scholarly journals Effects of Corn Silage Inclusion Level and Type of Anabolic Implant on Animal Growth Performance, Apparent Total Tract Digestibility, Beef Production per Hectare, and Carcass Characteristics of Finishing Steers

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 579
Author(s):  
Elizabeth M. Buckhaus ◽  
Zachary K. Smith
Keyword(s):  
Growth Performance ◽  
Dry Matter ◽  
Block Design ◽  
Average Daily Gain ◽  
Dietary Treatment ◽  
Corn Silage ◽  
Net Energy ◽  
Beef Production ◽  
Coated Implant ◽  
Inclusion Level

Maine-Anjou × Angus cross-bred steers (n = 156 steers; initial body weight (BW) 366 ± 37.2 kg) were used in a 132 d finishing study conducted at the Ruminant Nutrition Center (RNC) in Brookings, SD. Steers were blocked by weight (n = 5 BW blocks) and randomly assigned to an implant and dietary treatment of a randomized complete block design with each pen containing seven to eight steers (n = 20 pens). Dietary treatments consisted of (1) 15% (CS15) or (2) 30% corn silage (CS30) where corn silage displaced corn grain in the diet. Steers received one of two implants (both from Zoetis, Parsippany, NJ) containing equal doses of trenbolone acetate (TBA) and estradiol benzoate (EB): (1) Synovex PLUS (non-coated implant; 200 mg TBA and 28 mg EB; PLUS) or (2) Synovex ONE Feedlot (coated implant; 200 mg TBA and 28 mg EB; ONE-F). Bunks were managed using a slick bunk approach, and all diets contained dry matter (DM) basis 33 mg/kg monensin sodium. All steers were offered ad libitum access to feed, and feeding occurred twice daily in equal portions. There was no interaction between the implant and dietary treatment for any variables measured (p ≥ 0.08). Carcass-adjusted basis final BW, average daily gain (ADG), and grain to feed (G:F) were increased (p ≤ 0.02) by 2.2%, 6.5%, and 7.2%, respectively, for CS15. Observed net energy (NE) and the ratio of observed-to-expected NE for maintenance and gain was not influenced (p ≥ 0.15) by silage inclusion treatment. Beef production per hectare was not impacted (p ≥ 0.13) by corn silage inclusion level. Fecal output was increased, and digestibility coefficients for dry matter, organic matter, and crude protein were decreased in CS30 (p ≤ 0.03). Dressing percent and hot carcass weight (HCW) were greater (p ≤ 0.02) in CS15. Implant type did not influence any traits measured (p ≥ 0.14) except for marbling. Marbling was decreased for PLUS (433 vs. 466 ± 17.5; p = 0.02) compared to ONE-F steers. Similar beef produced per hectare of crop land-based upon silage feeding level means producers can feed greater inclusions of corn silage to finishing cattle without impacting carcass quality or beef production; implanting with a coated implant had no detrimental effects to growth performance but increases marbling scores.

scholarly journals Effect of Complete Replacement of Dry-Rolled Corn with Unprocessed Rye on Growth Performance, Efficiency of Dietary Net Energy Use, and Carcass Traits of Finishing Heifers

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 99
Author(s):  
Elizabeth M. Buckhaus ◽  
Warren C. Rusche ◽  
Zachary K. Smith
Keyword(s):  
Body Weight ◽  
Growth Performance ◽  
Dry Matter ◽  
Energy Use ◽  
Block Design ◽  
Average Daily Gain ◽  
Dietary Treatment ◽  
Net Energy ◽  
Final Body Weight ◽  
Complete Replacement

Continental crossbred beef heifers were used in a randomized complete block design experiment to evaluate the effects of replacement of dry-rolled corn with unprocessed rye on the finishing-phase growth performance and efficiency of dietary net energy (NE) use. Fifty-six heifers (433 ± 34.0 kg) were transported 241 km from a sale barn in North Central South Dakota to the Ruminant Nutrition Center in Brookings, SD. Heifers were blocked by weight grouping and allotted to treatment pens (n = 7 heifers/pen and 4 pens/treatment). Treatments included a finishing diet that contained 60% grain (diet dry matter basis) as dry-rolled corn (DRC) or unprocessed rye grain (RYE). On study day 14, all heifers were consuming the final diet and were implanted with 200 mg of trenbolone acetate and 28 mg of estradiol benzoate (Synovex-Plus, Zoetis, Parsippany, NJ, USA). The RYE heifers had decreased (p ≤ 0.01) final body weight, average daily gain, and gain efficiency; however, they tended (p = 0.08) to have a greater dry matter intake compared to DRC heifers. RYE heifers had decreased (p ≤ 0.01) observed dietary NE and decreased (p ≤ 0.01) observed-to-expected dietary NE ratio for maintenance and gain compared to DRC heifers. The dressing percentage, 12th rib fat thickness, ribeye area, and the distribution of yield and quality grades were not altered (p ≥ 0.12) by dietary treatment. The hot carcass weight, calculated yield grade, estimated empty body fat (EBF), and body weight at 28% EBF decreased (p ≤ 0.02) and retail yield increased (p = 0.01) in RYE compared to DRC heifers. These data indicate that unprocessed rye is a palatable feed ingredient for inclusion in finishing diets for beef cattle and that rye inclusion only minimally influences the carcass quality grade. The feeding value of unprocessed rye is considerably less (21.4%) than that of dry-rolled corn using current standards and approximately 91% of the NE value of processed rye (processing index = 78.8%). Rye grain fed as processed or unprocessed grain has an NE value that is less than 90% of that of dry-rolled corn.

159 Evaluation of Bacillus Subtilis PB6 Probiotic (CLOSTAT® 500) on Feedlot Phase Growth Performance, Efficiency of Dietary Net Energy Utilization, and Fecal and Subiliac Lymph Node Salmonella Prevalence

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 119-120
Author(s):  
Zachary K Smith ◽  
Paul Rand R Broadway ◽  
Keith Underwood ◽  
Warren C Rusche ◽  
Julie Walker ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Lymph Node ◽  
Lymph Nodes ◽  
Growth Performance ◽  
Block Design ◽  
Average Daily Gain ◽  
Energy Utilization ◽  
Experimental Unit ◽  
Net Energy ◽  
Fecal Samples

Abstract Yearling beef steers (n = 238; initial BW=402 ± 31.2 kg) were used to evaluate a Bacillus subtilis probiotic on growth performance, dietary net energy (NE) utilization, carcass characteristics, and fecal and subiliac lymph node Salmonella prevalence during a 140-d finishing period. Steers were allotted to 24 pens (n = 9 to 10 steers/pen) and assigned to one of two treatments (12 pens/treatment): no probiotic (CON) or 0.50 g·steer-1·d-1 of a Bacillus subtilis PB6 probiotic (CLOSTAT® 500, Kemin Industries, Des Moines, IA; CLO). Steers were transitioned to a 90% concentrate diet (DM basis) over 14-d. Steers were fed once daily at 0700 h; bunks were managed according to a slick bunk management. Fecal samples were collected on d 1, 28, 56, 112, and 140 from each pen (n = 5 steers/pen) via rectal palpation and composited by pen for determination of Salmonella prevalence. Upon harvest, subiliac lymph nodes were obtained from 60 steers in CON and 57 steers in CLO. Data were analyzed as a randomized complete block design; pen was the experimental unit; α of 0.05 determined significance. No differences were detected (P ≥ 0.25) between treatments for live or carcass-adjusted average daily gain, dry matter intake, gain efficiency, dietary NE utilization, nor calculated dietary NE content based upon performance. No differences were detected between treatments for any carcass traits (P ≥ 0.15). Salmonella was not recovered in any fecal samples except on d 112, where steers from CLO had a numerically lower (P = 0.17; 8.3 vs. 25.0%) incidence of fecal Salmonella compared to CON and on d 140 fecal, where Salmonella incidence did not differ (P = 0.34; 0.0 vs. 8.3%) for CON and CLO, respectively. Salmonella was not recovered in any subiliac lymph nodes. These data indicate that CLO did not influence growth performance or Salmonella prevalence.

PSX-B-5 Effect of replacement of dry-rolled corn with un-processed rye on growth performance, efficiency of dietary net energy utilization, and carcass traits of finishing heifers

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 458-459
Author(s):  
Keith M Buckhaus ◽  
Warren C Rusche ◽  
Zachary K Smith
Keyword(s):  
Body Weight ◽  
Growth Performance ◽  
Block Design ◽  
Average Daily Gain ◽  
Estradiol Benzoate ◽  
Energy Utilization ◽  
Net Energy ◽  
Final Body Weight ◽  
Trenbolone Acetate ◽  
Finishing Diets

Abstract Continental × British beef heifers were used in a randomized complete block design experiment to evaluate the effects of replacing dry-rolled corn with unprocessed rye on growth performance, efficiency of dietary net energy (NE) utilization, and carcass trait responses in finishing heifers. Heifers (n = 56; 433 ± 34.0 kg) were transported 241 km from a regional sale barn to the Ruminant Nutrition Center in Brookings, SD. Heifers were blocked by weight grouping and then allotted to pens (n = 7 heifers/pen and 4 pens/treatment). Treatments included a finishing diet that contained 60% grain (DM basis) as dry-rolled corn (DRC) or unprocessed rye grain (RYE). On d 14, heifers were consuming the final diet and were implanted with 200 mg of trenbolone acetate and 28 mg of estradiol benzoate (Synovex-Plus, Zoetis, Parsippany, NJ). RYE heifers had decreased (P ≤ 0.01) final body weight, average daily gain, and gain efficiency; but tended (P = 0.08) to have a greater dry matter intake compared to DRC. RYE had decreased (P ≤ 0.01) observed dietary NE and decreased (P ≤ 0.01) observed-to-expected dietary NE ratio for maintenance and gain compared to DRC. Dressing percentage, 12th rib fat thickness, ribeye area, and the distribution of USDA yield and quality grades were not altered (P ≥ 0.12) by diet. Hot carcass weight, yield grade, estimated empty body fat (EBF), and body weight at 28% EBF decreased (P ≤ 0.02) and retail yield increased (P= 0.01) in RYE compared to DRC. These data indicate that unprocessed rye is a palatable feed ingredient for inclusion in finishing diets for beef cattle and that rye inclusion only minimally influences carcass quality. The feeding value of unprocessed rye is considerably less (21.4%) than that of dry-rolled corn using current standards and approximately 91% of the NE value of processed rye.

scholarly journals Evaluation of an active live yeast (Levucell Saccharomyces cerevisiae, CNCM l-1077) on receiving and backgrounding period growth performance and efficiency of dietary net energy utilization in low health risk beef steers1

2020 ◽  
Vol 4 (3) ◽  
Author(s):  
Zachary K Smith ◽  
Kip Karges ◽  
Angel Aguilar
Keyword(s):  
Health Risk ◽  
Growth Performance ◽  
Block Design ◽  
Average Daily Gain ◽  
Energy Utilization ◽  
Feed Ratio ◽  
Experimental Unit ◽  
Net Energy ◽  
Respiratory Pathogens ◽  
Live Yeast

Abstract The objective of this experiment was to evaluate the influence of an active live yeast direct-fed microbial (DFM) product on receiving and backgrounding period growth performance and efficiency of dietary net energy (NE) utilization in low health risk beef steers. Maine-Anjou × Angus steers (n = 199; body weight [BW] = 252 ± 32.1 kg) were received from two sources at the Ruminant Nutrition Center in Brookings, SD, in November 2019 and used in a 77-d feedlot receiving and backgrounding experiment. Steers were provided access to long-stem hay and ad libitum water upon arrival. Steers were weighed, vaccinated for respiratory pathogens (source 2 only): infectious bovine rhinotracheitis, bovine viral diarrhea types 1 and 2, parainfluenza-3 virus, and bovine respiratory syncytial virus (Bovi-Shield Gold 5, Zoetis, Parsippany, NJ) vaccinated for clostridial species (Ultrabac 7/Somubac, Zoetis) and pour-on moxidectin (Cydectin, Bayer, Shawnee Mission, KS). Steers (n = 176 steers; initial unshrunk BW = 235 ± 27.6 kg) were allotted to pens (n = 20 pens; 10 pens per treatment; eight or nine steers per pen). Diets were based upon corn silage, dry-rolled corn, and dried distillers grains; dietary treatments were 1) no DFM (CON) and 2) DFM (Levucell SC, Advantage Titan, CNCM l-1077), fed at 10 g/steer/d providing 8 × 109 CFU of active live yeast to each steer daily (DFM). Initial BW was the average of day −1 and day 1 BW (n = 176 steers; initial BW = 253 ± 27.6 kg). On day 21, steers received a 200-mg progesterone and 20-mg estradiol benzoate implant. Data were analyzed from day 1 to 47 (receiving period), day 48 to 77, and from day 1 to 77 as a randomized complete block design; pen served as the experimental unit for all analyses. On day 47 of the experiment, DFM had greater BW (P = 0.01) by 0.9% and average daily gain (ADG; P = 0.01) by 4.2% and gain-to-feed ratio (G:F) tended (P = 0.13) to be 2.8% greater. Day 77 BW did not differ (P = 0.60), cumulative (days 1–77): ADG (P = 0.47), dry matter intake (P = 0.66), and G:F (P = 0.56) were similar. Yeast inclusion had no appreciable influence on performance-based dietary NE utilization or the ratio of observed/expected dietary NE (P ≥ 0.59). In low health risk steers, DFM improved performance during the feedlot receiving period. However, no improvements for DFM were detected for cumulative performance from day 1 to 77. The confirmation of yeast counts indicated the CFU to be above the expected level at the start of the trial but was found below expected level at the end of the trial. This may explain differences during the initial 47 d compared to cumulative growth performance results.

scholarly journals PSX-36 Effect of forage neutral digestion fiber level for feedlot lambs: growth performance

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 451-451
Author(s):  
Josue Godinez ◽  
Alejandro Plascencia ◽  
Francisco Castrejón-Pineda ◽  
Juan Carlos Ramírez-Orejel ◽  
Luis Corona
Keyword(s):  
Growth Performance ◽  
Block Design ◽  
Average Daily Gain ◽  
Neutral Detergent Fiber ◽  
Energy Utilization ◽  
Net Energy ◽  
Finishing Diets ◽  
Feedlot Lambs ◽  
Sheep Production ◽  
Daily Gain

Abstract The main objective of sheep production in Mexico is the production of meat. The greater demand of sheep meat in relation to the offer generated an attractive market that favored the intensification of the fattening, to take advantage of the growth of lambs in its different stages, and reduce the days of fattening. Thirty-two lambs (28.50± 2.67 kg initial shrunk weight) were used in a 63-day feeding trial (4 pens per treatment, randomized complete block design) to evaluate neutral detergent fiber level (4, 8, 12, and 16% diet DM) on finishing-phase growth performance, dietary energetics and carcass traits. Dietary treatments consisted of a cracked corn-based diet in which the NDF concentration of diet was manipulated by replacing cracked corn grain by corn stubble. Dietary NDF level showed a quadratic response on average daily gain and gain efficiency, being those maximal at 8% NDF level. Lambs fed 8% NDF level tended (P = 0.07) to shown greater dry matter intake than others treatments. The ratio of observed-to-expected dietary net energy was 3% lower (0.97) for lambs fed 4% NDF, while the ratio of observed-to-expected dietary net energy for lambs that were fed with 8, 16 and 16% NDF were closely to 1.00. Hot carcass weight (HCW) and dressing percentage (DP) were maximal for the lambs fed 8% NDF level (quadratic effect, P ≤ 0.03); beyond this level, HCW and DP percentage decreased as NDF level increased. Using corn stubble as source of NDF in growing-finishing diets for lambs, the optimal NDF level was 8%. Fiber level below 8% decreases net energy utilization, and this may be cause by digestive disorders. Fiber levels upper 8% did not affect energy utilization; however, affect negatively average daily gain, feed efficiency and carcass characteristics by effect of high levels of fiber on energy dilution of diet.

scholarly journals Use of barley silage or corn silage with dry-rolled barley, corn, or a blend of barley and corn on predicted nutrient total tract digestibility and growth performance of backgrounding steers

2020 ◽  
pp. 1-9
Author(s):  
B.D. Sutherland ◽  
J.A. Johnson ◽  
J.J. McKinnon ◽  
T.A. McAllister ◽  
G.B. Penner
Keyword(s):  
Growth Performance ◽  
Dry Matter ◽  
Near Infrared ◽  
Average Daily Gain ◽  
Nutrient Digestibility ◽  
Corn Silage ◽  
Neutral Detergent Fiber ◽  
Feed Ratio ◽  
Gross Energy ◽  
Barley Silage

The objective of this study was to determine the effects of feeding barley silage (BS) or corn silage (CS) with dry-rolled barley (BG), dry-rolled corn (CG), or a blend of barley and corn grain (BCG), on growth performance and nutrient digestibility, the latter predicted using near-infrared spectroscopy for backgrounding cattle. Steers (n = 288) were stratified by body weight (BW) into 24 pens and pens were randomly assigned to one of six treatments (n = 4) in a 2 × 3 factorial design. Main factors included BS or CS in combination with BG, CG, or BCG. There were no silage × grain interactions. Dry matter intake (DMI; P = 0.018) and final BW (P = 0.004) were greater for steers fed CS than BS, but average daily gain (1.01 kg d−1) and gain-to-feed ratio (0.10 kg kg−1) were not affected by silage or grain source. Steers fed CS also had greater dry matter, organic matter, crude protein (CP), acid detergent fiber (ADF), starch, and gross energy digestibility values (P < 0.01) than BS. Feeding BG increased starch, neutral detergent fiber, ADF, and CP digestibility values (P ≤ 0.01) over CG and BCG. Relative to BS, feeding CS increased DMI, final BW, and nutrient digestibility, whereas dry-rolled BG improved nutrient digestibility when compared with CG and BCG in backgrounding diets.

scholarly journals 2 Evaluation of Masters Choice Corn Silage on Growing Steer Performance

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 127-127
Author(s):  
jiehua Xiong ◽  
Bradley M Boyd ◽  
Levi J McPhillips ◽  
Kyle Vosburgh ◽  
Galen E Erickson
Keyword(s):  
Feed Efficiency ◽  
Dry Matter ◽  
Block Design ◽  
Average Daily Gain ◽  
Corn Silage ◽  
Corn Hybrids ◽  
Fiber Digestion ◽  
Randomized Block Design ◽  
Daily Gain ◽  
Corn Hybrid

Abstract Corn hybrids can be selected for improved digestion rates using lab techniques, which should impact animal performance. The objective of this study was to evaluate two Masters Choice corn silage hybrids on growing steer performance. In an 84-day growing study, 288 crossbred steers (initial BW = 303 ± 12 kg) were utilized in a generalized randomized block design with three diet treatments, 12 steers per pen and 8 pen replicates per treatment. Diets consisted of 80% corn silage (DM basis) of Masters Choice hybrid MCT6365 RIB (MC1, that has been selected to improve fiber and starch digestion) and MCT6733 GT3000 (MC2, that has been selected to improve fiber digestion) were compared to a conventional corn hybrid Farm Choice (CON, that is commonly grown in Eastern Nebraska). All corn was grown in one field under identity preserved method and harvested at 37-38% DM in three consecutive days. Relative to CON, feeding MC1 resulted in similar dry matter intake (DMI, P = 0.28), but numerically increased average daily gain (ADG, P = 0.14) which significantly improved feed efficiency (G:F, P = 0.02). Feeding MC2 led to greater DMI (P &lt; 0.01), similar ADG (P = 0.45), and lower G:F (P &lt; 0.01) compared to CON. The results suggest that feeding Masters Choice hybrid MCT6365 RIB (MC1) corn silage at 80% of the diet DM improved ADG and G:F by 4.2%, while feeding MC2 decreased G:F by increasing DMI compared to CON. Differences in corn hybrids exist when feeding growing cattle 80% silage.

scholarly journals PSIX-37 Evaluation of reducing dietary crude protein concentrations coupled with increasing essential amino acids on growth performance in fattening pigs

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 351-352
Author(s):  
S-M Hong ◽  
D Jung ◽  
S-J You
Keyword(s):  
Amino Acids ◽  
Growth Performance ◽  
Crude Protein ◽  
Negative Impact ◽  
Block Design ◽  
Average Daily Gain ◽  
Net Energy ◽  
Feed Conversion ◽  
Dietary Treatments ◽  
Fattening Pigs

Abstract A body of evidence suggests that low-protein diets in swine have benefits in view of environmental stewardship and economic returns. The present study was performed to evaluate essential amino acid (EAA) supplementation in the diets with reducing crude protein (CP) concentrations on growth performance in fattening pigs. We hypothesized that a low-CP diet with elevated EAA concentrations would result in similar growth performance in fattening pigs compared with a normal CP diet. Eighty finishing pigs with initial body weight (BW) of 72.0 ± 5.34 kg were assigned in a randomized complete block design with 5 replicates to test 4 dietary treatments: 1) 15.5% CP with EAA concentration at 109% of NRC requirement (control); 2) 14.0% CP with EAA concentration at 111% of NRC requirement (EAA111); 3) 14.0% CP with EAA concentration at 113% of NRC requirement (EAA113); and 14.0% CP with EAA concentration at 115% of NRC requirement (EAA115). The diets were isocaloric, whereas crystalline amino acids, L-Lys, L-Met, L-Thr, L-Trp, and L-Val were added to the diets to achieve the varying levels of EAA in the treatments. The Lys-to-net energy ratio in the diets was maintained at 3.06, 3.12, 3.18, and 3.24 to the control, EAA111, EAA113, and EAA115, respectively. Dietary treatments did not affect final BW. Additionally, average daily gain, average daily feed intake, and feed conversion ratio (FCR) were similar across the treatments. On average, pigs fed the control and EAA111 numerically decreased FCR compared to those fed EAA113 and 115 (3.21 vs. 3.35, respectively; P = 0.46). Total feed cost throughout the experiment was $9.0/head lessen in EAA111 relative to the control; however, total feed costs to EAA113 and EAA115 were greater than the control. In summary, a low-CP diet with increased EAA supplementations did not have any negative impact on growth performance of fattening pigs.

scholarly journals Increasing hay inclusion in silage-based receiving diets and its effects on performance and energy utilization in newly weaned beef steers

2020 ◽  
Vol 4 (2) ◽  
pp. 848-853
Author(s):  
Dathan T Smerchek ◽  
Elizabeth M Buckhaus ◽  
Katie D Miller ◽  
Zachary K Smith
Keyword(s):  
Growth Performance ◽  
Block Design ◽  
Corn Silage ◽  
Energy Utilization ◽  
Experimental Unit ◽  
Net Energy ◽  
Beef Steers ◽  
Linear Effect ◽  
Randomized Complete Block Design ◽  
Red Angus

Abstract The influence of grass hay (GH) inclusion in replacement of corn silage in receiving diets on growth performance and dietary net energy (NE) utilization was evaluated in newly weaned beef steers (n = 162 Charolais-Red Angus cross steers; initial body weight [BW] = 278 ± 13.4 kg). Treatments were (DM basis): 1) 0% GH, 2) 10% GH, or 3) 20% GH inclusion in replacement of corn silage in receiving diets fed to newly weaned beef steers for 56 d. The study was conducted from October to December of 2019. Data were analyzed as randomized complete block design with pen serving as the experimental unit for all analyses. Increasing dietary inclusion of hay had no influence (P ≥ 0.11) on final BW, ADG, gain:feed or observed/expected dietary NEM and NEG, observed/expected dry matter intake (DMI), or observed/expected ADG. GH inclusion increased (linear effect, P = 0.01) DMI. Observed DMI for all treatments was approximately 15% to 17% less than anticipated based upon steer growth performance and tabular NE values. Evaluation of observed/expected ADG was 31% to 37% greater than expected for the steers in the present study. Particles less than 4 mm increased (linear effect, P = 0.01) and greater than 4 mm decreased (linear effect, P = 0.01) as GH replaced corn silage in the receiving diet. As the proportion of particles greater than 4 mm increased, cumulative ADG was decreased. These data indicate that GH should be considered in corn silage-based receiving diets to improve DMI. In high-risk calves, improved DMI could result in a lesser incidence of morbidity, although no morbidity was observed in any steers from the present study.

scholarly journals Interrelationships between sex and dietary lysine on growth performance and carcass composition of finishing boars and gilts1

2020 ◽  
Vol 4 (3) ◽  
Author(s):  
Pau Aymerich ◽  
Carme Soldevila ◽  
Jordi Bonet ◽  
Mercè Farré ◽  
Josep Gasa ◽  
...  
Keyword(s):  
Growth Performance ◽  
Average Daily Gain ◽  
Dietary Treatment ◽  
Information Criterion ◽  
Deposition Potential ◽  
Linear Increase ◽  
Carcass Composition ◽  
Net Energy ◽  
Finishing Pigs ◽  
Large White

Abstract The main goals of this study were to determine whether boars and gilts respond differently to the standardized ileal digestible lysine to net energy ratio (SID Lys:NE) and model the response to optimize growth performance. A total of 780 finishing pigs, 390 boars and 390 gilts [Pietrain NN × (Landrace × Large White)], with an initial individual body weight of 70.4 ± 9.2 for boars and 68.7 ± 8.0 kg for gilts, were used in a 41-d dose–response experiment. Pens (13 pigs per pen) were randomly allocated to a dietary treatment (2.64, 3.05, 3.46, 3.86, 4.27 g SID Lys/Mcal NE) by block and sex, with six replicates per treatment and sex. Two isoenergetic diets (2,460 kcal NE/kg), representing the extreme SID Lys:NE, were formulated and then mixed. Pigs were individually weighed at days 0, 22, and 41, when the experiment finished. The differential effect of SID Lys:NE on growth performance and carcass composition between sexes was analyzed with orthogonal polynomial contrasts to compare the linear and quadratic trends in each sex. In addition, broken-line linear (BLL) models to optimize average daily gain (ADG), including average daily feed intake (ADFI) as a covariate, were fitted when possible. As expected, boars had a greater ADG and feed efficiency (G:F; P &lt; 0.001) than gilts, but there was no evidence of differences in ADFI (P = 0.470). Increasing SID Lys:NE had a greater linear impact on boars ADG (P = 0.087), G:F (P = 0.003), and carcass leanness (P = 0.032). In contrast, gilts showed a greater linear increase in SID Lys intake per kg gain (P &lt; 0.001) and feed cost per kg gain (P = 0.005). The best fitting BLL models showed that boars maximized ADG at 3.63 g SID Lys/Mcal NE [95% confidence interval (CI): (3.32 to 3.94)], although another model with a similar fit, compared with the Bayesian information criterion, reported the optimum at 4.01 g SID Lys/Mcal NE [95% CI: (3.60, 4.42)]. The optimum to maximize ADG for gilts was estimated at 3.10 g SID Lys/Mcal NE [95% CI: (2.74, 3.47)]. Thus, the present study confirmed that boars and gilts have a different linear response to SID Lys:NE, explained by the greater protein deposition potential of boars. Likewise, BLL models indicated that boars require a higher SID Lys:NE to maximize ADG from 70 to 89 kg. These results suggest that split feeding of finishing boars and gilts could be beneficial in terms of both performance and cost return.

Sign in / Sign up

Export Citation Format

Share Document