

Selection of Fecal Enterococci Exhibiting tcrB-Mediated Copper Resistance in Pigs Fed Diets Supplemented with Copper

ABSTRACT Copper, as copper sulfate, is increasingly used as an alternative to in-feed antibiotics for growth promotion in weaned piglets. Acquired copper resistance, conferred by a plasmid-borne, transferable copper resistance (tcrB) gene, has been reported in Enterococcus faecium and E. faecalis. A longitudinal field study was undertaken to determine the relationship between copper supplementation and the prevalence of tcrB-positive enterococci in piglets. The study was done with weaned piglets, housed in 10 pens with 6 piglets per pen, fed diets supplemented with a normal (16.5 ppm; control) or an elevated (125 ppm) level of copper. Fecal samples were randomly collected from three piglets per pen on days 0, 14, 28, and 42 and plated on M-Enterococcus agar, and three enterococcal isolates were obtained from each sample. The overall prevalence of tcrB-positive enterococci was 21.1% (38/180) in piglets fed elevated copper and 2.8% (5/180) in the control. Among the 43 tcrB-positive isolates, 35 were E. faecium and 8 were E. faecalis. The mean MICs of copper for tcrB-negative and tcrB-positive enterococci were 6.2 and 22.2 mM, respectively. The restriction digestion of the genomic DNA of E. faecium or E. faecalis with S1 nuclease yielded a band of ∼194-kbp size to which both tcrB and the erm(B) gene probes hybridized. A conjugation assay demonstrated cotransfer of tcrB and erm(B) genes between E. faecium and E. faecalis strains. The higher prevalence of tcrB-positive enterococci in piglets fed elevated copper compared to that in piglets fed normal copper suggests that supplementation of copper in swine diets selected for resistance.

Feed additives for swine: Fact sheets – high dietary levels of copper and zinc for young pigs, and phytase

This is the fourth in a series of peer-reviewed Practice tip articles, each including two or three fact sheets. Previous practice tips included fact sheets on acidifi ers and antibiotics in the September-October issue (J Swine Health Prod. 2009;17:270–275); on carcass modifi ers, carbohydrate-degrading enzymes, and proteases, and anthelmintics in the November-December issue (J Swine Health Prod. 2009;17:325–332); and on fl avors and mold inhibitors, mycotoxin binders, and antioxidants in the January-February issue (J Swine Health Prod. 2010;18:27–32) Future fact-sheet topics will include probiotics and prebiotics and phytogenic feed additives (phytobiotics or botanicals).

Feed additives for swine: Fact sheets – prebiotics and probiotics, and phytogenics

This is the last in a series of fipeer-reviewed Practice tip articles, each including two or three fact sheets. Previous practice tips included fact sheets on acidifi ers and antibiotics in the September-October issue ( J Swine Health Prod. 2009;17:270–275); on carcass modifi ers, carbohydrate-degrading enzymes, and proteases, and anthelmintics in the November-December issue (J Swine Health Prod. 2009;17:325–332); on fland mold inhibitors, mycotoxin binders, and antioxidants in the January-February issue (J Swine Health Prod. 2010;18:27–32); and on high dietary levels of copper and zinc for growing pigs and phytase in the March-April issue (J Swine Health Prod. 2010;18:87-91).

Effects of copper sulfate, tri-basic copper chloride, and zinc oxide on weanling pig performance

Three experiments were conducted to evaluate the effects of increasing dietary Cu and Zn on weanling pig performance. Diets were fed in 2 phases: phase 1 from d 0 to 14 postweaning and phase 2 from d 14 to 28 in Exp. 1 and 2 and d 14 to 42 in Exp. 3. The trace mineral premix, included in all diets, provided 165 mg/kg of Zn from ZnSO(4) and 16.5 mg/kg of Cu from CuSO(4). In Exp. 1, treatments were arranged in a 2 × 3 factorial with main effects of added Cu from tri-basic copper chloride (TBCC; 0 or 150 mg/kg) and added Zn from ZnO (0, 1,500, or 3,000 mg/kg from d 0 to 14 and 0, 1,000, or 2,000 mg/kg from d 14 to 28). No Cu × Zn interactions were observed (P > 0.10). Adding TBCC or Zn increased (P < 0.05) ADG and ADFI during each phase. In Exp. 2, treatments were arranged in a 2 × 3 factorial with main effects of added Zn from ZnO (0 or 3,000 mg/kg from d 0 to 14 and 0 or 2,000 mg/kg from d 14 to 28) and Cu (control, 125 mg/kg of Cu from TBCC, or 125 mg/kg of Cu from CuSO(4)). No Cu × Zn interactions (P > 0.10) were observed for any performance data. Adding ZnO improved (P < 0.02) ADG and ADFI from d 0 to 14 and overall. From d 0 to 28, supplementing CuSO(4) increased (P < 0.02) ADG, ADFI, and G:F, and TBCC improved (P = 0.006) ADG. In Exp. 3, the 6 dietary treatments were arranged in a 2 × 2 factorial with main effects of added Cu from CuSO(4) (0 or 125 mg/kg) and added Zn from ZnO (0 or 3,000 mg/kg from d 0 to 14 and 0 or 2,000 mg/kg from d 14 to 42). The final 2 treatments were feeding added ZnO alone or in combination with CuSO(4) from d 0 to 14 and adding CuSO(4) from d 14 to 42. Adding ZnO increased (P < 0.04) ADG, ADFI, and G:F from d 0 to 14 and ADG from d 0 to 42. Dietary CuSO(4) increased (P < 0.004) ADG and ADFI from d 14 to 42 and d 0 to 42. From d 28 to 42, a trend for a Cu × Zn interaction was observed (P = 0.06) for ADG. This interaction was reflective of the numeric decrease in ADG for pigs when Cu and Zn were used in combination compared with each used alone. Also, numerical advantages were observed when supplementing Zn from d 0 to 14 and Cu from d 14 to 42 compared with all other Cu and Zn regimens. These 3 experiments show the advantages of including both Cu and Zn in the diet for 28 d postweaning; however, as evident in Exp. 3, when 3,000 mg/kg of Zn was added early and 125 mg/kg of Cu was added late, performance was similar or numerically greater than when both were used for 42 d.