SC - A question about larding
Diana Skaggs
upsxdls at okway.okstate.edu
Tue Sep 15 08:02:37 PDT 1998
Here is an example of why I am hesitant to go into the subject of animal
husbandry on this list in any great detail: Although the following data does
not prove period pigs were fatter it clearly shows ongoning attempts at
breeding leaner pigs in the current MA. To follow this research back through
time and account for differences in recording the information gleaned in each
time period, given the different methods that evolved to record such data
would indeed be a daunting task. A task that i am niether prepared nor
inclined to pursue. ;-)
EFFECTS OF GENETICS AND DIETARY CRUDE PROTEIN ON PORK CARCASS CHARACTERISTICS
Currently genotypes that produce leaner carcasses are being selected and
utilized in commercial pork production. These leaner genotypes are typically
longer, leaner and have larger loin muscle areas; however, they also can
contain as much as 50% less intramuscular fat, have a higher shear force meat
(tougher) and are paler in color. In addition, research has shown that dietary
protein content does have a significant impact on carcass composition. If the
pig has the genetic potential, feeding high level of protein in the early
growing phase(s) can increase carcass leanness.
Researchers K.F. Goerl, S.J. Eilert, R.W. Mandigo, H.Y. Chen and P.S. Miller,
at the University of Nebraska, recently reported research results (J. Anim.
Sci. 73:3621) from a trial that evaluated the effects of genetic line and
crude protein on carcass characteristics. Two genotypes were evaluated: a low
lean growth potential line (GP) that has been selected for only reproductive
traits for 20 years and a leaner Hampshire (HAMP) line. Treatments (10, 13,
16, 19, 22 and 25% crude protein) were randomly assigned across pens of each
genotype. The gilts were fed the assigned diets from 60 to 230 lbs.
The results of the project presented in Table 1 indicated that the HAMP gilts
had larger loins and less backfat than the GP gilts. Backfat decreased
linearly with increased crude protein and the response of loin area to crude
protein was quadratic.
The longissimus muscle of the GP line had greater water-holding capacity than
the HAMP line, suggesting a decreased meat quality. Cooking yields of chops
from the GP line were greater than cooking yields of chops from the HAMP line.
This is another indication of the greater water-holding capacity of the GP
line as compared to the HAMP line. No differences in cooking yield were
observed in response to the protein treatments.
The shear values indicated a more tender meat from the HAMP line than the GP
line, which is not in agreement with previous research. Tenderness was also
shown to decrease with increasing levels of dietary crude protein, but had the
greatest impact in the 10% crude protein diet, which was a deficiency.
Ham yields of the HAMP line were greater than those of the GP line. Ham lean
yields also increased with increasing levels of dietary crude protein. No
significant differences were reported for the additional traits of moisture,
fat, protein, ash or pH values between the two populations.
This study characterized lean tissue composition, color, tenderness, and
water-holding capacity as affected by protein level and two genetic lines.
However, feeding only one dietary crude protein level during the grow-finish
period is not the most economical nutrition program and staged diets may have
an affect on carcass composition and meat quality characteristics. Gilts
selected for increased lean deposition exhibited greater protein accretion,
lower shear force, and lower water-holding capacity than gilts that received
no selection for carcass leanness. However, pork from leaner genetic lines was
more tender, likely due to increased protein turnover at the time of
slaughter. Dietary crude protein level dramatically altered composition and
changed tenderness, especially when deficiencies in dietary crude protein
occurred. To improve the quality and consistency of pork products through
genetics and nutrition more research will be required.
Table 1. Carcass and muscle characteristics as affected by
population and crude protein level
Genetic Population
Dietary Crude Protein Level(%)
Trait
HAMP
GP
Response 10 13 16 19 22 25
Response
Carcass backfat, in. 1.12 1.63 P<.01 1.46 1.47 1.43 1.25 1.31
1.33 linear
Carcass loin muscle area, sq. in. 5.32 4.00 P<.01 3.71 4.71 5.05 4.64
4.88 4.98
quadratic
Water-holding capacity 3.05 2.14 P<.01 2.34 2.58 2.64 2.80 2.71
2.52 NS
Warner Bratzler peak force 30.78 35.01 P<.01 29.19 32.19 33.09 35.38
35.83 31.69
quadratic
Ham lean yield % 56.26 51.97 P<.01 50.56 52.33 54.34 55.44 55.85
56.16 linear
Cook yield % 71.02 74.28 P<.01 71.89 73.64 72.69 72.86 71.69 73.16
NS
Todd See ON-THE-FARM PERFORMANCE TESTING
The following breeders with validated herds have tested animals in the past 30
days.
Breeder Address Breed
Beaver Swamp Farm 355 Ryland Road, Tyner 27980 Y,P,X
Mike & Billy Davis* 2700 Zion Church Rd., Shelby 28150 X
Randall Dawson Rt. 3, Box 41A, Kinston 28501 D,X
Gus's Chesters 264 Park Road, Seven Springs 28578 CW
Bob Ivey 314 NC 111 S, Goldsboro 27530 S,CW,X
G.P. Kittrell, Jr. Rt. 1, Box 4, Corapeake 27926 X
Wesley Looper* 4695 Petra Mill Rd. Granite Falls 28630
Y,L,H,D,X
M & R Livestock Farm 2001 Johnson Field Lane Trenton 28585 Y,C,X
Rick Morgan Rt. 1, Box 50, Corapeake 27926 X
Nahunta Farm, Inc. 189 Nahunta Farm Rd. Pikeville 27863 CW,D,H
Jake & McKinley Price 5406 NC 111 S (Business) Seven Springs 28578 X
Jesse & J.B. Riddick Rt. 1, Box 113A, Corapeake 27926 H
Thad Sharp, Jr. & Sons 5171 NC 581 Hwy., Sims 27880 Y,D,X
Simmons Brothers 4190 Hwy 111 N, Albertson 28508 X
Tommy Spruill Rt. 1, Box 149, Columbia 27925 X
Swan Acre Farm Rt. 1, Box 6, Swan Quarter 27885 X
Spencer Heritage Farms,Inc. Rt. 1, Box 88, Swan Quarter 27885 X
Thomas Farms Rt. 1, Box 653, Timberlake 27583 X
Pete Thomas 8109 Oxford Rd., Timberlake 27583 X
UCPRS Rt. 2, Box 400, Rocky Mount 27801 X
(Swine Development Center)Williams Farm of N.C.* PO Box 416, Moyock
27958 X
*Realtime Ultrasound
Frank Hollowell
David Lee
INFLUENCE OF MATING TIME ON PIG PARENTAGE
If a sow is bred three times in two days, which mating contributed the most
number of pigs to the litter when she farrows? This question has always been
important, but it takes on new significance with the use of combination
matings (natural followed by A.I.). If there is a difference with mating time,
then the genetic merit of the sires used for both natural service and for
artificial insemination needs to be taken into account.
Dr. Billy Flowers, reproductive physiologist at North Carolina State
University, recently released data from an experiment which he designed and
conducted to answer this specific question, i.e., what is the influence of
timing of matings during estrus on the paternity of individual pigs in the
litter. He used 40 multiparous sows and 17 mature boars in an experiment,
where estrus was checked twice daily and each female was bred three times at
12 hour intervals beginning at the first detected estrus.Thirty-five of the
sows received combination matings with a single different boar used for each
mating. Matings were arranged o that every possible combination of matings
from boars occurred an equal number of times. Blood samples were obtained
from all piglets in the experimental litters ten days after farrowing. These
blood samples were submitted to DNA extraction and
analysis to establish piglet parentage. The proportion of piglets sired by
the first, second and third boar in the breeding sequence is presented in
Table 1. In those litters with piglets from two different sires, the second
and third boar used in the breeding sequence sired more (p<.05) piglets than
the first boar (boar 1, 23.7 ± 2.3; boar 2, 45.0 ± 3.4; boar 3, 31.3 ± 4.5%).
Also, in litters containing piglets from all three sires, the second and third
boars in the breeding sequence sired more (p<.05) piglets than the first boar,
even though the
distribution tended to be more uniform than in litters with two sires.
Overall, 25.7 ± 2.3, 41.5 ± 3.7 and 32.8 ± 4.5% were sired by the first,
second and third boars in the sequence, respectively.
According to Dr. Flowers, the results demonstrate that the majority of the
pigs in a litter are the result of a single mating. Further, this mating
usually is not the first one the sow receives during estrus. In this
experiment, approximately 75% of the pigs farrowed were the product of the
A.I. matings. Consequentlx, Dr. Flowers emphasizes that the genetic merit of
the A.I. sires used in combination matings is very important.
Table 1. Distribution (% ± s.e.) of pigs sired within a litter sired by the
first, second and third boar in the breeding sequence.
Variable First Sire Second Sire Third Sire
Litters with 2 sires 23.7 ± 2.3x 45.0 ± 3.4y 31.3 ± 4.5z
Litters with 3 sires 27.7 ± 3.5x 37.0 ± 4.0y 35.3 ± 4.7y
All litters 25.7 ± 3.3x 41.5 ± 3.7y 32.8 ± 4.5y
x,y,z Means with different superscripts within rows are different (p < .05).
Charles Stanislaw
CALENDAR OF EVENTS June 5 P.O.R.K. Academy, Des Moines, IA
6-8 World Pork Expo, Des Moines, IA
============================================================================
To be removed from the SCA-Cooks mailing list, please send a message to
Majordomo at Ansteorra.ORG with the message body of "unsubscribe SCA-Cooks".
============================================================================
More information about the Sca-cooks
mailing list