Hampshire Pigs Research Articles

A Quantitative Ethogram of Aggressive and Submissive Behaviors in Recently Regrouped Pigs1

Twenty prepubertal Yorkshire X Hampshire pigs were mixed in groups of four. Their behaviors were recorded on video tape for 48 h, and a detailed behavioral analysis was performed. Aggressive interactions of 10 unique pairs of pigs were observed. Twenty-five distinct behavioral categories were identified in the total data set, which contained 1,846 behaviors. On average, an interacting pair showed 92 behavioral elements (range: 10 to 307). Eighty-one percent of the behaviors observed consisted of bites and pushes given and received. Bites were targeted mainly at the ears (55%), face (17%) and neck (23%). Most bites to the rump and turning the body 180 degrees occurred during the last third of the fight. Pigs that eventually won fights showed higher incidences of ear bites and lower incidences than expected of head-under-head pushing and body-turning. Pigs that lost fights showed higher frequencies of head-under-head pushing and body-turning. Losers also showed a lower frequency of rump biting. Overall, many of the behaviors performed by the losing pigs were followed by the loser receiving an ear bite. Body-turning was a sign of submission and was always preceded by, and often followed, ear-biting. Once a pig showed body-turning, it generally avoided further face-to-face interaction. Behaviors exhibited as signs of submission were found in each of the 10 pairs observed.

Pork of low technological quality with a normal rate of muscle pH fall in the immediate post-mortem period: The case of the Hampshire breed

The aim of the experiment was to determine the technological properties of meat from Hampshire pigs, as compared to good quality meat from Large White pigs and to exudative meat from halothane-positive (HP) Pietrain pigs. All Hampshire and Large White pigs were halothanenegative (HN). In 129 females and castrated males (47 Large White, 20 HN Pietrain, 27 HP Pietrain, 35 Hampshire), several quality characteristics were measured on raw meat and one ham was processed into cooked 'Paris ham'. Although the pH was normal I h post mortem in Hampshire pigs (which, in this respect, did not differ from Large White pigs) pork from Hampshire pigs, especially females, showed a very low ultimate pH and the highest cooking loss in processing. However, meat was much less exudative when fresh and generally darker (reflectance measured at 630 nm or subjective colour score) in Hampshire than in HP Pietrain pigs. A low ultimate pH occurred in muscle from Hampshire pigs owing to a very high 'glycolytic potential' (essentially glycogen content). It is proposed to use the term 'Hampshire type' to denote meat whose qualitative inadequacies basically result from an abnormally lowered ultimate pH, and to keep the term 'PSE' to refer to meat whose exudative state comes from an abnormally rapid pH fall in the immediate postmortem period.

Skeletal muscle characteristics in different breeds of pigs in relation to sensory properties of meat

Fibre type composition, activities of enzymes used as indicators for oxidative (citrate synthase and 3-OH-acyl-coA dehydrogenase) and glycolytic (lactate dehydrogenase and triose phosphate dehydrogenase) capacity as well as glycogen and triglyceride levels were analysed on muscle biopsies (M. longissimus dorsi and M. gluteus medius) obtained preslaughter from pure breed Hampshire (n = 5), Swedish Landrace (n = 5) and Swedish Yorkshire (n = 5) pigs. The biopsied muscles were evaluated after slaughter for the sensory properties of the meat. Fibre type composition was similar in all breeds, whereas the metabolic profile differed. The Hampshire pigs had a significantly higher oxidative capacity, lower glycolytic capacity, and greater storage of both glycogen and triglycerides compared with the Yorkshire pigs. Values for the Swedish Landrace pigs were inbetween the other breeds. Tenderness of meat was significantly lower in the Yorkshire pigs compared with the other breeds. These results suggest that of the sensory properties of meat, tenderness seems to be especially related to the metabolic profile of the muscles in the living pig.

Percutaneous absorption of clindamycin in the pig and the rat.

Clindamycin HCl in a 3% formulation was applied twice daily to the back skin of three white (Yorkshire) and three black (Hampshire) pigs for 22 days. Partial thickness samples of skin were obtained by use of a dermatome on shaved opposite sides at 4 hours and 5 days posttreatment. More than twice the antibiotic activity (P less than or equal to .001) was found in thinner (254 micrometers epidermis) samples than in thicker (1016 micrometers epidermis and dermis, 1 to 3) samples. A significantly higher content of antibiotic (P = 0.015) was retained in the skin of black pigs at five days posttreatment. Groups of ten Upjohn Sprague-Dawley rats were treated similarly with clindamycin phosphate in a 3% formulation three times daily for 22 days. At termination of treatment antibiotic activity was widely distributed, whereas at five days posttreatment residual activity was confined largely to samples of treated skin. No cutaneous irritation due to treatment was observed in either study.

A comparison of tissue weight distribution in Landrace, Hampshire and Duroc Jersey pigs

SUMMARYThe carcasses of 20 Landrace, 20 Hampshire and 20 Duroc Jersey barrows were dissected in order to study the influence of the breed on tissue weight distribution.After weaning, at 56 days of age, the animals were allocated to individual pens and fed a standard diet containing 18% crude protein and 13 MJ ME/kg, until they reached their designated slaughter weight.The Landrace and Hampshire pigs were slaughtered between 60 and 115 kg and the Duroc Jersey ones between 40 and 115 kg live weight. The right half carcasses were completely dissected using strictly anatomical criteria. Individual muscles were classified into eight anatomical groups (Carden & Goenaga, 1977).The results were examined by covariance analyses utilizing the allometric equation. Carcass tissue composition was studied using the weight of the dissected side as covariate. When muscle: bone ratio was examined, the weight of total side muscle was used as the independent variable. The growth of different parts of a tissue relative to the corresponding whole tissue was studied.Concerning carcass composition, there were significant breed differences in muscle and fat contents and in the muscle:bone ratio.Breed differences were found in muscle distribution. The 6 values of muscle groups 1 (proximal hind limb), 2 (distal hind limb), 6 (distal forelimb) and 7 (muscles connecting forelimb to thorax) were statistically different as were the adjusted means of groups 3 (spinal column), 5 (proximal forelimb) and 8 (muscles connecting forelimb to neck and intrinsic muscles of neck and thorax).Significant differences were also found in bone weight distribution. Slope values of the tarsals, os coxae, scapula and sternum were statistically different. Adjusted means of tibia-fibula, sacrum, spinal column, radius-ulna, carpals and ribs were also significantly different.Finally, there were breed effects in the distribution of fat, the relative weight of subcutaneous and of intermuscular fat being statistically different.

Scanning Electron Microscopy of the Lip Denticles of Ascaris suum Adults of Known Ages

Purebred Hampshire pigs, farrowed and maintained under conditions precluding extraneous helminth infection, were exposed to a single dose of 10,000 Ascaris suum infective eggs. The pigs were killed at intervals of 28, 41, 55, 86, 115, 145, 175, and 206 days after infection. At necropsy, no gross lesions were found in the lungs or livers of infected pigs. The worms were recovered from the small intestine, identified, counted, and fixed. The heads were excised, critical point dried, mounted en face, and examined by scanning electron microscopy. Worms 28 to 115 days old had unworn denticles that were triangular when viewed laterally but blunt when viewed tangentially. Wearing of the denticles was observed first with 145-day-old worms; wearing increased with age both in numbers of denticles affected and in degree of wear so that by 206 days after inoculation, almost all denticles in the center of the lip were worn. Worn denticles appear truncated when viewed from any angle. The denticles outside the central area were not affected by wear. The size of the denticles varies not only between specimens of the same age, but also on each specimen. However, average denticle size is directly related to the size and, accordingly, to the age of the worm. External to each denticle is a corresponding depression that we have called the denticular groove. One 28-day-old specimen had some extra denticles aligned irregularly along the lip; this irregularity gave the appearance of a double row. The denticles of the two subventral lips are similar to those of the dorsal and are equally affected by wear. There was no detectable difference in denticles of male and female worms. Since wear can now be specifically correlated with age, we conclude that the denticles are functional and become worn through use. Consequently, adult A. suum may be an even more injurious pathogen than heretofore supposed.

Effects of a diet containing 40% dried whey on the performance and lactase activities in the small intestine and cecum of Hampshire and Chester White pigs.

Effects of a diet containing 40% dried whey on the performance and lactase activities in the small intestine and cecum of Hampshire and Chester White pigs.

Sleep-stage regulation of ventricular arrhythmias in the unanesthetized pig.

In two groups of purebred juvenile Hampshire pigs, left anterior descending coronary occluders were implanted. The pigs were then adapted to the recording chamber until they would manifest a criterion pattern of sleep while in it. In group A, permanent coronary artery occlusions were produced, and the effects of various sleep stages on the resultant cardiac arrhythmias were observed. Sleep intervals during which transitional and slow wave (SW) sleep alternated were correlated with increased arrhythmias relative to the awake state (P less than 0.04). The increase was maximum during sustained periods of SW sleep. Intervals during which rapid eye movement (REM) sleep predominated were correlated with a reduction in arrhythmias. In group B, temporary occlusions were made during both an awake condition and after criterion patterns of either SW or REM sleep. Occlusions after SW sleep reduced the ventricular fibrillation latency compared with that during the awake control state (P less than 0.05), whereas occlusions after REM sleep increased ventricular fibrillation latency (P less than 0.05). We conclude that SW SLEEP, BUT NOT REM sleep, has a deleterious effect on the ischemic myocardium. REM sleep may have a beneficial effect, since it increases ventricular fibrillation latency. Heart rate changes do not appear to be correlated with the effects of either sleep stage.

Changes in the Intestinal Lactase Activity in the Small Intestine of Two Breeds of Swine from Birth to 6 Weeks of Age

Total and specific lactase activities in the small intestine of Chester White and Hampshire pigs were measured at 1, 8, 15, 22, 29, and 43 days of age. The small intestine was divided into 10 segments of equal length, the proximal 10 cm of each segment was scraped, and the scrapings were homogenized for use in the lactase determinations. Significant breed, age, and segment differences were observed for both specific and total activities. In both breeds, the total lactase activity at 1 day of age was lower than that at any other age. After reaching maximal levels at 15 days of age, the total activity declined with the loss of activity occurring primarily in the ileum. At 1 and 8 days of age, the total lactase activities for the two breeds were similar, but the Chester White pigs had higher activities at all other ages. The pattern of changes in specific activity with age was similar for both breeds. The mean specific activity was highest at 1 and 8 days of age and then fell progressively to minimal levels at 43 days of age. Chester Whites had higher specific activities than Hampshires during the first 4 weeks of life, but at 6 weeks of age there was little difference between the breeds. The peak lactase activity, expressed as total or specific activity, occurred in the proximal one-third of the small intestine of both breeds, and the distal one-third of the gut had relatively low activities as the animals matured.

Retarded growth in hampshire piglets

Imported Hampshire pigs were observed to have low average weights at weaning. To investigate this problem three cross-fostering experiments were carried out between Hampshire and Saddleback females, the latter breed being characterized by heavy weaning weights. The first experiment used ten pairs of gilts of the two breeds and used a simple creep ration for the piglet. Least squares estimates of the 50-day weights of Hampshire and Saddleback piglets were 10.6 ± 0.2 and 13.4 ± 0.2 kg respectively, but the differences due to breed of sow were not significantly different. Similar results were obtained in a second experiment using five pairs of sows and the same creep ration. A third experiment was carried out with eight pairs of females using a more sophisticated creep food with higher protein and energy content. The least squares estimates of 50-day weights for Hampshire and Saddleback piglets were 13.7 ± 0.4 and 16.0 ± 0.3 kg respectively. The retarded growth rate of Hampshire piglets is particularly apparent in the 21–50-day period, and possible explanations are discussed.

Effect of Breed and Diet Containing Cooked Soybeans vs. Extracted Soybean Meal on Pork Carcass Characteristics

Two feeding trials involving 64 pigs from four breeds were conducted to evaluate the effect diets containing either whole roasted soybeans (WRS) or extracted soybean meal have on live animal performance and various quantitative and qualitative carcass characteristics. The initial weight of the pigs at the beginning of the experiment was approximately 31 kilograms. All pigs were slaughtered at a live weight of approximately 102 kilograms. Pigs on diets of either WRS or extracted soybean meal performed similarly in terms of rate of gain and feed efficiency and no significant differences were observed in quantitative carcass characteristics attributable to diet. Adipose tissues from the 10th to 12th rib area over the longissimus muscle and from the perirenal depot were softer (P<.05) from pigs that received WRS than from pigs that received soybean meal. Similarly, extracted lipid from these tissues was more unsaturated in pigs that received WRS in their diet. Backfat and perirenal fat from Hampshire pigs was softer and more unsaturated (P<.05) than that from Duroc, Yorkshire or Crossbred pigs. Dry cured bacon from Hampshire pigs was softer than that from Duroc pigs. Bacon from pigs that received WRS was softer than that from pigs that received soybean meal, however, slicing characteristics were not adversely affected.

INFLUENCE OF SLICING WARM PORCINE MUSCLE ON FIBER DIAMETER, KINKINESS AND SHEAR FORCE

SUMMARYTen market‐weight Hampshire pigs were used to test 2 methods of fabricating hotprocessed pork Ioins. Longissimus dorsi muscle sliced before removal of body heat had significantly higher shear values than the corresponding muscle sliced after a 24‐hr chill. This difference was believed to be due to the contraction of the muscle fibers caused by slicing the muscle soon after death. Fiber diameter and percent kinkiness were also significantly affected by method of slicing, but the larger fiber diameter and greater percent kinkiness were found for the cold‐sliced muscle. An interaction between side and treatment was attributed to the manner in which the animal was suspended during death.

Glucose metabolism of the isolated, perfused pig spleen. Effect of perfusate oxygen tension and flow rate.

Excised pig spleens perfused with oxygenated blood have been shown to function for up to six hours.1-4Use of an asanguinous perfusate has permitted perfusions of up to five days (Atkins, R., et al, unpublished data). Such in vitro asanguinous perfusion introduces many nonphysiologic factors. The purpose of this study was to determine the optimal oxygen tension and rate of perfusion for maximum splenic metabolic function under these unnatural conditions. Metabolic effectiveness was judged by oxygen utilization, glucose consumption, and lactate production. Methods and Material Splenectomy and Washout.—Spleens were aseptically removed from heparinized 10- to 20-kg Hampshire pigs as described previously5and rendered asanguinous by rinsing with 2 liters of saline solution containing 10,000 units of heparin sodium, 90 mg procaine hydrochloride, and 7 mEq sodium bicarbonate per liter. Washout was done at room temperature, under 120 mm Hg pressure. Perfusion Apparatus.—The perfusion apparatus has been described

Serum protein variation in Duroc and Hampshire pigs.

Serum protein variation in Duroc and Hampshire pigs.

Serum Protein Variation in Duroc and Hampshire Pigs

Serum Protein Variation in Duroc and Hampshire Pigs

Effects of Dietary Safflower Oil or Hydrogenated Coconut Oil on Growth Rate and on Some Blood and Tissue Components of Pigs fed a Fat-free Diet

The effects of feeding diets containing no fat, 3% hydrogenated coconut oil (HCO) or graded levels (0.1, 0.5, 1.0 or 3%) of safflower oil (SO) on serum cholesterol, lipids and protein level; on total heart and liver cholesterol and lipid level and on growth rate and skin condition were studied in weanling Yorkshire and Yorkshire × Hampshire pigs. Pigs fed the fat-free diet for 21 weeks developed severe skin lesions not observed in pigs fed HCO diets. Highly significant elevation of serum, liver and heart lipid and liver cholesterol, and a highly significant depression of total serum protein were observed with the feeding of HCO or fat-free diets. Serum cholestrol was significantly increased by HCO as compared with the fat-free diet or diets containing SO during the repletion period. Total heart cholesterol, growth rate and erythrocyte fragility were unaffected by diets. It is concluded that growth rate is not adversely affected in the pig by fat-free diets and that HCO does not produce skin lesions in the pig characteristic of fatty acid deficiency. Of all the correlation coefficients analyzed, only the serum cholesterol and total serum lipids were consistently highly significantly correlated, while serum protein was significantly inversely related to the total liver lipid.

Social dominance in swine

Summary Data on social dominance value (DV) of 1629 Duroc and Hampshire pigs were obtained from Iowa State University's swine irradiation project. Two measures of DV were analysed within subclasses differentiated by irradiation treatment of sires, and breeds. The analysis of DV was done on a within-litter basis as pigs were raised in litter groups. Angular dominance value (the proportion of animals dominated, transformed to angles) and least-squares dominance value (the result of least-squares minimization of dij — (DVi — DVj) where dij is the observed difference in DV between animals i and j) were highly correlated within sex, within litters. Evaluation of pigs was practically identical by the two methods. Barrows were more dominant than gilts. The sex difference was larger in Hampshires than in Durocs. Scrotal irradiation of sires increased the variance component for interaction of sire by sex and increased variance within litters. Within sex, within litter, DV was most significantly correlated with weight at all ages. It was not correlated with backfat thickness if weight was held constant.

Effects of Environmental Temperature and Humidity During Growth on Muscle Properties of Two Porcine Breeds

SUMMARYStudies were conducted on the muscle properties of pigs reared in one of several combinations of environmental temperature and humidity. Longissimus dorsi muscle of pigs reared in alternating temperatures (29 and 18°C) was inferior in structure to that of pigs reared in 29 or 18°C constant temperatures if the relative humidity was low (30%). High relative humidity (85%) during growth tended to improve muscle structure and tenderness (68 and 72°C cooking temperature), regardless of environmental temperature. Breed‐treatment interactions for muscle structure score indicated that Poland China and Hampshire pigs differed in response to environment. Breed comparisons over all treatments revealed that muscle from Poland China pigs was less tender than muscle from Hampshire pigs when it was heated to 60°C. The data on tenderness suggest that the major environmental effects were exerted on the muscle constituents which are susceptible to high cooking temperatures (protein hardening range) whereas the breed differences were evident at low cooking temperatures (collagen shrinkage range).

Variation of some Physical and Biochemical Properties within and among Selected Porcine Muscles

The l. dorsi, psoas major, rectus femoris, biceps femoris and semimembranosus muscles were excised from the right side of fifty-two Hampshire pigs. The l. dorsi muscles were divided into anterior, center and posterior sections, while the three ham muscles were divided into proximal and distal portions (relative to the femur). Total moisture, ether extract and myoglobin concentrations were determined for each muscle, while ultimate pH, Munsell values and juice-retaining properties were measured. Total moisture was highest in the rectus femoris and lowest in the l. dorsi muscles; percent ether extract followed an inverse pattern in all muscles. While myoglobin content was highest in the psoas major and lowest in the l. dorsi, the values among all muscles were significant (P<.01). However, there were no significant differences in myoglobin concentration among the three sections of the l. dorsi muscle. In general, the differences in ultimate pH, Munsell value and juice-retaining properties between the sections of the l. dorsi muscle were small. Ultimate pH Munsell values and juice-retaining properties of the three ham muscles were not entirely consistent between proximal and distal portions, but the proximal portion usually had higher pH values and greater juice-retaining properties and lower Munsell values (darker) than the corresponding distal portion. These results emphasize the necessity for uniform sampling techniques within given muscles. The data also indicate the need for measuring more than one or two characteristics when evaluating porcine quality, since all of these characteristics are not interrelated.

Post‐Mortem Changes in Muscle II. Chemical and Physical Changes in Pork

SUMMARYThe chemical changes occurring from 0 to 24 and/or 48 hr post‐mortem were followed in longissimus dorsi muscle from 18 pork carcasses. In an attempt to induce soft, watery pork, one side from each of 13 carcasses was placed at 37°C immediately after slaughter, and the other side of each carcass was subjected to ‐29°C. Values for pH, glycogen, total reducing sugars, and lactic acid differed markedly at 0 time. Carcasses from Poland China pigs showed a stoichiometric relationship between the post‐mortem decrease in glycogen and the corresponding accumulation of lactic acid and total reducing sugars. This relationship was less apparent in Hampshire pigs. The 37°C treatment did not consistently result in soft, watery and pale muscle, as was expected from other reports. This suggests that exposure of muscle to a low pH at a high temperature per se does not necessarily cause the soft, watery, and pale appearance. A loss in fibrillar water‐binding capacity as a result of low pH values and high muscle temperatures confirmed earlier investigations. However, the decrease in fibrillar water‐binding capacity as a result of the low pH at high muscle temperatures did not usually make the muscle appear soft and watery. Results indicate that even though a loss in fibrillar water‐binding capacity occurs as a consequence of a low pH and high temperature, and is a characteristic frequently encountered in soft, watery muscle, low fibrillar water‐binding capacity by itself is not the primary causal factor in making pork muscle appear soft and watery. Post‐mortem levels of ATP, creatine phosphate, lactic acid, total reducing sugars and glycogen are reported and compared with literature values.