Greater Gain Efficiency Research Articles

A systems approach to evaluate nitrogen utilization efficiency and environmental impacts of swine growing-finishing feeding programs in U.S. pork production systems.

Traditionally, swine diets have been formulated to meet nutrient requirements at the lowest cost with little regard toward minimizing environmental impacts. The overall objective of this study was to evaluate the relative differences among four grower-finisher feeding programs, using precision diet formulation practices, on growth performance, carcass composition, nitrogen utilization efficiency, and environmental impacts. In Exp. 1, four 4-phase growing-finishing feeding programs consisting of diets containing corn and soybean meal (CSBM), low protein CSBM supplemented with crystalline amino acids (LP), CSBM with 30% distillers dried grains with solubles (DDGS), and DDGS supplemented with crystalline Ile, Val, and Trp (DDGS+IVT) were fed to 288 mixed sex pigs (initial BW = 36.9 ± 4.2kg) for 12-wk to determine effects on growth performance and carcass characteristics. Pigs fed CSBM had greater (P < 0.05) final BW than those fed LP and DDGS, and greater gain efficiency than pigs fed LP. Pigs fed DDGS+IVT tended to have greater (P = 0.06) backfat depth than pigs fed DDGS, and less (P < 0.05) loin muscle area than pigs fed CSBM. In Exp. 2, nitrogen (N) and phosphorus (P) balance of barrows (n = 32; initial BW = 59.9 ± 5.1kg) fed each of the phase-2 diets from Exp. 1 was determined in a 12-d metabolism study (7-d adaptation and 5-d collection). Pigs fed CSBM had a greater (P < 0.05) amount of N retained than pigs fed other diets, but also had a greater (P < 0.05) amount of urinary N excretion and blood urea N than pigs fed LP and DDGS+IVT diets. Pigs fed LP tended (P = 0.07) to have the greatest N utilization efficiency but the least (P < 0.05) P retained as a percentage of P intake among dietary treatments. Diet composition and data collected from Exp. 1 and 2 were used to calculate life cycle assessment environmental impacts using Opteinics™ software (BASF, Lampertheim, Germany). The CSBM feeding program had the least impact on climate change, marine and freshwater eutrophication, and fossil resource use. The LP feeding program had the least impact on acidification, terrestrial eutrophication, and water use, while the DDGS feeding programs had the least impact on land use. These results indicate that feeding corn-soybean meal diets optimized growth performance and carcass composition while simultaneously reducing impacts on climate change, marine and freshwater eutrophication, and fossil resource use compared with the other feeding programs evaluated.

340 Growth Performance and Carcass Characteristics of Beef Steers Consuming Finishing Diets with an Added Nutritional Packet in a Calf-fed System

Abstract The effects of a nutritional packet containing a direct-fed microbial combined with vitamins/electrolytes offered to beef steers in a calf-fed system on growth performance and carcass characteristics were evaluated. Angus crossbred steer-calves (n = 60; BW = 234 ± 4 kg) were assigned to a randomized complete block design (block = body weight; steer = experimental unit) and stratified into two treatments: a) control (no packet, finely-ground corn carrier only); and b) 30 g of DM/animal-daily of a nutritional packet [live-yeast (Saccharomyces cerevisiae; 8.7 Log CFU/g), Vitamin C (5.4 g/kg of Ascorbic acid), Vitamin B1 (13.33 g/kg of Thiamine hydrochloride), and electrolytes of sodium chloride (80 g/kg) and potassium chloride (80 g/kg)]. Animals were individually offered [electronic feed-bunks (Smart-Feed/C-Lock Inc.)] a steam-flaked corn-based finishing diet ad libitum, once daily for 233 d. Treatments were offered during the first (phase-1) and last (phase-2) 60 d on feed. Body weight measurements were taken every 30 d before feeding. Data were analyzed using the GLIMMIX procedure of SAS. Steers offered the nutritional packet had 14% less (P &amp;lt; 0.01) intake and 18% greater gain efficiency during the initial 30-d on feed, while such advantage did not (P ≥ 0.26) persist when accounting for the initial 60 d for either variable. Overall intake (d0 to d233) was 6% greater (P = 0.02), while carcass-adjusted ADG (1.61 vs. 1.56), and carcass-adjusted gain efficiency (0.198 vs. 0.204) were unaffected (P ≥ 0.44) compared with control, respectively. Dressing percent of steers offered the packet was 1 percentage-unit greater (P = 0.02), while other carcass variables were unaffected (P ≥ 0.33). Calf-fed steers seem to benefit from such nutritional packet during the initial 30 d after feedlot arrival, while both superior intake and dressing percentage appears to last until cattle harvest.

Effects of housing beef cow-calf pairs on drylot or pasture in the Midwest on production parameters and calf behavior through feedlot receiving.

The objectives were to analyze the effects of housing cow-calf pairs in drylots (DL) or pasture (PAST) on cow performance and reproduction as well as calf performance and behavior through feedlot receiving. Simmental × Angus (2 yr; 108/yr; 81 ± 15.3 d postpartum) spring-calving cows were stratified by age, body weight (BW), body condition score (BCS), and calf sex and allotted to six groups per year. Groups were randomly assigned to one of two treatments: DL or PAST. Cows in DL were limit-fed at maintenance and calves had ad libitum access to the cow diet in an adjacent pen. Pairs on PAST were rotationally grazed and calves received creep ad libitum 3 wk prior to weaning. On day 110, calves were fence-line weaned and behavior was observed on days 111 and 112. On day 116, calves were transported 272 km to a feedlot for a 42-d receiving period. Behavior was evaluated again on days 117 and 118. Data were analyzed using the MIXED procedure of SAS except reproductive data which was analyzed using the GLIMMIX procedure. Cows on DL had greater (P ≤ 0.01) BW and BCS at weaning. There were no differences (P ≥ 0.42) detected in reproductive data. Cows on DL had greater (P = 0.02) milk production. Calves on DL had greater BW (P ≤ 0.01) on day 55 and at weaning and greater preweaning average daily gain (ADG). There were treatment × time effects (P = 0.01) for lying and eating on days 111 and 112. More DL calves were eating in the morning and lying in the evening. More (P < 0.01) PAST calves were walking on day 111. Pasture calves vocalized more (P ≤ 0.01) on day 112. On day 117, more (P ≤ 0.05) pasture calves were lying and eating, and DL vocalized more. On day 118, treatment × time and treatment effects were detected (P ≤ 0.02) for lying and walking. More PAST calves were lying and more DL calves were walking. Drylot calves had greater (P ≤ 0.02) BW at the beginning and end of the receiving phase. Pasture calves had greater (P < 0.01) ADG and tended (P = 0.10) to have greater gain efficiency during feedlot receiving phase. In conclusion, housing cow-calf pairs in drylots improved BW, BCS, and milk production of cows but did not affect reproductive performance. Drylot calves had increased BW and ADG during the preweaning phase. Calf behavior at weaning and receiving was influenced by preweaning housing. Pasture calves had improved receiving phase ADG and feed efficiency but were still lighter than drylot calves after 42-d receiving phase.

Influence of forage NDF level and source in growing–finishing diets on growth performance of feedlot lambs

ABSTRACTThe effect of two forage neutral detergent fiber (NDF) levels (6 vs. 9%) and two forage sources (sorghum stover vs. alfalfa hay) on growth performance was evaluated in 20 feedlot lambs (17.45 ± 2.75 kg) for a 60-d feeding-period. Final longissimus area and subcutaneous fat were measured by ultrasound. There were no treatment interactions. Lambs receiving sorghum stover had greater gain efficiency (p = .04), estimated dietary net energy (NE; p = .04), longissimus area (p = .02) and tended to greater average daily gain (ADG; p = .06) than lambs fed alfalfa hay. Lambs receiving 6% forage NDF had greater ADG (p = .03), gain efficiency (p = .03) and tendency toward for dietary NE (p = .06) than those fed 9% forage NDF. Treatments did not influence subcutaneous fat. In conclusion, at equivalent forage NDF level, sorghum stover may be superior to alfalfa hay for feedlot lambs which may depress growth performance at 9% forage NDF in isocaloric diets including a 50:50 blend of whole and ground sorghum grain.

Utilization of distillers grains from the fermentation of sorghum or corn in diets for finishing beef and lactating dairy cattle.

Beef finishing and dairy lactation experiments were conducted to evaluate the nutritional value of distillers grains (DG) from sorghum or corn fermentation, in both wet (35.4% DM) and dry (92.2% DM) form (dairy trial only). In the finishing experiment, 60 yearling steers were used in a completely randomized design with three diets that were fed for 127 d: 1) control diet with 86% (DM basis) dry-rolled corn and no DG; 2) 30% of ration DM as wet corn DG in place of dry-rolled corn; and 3) 30% of ration DM as wet sorghum DG in place of dry-rolled corn. All diets contained a minimum of 6.8% degradable intake protein and 13.0% CP. Steers fed DG had 10% greater ADG (< 0.01) and 8% greater efficiency of gain (P < 0.01) than steers fed the control diet. Wet corn and sorghum DG resulted in similar ADG and efficiency of gain. Hot carcass weights, fat thickness, and yield grades were greater for steers fed DG than for controls (P < 0.07). Improvements in ADG and feed efficiency observed when DG replaced dry-rolled corn indicated that the NEg content of wet DG is approximately 29% greater than that of dry-rolled corn. In the dairy lactation experiment, 16 lactating Holstein cows (eight multiparous, including four fistulated) were used in a replicated 4 x 4 Latin square design with 4-wk periods. Corn and sorghum DG were fed at 15% of the ration DM in either wet or dry form. Diets were fed as total mixed rations that contained 50% of a 1:1 mixture of alfalfa and corn silages, 24.3% ground corn, and 9.1% soybean meal (DM basis). There was no effect of source or form of DG on DMI, ruminal pH and VFA, or in situ digestion kinetics of NDF from DG. Efficiency of milk production was unaffected by diet. Corn and sorghum DG resulted in relatively similar performance when fed to beef or dairy cattle in this study.

Neutral detergent fiber concentration in corn silage influences dry matter intake, diet digestibility, and performance of Angus and Holstein steers.

Twelve Angus (237 +/- 13 kg) and twelve Holstein (235 +/- 15 kg) steers were used to determine whether corn silage-based diets with different NDF levels influence DMI to a similar extent in Angus and Holstein steers and as body weight of the steers increase. Steers were randomly assigned to individual slatted-floor pens and used in a crossover design consisting of six 14-d periods. Experimental diets contained corn silage from a normal hybrid (low-fiber; LF) and its male-sterile counterpart (high-fiber; HF) and were alternated each period. The LF and HF diets contained 33.8 and 50.8% NDF, respectively. The HF diet decreased (P < 0.01) overall steer mean DMI 14.0% relative to LF, with mean differences increasing as steers increased in BW (P < 0.01). Feeding the HF diet also reduced ADG by an average of 13.8% relative to the LF diet (P < 0.01). Holstein steers consumed 14.4% more DM and gained 14.3% faster (P < 0.01) than Angus steers. There was a fiber level x breed-type interaction (P = 0.08) for efficiency of gain. Angus steers receiving the HF diet had greater efficiency of gain than Angus steers consuming the LF diet; however, Holstein steers consuming the LF diet had greater efficiency of gain than those receiving the HF diet. The HF treatment reduced total-tract digestibility of DM and GE by 4.6 and 4.5%, respectively (P < 0.01), and decreased DE intake by 20.5% (P < 0.01) but increased apparent totaltract digestibility of NDF and ADF (9.4 and 8.4%, respectively; P < 0.01). Holstein steers had similar digestibility of DM and GE (P > 0.10) but had greater DE intake (P < 0.01) compared to Angus steers. There were fiber level x breed-type interactions for total-tract digestibility of NDF and ADF (P < 0.06). The difference in DM digestibility was negatively associated with the difference in DMI (r2 = 0.23; P < 0.01) for LF minus HF within Angus steers, but not within Holstein steers (P = 0.42). Total-tract digestibility of NDF and ADF was 4.1 and 3.4% lower for the HF diet but was only 1.1 and 0.6% lower for the LF diet when fed to Holstein compared to Angus steers. Results from this trial demonstrate that high-NDF corn silage-based diets reduced intake of both Angus and Holstein steers, and this reduction in DMI continued as steers increased in BW from 235 to 330 kg. Breed differences were also noted for digestible energy intake as influenced by fiber level.

Growth performance, carcass characteristics, and sensory attributes of boars administered porcine somatotropin by sustained-release implant for different lengths of time.

We investigated the effect of sustained-release implant administration of porcine somatotropin (pST) (4 mg/d) to male pigs for different lengths of time before slaughter. Crossbred white boars were assigned to six groups (n = 10/ group); B0, non-implanted boars; B6, boars implanted from 22 to 28 wk of age; B12, boars implanted from 16 to 28 wk of age; B18, boars implanted from 10 to 28 wk of age;C0, non-implanted castrates; and C18, castrates implanted from 10 to 28 wk of age. Castration was at 65 d of age. All pigs were slaughtered at 28 wk of age, and measures of offal and carcass components were recorded. Loin chops were collected for sensory evaluation. During the trial the pigs were maintained in individual pens with ad libitum access to water and a 19% CP corn-soybean meal diet containing 1.08% calculated lysine. Although pST reduced feed intake in castrates (P < .01), the effect in boars was nonsignificant. Slaughter weight was increased in a linear (P < .04) manner with length of pST treatment of boars, and slaughter weights of castrates given pST were greater (P < .01) than those of control castrates. The product of the changes in feed intake and gain resulted in greater efficiency of gain in pST-treated pigs than in control pigs (P < .01). A linear effect (P < .06) of length of pST treatment on trimmed lean cut weights of boars was noted. The weights of trimmed lean cuts produced by castrates treated for 18 wk with pST and boars treated for 12 or 18 wk were similar. Boars given pST for 18 wk had improved (P < .10) boar taint scores compared with untreated boars. Boars and castrates given pST for 18 wk had a similar rates of gain and weights of trimmed lean cuts. Efficiencies of gain were greater in pST-treated boars and castrates than in untreated boars, which were superior to untreated castrates in efficiency of gain.

Influence of Porcine Somatotropin Administration and Sex on Glucose and Endocrine Responses in Obese Pigs

The endocrine and hyperglycemic responses to chronic administration of exogenous porcine somatotropin (pST) were investigated in genetically obese intact and castrate male (boars and barrows) and female (gilts) swine. Somatotropin was administered at a dose of 4 mg.pig-1/day by daily im injection. After a 26-hr fast on Day 22 of treatment, a loading dose of glucose (0.5 g/kg body wt) was administered iv, and blood samples were collected to determine parameters of glucose clearance and responses to a glucose bolus. Blood samples were assayed for glucose, insulin, insulin-like growth factor (IGF)-I, IGF-II, and pST. On Day 24 of treatment, blood samples were similarly collected every 15 min for 8 hr, to examine metabolic and endocrine measures in the fed state. After collection of the 6-hr sample, porcine growth hormone-releasing factor (pGHRF, 0.5 microgram/kg body wt) was administered iv. Administration of pST reduced feed consumption, increased gain, and resulted in 50% greater efficiency of gain. Plasma glucose was increased with pST treatment in both fasted (44%) and fed (64%) pigs. After administration of glucose bolus, glucose distribution volume and half-life (t1/2) were approximately doubled and MCR was reduced 75% in pST-treated pigs. Peak glucose-induced insulin concentrations were increased in pST-treated gilts and barrows but not boars. Concentrations of IGF-I were increased with pST treatment. Concentrations of pST during the sampling periods were influenced by sex and pST treatment. Control pigs responded to GHRF administration with increased plasma concentrations of pST, whereas, no pST response to GHRF administration was observed in the pST-treated pigs. The glucose and insulin results indicate chronic administration of pST to gilts and barrows induces insulin insensitivity and enhances insulin responses to a glucose challenge. The differences among the sexes in pST concentrations in the pST-treated pigs suggest differences in sexual differentiation or activation of the mechanisms of pST clearance.

Effects of hammermills and roller mills on growth performance, nutrient digestibility, and stomach morphology in finishing pigs (1993)

The effects of particle size and mill type used to grind corn were determined with 128 pigs (122 lb average initial body wt). Treatments were corn ground in a hammermill and a roller mill to 800 and 400 μm. The roller mill was more efficient than the hammermill when grinding the corn, with less energy consumption and greater production rate per horsepower hour. For the 800 μm treatments, greater uniformity of particle size was achieved with the roller mill than the hammermill; however, at the 400 μm treatments, corn ground with the hammermill was slightly more uniform. Pigs fed corn ground to 400 μm had 7% greater efficiency of gain, and had greater digestibilities of dry matter, nitrogen, and energy than pigs fed corn ground to 800 μm. Mill type did not affect growth performance, but pigs fed corn ground in the roller mill had greater digestibilities of dry matter, nitrogen, and energy and excreted 18% less dry matter and 13% less nitrogen as feces than pigs fed corn ground in a hammermill. There were interactions among mill type and particle size, with digestibilities much greater for the diet with corn ground to 800 μm in the roller mill compared to the hammermill, but only small advantages in nutrient digestibility for diets with corn ground to 400 μm in the roller mill. Mill type did not affect rate or efficiency of gain, but pigs fed diets with roller-milled corn had greater digestibilities of nutrients and, thus, lower excretions of nutrients in feces.; Swine Day, Manhattan, KS, November 18,1993

Does diet form (pelleted vs meal) affect optimum particle size of corn for finishing pigs? (1992)

One hundred and sixty pigs, with an average initial wt of 121 lb, were used in an experiment to determine the effects of diet form and particle size on growth performance and nutrient digestibility. The pigs were fed corn-soybean meal-based diets with the corn milled to particle sizes of 1,000, 800, 600, or 400 p,m. The diets were fed in meal and pellet forms. In general, reducing particle size increased electrical energy required for milling and decreased production rate. Milling to 400 p,m, as opposed to 600 JLm, required twice as much electrical energy and reduced production rate by 50%. Reducing particle size of the corn from 1,000 to 400 p,m resulted in a 4% increase in DE of the diets and 6% decrease in ADFl. The net result was similar DE intakes, with 22% less daily fecal excretion of DM, 25% less daily fecal excretion of N, and 7% greater efficiency of gain when particle size was reduced from 1,000 to 400 /Lm. Pelleting the diets resulted in 3% greater ADG and 6% greater efficiency of gain. Also, pelleting increased digestibilities of DM, N, and GE by 5 to 7 %. Stomach keratinization and lesions increased with reduced particle size and pelleting, but performance was not affected. In conclusion, particle size reduction and pelleting improved efficiency of gain and decreased daily excretion of DM and N in the feces, with some increase in ADG because of pelleting.; Swine Day, Manhattan, KS, November 19, 1992

Effects of pelleting low-lysine diets with fermentation products for weanling pigs (1991)

One hundred twenty pigs (13.2 lb avg initial wt) were used in an experiment to determine the effects of pelleting on the ability of fermentation products to improve growth performance of nursery-age pigs fed low-lysine diets. Treatments were: 1) positive control (1.15 and .95% lysine for d 0 to 14 and 14 to 35, respectively); 2) diet 1 pelleted; 3) low-lysine regimen (1.05 and .85% lysine for d 0 to 14 and 14 to 35, respectively) supplemented with fermentation product (FP)l; 4) diet 3 pelleted; 5) low-lysine regimen supplemented with modified fermentation product (MFP)2; and 6) diet 5 pelleted. For pelleting, the diets were pre-conditioned to 131°F and pelleted (5/32" diameter pellets) at an avg production rate of 3,550 lb/h, with an avg exit temperature of 144oF. The pigs were allowed to consume feed and water ad libitum during the 35-d experiment. For d 0 to 7 and 0 to 14, pigs fed the pelleted diets had greater ADO and efficiency of gain than pigs fed diets in meal form. At d 14, apparent digestibilities of DM and N of the control diet were increased by pelleting, but those of the diets with fermentation products added were not affected. CFUs of lactobacilli, streptococci, and coliforms in feces were not affected by treatment. From d 14 to 35, pigs fed pelleted diets were more efficient but consumed less feed and had lower ADG than pigs fed diets in meal form. For d 0 to 35, ADG was not affected by treatment, but pigs fed pelleted diets consumed 8% less feed and had 8% greater efficiencies of gain than pigs fed diets in meal form. Growth performance of pigs fed the low-lysine diets plus the fermentation products was not different than that of pigs fed diets with adequate lysine concentrations. Performance of pigs fed FP or MFP was not different. At d 35, CFUs of lactobacilli in feces were not affected by treatment. CFUs of streptococci were greater for pigs fed the control diet than for pigs fed the treatment diets, but were decreased by pelleting the control diet, whereas pelleting the treatment diets increased CFUs of streptococci in feces. CFUs of coliforms were greater for pigs fed diets with MFP than those fed diets with FP. In conclusion, growth performance of pigs fed low-lysine diets plus fermentation products was equal to that of pigs fed diets with adequate lysine concentrations.; Swine Day, Manhattan, KS, November 21. 1991

Effects of pelleting low-lysine diets with fermentation products for weanling pigs (1991)

One hundred twenty pigs (13.2 lb avg initial wt) were used in an experiment to determine the effects of pelleting on the ability of fermentation products to improve growth performance of nursery-age pigs fed low-lysine diets. Treatments were: 1) positive control (1.15 and .95% lysine for d 0 to 14 and 14 to 35, respectively); 2) diet 1 pelleted; 3) low-lysine regimen (1.05 and .85% lysine for d 0 to 14 and 14 to 35, respectively) supplemented with fermentation product (FP)l; 4) diet 3 pelleted; 5) low-lysine regimen supplemented with modified fermentation product (MFP)2; and 6) diet 5 pelleted. For pelleting, the diets were pre-conditioned to 131°F and pelleted (5/32" diameter pellets) at an avg production rate of 3,550 lb/h, with an avg exit temperature of 144oF. The pigs were allowed to consume feed and water ad libitum during the 35-d experiment. For d 0 to 7 and 0 to 14, pigs fed the pelleted diets had greater ADG and efficiency of gain than pigs fed diets in meal form. At d 14, apparent digestibilities of DM and N of the control diet were increased by pelleting, but those of the diets with fermentation products added were not affected. CFUs of lactobacilli, streptococci, and coliforms in feces were not affected by treatment. From d 14 to 35, pigs fed pelleted diets were more efficient but consumed less feed and had lower ADG than pigs fed diets in meal form. For d 0 to 35, ADG was not affected by treatment, but pigs fed pelleted diets consumed 8% less feed and had 8% greater efficiencies of gain than pigs fed diets in meal form. Growth performance of pigs fed the low-lysine diets plus the fermentation products was not different than that of pigs fed diets with adequate lysine concentrations. Performance of pigs fed FP or MFP was not different. At d 35, CFUs of lactobacilli in feces were not affected by treatment. CFUs of streptococci were greater for pigs fed the control diet than for pigs fed the treatment diets, but were decreased by pelleting the control diet, whereas pelleting the treatment diets increased CFUs of streptococci in feces. CFUs of coliforms were greater for pigs fed diets with MFP than those fed diets with FP. In conclusion, growth performance of pigs fed low-lysine diets plus fermentation products was equal to that of pigs fed diets with adequate lysine concentrations.; Swine Day, Manhattan, KS, November 21, 1991