The purpose of the two successive experiments reported herein was to determine the protein requirement of swine from a weight of approximately 44 to 245 lb

Gilsner, Keith E.

Wahlstrom, Richard C.

English

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South Dakota State UniversityOpen PRAIRIE: Open Public Research Access InstitutionalRepository and Information ExchangeSouth Dakota Swine Field Day Proceedings andResearch Reports, 1971 Animal Science Reports1971Effect of Protein Level in Growing-Finishing SwineDiets Fed to Pigs Marketed at Heavy WeightsKeith E. GilsnerSouth Dakota State UniversityRichard C. WahlstromFollow this and additional works at: http://openprairie.sdstate.edu/sd_swine_1971This Report is brought to you for free and open access by the Animal Science Reports at Open PRAIRIE: Open Public Research Access InstitutionalRepository and Information Exchange. It has been accepted for inclusion in South Dakota Swine Field Day Proceedings and Research Reports, 1971 byan authorized administrator of Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange. For moreinformation, please contact michael.biondo@sdstate.edu.Recommended CitationGilsner, Keith E. and Wahlstrom, Richard C., "Effect of Protein Level in Growing-Finishing Swine Diets Fed to Pigs Marketed at HeavyWeights" (1971). South Dakota Swine Field Day Proceedings and Research Reports, 1971. Paper 10.http://openprairie.sdstate.edu/sd_swine_1971/10South Dakota S tate Univers i ty Brookings , South Dakota Department of Animal S cience Agricultural Experiment S tation A. S. Series 71-38 Effect of Protein Level in Growing-Finishing Swine Diets Fed to Pigs Marketed at Heavy Weights Kei th E. Gils ter and Richard C. Wahls trom The mos t common s laughter weigh t of market barrows and gilts is 200 to 230 lb. The price paid for market swine s laughtered at a weight heavier than 230 lb. is often dis coun ted. In addition ,  feed efficiency appears to decrease as pigs are fed to heavier weights. Therefore , both the producer and the buyer often dis criminate agains t marketing swine at heavier weigh ts. However , marketing at heavier weigh ts would allow the production of more pounds of pork per sow uni t and also enable the packer to process more pork from a given number of hogs , thus lowering the total processing cos t. It has b een observed that certain s trains of well mus cled pigs can grow effi­ciently to a weigh t beyond 230 lb. without depos i ting excess fat in the carcass. However ,  the nutritional requirements of the market pig for weights ab ove 220 lb. have not b een well es tab lished. To produce a pig that is trim , muscular and efficient at a heavy weigh t requires a pig that has the proper genetic background and one that is fed a diet that will express his genetic capabili ties. The purpose of the two s uccess ive experiments reported herein was to determine the protein requirement of swine from a weight of approximately 44 to 245 lb. Experimental Procedure Ninety-six crossbred barrows averaging approximately 50 lb. were divided into four replicates. Within each replicate , four pigs were randomly assigned on the basis of weigh t and sire to one of the following six dietary treatments: Percent protein ( calculated) Ini tial Treatment wt. 100 lb. 100-170 lb. 170-245 lb. A 20 20 20 B 20 16 12 c 12 12 12 D 12 16 20 E 16 12 12 F 16 12 16 The composi tion of the diets fed is shown in tab le 1. Feed and water were provided ad lib i tum. Pigs were housed in por tab le wood frame houses with concrete floors an�a connecting 6 x 12 ft. concrete outside pen where waterers and feeders were located. This experiment was conducted during the spring and summer , 1970. Diets , when changed in level of protein , were al tered when a lot averaged approxi­mately 100 and 170 lb. As pigs approached 245 lb. , they were weighed weekly . If 37 i 'I i ' '  : i 1 ii - 2 -a pig weighed at least 245 lb . ,  he was removed from the experiment and allowed access to water but not feed for 24 hours. After the 24-hour shrink period, the pigs were s laughtered. Carcas s  data were collected after the carcasses had cooled a minimum of 24 hours . Dressing percent was calculated using the unshrunk live weight and the chilled carcass weight. Ham and loin percent was b as ed on the chilled carcass weight and the weight of the closely trimmed, boneless ham and bone-in loin. Percent lean cuts was based on the chilled carcass weight and the clos ely trimmed boneless ham, b oneless shoulder and the b one-in loin. Prior to shear tes t and taste panel evalu­ation, loin mus cle samples were cooked to an internal temperature of 165° F. Loin eye samples were removed from the 10th rib for chemi cal analyses, from the 11th rib for shear tes t and from the 12th and 13th ribs for taste panel evaluation. Res ults and Dis cussion Growth Performance The growth performance data are summarized in tab le 2. Up to a weight of 100 lb . ,  pigs fed a 20% protein diet had an average daily gain of 1 . 70 lb . as compared to 1 . 67 lb . for pigs fed 16% protein diets and 1 . 39 lb . for thos e fed 12% protein diets. The gains of pigs fed the 20 and 16% protein diets were signifi­cantly (P < . 01) faster than the gains of pigs fed the 12% diet during this initial feeding period. A significant dif ference in average daily gain was also noted for the period from 100 to 170 lb . Pigs fed the 16% protein diet gained most rapidly, 1. 89 lb . and 2. 02 lb . for treatments B and D, respectively. The faster gain of pigs on treatment D may have been due, at least in part, to compens atory growth. This group gained only 1 . 37 lb . per day up to 100 lb . when they were fed the 12% protein diet, while treatment B gained 1. 67 lb . daily during the same period when they received the high protein ( 20%) diet. There were no signi ficant differences in rate of gain between treatments during the 170 to 245 lb . weight period. For. the entire experiment, 50 to 245 lb . ,  pigs fed the 20-16-12% protein s equence gained the most rapidly, 1 . 87 lb . per day. Pigs fed the 12-12-12% and 12-16-20% protein sequences gained the mos t  slowly, 1 . 72 lb . and 1 . 78 lb . per day, respectively . This appeared to be due to the s lower growth of thes e pigs during the initial growth period. The differences among treatments for average daily gain during the total period were signif icant (P < . 05) • Gain and feed data were also obtained when the res pective lots of pigs averaged 210 lb . so that a comparison could be made o f  pigs fed to 210 or 250 lb . market weight. Similar treatment results were ob served in average gains from initial weight to 210 or 250 lb. There was a highly s ignificant difference in feed per gain during the initial growth period (up to 100 lb . ) with pigs requiring signi ficantly less feed as the protein content o f  the diet increased. Feed per gain averaged 3. 24, 2. 85 and 2.49 lb. for pigs fed the 12, 16 and 20% protein diets , respectively. There were no significant differences in feed per gain due to dietary protein level during any of the other feeding periods . Likewise, for the entire experiment the dif­ferences in feed p er gain were not s ignificantly different, ranging from a low o f  3. 33 lb . for pigs fed the 20-16-12% protein sequence to 3. 61 lb . for the pigs fed the 12-16-20% protein sequence. I t  is also interes ting to note the increase in feed required by all treatment groups when pigs were fed to 245 lb . compared to the feed requirement at a weight of 210 lb . 3 8  j 1 - 3 -There was no difference in feed consumption by pigs due to level o f  protein in the diet. Carcass Characteristics The carcass data are summarized in tables 3 and 4 .  Signi ficant differences in carcass traits were found only in percent ham and loin and percent lean cuts . There appeared to be a trend toward s lightly meatier carcasses when pigs were fed higher protein diets. Carcass es from pigs fed the 12-12-12% protein sequence had the s mallest loin eye area, percent ham and loin and percent lean cuts . Also , the three treatment groups that were fed the 12% protein diet from 170 lb . to s laughter had less average percent ham and loin and lean cuts than did carc ass es from pigs fed 16 or 20% protein during this period. Chemical analyses of the loin mus cle showed a statistically signifi cant dif ­ference in fat content. Loin mus cles from pigs fed the high protein diet for the entire trial had the least fat (2 . 84%) and those from pigs fed the low protein diet for the entire trial had the highest percent fat ( 4 . 97%) . Percent protein in the loin mus cle also followed this trend with a relatively high percent of protein in the muscles of pigs fed the high protein diet and the lowes t percent in mus cles o f  pigs fed the low protein diet. Other treatment groups were inter­mediate in both fat and protein content. Marbling s core appeared to be related to fat content as the higher marbling levels were present in the groups fed the lower protein diets that had higher levels of fat in the loin muscle. Likewise, shear force was s lightly less when the muscle contained more fat. There were no signi ficant differences in any of the taste panel data. This would indicate that dietary protein levels of the magnitude used in this experiment do not affect the acceptab ility of pork by the consumer. Summary Pigs weighing approximately 50 lb . initially gained significantly faster and more efficiently up to 100 lb . when fed either a 20% or 16% protein diet as compared to a 12% protein diet. Pigs fed the 20-16-12% protein s equence gained the fas test and most efficiently up to a weight of both 210 lb . and a final wei ght of 250 lb. Pigs fed the 12-16-20% protein sequence had the lowest backfat, longes t carcasses, highes t percent ham and loin and percent lean cuts. Pigs fed the low protein sequence possessed loins with the mos t  intramus cular fat, lowest percent protein and moisture, and highest p ercentage of cooking loss . 39 ! : I - 4 -Table 1. Composition of Diets (Percent) Percent protein (calculated) Ingredient 20 16 12 Ground yellow corn 63.90 75.00 86.10 S oybean meal (44%) 33.10 21.87 10.62 Dicalcium phosphate 1.92 2.10 2.30 Ground limestone 0.45 0.40 0.35 Trace mineral salt 0.50 0.50 0.50 Vitamin-antibiotic premixa 0.13 0.13 0.13 Calculated analysis , % Calcium 0.73 0.73 0.73 Phosphorus 0. 71 o .  71 o .  71 Chemical analysis , % Protein 20.73 16.27 12.37 Moisture 10.99 11.27 10 .97 Fat 1.69 2.01 2.07 a Provided per lb. of diet: 1 , 500 I.U. of vitamin A ,  180 I.U. of vitamin D ,  1 1  I.U. of vitamin E ,  2.93 mg. of riboflavin, 5 . 51 mg. of pantothenic acid,  13.48 mg. of  niacin , 14.98 mg. of choline , 5.30 mcg. of vitamin B12, and 16.74 mg. of tylan. 4 0  +: I-' � � Table 2. Results of the Ef fect of Protein Level on the Performance Traits of Growing-Finishing Swine Treatment A B c D E F P rotein, %a 20-20-20 20-16-12 12-12-12 12-16-20 16-12-12 16-12-16 No. of pigsb 16 16 16 16c 16 16c Avg. init. wt. , lb. 50.2 50.3 50.3 49.9 50.6 50.2 Avg. final wt. , lb. 251.8 249.5 247.9 24 7 .8 250 .1 249.4 Avg. daily gain2 lb. Init. wt. to 100 lb.** 1. 72 1.67 100 to 170 lb.* 1.84 1.89 170 lb. to final wt. 1.87 1.98 Init. wt. to 210 lb.* 1.83 1.85 Init. wt. to final wt. * 1.82 1.87 Avg. feed Eer lb. gain2 lb. Init. wt. to 100 lb.** 2.49 2 .48 100 to 170 lb. 3.51 3.38 170 lb. to final wt. 4.09 3.83 Init. wt. to 210 lb. 3.25 3.14 Init. wt. to final wt. 3.49 3.33 Avg. daily feed 2 lb. Init. wt. to 100 lb. 4.27 4.13 100 to 170 lb. 6.51 6.45 170 lb. to final wt. 7.52 7.49 Init. wt. to 210 lb. 6.00 5.87 Init. wt. to final wt. 6.31 6.19 a Diets changed at average lot weights of 100 and 170 lb. b Four lots of four pigs each per treatment. 1.40 1.37 1.69 1.80 2.02 1.81 1.91 1.90 1.85 1.67 1. 72 1. 78 1. 72 1. 78 1.80 3.30 3.18 2.86 3.35 3.11 3.52 3.97 4.03 3.74 3.42 3.28 3.26 3.58 3.61 3.44 4.62 4.32 4.86 6.03 6.33 6.43 7.46 7.56 6.79 5.79 5. 71 5.84 6.02 6.41 6.13 c One pig removed during the period of 170 lb. to final weight. Data are not included for that period. * Significant (P < .05). ** Significant (P < .01). 1.65 1.83 1.84 1.80 1.81 2.83 3.31 3 .91 3.25 3.54 4.65 6.17 7.10 5.90 6 .39 Vt + l'0 Table 3 .  Effect o f  Protein Level on Carcass Traits of Growing-Finishing Swine Treatment A B c Protein� 20-20-20 20-16-12 12-12-1 2 No . of  pigsa 16 16 16 Avg . loin eye area , sq . in . 4 . 87 4 . 74 4 . 50 Avg . backfat , in . 1 . 44 1 . 44 1 . 49 Avg . length , in . 31 . 16 31 . 30 31 . 25 Avg .  ham and loin, %* 3 1 .  73 31 . 21 30 . 76 Avg . lean cuts , %** 44 . 73 43 . 86 43 . 58 Avg . dressing percent 69 . 16 69 .64  69 . 73 Avg . live probe , in . d 1 . 18 1 . 18 1 . 24 - -----·--·- - -- ----a Four lots of four pigs each per treatment . b Closely trimmed , boneless ham and bone-in loin . c Closely trimmed,  boneless ham ,  boneless shoulder and b one-in loin . d Backfat probe at 210 lb . * Significant (P < . 05) . ** Significant (P < . 01) . D 12-16-20 15 4 . 84 1 . 39 31 . 35 32 . 39 45 . 4 3  69 . 18 1 . 13 E 16-12-12 16 4 . 87 1 . 50 3 1 . 11 31 . 17 43 . 69 7 0 . 6 4  1 . 23 � ""' F 16-12-16 15 4 . 75  1 . 48 31 . 0 8  31 . 4 4  44 . 25 72 . 0 2 1 .  23 "' + w Table 4. Results of the Ef fect of Protein Leve l on the Chemical, Physical, and Cooking Characteris tics of the Pork Loin of Growing-Finishing Treatment Protein, % No. of pigs Loin musclea Avg. mois ture, % Avg. protein, % Avg . fat, %* Avg. marblingb Avg. color and finnness c . d Avg. shear, lb. Avg. cooking loss, % Avg. tendernesse Avg. flavorf Avg. j uiciness g a Fresh basis. A 20-20-20 16 72.19 22.14 2.84 2.63 2.56 15 .20 12.48 3.79 3.76 3.88 B 20-16-12 16 71. 76 22.17 3.61 2.75 2.56 15.15 12.61 3.66 3. 71 3.98 b Based on a 1 to 5 scale, 1 = trace to 5 = abundant. c 12-12-12 16 71.27 21.22 4 .97 3.06 2.69 14.90 14.35 4.21 3.75 4.20 c Based on a 1 to 5 scale, 1 = pale, sof t and watery to 5 = dark and finn. d Pounds of force to shear a one inch core. D 12-16-20 15 71. 70 21.93 3 .32 2.73 2.81 15 .26 13.35 4.03 3.81 4.04 e Based on a 1 to 8 scale, 1 = extremely tender to 8 = extremely tough. f Based on a 1 to 8 scale, 1 = extremely desirable to 8 = extremely undes irab le. g Based on a 1 to 8 scale, 1 = extremely j uicy to 8 = extremely dry. * Significant (P < .05) . Tas te Panel Swine ----E F 16-12-12 16-12-16 16 15 71.31 71.69 22.13 22.03 3.97 3.20 3.31 2.58 2.56 2.35 14.21 15.35 11.69 14.20 3.62 4.00 3.78 3.94 3.38 4 .16 ....... 

Effect of Protein Level in Growing-Finishing Swine Diets Fed to Pigs Marketed at Heavy Weights

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Effect of Protein Level in Growing-Finishing Swine Diets Fed to Pigs Marketed at Heavy Weights

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