RECEIYT PORK RESEARCH

Transcription

1 RECEIYT PORK RESEARCH RICHARO Ha ALSUEYER UN I V E R S l T Y OF FtOR I O A ~ Pork carcass research vas w e l l Since t h a t date, work has been published on carcass c h a r a c t e r i s t i c s and objective would first l i k e t o cover t h e effects of covered i n the 1953 Conference. primarily on the e f f e c t s of feeding evaluations of carca8s leanness. I feeding on carcass quality. Bohman, Hunter and McCormick (6) and Kidwell and Hunter (20) reported t h a t a l f a l f a, a s 50 percent of t h e r a t i o n produced leaner carcasses with a higher cut-out value f o r l e a n cuts; t h i s feeding regime, however, reapuced dressing percentage. Feeding l e v e l s of 10 t o 40 percent of a l f a l f a meal, Becker end coworkers (3) a t I l l i n o i s a l s o observed decreased dressing; percentage. Lately, there has been considerable i n t e r e s t i n t h e e f f e c t s of a n t i b i o t i c s on c e r t a i n carcass c h a r a c t e r i s t i c s. Kelly, Bray and P h i l l i p s (19) a t Wisconsin reported an increase i n backfat thickness a s a result of aureomycin supplementation. Although Kline, Kastellc and Ashton (22) a t Iowa noted an tncrease in backfat thickness and lower carcase s p e c i f i c gravity, carcass quality, a s measured by length of body, thickness of backfat, s p e c i f i c gravity and percentage of lean cuts, was not appreciably affected by a n t i b i o t i c feeding. Kropf and coworkers (23) a t Wisconsin found t h a t a n t i b i o t i c feeding had no s i g n i f i c a n t e f f e c t on dressing percentage or carcass length. Wallace and others (38) a t Florida observed l i t t l e e f f e c t of a n t i b i o t i c feeding on phyeic a l carcass measurements. Clawson, Sheffy and Reid a t Cornel1 (lo), Ashton and coworkers (1) a t Iova and Hanaon and other Minnesota workers f a i l e d t o demonstrate any important e f f e c t of a n t i b i o t i c feeding on carcass characteri s t i c s. It thus appears t h a t i f there a r e any e f f e c t s of a n t i b i o t i c feeding on carcaes fatness, t h e magnitude of t h e e f f e c t s a r e not great. Other workers have studied the effect of adding f a t t o swine r a t i o n s either t o mask t h e efoect of soft-pork producing feeds or a s a feeding use f o r various surplus f a t s. I n several experiments, Blumer and coworkers (5) using ooconut oil a s 10 percent of t h e ration, s u f f i c i e n t l y hardened depot f a t o f soybean oil-fed pigs. Baird (2) working, a t Georgia, added 5 percent tallow t o a swine r a t i o n and produced carca8ses with a firmer f a t than t h e i r controls. I n an attempt t o produce leaner pork carcasses, several studies on t h e e f f e c t s of high f i b e r r a t i o n s were undertaken and a r e reported. In 1954, workers in Canada (13) and England (11) increased the fiber content of swine r a t i o n s and thereby increased carcass leanness; however, Teague and Hanson (35) found no correlation between t h e l e v e l of fiber fed and carcass

2 155 Recently, the e f f e c t s of homone treatment on pork carcass charact e r i s t i c s have been studied, Purdue workers (4, 37) administered diethyls t i l b e s t r o l and methyl testosterone o r a l l y and a n t e r i o r p i t u i t a r y growth hormone intermuscularly t o s w i n e and reported t h a t pigs o r a l l y receiving 20mg. of testosterone d a i l y yielded carcasses with a higher percentage of lean c u t s. Chemical analysis indicated t h a t pigs receiving t h e testosterone had 5 percent less f a t and 5 percent more lean. Growth hormone injected pigs had longer carcasses, less backfat, more p r o t e i n and moisture than the control pigs. Bratzler and coworkers (e), however, found no s i g n i f i c a n t differences i n carcass c h a r a c t e r i s t i c s when barrows were implanted with testosterone propionate. Attempts have been made t o regulate carcass composition and development by r e s t r i c t i n g n u t r i e n t intake. Merkel and coworkers (28) a t Wisconsin produced carcasses with a s l i g h t l y higher percentage of l e a n by l i m i t i n g feed consqlzkon. Similar r e s u l t s were obtained & Tribble and Pfander (36) of Missouri; Jordan, Beeson and Wiley (18) of Purbue; Lucas and Calder (27) of Great Britain; Wallace and other8 (38) a t Florida and Crampton, Ashton and Lloyd (12) a t McDonald College. Other researchers have studied e f f e c t s of l e v e l and quality of prot e i n on carcass c h a r a c t e r i s t i c s, Kropf and coworkers (231 i n 1953 reported t h a t a r a t i o n of 1 2 percent, l o w quality protein produced c a r c a ~ s e swith a lower percentage of f a t cuts and a higher percentage of picnic and Boston b u t t. Ashton and others (1) a t Iowa, using l e v e l s of 10 t o 20 percent protein, noted a tendency toward leaner carcasses with an increase i n protein l e v e l. Tribble and Pfander (36) a t Missouri observed a 1.6 percent increase i n l e a n cuts and 4.6 percent less f a t i n carcasses of pigs fed a 16 percent protein r a t i o n Compared w i t h pigs fed a 1 2 percent ration. In 1955, Stevenson, Hiner and Ellis (34) obtained similar r e s u l t s using 14 and 16 percent p r o t e i n rations. Brady, Zobriskey and M u l l i n s (7) studied the r a t i o of f a t t o lean i n t h e ham of pigs a t various weights. They observed s t r i k i n g increases i n fat t i s s u e and only s l i g h t increases i n l e a n t i s s u e of hams of pigs slaught e r e d a t 100, 200 and 300 pounds compared with pigs k i l l e d weighing 50 pounds. In other work, Herbert and Crown (17) reported t h a t g i l t carcasses produced a higher percentage of ham and loin, l a r g e r l o i n areas and a higher percentage of separable lean i n t h e ham than barrow carcasses. Lasley and Kline (25) noted t h a t s p l i t t i n g and c u t t i w e r r o r s may l i m i t t h e r e l i a b i l i t y of estimates abtained by evaluation of one half of the carcass. They reported heavier ham, picnic, l o i n and Boston butt weights from t h e l e f t half of the carcass and g r e a t e r l o i n eye area a t the 10th and l a s t r i b s f o r r i g h t l o i n s. Lately, many papers have been published on pork carcass evaluation techniques. Clawson, Shefw and Reid (10) of Cornell found a high correlat i o n between carcass s p e c i f i c gravity and carcass moisture using t h e a n t i pyrine d i l u t i o n method. They postulated t h a t i f t h e water content of t h e whole, empty body i s known, t h e t o t a l composition of t h e body of swine may be accurately predicted. Based on correlations, Whiteman and Whatley (39) a t Oklahoma s t a t e d t h a t s p e c i f i c gravity, average backfat thickness and l o i n l e a n area a r e preferred measures of carcass evaluation. They l a t e r reported high correlations between carcass and ham s p e c i f i c g r a v i t i e s and t h a t specific gravity was more closely associated with other measures of leanness than was

3 156. backfat thickness. These workers reported the following t o be important i n measuring specific gravity i n water: 1. Water temperature is of no p r a c t i c a l consequence i f within a 2OoF. range. 2. Weight in water must be read rapidly since specific gravity becomes less as t h e meat temperature increases. 3. The amount of exposed surface is not important. 4. Changes i n water purity a r e important i f it changes i t s density. 5. The longer the object i s submerged, t h e less will be t h e density. 6. When weighing i n water, weight t o t h e nearest one hundredth of a pound is sufficient. Price, Pearson and B e m e (33) recently reported that specific gravity of t h e barn or carcass more nearly measures muscling ger se than l i v e probe or backfat thickness. Also, t h e l o i n lean area a t t h e 10th r i b more closely predicted carcass cut-out than area a t the last rib. Pearson and coworkers (29) l a t e r reported t h a t t h e single untrimmed ham, shoulder or l o i n call be used t o estimate the specific gravity of %he mrcass, however, t h e ham is preferred due t o t h e ease of handling. Specific gravity of either the carcass or t h e ham proved superior t o backfat thickness a s a measure of carcass leanness. The percentage of prote-ln, moisture and ether extract of t h e ham was reported by Whiteman, Whatley and Eillier (40) t o be highly correlated w i t h specific gravity of t h e lean of t h e ham. Kline, Ashton and Kastelic (21) observed d i f ferences between specific gravity a t time of slaughter, a r t e r 24, 4Ll and 72 hours of chilling. Therefore, changes i n specific gravity during c h i l l i n g i n dicates that carcasses must undergo a uniform c h i l l i n g time. Liuzzo, Reineke and Pearson (26) have developed an a i r displacement method of determining specific gravity using two chambers. A highly significant correlation was noted between a i r displacement and water displacement techniques of determining specific gravity of guinea pigs. -- In 1952, the live probe technique was developed and l a t e r the lean meter was perfected. I n 1957, Pearson and coworkers (33 compared t h e lean meter and live probe methods on 99 hogs. Tney noted l i t t l e difference between them in e s t a a t i n g backfat thickness or carcass cut-out; however, a higher correlation was reported f o r the l i v e probe with specific gravity, both l o i n areas and f a t trim. Zobrlskey and others (42) a t Missouri reported backf a t measures t o be t h e most accurate estimate of f a t yield. The hip probe was the best indicator of carcass leanness. In 1956, Lasley, Hazel and Kline (24) observed a high correlation (0.88) between ham weight and the lean cuts. A squared multiple correlation coefficient of 0.91 for predicting lean cuts was reported f o r carcass weight, backfat, length, l o i n eye area and ham weight. Recently, l o i n eye areas a t t h e 10th and l a s t ribs, lean a r e of t h e ham and f a t t o lean r a t i o of the untrimmed l o i n have been studied a s r e l a t e d t o carcass leanness. Cahill, Sutton and Kunkle (9) a t Ohio S t a t e obtained

4 157. high correlations between area of Longisimus d o r s i a t t h e 10th r i b and weight and percentage of primal cuts. However, i n 1955, FTedeen, Bowman and Stothart (15) comparing several techniques of estimating carcass leanness, reported a high association of l o i n eye area a t t h e last r i b with percent lean of t h e ham. They found t h e percentage of lean i n t h e proximal face of t h e ham a superior measure of carcass leanness t o t h e l o i n eye area measure. I n 1956, Pearson and coworkers (30) indicated t h e area of l e a n a t t h e l a s t r i b t o have a s l i g h t l y higher correlation with cut-out than area a t t h e 10th r i b. Although only moderate correlations were found between t h e f a t t o l e a n r a t i o of t h e rough l o i n and carcass cut-out, t h e f a t t o l e a n r a t i o could be useful i f carcass cut-out is unavailable. In 1954, Bratzler and others (8) obtained a correlation of 0.86 between cut-out and area of t h e rough l o i n. Working on ham leanness, Fredeen, Bowman and Stothart (14) used the percent lean of t h e open face of t h e ham, physical separation and s p e c i f i c gravity of t h e ham t o obtain a r e l i a b l e estimate of h a m leanness. The percent lean in ham face was t h e most accurate with a p r e d i c t a b i l i t y of 64 percent. Jordan, Beeson and Wiley (18) using chemical analysis a s a c r i t e r i a, reported t h e percent of l e a n cuts t o be a more accurate estimate of carcass leanness than average backfat thickness. I n summary, it has been shown that an increase i n r a t i o n f i b e r, limited feeding, increased p r o t e i n levels and testosterone given o r a l l y and a n t e r i o r p i t u i t a r y growth hormone injected intermuscularly, tend t o increase carcass leanness. The inclusion of coconut o i l and tallow i n r a t i o n s produces a firmer fat. Differences i n weights of cuts and areas of the l o i n eye have been noted between halves of carcasses. The more promising and r e l i a b l e techniques of carcass evaluation are: specific gravity of t h e carcass or c e r t a i n cuts, t h e antipyrine d i l u t i o n method of estimating carcass moisture, a i r displacement s p e c i f i c gravity, t h e l i v e probe and lean meter f o r backfat thickness and t h e l e a n area of t h e l o i n a t t h e 10th and last ribs. Literature Cited Ashton, G. C., J. Kastelic, D. C. Acker, A. H. Jensen, H. M. Maddock, E. A. Kline and D. V. Catron Different Protein Levels With and Without Antibiotics for Growing-Finishing Swine: Effect on Carcass Leanness J. Ani. SCi. 14:82.. Baird, D. M Effect of Tallow, Lecithin and Antibiotics on Growth and Carcass Quality of Diylot Hogs. Proc. Am. SOC. Ani. Prod Becker, D. E., L. J. Hanson, A. E. Jensen, S. W. T e r r i l l and H. W. Norton Dehydrated Alfalfa Meal a s a Dietary Ingredient f o r Swine. J. Ani. SCi. 15:820. Beeson, W e M., F. Ne Andrews, T. W. Perry and M. Stob The Effect of Orally Administered S t i l b e s t e r o l and Testosterone on Growth and Carcass Composition of Swine J. Ani. Sci. 14:475.

5 158. Blumer, T. N., E. R. Barrick, W. L. Brown, F. H. Smith and W. tj. CJ. Smart, Jr Influence of Changing the Kind of Fat i n the M e t 8 t Various Weight Intervals on Carcass Fat Characteristics of Swim. J. Ani. Sci. 16: 68. Bohan, V. R., J..E. Hunter and J. A. McConnick The Effect of Graded Levels of Alfalfa and Aureomycin Upon Growing-Egttening Swine. J. Ani. SCi. 14:499. Brady, D. E., S. E. Zobriskey and A, M. Mullins Differential Tissue Development i n Hams During Growth of Swine. ProC. Am* SOC. Ani, Prod Bratzler, L. J., R. P. Soule, Jr., E. P. Reineke and PC Paul The Effect of Testosterone and Castration on the Growth am3 Carcass Characteri s t i c s of Swine. J. Ani. Sci. 13:171. Cahill, V. R., T. s. Sutton and L. Kunkle Relationship of Area of Longisimus Dorsi Muscle t o Other Carcass Characteristics. J. Ani. Sci. 12:899. Clawson, A, J., B. E. S h e w a d J. T,,Reid Some EXfects of Feedfng Chlortetracycline Upon the Carcass Characteristics and t h e Body Composit i o n of Swine and R Sehemb for the Resolution of the Body Composition. J. Ani. SCi. 14;.U22. Coey, W. E. and K. I,. Robinson Son6 Effects of Dietary Crude Fiber on Livestock Gains and Carcass Conformition of Pigs. J. Agric. Sei. 45:QL. Crampton, W. E., G. C. Ashton and L. E. Lloyd The Effect of Restricting Feed Intake of Market Hogs During the Finishing Period on the Quality of the Bacon Carcass. J. Ani. Sei, 13:321. Crampton, E. W., (3. C. Ashton and L. E. Lloyd Improvement of Bacon Carcass Quality by t h e Introduction of Fibrous Feeds Into t h e Hog Finishing Ration. J. A n i. Sci. 13:327. Fredeen, H. T., G. E. Bowman and J. G, Stothart Appraisal of Certain Methods f o r kraluation of Ham Quality. Can. J. Agric. Sei. 35:91. F redeen, H. T., G. H. Bowman and J. 0, Stothart Relationships Between Certain Measurements of Ham and Carcass Quality. Can. J. Agric. Sei. 35: 95. Hanson, L. E., E. F. Ferrin, P. A. Anderson and W. J. Aunan Growth and Carcass Characteristics of Pigs Fed Antibiotics for Part or All of the Growing-Fattening Period. J. Ani. Sci. 14:300 Berbert, 0. J. and R. M. Crown Carcass Quality Characteristics of Market Barrows and G i l t s. Proc. Am. SOC. Ani. Prod

6 159. Jordan, C. E., 17. M. Beeson and J. R. Wiley Producing Leaner Market Hogs by Different Feed Combinations and Controlled Corn Intake. J. Ani. SCi. 15:869. Kelly, R. F., R. W, Bray and P, H, Phillips The Influence of Chlortetracycline Supplementation of t h e Ration on Distribution, Quantity and Quality of Fat Deposited in Swine. I. Metabolic Effects i n Relation t o Carcass Composition. J. Ani. Sci. 16:74. K i d w e l l, J. F. and J. E. Hunter The U t i l i z a t i o n of a High Level of Alfalfa by Growing-Fbttening Swine. J. Ani. Sci. 15:1067. Kline, E. A., G. C. Ashton and J. Kastelic Effect of Chilling Time on t h e Specific Gravity of Hog Carcasses and Upon t h e Correlation Between Specific Gravity and Measures o f Fatness. Proc. Am. Soc. Ani. Prod M i n e, E, A., J. Kastelic and G. C. Ashton Effect o f Biz, Cobalt and Antibiotic Feeding on t h e Composition of Pork Tissue of 100 lb. Pigs. J. Nutr. 56:321. Kropf, D. H., P. K. L e w i s, Jr., 3. R. OrMnner, R. W. Bray and P. H. P h i l l i p s Effect of Protein Level, Protein Quality and Chlortetracycline (Aureomycin) Upon Growth, Feed Efficiency and Carcass Composition of Swine. Proc. Am. SOC. Ani. Prod Lasley, E. L., 1;. BI. Hazel and E. A, Kline Predicting Lean Cuts From Live Bog arid Easily Measured Cdrcass T r a i t s. Proc. Am. SOC. Ani. Prod Lasley, E. L. and E. A. Kline S p l i t t i n g and Cutting Errors i n Swine Carcass Evaluations. Proc. Am. SOC. Ani. Prod Liuzzo, J. A., E. P. Reineke and A. M. Pearson An A i r Displacement Method for Determining Specific Gravity. Proc. Am. SOC. Ani. Prod Lucas, I. A. M. and A. F. C. Calder Response of Different Types of Pigs t o Various Levels of Feeding from Weaning t o Bacon Weight, with Part i c u l a r Reference t o Carcass Quality. J. Agric. Sci. 47:287. Merkel, R. A., R. W. Bray, R. H. Grimmer, P. E. P h i l l i p s and G. Bohstedt Influence of Limited Feeding, by Use of High-Fiber Rations, Upon Growth, Fattening and Carcass Characteristics of Swine. J. Ani. Sci. 12:903 Pearson, A. MI, L. J. Bratzler, R. J. Deans, J. F. Price, J. A. Hoefer, E. P o Reineke and R. W. Luecke The Use of Specific Gravity of Certain Untrimmed Pork Cuts a s a Measure of Carcass Value. J. Ani. Sci. 15:86. Pearson, A. M., L. J. Bratzler, J. A. Hoefer, J. F. Price, W. T. Magee and R. J. Deans The Fat-Lean Ration i n t h e Rough Loin a s a Tool i n Evaluation of Pork Carcasses. J. Ani. Sci. 15:896.

7 160. Pearson, A. M., J. F. Price, L. J, Bratzler, W. T. Magee and J. A. Hoefer A Comparison of the Live Probe and the Lean Meter for Predicting Carcass Measurements of Swine. J. Ani. Sci. 16:481. Pierce, E. A The Effects of' Ratione Containing Antibkotics and Trace Mineral Salt on the Chemical Ccarpoeition and Physical Characteristics of Pork Carcasses. J. Ani. S c i. 13:338. Price, J. F., A. M. Pearson and E. J, Benne Specific Gravity and Chemical Canposition of the Untrimmed Ham as ReLaOed t o Leanness of Pork Carcasses. J. Ani. Sci. 16:85. Stevenson, J. W., R. L, Hiner and N. R,. E l l i s Some Effect of Different Levels of Protein and Fiber, and AntibPotic Supplementation on Qrowth and Carcass Characteristics of Swine. Proc. Am. SOC. Ani. Prod Teague, H. S. and L. E. Hanson The Effect of Feeding Mfferent Levels of a Cellulosic Material t o Swine. J. Ani. Sci. 13:206. Tribble, L. F. and W, H. Wander Growth, Feed Efficiency, and Carcass Desirability of Swine a s Affected by Level o f Protein, Chlortetracycline(Aureomycin) and Feed Intake. Proc. Am. Soc. Ani. b o d Turman, E. J. and F. N. Aribews Some Effects of Purified Anterior Pituitary Growth Hornone on Swine. J. Ani. Sci. 14:7. Wallace, E. D., J. I. McKigney, A. M, Pearson and T. J. Cunha Influence of Chlortetracycline on the G r o w t h and Carcass Characteristics of Swine Fed Restricted Rations. J. Ani. Sci. 14:1095. Whiteman, J. V. and 3. A. Whatley An Evaluation of Some Swine Carcass Measurements. J. A n i. S c i. 12:591. Whiteman, J. V., J. A, Whatley and J. C. Hillier A FUrther Investigation of Specific Gravity a s a Measure of Pork Carcass Value. J. Ani. SCi. 12:859* Wingert, F. C., W. J. Aunan, E, F. Ferrin and L A Method of &terminin$ the Composition of Swine Carcasses; and t h e Effects of Chlortetracycline (Aureornycin) Feeding on Swine Carcass Quality Proc Am. SOC.Ani. Prod Zobrisky, S. E., J. F. Lasley, D. E. Brady and L. A. Weaver. Stat. Res. B u l l Carcass Evaluation. Mo. Ag. mt Pork DR. STRONG: Thank you, Dick, We appreciate your efforts i n bringing together into one spot these results of recent research and t h e good l i s t 0f.references accompanying your paper.

8 161. I would probably be t h e l a s t one i n t h e room t o t e l l embarrassing s t o r i e s on t h e next speaker-. (Laughter) We a r e not exactly ahead of schedule; so t o take time t o e x t o l h i s v i r t u e s, might not be popular. So let's j u s t consider grading as an evaluation t o o l. #########