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Nutrients, such as dietary lipids, can influence development of the central nervous system [1, 2]. Particularly, an increase in plasma concentrations of cholesterol, which is an essential constituent of all animal cells (especially of brain) and abundant in milk, is positively associated with enhancement of cerebrum weight gain and behavioral development [2–4]. Additionally, docosahexaenoic acid (DHA) is a component of complex lipid in membranes, nerve insulation, as well as a precursor for signaling molecules (including prostaglandins). The availability of long-chain polyunsaturated fatty acids, including DHA, also modulates eicosanoid metabolism and myelination during growth spurt of the brain [5,6]. Interestingly, dietary DHA supply enhances visual and neurological development both in prematurely born infants [7] and in term infants [8,9], while promoting problem-solving and childhood intelligence [10]. The beneficial influences of dietary cholesterol and DHA on brain development are currently interpreted as modification of the membrane structure and functions of membrane-associated proteins [11]. Nitric oxide (NO), synthesized from L-arginine by NO synthase (NOS), plays an important role in development and function of the brain [12]. All isoforms of the NOS [neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS)] are present in neurological tissue. Of particular interest, nNOS activity is decreased when the protein is phosphorylated at the inhibition site of Ser 852, whereas eNOS activity is increased when the enzyme is phosphorylated at the activation site of Ser 1177 [12]. GTP-CH activity, Tetrahydrobiopterin (BH4), which is synthesized from GTP via the GTP cyclohydrolase I (GTP-CH) pathway [13], is an essential cofactor of NOS [14]. NO is a potent signal that regulates many physiological processes affecting behavior and cognitive function, including synaptic plasticity during long term potentiation and depression [15]. NO also acts as a retrograde messenger to stabilize or refine synapse during development, as a regulatory second messenger involved in the control of brain blood flow, and as an agent that contributes to both brain degeneration and neuropotection [16]. Additionally, NO promotes angiogenesis, redox state, cell immunity, and neuronal survival [14,17]. Cholesterol and DHA are known to regulate NO synthesis in vascular endothelial cells [17]. We hypothesized that dietary supplementation with cholesterol and DHA can influence the arginine-NO pathway in the brain of neonatal animals. This hypothesis was tested with piglets by measuring NOS activity, total and phosphorylated levels for the three NOS isoforms, as well as concentrations of arginine, BH4 and NADPH in brain. To determine whether the effects of DHA and cholesterol are specific to the neuronal tissue, we also analyzed the above parameters in skeletal muscle and liver.

Cholesterol and docosahexaenoic acid (DHA) are important nutrients for neural development of infants. However, little is known about the effect of cholesterol or DHA on concentrations of amino acids (AA) in neonatal tissues. This study was conducted with the piglet (an established model for studying human infant nutrition) to test the hypothesis that dietary supplementation with the lipids may modulate AA availability in tissues. Sixteen newborn pigs were nursed by sows for 24 h and then assigned to one of four treatment groups, representing supplementation with 0.0% (control), 0.2% cholesterol, 0.2% DHA, or cholesterol plus DHA to the basal milk-formula. All piglets were euthanized at 49 days of age. In brain, cholesterol supplementation reduced (P < 0.05) concentrations of glutamate, serine, glutamine, threonine, β-alanine, alanine, methionine, isoleucine, leucine, and γ-aminobutyrate but increased (P < 0.05) concentrations of glycine and lysine, whereas DHA supplementation similarly affected (P < 0.05) concentrations of the same AA (except for isoleucine and lysine) and taurine. In addition, concentrations of most AA in liver, muscle and plasma were substantially altered by dietary supplementation of cholesterol and DHA in a tissue-dependent manner. Further, DHA reduced concentrations of carnosine in skeletal muscle, as well as ammonia in both plasma and brain. The results reveal that cholesterol and DHA can regulate AA metabolism and availability in various tissues of piglets. These novel findings have important implications for designing the next generation of infant formula to optimize neonatal growth and development.

The objective of this study was to determine possible synergistic effects of supplementing one of three fungal phytases: Aspergillus fumitagus PhyA (AFP),A. niger PhyA (ANP), or Peniophora lyci phytase (PLP) with an Escherichia coli AppA phytase (EP) in diets for pigs. Three experiments, each lasting for 4 wk, were conducted with a total of 106 weanling pigs (5 wk old). The corn-soybean meal basal diet (BD) contained no supplemental inorganic P. In Exp. 1, 35 pigs (8.6 +/- 1.0 kg BW) were fed (as-fed basis) BD + AFP at 750 U/ kg of feed, BD + inorganic P (0.2% P), or BD + PLP at 500, 750, or 1,000 U/kg feed. Pigs fed BD + AFP or BD + 0.2% P had higher (P < 0.05) plasma inorganic P concentrations than those fed BD + PLP at the end of the trial (wk 4). In Exp. 2, 35 pigs (8.1 +/- 0.9 kg BW) were fed BD + AFP, EP, PLP, a 1:1 mix of AFP:EP, or a 1:1 mix of PLP:EP at 500 U/kg. Pigs fed the AFP:EP mixture had growth performance and plasma measures similar to those fed either enzyme alone. Pigs fed the PLP:EP mixture had lower (P < 0.05) plasma alkaline phosphatase activity than those fed BD + PLP. Pigs fed BD + PLP had lower (P < 0.05) plasma inorganic P concentrations than pigs fed BD + EP, and higher (P < 0.05) plasma alkaline phosphatase activity than all other groups at wk 4. In Exp. 3, 36 pigs (9.1 +/- 1.2 kg BW) were fed BD + ANP, EP, or a 1:1 mix of ANP:EP at 500 U/kg feed. Pigs fed the two enzymes together had lower (P < 0.05) plasma inorganic P concentration than those fed BD + EP and lower (P < 0.05) plasma alkaline phosphatase activity than pigs fed BD + ANP at wk 4. In conclusion, although the four phytases showed different effects on plasma P status of weanling pigs, there was no synergistic effect between any of the three fungal phytases and the bacterial phytase on the plasma measures or growth performance under the conditions of the present study.

Consensus phytase is a new biosynthetic, heat-stable enzyme derived from the sequences of multiple homologous phytases. Two experiments were conducted to determine its effectiveness, relative to inorganic P and a mutant enzyme of Escherichia coli phytase (Mutant-EP), in improving dietary phytate-P availability to pigs. In Exp. 1, 36 pigs (3 wk old, 7.00 +/- 0.24 kg of BW) were fed a low-P corn-soybean meal basal diet plus consensus phytase at 0, 250, 500, 750, 1,000, or 1,250 U/kg of feed for 5 wk. Plasma inorganic P concentration, plasma alkaline phosphatase activity, bone strength, and overall ADG and gain:feed ratio of pigs were improved (P < 0.05) by consensus phytase in both linear (R2 = 0.20 to 0.70) and quadratic (R2 = 0.30 to 0.70) dose-dependent fashions. In Exp. 2, 36 pigs (4 wk old, 9.61 +/- 0.52 kg BW) were fed the basal diet + inorganic P at 0.1 or 0.2%, consensus phytase at 750 or 450 U/kg of feed, Mutant-EP at 450 U/kg of feed, or 225 U consensus + 225 U Mutant-EP/kg of feed. Pigs fed 750 U of consensus phytase or 450 U of Mutant-EP/kg feed had plasma inorganic concentrations and bone strength that fell between those of pigs fed 0.1 or 0.2% inorganic P. These two measures were 16 to 29% lower (P < 0.05) in pigs fed 450 U of consensus phytase/kg of feed than those of pigs fed 0.2% inorganic P. Plasma inorganic P concentrations were 14 to 29% higher (P < 0.05) in pigs fed Mutant-EP vs. consensus phytase at 450 U/kg at wk 2 and 3. In conclusion, the experimental consensus phytase effectively releases phytate P from the corn-soy diet for weanling pigs. The inorganic P equivalent of 750 U of consensus phytase/kg of feed may fall between 0.1 and 0.2%, but this requires further determination.

Little is known about the mechanism responsible for retarded placental and fetal growth induced by maternal dietary protein malnutrition. On the basis of the recent finding that nitric oxide (NO) and polyamines (products of L-arginine) play an important role in embryonic and placental development, the present study was designed to determine whether protein deficiency decreases placental and endometrial activities of NO synthase (NOS) and ornithine decarboxylase (ODC) (the first and key regulatory enzyme in polyamine synthesis). Primiparous gilts selected genetically for low or high plasma total cholesterol concentrations (low line and high line, respectively) were mated and then fed 1.8 kg/d of isocaloric diets containing 13% or 0.5% crude protein. At d 40 or 60 of gestation, they were hysterectomized, and placenta and endometrium were obtained for incubations, NOS and ODC assays, and measurements of free amino acids and polyamines. Maternal dietary protein restriction decreased arginine and ornithine concentrations, constitutive and inducible NOS activities and NO production, as well as ODC activity and polyamine concentrations in placenta and endometrium of both lines of gilts. Placental NO synthase activity and NO generation were lower in high line gilts than in low line gilts. ODC activities and polyamine concentrations in placenta and endometrium were decreased at d 60 compared with d 40 of gestation. These changes in placental and endometrial synthesis of NO and polyamines during early gestation may be a mechanism responsible for reduced placental and fetal growth in protein-deficient gilts and for altered conceptus development in high line gilts.

Sixty-eight female neonatal pigs selected for seven (Experiment 1) or eight (Experiment 2) generations for high (HG) or low (LG) plasma cholesterol were used to test the hypothesis that neonatal dietary cholesterol fed during the first 4 or 8 wk of postnatal life increases the cholesterol content of the cerebrum in young adulthood following free access to a high-fat (15%), high-cholesterol (0.5%) diet from 8 to 20 or 24 wk of age. Pigs were removed from their dams at 1 d of age and given free access to a sow-milk replacer diet containing 9.5% coconut fat and 0 or 0.5 % cholesterol. All pigs (except four HG and four LG pigs in Experiment 2, which were deprived of cholesterol throughout the study) were fed the high-fat, high-cholesterol diet from 8 wk to termination at 20 or 24 wk of age. Cerebrum weight and cholesterol concentration were higher in pigs fed cholesterol neonatally than in those deprived of cholesterol neonatally in both experiments, but weight and cholesterol concentration were unaffected by genetic line. Cholesterol concentrations in longissimus and semitendinosus muscles and in subcutaneous fat were unaffected by diet or genetic line. We conclude that dietary cholesterol deprivation during the first 4 to 8 wk of life in piglets is associated with lower cholesterol concentration and total content in the young adult cerebrum than in pigs supplemented with cholesterol in early life. These data support previous observations and suggest the possibility of a metabolic need for neonatal dietary cholesterol in normal brain development.

Sixty-eight neonatal female pigs from populations selected for high (HG) or low (LG) plasma total cholesterol were used in two experiments to test the hypothesis that dietary cholesterol deprivation during the first 4 or 8 weeks of postnatal life increases plasma total cholesterol and exacerbates early aortic atherogenic lesions following free access to a high fat (15 g/100g)-high cholesterol (0.5 g/100g) diet from 4 or 8 weeks to 5 or 6 mo of age. Pigs were removed from their dam at one d of age and given free access to a modified sow-milk replacer diet containing 0 or 0.5% crystalline cholesterol. In each experiment, half of the HG and LG pigs were fed a sow-milk replacer diet containing 0 cholesterol and half were fed the same diet containing 0.5% added cholesterol. All pigs (except HG and Lg pigs in experiment 2 deprived of cholesterol throughout) were fed a 15% fat-0.5% cholesterol diet from 57 d to 6 mo (experiment 1) or 5 mo (experiment 2) of age. Overall total cholesterol and high density lipoprotein cholesterol were greater in HG than in LG pigs (P

Twenty-eight young adult boars (age 7 to 8 mol genetically selected for four generations for high (HG) or low (LG) plasma cholesterol were studied to assess dietary and genetic effects and their interactions on cholesterol metabolism. Boars within a genetic group were paired according to their plasma cholesterol concentration at 8 wk of age and were fed for 15 wk (2.7 kg/d) one of two diets (16.5% fat and 1,156 mg of cholesterolkg diet, HD; or 3.1% fat and 0 cholesterol diet, LD) in a 2 x 2 factorial arrangement. Plasma total cholesterol ( P < .O 1) and HDL- cholesterol ( P < .O 1) concentrations were higher in boars fed HS (P < .01) and in HG boars (P < .01). There was a trend toward a diet x genotype interac- tion for plasma HDL-cholesterol ( P < .06). Plasma insulin concentration tended to be lower in boars fed HD (P < .09) or HG boars (P < .lo). There was a diet x genotype interaction for plasma glucagon ( P < .04) concentration and a trend toward an interaction for insulin (P < .07). After 15 wk, all boars were killed by electrocution and exsanguination and measurements were taken. Backfat thickness was greater ( P < .01) and carcass length ( P < .Ol) and weights of the four lean cuts (P < .02) were lower in LG than in HG boars. No microscopic atherosclerotic plaques were observed in aorta or coronary arteries. Cholesterol concentration in subcutaneous fat was lower (P < .04) in LG boars, suggesting that cholesterol content of depot fat can be reduced by genetic selection in swine.

People who supplement their diets with extra zinc usually have potentially harmful changes in lipoprotein metabolism. Because zinc can interfere with copper metabolism and copper deficiency has produced similar changes in lipid metabolism in animals and people, the hypothesis that lipid alterations from high zinc intakes are accompanied by changes in copper metabolism was tested. Progenies of swine fed a high zinc (5000 mg/kg diet) or normal zinc (150 mg/kg diet) diet during pregnancy and lactation were weaned to practical diets of natural products containing similar amounts of zinc. Concentrations of apoprotein A-I (p

Comprehensive information on the composition of the whole spectrum of essential inorganic elements in sow milk is very limited. The objectives of this study were to measure concentrations of major and trace mineral elements in milk of third-generation sows selected for high (H) or low (L) serum cholesterol concentrations at 8 wk of age and to determine correlations between concentrations of milk cholesterol and major and trace mineral elements in sow milk. Twenty-one H and 21 L and 8 contemporary unselected control (U) Chester White x Landrace x Large White x Yorkshire crossbred sows were milked on d 20 or 21 of their first lactation. A standard corn and soybean meal-based diet was fed to all sows during pregnancy and lactation. There were no differences among the sow groups in milk concentrations of Ca, K, Mg, Na, and P, indicating that the genetic selection for serum cholesterol did not affect major mineral contents of the milk. Concentration of S in milk of the H sows was significantly (P < .05) higher than that of the U sows. Effects of genetic group were significant for concentrations of B, Al, Cu, and Mn in the milk, but not for Mo and Zn concentrations. Milk cholesterol concentration was negatively correlated with milk Al (P < .05), B (P < .01), and Mn (P < .05) for pooled data; there was no relationship between milk cholesterol concentration and that of other mineral elements.

What constitutes animal welfare? With animals being used for companionship, service, research, food, fiber, and by-products, animal welfare is a topic of great interest and importance to society. As the world's population continues to increase, a major challenge for society is the maintenance of a strong and viable food system, which is linked to t

Three generations of selection for 56-d blood cholesterol concentrations were used to establish low and high cholesterol lines of pigs in which cholesterol concentrations differed by 39% in the last generation. Litter size (number of fully formed pigs born per litter) diverged with each successive generation of selection and, at the third generation, litter size differed between the low and high line by two pigs (high line = 8.5 +/- .6; low line = 10.5 +/- .5; P < .05). A random selection of offspring (gilts, n = 109; boars, n = 46; barrows, n = 94) from the third generation and a control line maintained throughout the experiment were monitored for hormonal and anatomical relationships that might provide insight into the mechanisms that altered fecundity. Ovulation rate (number of corpora lutea) as determined on d 60 of pregnancy was increased in the low (n = 29) compared with the high cholesterol line (n = 38; 11.8 +/- .3 vs 9.8 +/- .3, respectively; P < .05), and litter size continued to be increased in the low cholesterol line (P < .05). No differences were noted between lines in kidney, ovarian, or total corpora lutea weight. Empty uterine weight and adrenal weight were increased in the high cholesterol line (P < .05) in randomly selected offspring of the third generation, and liver weight increased in the low line (P < .05). Associated with increased concentrations of cholesterol were increased serum concentrations of progesterone (gilts) and testosterone (boars) in the high cholesterol line (P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)

We determined the relationship of BW at birth, weaning (4 wk of age), and 8 wk of age to serum total cholesterol (C), high-density lipoprotein-cholesterol (HDL-C), and triglycerides (TG) at 8 wk of age in pigs, from the fourth generation that had been selected for low (10 litters, 75 pigs, LC) or high (10 litters, 63 pigs, HC) C at 8 wk of age. Mean C concentration at 8 wk of age was 81 +/- 30 mg/dL for LC groups and 136 +/- 19 mg/dL for HC groups. Serum C, HDL-C, and TG concentrations were not correlated with birth weight, suggesting that the physiological factors that may cause reduced weight gain in older animals are not operative in newborn pigs. All three constituents were correlated (P < .05) with BW at weaning and at 8 wk. However, only 4% of the variation in weight at weaning and 7% at 8 wk could be explained by a relationship with serum TG. There was a positive correlation between C and BW at 8 wk (r = .46, P < .05), which was apparent within the subgroups of LC and HC females and LC males (r = .46, .48, .68, respectively); the correlation was low (r = .26) in HC males.

Two identical trials, each with 128 crossbred weanling barrows (6.8 +/- .2 and 7.6 +/- .2 kg for Trials 1 and 2, respectively), were conducted. In each trial, pigs were allowed to consume ad libitum a 16% CP corn-soybean meal basal diet (B), B + 55 ppm of carbadox, B + 250 ppm of copper (Cu), or B + 125 ppm of Yucca shidigera extract for 56 d (four pens/diet; eight pigs/pen). At d 56 of the test, eight pigs/diet (two pigs/pen) were slaughtered for carcass and viscera measurements. Data of carbadox treatment in Trial 1 are excluded from this paper because of an error in mixing of the diet. In Trial 1, during the test period from d 0 to 28, pigs fed Cu had greater (P .05) compared with those fed B. During the period from 29 to 56 d, ADG was similar among pigs fed different diets (P > .05) but ADFI was affected (P Cu > B). No differences (P > .05) among diets were detected for gain/feed (G/F) and visceral weights expressed as a percentage of slaughter BW. In Trial 2, during the first 28 d, the ADG, ADFI, and G/F responses of pigs to Cu, yucca extract, and B were similar to those observed in Trial 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Female crossbred swine (Chester White x Landrace x Large White x Yorkshire) selected for three generations for low (L, n = 24) or high (H, n = 26) serum cholesterol at 8 wk of age were milked at d 20 or 21 of their first lactation to measure cholesterol, fat, lactose, protein, and ash concentrations. A contemporary, unselected control (C) group from the same original population (third lactation, n = 7) was sampled concurrently. All sows were fed a standard gestation, then lactation, diet that contained no cholesterol or added fat (all plant, corn-soybean meal). Genetic selection for low or high serum cholesterol at 8 wk of age induced corresponding changes in milk cholesterol and fat concentration in the third generation of selection, but not in any other milk constituents. Milk cholesterol concentrations (milligrams/100 grams fresh weight) were L, 25.3 +/- 3.0; C, 35.7 +/- 8.0; and H, 41.4 +/- 6.9 (L < C < H, P < .01). Corresponding values for milk fat were 5.7 +/- 1.3, 7.2 +/- .8, and 7.0 +/- .8 mg (L < C = H, P < .01). Serum cholesterol concentrations at 8 wk of age were L, 66.1 +/- 8.1; C, 93.7 +/- 13.7; and H, 126.2 +/- 9.7 mg/dL (P < .01). Milk cholesterol concentration was significantly correlated with serum cholesterol (r = .782, P < .01) and milk fat (r = .36, P < .01). It seems that selecting swine for low or high serum cholesterol at 8 wk of age induced changes in lipid metabolism reflected in differences in milk cholesterol concentrations.

Food and Agriculture in Human History Emergence and Evolution of Agriculture: The Impact on Human Health and Lifestyle Clark Spencer Larsen The Evolving Knowledge of Nutrition Buford L. Nichols and Roberto Quezada-Calvillo Foods by Choice Role of Religion, Spirituality, and Faith in Food Choices Jeffrey Stanton Kellam The Influence of Culture and Customs on Food Choices Cindy M. Imai, Dustin J. Burnett, and Johanna T. Dwyer The Required Nutrients Digestion and Absorption of Carbohydrates Roberto Quezada-Calvillo and Buford L. Nichols Lipids Duane E. Ullrey Protein and Amino Acids Duane E. Ullrey Vitamins and Mineral Elements Duane E. Ullrey Foods and Health Overweight, Obesity, and Related Diseases Gail G. Harrison and Summer Hamide Diseases of Nutrient Deficiencies Barbara Elaine Golden Effects of Growth Retardation and Nutrient Deficiencies on Cognitive Function and Behavior in Infants and Children Susan P. Walker and Julie M. Meeks Gardner Animal Source Foods: Effects on Nutrition and Function in Children in Developing Countries Monika Grillenberger Functional Foods John W. Finley Global Food Safety Issues Mindy Brashears and Tyler Stephens Food Production: Synergy of Science, Technology, and Human Ingenuity Challenge and Threats to Sustainable Food Production Larry W. Harrington and Peter R. Hobbs Global Climate Change and Agriculture Roberto Cesar Izaurralde Bioenergy: Energy Sources and Costs for Agriculture Donald C. Erbach and Wallace W. Wilhelm Soil Science: Management and Conservation R. Lal Advances in Water Science, Management, and Conservation B. A. Stewart Crop Science and Production Technology Peter R. Hobbs and Larry W. Harrington Animal Science and Production Technology G. Eric Bradford, Wilson G. Pond, and Kevin R. Pond Global Food Security World Population and Food Availability Shahla Shapouri and Stacey Rosen Changing Food Supply, Demand, and Marketing Issues: What Affects Price and Affordability? Miguel I. Gomez, Charles F. Nicholson, and Paul E. McNamara Food Availability and Quality: Situations and Opportunities in Developing Countries Dan L. Brown

Chronic cannulas were placed in the hepatic portal vein, ileal vein, and carotid artery in seven crossbred growing gilts trained to consume once daily 1.2 kg of a 16% CP corn-soybean meal diet. Eleven days after surgery, each pig (37.4 kg BW) was placed in an open-circuit calorimeter and its cannulas were connected to a system for determining portal absorption of nutrients. The whole-animal heat production and net portal absorption of gut VFA were measured simultaneously for 12 h after the pig was fed 1.2 kg of feed. Plasma concentrations of VFA, including acetic, propionic, isobutyric, butyric, isovaleric, and valeric acids, in portal and arterial samples were determined by gas chromatography after a cleanup by ion-exchange chromatography. The net portal absorption of VFA was calculated by multiplying the porto-arterial plasma concentration difference of the VFA by portal vein plasma flow. Plasma flow was estimated by the indicator-dilution technique using p-aminohippuric acid as the indicator. The energy value of absorbed VFA was the sum of products of each individual VFA multiplied by its corresponding value of the heat of combustion. The mean hourly energy value of absorbed VFA during the 12-h postprandial period was .65 +/- .03 kcal.h-1.kg BW-1. The mean hourly whole-animal heat production was 2.70 +/- .04 kcal.h-1.kg BW-1. Thus, in our 37.4-kg pigs, which were trained to consume 1.2 kg of a 16% CP corn-soybean meal diet once daily, the gut VFA absorbed into the portal vein could contribute 23.8 +/- 1.1% to whole-animal heat production if all of the absorbed VFA were combusted to CO2.

Three four-way cross (Chester White × Landrace × Large White × Yorkshire) female pigs from each of twelve litters were used. One pig from each trio remained with its primiparous dam and its other littermates to age 28 d. Two pigs from each trio were removed to individual boxes at age 24 to 36 h and fed liquid sow-milk substitute containing low cholesterol (14 mg/100 g) or high cholesterol (151 mg/100 g) to age 28 d. All pigs were weaned to a dry diet containing 182 mg cholesterol/100 g to age 12 wk and 115 mg cholesterol/100 g from age 12 wk to 20 wk. Carcass measurements and organ weights were recorded at slaughter (20 wk) and liver was analyzed for cholesterol. Body weights were recorded weekly to 28 d and bi-weekly thereafter; serum total cholesterol was determined on d 1, 28, 56, 84, 112 and 136. Sow-reared (SR) pigs were heavier (P

To test the hypothesis that maternal protein deprivation in early pregnancy retards body and organ growth of 63-d (midterm) pig fetuses, 16 primiparous domestic four-way crossbred swine were fed a diet adequate in protein (13% protein) (A) or a protein-restricted (0.7% protein) diet (PR) from d 1 to 63 of pregnancy or to parturition. Maternal body weight, plasma protein, hematocrit, and heart and spleen weights were reduced, and indices of body fatness were increased by the PR diet. Fetal body weights were reduced and fetal placental weights were increased at d 63 by protein restriction. Length from crown to rump and weights of liver, kidney, gastrointestinal tract, and cerebrum were lower in PR than in A fetuses. Concentrations of protein, RNA and DNA in liver, cerebrum and longissimus muscle were unaffected by maternal diet, but total amounts of all three constituents in liver and cerebrum were lower in PR than in A. Relative organ weights were similar in A and PR fetuses except that kidneys and gastrointestinal tract were greater in A fetuses. Newborn body weights and absolute organ weights were generally lower in PR than in A, but relative weights were similar. The observed reduction in body and organ weights and amounts of protein, RNA and DNA in 63-d fetuses and newborn progeny of PR swine establishes that the stunting effect of maternal protein restriction can be initiated by midterm, preceding the period of most rapid accretion of body tissues during prenatal life in the pig.

Chronic cannulas were placed into the hepatic portal vein, ileal vein and carotid artery of growing pigs trained to consume their daily allowance of 1.2 kg of feed (16% protein corn-soybean meal basal diet) in a single meal. The average preoperative BW of pigs was 44.7 kg for Trial 1 (three pigs) and 35.3 kg for Trial 2 (seven pigs). In Trial 1, net absorption of ammonia (NH3) and glucose into the portal vein was determined three times at weekly intervals. The net portal absorptions were derived by multiplying the porto-arterial plasma concentration difference of NH3 and glucose by portal vein plasma flow rate estimated with the p-aminohippuric acid indicator-dilution technique. Differences in the net portal absorptions of NH3 and glucose among the three weekly measurements were small (P greater than .05). In Trial 2, the first sequence of net portal absorption measurements was conducted when pigs were fed the basal diet, and the second sequence of measurements was conducted after the pigs had been fed the diet supplemented with 55 ppm of carbadox for 7 d. Carbadox supplementation reduced (P less than .05) plasma NH3 concentration in portal plasma during the 2.5-h to 5-h postprandial period and decreased (P less than .05) net portal absorption of NH3 during the 2.5-h to 4-h postprandial period. Carbadox, however, did not affect (P greater than .05) net portal absorption of glucose. We suggest that carbadox suppresses the production of cell-toxic NH3 by intestinal microorganisms and, thus, reduces the injury and turnover of intestinal cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Thirty-two castrated male crossbred growing pigs (average initial wt 26.9 kg) were used to determine the effect of a high level of dietary protein (37%) compared with a normal level of protein (15%) on enterobacteria and Campylobacter sp. inhabitation in the large intestine and on visceral organ hypertrophy and the interrelationships between these two factors. Pigs were kept in pairs (eight pens of two pigs/diet) and fed their respective diets and libitum. Eight pigs (two pens of two pigs fed each diet) were killed at wk 4, 8, 12 and 16 without fasting. Fecal samples were obtained every 2 wk from animals scheduled for necropsy at 16 wk, and colon contents were obtained from all pigs at necropsy; samples were enumerated individually for enterobacteria and Campylobacter sp. Weights of heart, lungs, liver, kidneys, perirenal fat and empty stomach, small intestine and large intestine were recorded at necropsy. Stomach, cecum and proximal colon were sectioned for histopathologic examination. Daily body weight gain was depressed by high dietary protein, but liver and kidneys were heavier in the high protein group than in controls at each time interval. Mild lymphoid hyperplasia of Peyer's patches in the small intestine in some pigs in both groups was indicative of antigenic stimulation but not of pathologic significance. There was no effect of diet on counts of enterobacteria or Campylobacter sp. in feces or colon contents during the 16-wk experiment. We conclude that the hypertrophic response of the tissues of growing pigs to high dietary protein is not the result of the presence of Campylobacter sp. or enterobacteria in the colon contents.

"Written and edited by a distinguished team of experts, this encyclopedia encompasses animal physiology; animal growth and development; animal behavior; animal reproduction and breeding; alternative approaches to animal maintenance; meat science and muscle biology; farmed animal welfare and bioethics; and food safety. Organized with reader-friendly descriptions of technologies, the second edition consists of more than 300 entries--many of which are new--ranging from adaptation and stress, to zoos and aquariums. With 2500 references and hundreds of figures, equations, and tables, it covers new developments in genomics, transgenesis, cloning, and mathematical model constructions"

High iron consumption has been proposed to relate to an increase in the risk of colon cancer, whereas high levels of supplemental sodium phytate effectively reduce iron-induced oxidative injury and reverse iron-dependent augmentation of colorectal tumorigenesis. However, the protective role of intrinsic dietary phytate has not been determined. In this study, we examined the impact of removing phytate present in a corn-soy diet by supplemental microbial phytase on susceptibility of pigs to the oxidative stress caused by a moderately high dietary iron intake. Thirty-two weanling pigs were fed the corn-soy diets containing two levels of iron (as ferrous sulfate, 80 or 750 mg/kg diet) and microbial phytase (as Natuphos, BASF, Mt. Olive, NJ, 0 or 1200 units/kg). Pigs fed the phytase-supplemented diets did not receive any inorganic phosphorus to ensure adequate degradation of phytate. After 4 months of feeding, liver, colon, and colon mucosal scrapings were collected from four pigs in each of the four dietary groups. Colonic lipid peroxidation, measured as thiobarbituric acid reacting substances (TBARS), was increased by both the high iron (P< 0.0008) and phytase (P< 0.04) supplementation. Both TBARS and F2-isoprostanes, an in vivo marker of lipid peroxidation, in colonic mucosa were affected by dietary levels of iron (P< 0.03). Mean hepatic TBARS in pigs fed the phytase-supplemented, high iron diet was 43%-65% higher than that of other groups although the differences were nonsignificant. Moderately high dietary iron induced hepatic glutathione peroxidase activity (P= 0.06) and protein expression, but decreased catalase (P< 0.05) in the colonic mucosa. In conclusion, intrinsic phytate in corn and soy was protective against lipid peroxidation in the colon associated with a moderately high level of dietary iron.

Pork, along with other animal products, provides protein of higher nutritive value than that present in most plant proteins and also provides other nutrients not found in adequate amounts in plants. Pork supplies nearly one-half of the meat production from domestic animals in the world and about 40% of the meat (excluding poultry) in the United States. The long-term acceptance of pork as a major food source has been a result of its high nutritive value as well as the variety of processing and cooking methods available for its inclusion in many cultures. Those associated with the swine industry must not lose sight of the fact that the consumer ultimately determines the amount and kind of pork produced. The purpose of this chapter is to characterize pork as to its nutrient composition and other properties that affect its acceptability to humans.

In Chapter 3, it was stated that the genetic aspects of the production system set both the limits and potential for performance of the system. The breeding stock input into the system introduces potentials for animal performance but these are not usually exceeded (experimental lean growth promotants such as ractopamine and somatotropins do increase lean growth potential above that expressed without their use). In this chapter, we will examine alternative breeding systems to provide that input, tools available to the breeder and producer to improve the potential for that input, and the evolution of genetic improvement tools from the traditional showring-based visual appraisal approach to modern computer-based performance testing and genetic evaluation procedures.

The evolution and domestication of the pig has been described in several books (Towne and Wentworth 1950; Mellen 1952; Briggs 1969; Mason 1969), and the student interested in a detailed account of this fascinating story is referred to them. Recorded domestication appears in Biblical accounts as early as 2000 B.C. Despite some ancient cultural and religious taboos forbidding the consumption of pork, the domestication of the pig as a source of human food has persisted, and the continued increases in numbers of swine throughout the world up to the present time provide evidence of the contribution of the pig to human nutrition through the ages.

Some decades ago, “raising pigs” was primarily a subsidiary farm activity that took place in mud lots (Fig. 3.1), with minimal shelter, to utilize garbage and leftover grains to produce meat for the farm family. Pasture production systems (Fig. 3.2) predominated through the 1950s, with more intensive systems starting in the 1960s. From these origins, “pork production” has evolved to be a primary enterprise on many specialized farms to convert processed feedstuffs and breeding stock resources into marketable pork products. This modern production often occurs in insulated, ventilated facilities with automated feed delivery and manure disposal. This requires labor competent to care for the stock and operate the equipment which is supervised by managers (who may be the owners) with considerable expertise. This trend is likely to continue.

Feed represents 55–85% of the total cost of commercial swine production, depending mainly on the relative costs of feed, labor, and housing in a particular situation. For this reason, it is highly important that economical as well as nutritionally balanced diets are provided during all phases of the life cycle. The economics of swine feeding are largely dependent on local conditions of feedstuff availability and competition for the same foodstuff for use by either humans or other animals. The pig has a digestive system with limited ability to utilize large quantities of forage so that, like the chicken, it is in direct competition with man for available food supplies. The degree of competition is related to cultural differences in food preferences. For example, wheat and potatoes are not usually fed to swine in the United States as the demand for human consumption holds the price too high, but in many other parts of the world these crops are commonly fed to swine. Similar relationships exist for other crops in other parts of the world.

The world pig population continues to increase faster than the human population, which is now about 5.5 billion and expected to reach 7 to 8 billion by the year 2020. One often hears the assertion that because pigs compete directly with humans for some of the available food supplies, the importance of pork in the food supply must decline, both on moral and economic grounds, as the population increases. Science and technology are creating changes—in the pig, as well as in production systems —that may assure continued growth of swine numbers and pork consumption throughout the world in the foreseeable future.

Various aspects of growth are covered in other chapters, but because it is such an important topic, it is discussed more directly here. The characteristic S-shaped growth curve of all biological systems, whether it be an increase in weight gain of a plant or animal or increase in number of yeast cells in a population (Brody 1945) is shown in Fig. 5.1. The term growth, as applied to animal production, is often considered to be synonymous with increase in body weight of the animal from conception to maturity. Brody (1945) has defined growth as “the constructive or assimilatory synthesis of one substance at the expense of another (nutrient) which undergoes dissimilation.” The energetic efficiency of growth as just defined is, therefore, the energy stored in the animal per unit of energy consumed. The pig is especially efficient in growth, in comparison with other farm animals. Detailed discussion of the energetic efficiency of growth in meat-producing animals has been provided by Webster (1980). The complex metabolic and endocrine aspects of tissue and animal growth are exciting areas of animal biology and have been reviewed by Trenkle and Marple (1983>) and in a symposium, Concepts of Animal Growth (American Society of Animal Science, 1988).

A high reproductive rate is essential in a successful purebred or commercial swine enterprise. A knowledge of the normal anatomy and physiology of the female and male reproductive tract is fundamental to the achievement of a high reproductive rate of swine. In this chapter, the following topics are discussed: anatomy of the female and male reproductive tracts, puberty, the estrous cycle, ovulation, factors affecting ovulation rate and time of estrus, movement and survival of sperm in the female reproductive tract, conception rate, duration of gestation, uterine capacity, parturition, male puberty and sexual behavior, composition of semen, sperm survival and storage, artificial insemination, and potentially important techniques, though presently in limited use, such as embryo transfer, artificial control of the estrous cycle, superovulation, and storage of sperm by freezing. Each of the above subjects is of significance in the total picture of reproduction. Overviews of current knowledge of male and female reproduction in swine are recommended (Dziuk 1977; Dziuk and Bellows 1983; Bazer and First 1983; Amann and Schanbacher 1983; Kirkwood and Aherne 1985; Christenson 1986).