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1.
The objectives of this study were to characterize the quantitative changes in various body tissues of high-lean type gilts during gestation and to determine the protein needs of pregnant gilts based on changes in tissue contents. Thirty-five gilts (158.2 +/- 8.3 kg) were housed in individual gestation crates with six unbred gilts randomly selected and slaughtered to provide data for d 0 of gestation. The remaining gilts were bred and assigned randomly to one of six slaughter groups: d 45, 60, 75, 90, 102, and 112. Gilts were fed 2 kg (as-fed basis) of gestation diet daily (3.1 Mcal/kg of ME and 0.56% lysine). Carcass soft tissue, bone, gastrointestinal tract, spleen, pancreas, kidney, liver, uterus, fetus, mammary gland, and the remaining viscera were separated and weighed. Carcass soft tissue, liver, remaining viscera, uterus, and gastrointestinal tract were ground, freeze-dried, and analyzed for composition. Body weights of the gilts increased quadratically (P < 0.001) during gestation. Weights of carcass soft tissue and uterus, including placenta, increased linearly (P < 0.001) during gestation. Weights of individual fetuses, fetal litters, individual mammary glands, and the entire mammary glands increased cubically (P < 0.001) during gestation. Crude protein in carcass soft tissue increased cubically (P < 0.01), whereas DM and ether extract (EE) in carcass soft tissue increased linearly (P < 0.01). The DM, CP, and EE in the entire mammary glands increased quadratically (P < 0.001) during gestation. The DM, CP, and EE in fetal litter increased cubically (P < 0.01) as gestation progressed. The accretion rates of the conceptus, fetal litter, individual fetus, individual mammary gland, and CP in fetal litter differed (P < 0.05) before and after d 70 of gestation. The CP daily gain from all maternal and fetal tissues was 40 and 103 g/d before and after d 70 of gestation, respectively, suggesting that pregnant gilts may require different quantities of dietary protein during gestation. Based on the maintenance requirement, maternal tissue gain, and conceptus gain, pregnant gilts require 6.8 and 15.3 g/d of true ileal-digestible lysine (or 147 and 330 g/d of true ileal-digestible protein) before and after d 70 of gestation, respectively, to support their true biological needs.  相似文献   

2.
The aim of this study was to investigate whether dietary protein intake during gestation less than or greater than recommendations affects gilts growth and body composition, gestation outcome, and colostrum composition. German Landrace gilts were fed gestation diets (13.7 MJ of ME/kg) containing a low (n = 18; LP, 6.5% CP), an adequate (n = 20; AP, 12.1%), or a high (n = 16; HP, 30%) protein content corresponding to a protein:carbohydrate ratio of 1:10.4, 1:5, and 1:1.3, respectively, from mating until farrowing. Gilts were inseminated by semen of pure German Landrace boars and induced to farrow at 114 d postcoitum (dpc; Exp. 1). Energy and protein intake during gestation were 33.3, 34.4, and 35.8 MJ of ME/d (P < 0.001) and 160, 328, and 768 g/d, respectively, in LP, AP, and HP gilts (P < 0.001). From insemination to 109 dpc, BW gain was least in LP (42.1 kg), intermediate in HP (63.1 kg), and greatest in AP gilts (68.3 kg), whereas increase of backfat thickness was least in gilts fed the HP diet compared with LP and AP diets (3.8, 5.1, 5.0 mm; P = 0.01). Litter size, % stillborn piglets, and mummies were unaffected (P > 0.28) by the gestation diet. Total litter weight tended to be less in the offspring of LP and HP gilts (14.67, 13.77 vs. 15.96 kg; P = 0.07), and the percentage of male piglets was greater in litters of HP gilts (59.4%; P < 0.01). In piglets originating from LP and HP gilts, individual birth weight was less (1.20, 1.21 vs. 1.40 kg; P = 0.001) and birth weight/crown-rump length ratio was reduced (45.3, 46.4 vs. 50.7 g/cm; P = 0.003). Colostrum fat (7.8, 7.4 vs. 8.1%) and lactose concentrations (2.2, 2.1 vs. 2.6%) tended to be reduced in LP and HP gilts (P = 0.10). In Exp. 2, 28 gilts (LP, 10; AP, 9; HP, 9) were treated as in Exp. 1 but slaughtered at 64 dpc. At 64 dpc, LP gilts were 7% lighter than AP gilts (P = 0.03), whereas HP gilts were similar to AP gilts. Body composition was markedly altered in response to LP and HP feeding with less lean (P < 0.01) and greater fat content (P = 0.02 to 0.04) in LP and less fat content (P = 0.02 to 0.04) in HP gilts. Fetal litter weight and number, and embryonic survival at 64 dpc were not affected by the diets. These results indicated that gestation diets containing protein at 50 and 250% of recommendations and differing in protein:carbohydrate ratio led to marked changes in protein and fat metabolism in gilts resulting in fetal growth retardation of 15%, which mainly occurred during the second half of gestation.  相似文献   

3.
Prolactin is required for mammary development in various species but its possible role for mammogenesis in pigs is not known. The goal of the present study was therefore to determine the effect of prolactin inhibition by bromocriptine during the last third of gestation on mammary gland development in gilts. Twenty-eight primigravid gilts were assigned as controls (n = 15) or received 10 mg of bromocriptine orally thrice daily (n = 13) from d 70 to 110 of gestation. Jugular blood samples were collected on d 70 of gestation and every 8 d thereafter and were assayed for prolactin, IGF-I, estradiol, and progesterone. Gilts were slaughtered on d 110 of gestation and fetuses were counted and weighed. One row of mammary glands was used for dissection of parenchymal and extraparenchymal tissues and for determination of DNA, RNA, dry matter, protein, and fat contents. Tissue from the other row was used for measures of prolactin receptor number and affinity. Concentrations of prolactin were drastically reduced throughout the bromocriptine treatment period (P < .001), whereas there was no overall treatment effect on progesterone and IGF-I levels (P > .10). Total weight and extraparenchymal tissue weight of the mammary glands were unaffected by treatment (P > or = .1), but weight of parenchymal tissue, total DNA, and total RNA decreased (P < .01) with bromocriptine treatment. Percentages of fat and dry matter in parenchymal tissue increased with bromocriptine treatment (P < .01) and the percentage of protein decreased (P < .01). Number of prolactin receptors in parenchymal tissue decreased with bromocriptine treatment (P < .001) and receptor affinity increased (P < .001). Average fetal weight was lower in gilts receiving bromocriptine than in control gilts (P = .05), but fetal number did not differ (P > .1). These results clearly demonstrate that prolactin is essential for normal mammary gland development and can affect fetal growth during the last third of gestation in gilts.  相似文献   

4.
The objective of this study was to determine the effects of maternal treatment with porcine somatotropin (pST) during early gestation on embryonic survival, fetal development, and internal environment for fetal growth. Sixty-two crossbred gilts received daily injections of either 3 mL of a placebo (control, n = 31) or 6 mg of pST (n = 31) from d 10 to 27 of gestation. Representative gilts were slaughtered on d 28, 37, and 62 of gestation. The remaining gilts were allowed to farrow. It was found that embryonic survival was not influenced by pST treatment (P > 0.10). However, pST affected the growth and composition of the maternal (endometrium) and fetal (chorion) parts of the placenta. Thus, endometrial RNA concentration tended to be increased by pST at d 37 (P = 0.15), and it was increased at d 62 (P < 0.05) of gestation, which is indicative of increased capacity for protein synthesis. At birth, placental chorion weight (P < 0.10) and contents of DM and protein (P < 0.05) were increased due to pST treatment, but no effects were detectable up to d 62 of gestation. Maternal pST treatment was effective at increasing nutrient supply to the embryo as suggested from elevated glucose concentrations in amniotic and allantoic fluids (P < 0.05) at d 28 of gestation. With regard to prenatal growth, embryonic DNA concentration was slightly elevated at d 28 (P < 0.10), but pST did not induce any changes in average embryonic, fetal, or neonatal weights. However, within litters, the birth weights of piglets in the 25% lowest weight group (LW) were increased by pST treatment vs control LW pigs (1,241+/-55 vs 1,099+/-59 g, P < 0.10). Thirty-eight neonates from 15 litters divided among the three weight groups were examined for body composition. The weight of the intestinal tract was increased above average after maternal pST treatment (P < 0.01). Additionally, the amounts of tissues such as bone (P = 0.12) and s.c. fat (P = 0.06), and of protein, fat (P = 0.10), and ash (P < 0.05) were increased, whereas the relative body composition remained unchanged by pST (P > 0.10). On average, muscle protein concentration was elevated due to pST (P < 0.01), and, in LW piglets, plasma IGF-I concentration was increased (P < 0.10). The results suggest that maternal somatotropin is a critical factor in early pregnancy capable of influencing placental nutrient transfer and placental growth. It thereby selectively improves the growth conditions for the smaller littermates.  相似文献   

5.
Thirty-six crossbred gilts were fed three levels of protein (146, 255 and 364 g/d) and two levels of energy (6,200 and 7,440 kcal of digestible energy/d) throughout gestation in a 3 x 2 factorial arrangement of treatments. Five-day N balance studies were conducted in early (0 to 30 d), mid- (30 to 60 d) and late (60 to 90 d) gestation. At slaughter (90 d of gestation), reproductive tracts were weighed and evaluated for reproductive performance and samples of the reproductive tract, liver and semimembranosus muscle (SM) were analyzed for crude protein. The right half of the carcass was subjected to a physical separation of fat, lean and bone. Neither dietary protein nor energy level significantly affected weight gain or reproductive performance. Nitrogen retention increased as dietary protein level increased and stage of gestation progressed (linear effect, P less than .01), but efficiency of N utilization and dry matter digestibility decreased with increasing protein intakes (quadratic effect, P less than .05 and linear effect, P less than .01, respectively). Nitrogen retention (P less than .01), efficiency of N retention (P less than .05) and dry matter digestibility (P less than .01) were higher in gilts fed high (H) energy compared with gilts receiving moderate (M) energy diets. Increasing dietary protein increased total carcass separable lean tissue (quadratic effect, P less than .01), liver weight (linear effect P less than .01) SM weight (quadratic effect, P less than .05) and SM percentage M (linear effect P less than .10). Similarly, total carcass N and carcass lean N increased as protein level increased (quadratic effect, P less than .10, P less than .05, respectively). In contrast to the increase in muscle N, N in uterine tissue and fluids was not affected by dietary protein level. The results of this experiment suggest that 146 g of crude protein/d during gestation is just as effective as higher levels of crude protein for litter size or storage of N in reproductive tissue, but 255 to 364 g of protein/d are required to maximize muscle N.  相似文献   

6.
Systemic ketosis was induced in first-parity gilts by the isocaloric substitution of glucose with 1,3-butylene glycol to supply 20% of the total dietary energy beginning on d 23 (23 BG) or d 60 (60 BG) of gestation. Ketosis reduced (P less than .05) maternal plasma glucose, urea N and insulin concentrations. Fetal carcass dry matter and carcass glycogen contents were reduced (P less than .05) by maternal ketogenic calorie substitution, whereas fetal hepatic glycogen and lipid contents were not influenced by maternal treatment. Neural acetate oxidation was reduced (P less than .05) in the 23 BG and 60 BG fetuses, with a concurrent increase (P less than .05) in beta-hydroxybutyrate (BOHB) oxidation. Neural lipogenesis measured from acetate and BOHB substrates was nominal in the d 105 pig fetus. Fetal hepatic acetate and BOHB utilization for lipogenesis were increased (P less than .05) by maternal ketosis. Reproductive performance characteristics (litter size, number stillborn and birth weight) were not improved by maternal ketosis. The substantial improvement in lactation weight gain by litters from 23 BG and 60 BG dams (20%, P less than .05) may suggest a carryover effect of gestation dietary treatment on lactation performance.  相似文献   

7.
Prolactin is required from d 70 to 110 of gestation for normal mammary development of gilts. The goal of the present study was to determine the effect of inhibiting prolactin with bromocriptine during specific time windows during the second half of gestation on mammary gland development in gilts. Crossbred primigravid gilts were assigned as controls (n = 12) or received 10 mg of bromocriptine orally three times daily from d 50 to 69 (BR50, n = 12), d 70 to 89 (BR70, n = 12), or d 90 to 109 (BR90, n = 12) of gestation. Jugular blood samples were collected on d 50, 70, 90, and 109 of gestation and assayed for prolactin and estradiol. Gilts were slaughtered on d 109 of gestation and fetuses were counted and weighed. One row of mammary glands was used for dissection of parenchymal and extraparenchymal tissues, and for biochemical analyses. Tissue from the other row was used for measures of prolactin receptor number and affinity. Concentrations of prolactin were decreased markedly (P < 0.001) at the end of each bromocriptine treatment period compared with controls, but there was no overall treatment effect (P > 0.1) on estradiol concentrations. Extraparenchymal tissue weight of the mammary glands was unaffected by treatments (P > 0.1), but weight of parenchymal tissue, total DNA, and total RNA were lower (P < 0.01) in BR90 than control gilts. The percentage of DM in parenchymal tissue was unaffected by treatments (P > 0.1), but percentage of fat was higher and percentage of protein lower (P < 0.01) in BR90 gilts compared with controls. Cell size, as estimated by the protein:DNA ratio, also was lower (P < 0.01) in the BR90 group. Number and affinity of prolactin receptors in parenchymal tissue were not significantly altered by treatments. In conclusion, there is a specific time period in the second half of gestation, from 90 to 109 d, during which prolactin is essential for normal mammary parenchymal tissue development.  相似文献   

8.
We hypothesized that the ability of the fetus to alter nutrient shunting and organ growth might be associated with uterine capacity. White crossbred gilts from a randomly selected control line, a line selected for ovulation rate, and a line selected for uterine capacity (UC) were unilaterally hysterectomized-ovariectomized at 160 d of age, mated at estrus, and slaughtered at 45, 65, 85, and 105 d of gestation (9 to 18 gilts for each line x day combination). Analysis of the data revealed that heart weights and fetal weights were decreased in the ovulation rate line. No significant differences were obtained in fetal, placental, or fetal organ weights between the control and UC lines. Allometric growth of organs was assessed by examination of the slopes of the relationships between fetal weights and fetal organ weights after natural log transformation. Only the relative growth of the liver differed between selection lines and was greater (P = 0.01) in the UC compared with the control line during early pregnancy (d 45 and 65). Allometric growth of the fetal brain, liver, and heart differed with day of gestation. A brain-sparing effect was greater (P < 0.01) on d 85 and 105 compared with d 45 and 65. By contrast, a heart-sparing effect was present during early gestation and disappeared in later gestation. Fetal liver weights were hypersensitive to differences in fetal weights on d 45, possibly associated with placental effects on fetal liver weight. Fetal spleen weights were proportional to fetal weights throughout gestation. These results indicate that selection for ovulation rate decreased total fetal and fetal heart weights, and that selection for UC altered the relationship between total fetal and fetal liver weights during early gestation. Results further indicate significant changes in allometric growth of organs during gestation.  相似文献   

9.
In a previous report, it was suggested that intrauterine crowding impaired fetal erythropoiesis and that fetal erythropoiesis was accelerated in Meishan pigs during early pregnancy. Because these conclusions were based on limited numbers of observations, the present experiment was undertaken to provide a more extensive investigation of these phenomena. Intact white crossbred gilts, unilaterally hysterectomized-ovariectomized (UHO) white crossbred gilts, and intact Meishan gilts (n = 13 to 16 per group) were mated after at least one estrous cycle of normal duration (17 to 23 d). Gilts were laparotomized at d 35 of pregnancy, the uterine horns were exteriorized and opened near each fetus, and a blood sample was collected from each fetus. The uterine horn was then surgically removed, and each fetus and placenta was weighed. All fetal blood samples were measured for hematocrit, red blood cell number, and hemoglobin. Erythropoietin and the percentages of nucleated cells and reticulocytes were also measured in blood samples from the largest and smallest living fetus in each litter. Fetal hematocrits were not affected by treatment. Blood cell counts were greater (P < 0.01) in fetuses of Meishan gilts than in White crossbred intact or UHO gilts. Hemoglobin was less (P < 0.01) in fetuses of Meishan gilts than in fetuses of White crossbred intact or UHO gilts. The percentages of nucleated (immature) cells and reticulocytes were both less (P < 0.01) in fetuses of Meishan intact gilts. Erythropoietin was also lower (P < 0.01) in fetuses of Meishan gilts. As observed previously, fetal weight was correlated (r = 0.38; P < 0.01) with blood hemoglobin concentration. These results confirm that fetal erythropoiesis in Meishan gilts is accelerated compared with White crossbred gilts. These results are consistent with the hypothesis that faster blood cell development could be beneficial to fetal survival in swine.  相似文献   

10.
Maternal nutrient restriction leads to alteration in fetal adipose tissue, and offspring from obese mothers have an increased risk of developing obesity. We hypothesized that maternal obesity increases fetal adipogenesis. Multiparous ewes (Columbia/Rambouillet cross 3 to 5 yr of age) carrying twins were assigned to a diet of 100% (Control; CON; n = 4) or 150% (Obese; OB, n = 7) of NRC maintenance requirements from 60 d before conception until necropsy on d 135 of gestation. Maternal and fetal plasma were collected and stored at -80°C for glucose and hormone analyses. Fetal measurements were made at necropsy, and perirenal, pericardial, and subcutaneous adipose tissues were collected from 7 male twin fetuses per group and snap frozen at -80°C. Protein and mRNA expression of fatty acid translocase [cluster of differentiation (CD) 36], fatty acid transport proteins (FATP) 1 and 4, insulin-sensitive glucose transporter (GLUT-4), fatty acid synthase (FASN), and acetyl-coA carboxylase (ACC) was evaluated. Fetal weight was similar, but fetal carcass weight (FCW) was reduced (P < 0.05) in OB versus CON fetuses. Pericardial and perirenal adipose tissue weights were increased (P < 0.05) as a percentage of FCW in OB versus CON fetuses, as was subcutaneous fat thickness (P < 0.001). Average adipocyte diameter was greater (P < 0.01) in the perirenal fat and the pericardial fat (P = 0.06) in OB fetuses compared with CON fetuses. Maternal plasma showed no difference (P > 0.05) in glucose or other hormones, fetal plasma glucose was similar (P = 0.42), and cortisol, IGF-1, and thyroxine were reduced (P ≤ 0.05) in OB fetuses compared with CON fetuses. Protein and mRNA expression of CD 36, FATP 1 and 4, and GLUT-4 were increased (P ≤ 0.05) in all fetal adipose depots in OB versus CON fetuses. The mRNA expression of FASN and ACC was increased (P < 0.05) in OB vs. CON fetuses in all 3 fetal adipose tissue depots. Fatty acid concentrations were increased (P = 0.01) in the perirenal depot of OB versus CON fetuses, and specific fatty acid concentrations were altered (P < 0.05) in subcutaneous and pericardial adipose tissue because of maternal obesity. In conclusion, maternal obesity was associated with increased fetal adiposity, increased fatty acid and glucose transporters, and increased expression of enzymes mediating fatty acid biosynthesis in adipose depots. These alterations, if maintained into the postnatal period, could predispose the offspring to later obesity and metabolic disease.  相似文献   

11.
A total of 59 gilts (BW = 137.7 kg) from 3 breeding groups were used to assess the effects of feeding l-carnitine during gestation on gilt growth characteristics, blood metabolites, and uterine and chorioallantoic expression of IGF axis components at d 40, 55, and 70 of gestation. Experimental treatments were arranged in a 2 x 3 factorial, with main effects of added l-carnitine (0 or 50 ppm) and day after initial breeding (d 40, 55, or 70 of gestation). All gilts received a constant feed allowance of 1.75 kg/d and a top-dress containing 0 or 50 ppm of l-carnitine beginning on the first day of breeding through the assigned day of gestation. No dietary treatment differences were observed for gilt BW, backfat, or estimated protein or fat mass at any day of gestation. No differences were observed in circulating total and free carnitine at breeding, but concentrations increased (P < 0.01) as day of gestation increased for gilts fed diets containing l-carnitine compared with those fed the control diet. Maternal IGF-I concentration decreased (P < 0.01) from d 0 to 70 for all gilts, with no differences between treatments. Insulin-like growth factor binding protein-3 mRNA (P = 0.05) and IGFBP-5 mRNA (P = 0.01) increased in the endometrium of gilts supplemented with l-carnitine. These data demonstrate that l-carnitine supplementation and day of gestation alter the expression of the IGF axis by changing the expression of IGFBP at the fetal-maternal interface in swine. These changes in the IGF axis at the fetal maternal interface may aid in determining the reasons for the effects of l-carnitine on reproductive traits.  相似文献   

12.
Characterization of mammary gland development in pregnant gilts   总被引：2，自引：0，他引：2  
The purpose of this study was to quantify mammary gland (MG) growth during pregnancy in gilts and to determine the effect of anatomical location on gland growth. Size, composition, and histomorphology of MG were determined during gestation in 29 primigravid gilts. Gilts were allotted randomly to 6 slaughter groups: d 45 (n = 6), 60 (n = 4), 75 (n = 5), 90 (n = 4), 102 (n = 5), and 112 (n = 5) of gestation. Mammary glands were obtained at slaughter, and skin and extraneous fat pad were removed to obtain parenchymal MG tissue. Mammary glands were further separated into individual MG, and their locations were recorded. Individual MG were weighed and bisected in an approximate midsagittal section to measure cross-sectional area. Mammary glands were ground individually and pooled according to anatomical region: the first and second pairs of MG = anterior MG; the third, fourth, and fifth pairs of MG = middle MG; the sixth, seventh, and eighth pairs of MG = posterior MG. Contents of DM, CP, ether extract, and crude ash were measured. Wet weight, DM, CP, and ash content of total and individual MG increased (P < 0.01) between d 45 and 112 of gestation. Cross-sectional area of individual MG increased (P < 0.01) as gestation progressed. Percentage of CP and ash increased (P < 0.01), whereas percentage of ether extract decreased (P < 0.01) as gestation progressed. This inverse relationship between percentages of CP and ether extract (r = -0.999; P < 0.0001) was consistent with the histological shift from primarily an adipose tissue in early gestation to one containing extensive lobuloalveolar tissue in late gestation. Wet weight of middle MG was greater (P < 0.05) than that of posterior MG at d 102 and 112 of gestation, and amount of CP in middle MG was greater (P < 0.05) than that in anterior and posterior MG at d 102 and 112 of gestation, indicating that middle MG grow faster than other MG during late gestation. Rates of wet weight gain and protein accretion were accelerated (P < 0.01) after d 74 and 75 of gestation, respectively, indicating the importance of MG growth during the last trimester of gestation. The increase in rate of protein accretion after d 75 indicates a greater protein requirement for MG growth during later gestation.  相似文献   

13.
Barrows and gilts of 2 genetic lines with differing lean gain potentials (high-lean = 375 g of fat-free lean/d; low-lean = 280 g of fat-free lean/d) were used to determine tissue and organ weights and compositions from 20 to 125 kg of BW. The experiment was a 2 (genetic line) x 2 (sex) x 5 (BW) factorial arrangement of treatments in a completely randomized design conducted with 2 groups of pigs in 6 replicates (n = 120 pigs). Six pigs from each sex and genetic line were slaughtered at 20 kg of BW and at 25 kg of BW intervals to 125 kg of BW. At slaughter, the internal tissues and organs were weighed. Loin and ham muscles were dissected from the carcass and trimmed of skin and external fat, and the ham was deboned. Residuals from the loin and ham were combined with the remaining carcass. Body components were ground, and their compositions were determined. The results demonstrated that tissue weights increased (P < 0.01) as BW increased. Loin and ham muscle weights increased but at a greater rate in the high-lean line and in gilts resulting in genetic line x BW and sex x BW interactions (P < 0.01). Liver and heart expressed on a BW or a percentage of empty BW basis increased at a greater rate in the high-lean line resulting in a genetic line x BW interaction (P < 0.01). Liver and intestinal tract weights were heavier in barrows than in gilts, significant only at 45 (P < 0.05), 75 (P < 0.01), and 100 (P < 0.05) kg of BW. Loin and ham muscles from the high-lean genetic line and gilts had greater (P < 0.01) water, protein, and ash contents compared with the low-lean genetic line and barrows resulting in genetic line x BW and sex x BW interactions (P < 0.01). The remaining carcass (minus loin and ham muscles) had greater (P < 0.01) amounts of water and protein, and less (P < 0.01) fat in the high-lean genetic line and gilts. The high-lean genetic line and gilts had more total body water, protein, and ash, but less body fat, with these differences diverging as BW increased, resulting in a genetic line x BW interaction (P < 0.01). The results indicated that liver and heart weights were greater in high-lean pigs, reflecting the greater amino acid metabolism, whereas the liver and intestinal tract weights were greater in barrow than gilts, reflecting their greater feed intakes and metabolism of total nutrients consumed.  相似文献   

14.
Crossbred pigs (n = 200) from Duroc sires mated to Landrace x Large White dams, with a mean BW of 107.0 +/- 2.4 kg and intended for highquality dry-cured hams (Teruel ham) from Spain, were used to investigate the effects of sex (barrows and gilts) and slaughter weight (SW; 120, 125, 130, 135, and 140 kg of BW) on growth performance and carcass characteristics. For productive performance, there were 5 treatments based on 5 SW; each treatment was replicated 4 times and the replicate was a pen made up of 5 barrows and 5 gilts allotted together. For carcass traits, there were 10 treatments based on 2 sexes and 5 SW; each treatment was replicated 20 times and the replicate was a carcass. Barrows had fatter carcasses (P < 0.001) and wider hams (P < 0.01) but a lower yield of trimmed shoulder (P < 0.05), loin (P < 0.001), and ham (P < 0.001) than gilts. Also, castrates tended to show a greater proportion of final suitable carcasses for Teruel ham (P < 0.10) than females because more barrows than gilts fulfilled the minimum requirement of carcass weight and fat thickness in the gluteus medius (GM) muscle (P < 0.01). An increase in SW tended to decrease ADG and G:F (P < 0.10). In addition, dressing percentage, fat, and dimensions of carcass and ham increased as SW increased (P < 0.001). Although the weight of trimmed primal cuts (shoulder, loin, and ham) increased with SW, the yield of trimmed loin or ham decreased (P < 0.01). The proportion of final suitable carcasses for Teruel ham improved as SW increased up to 130 kg of BW but not thereafter (P < 0.001) because of an increase in percentage carcasses that fulfilled the minimum carcass and ham weight (P < 0.001) and fat in GM (P < 0.05). We can conclude that barrows were better than gilts when intended for Teruel ham. Furthermore, an increase in SW up to 130 kg in pigs impaired growth performance but improved some aspects of carcass quality that are required by the Teruel ham industry.  相似文献   

15.
To examine effects of nutrient restriction and dietary Se on maternal and fetal visceral tissues, 36 pregnant Targhee-cross ewe lambs were allotted randomly to 1 of 4 treatments in a 2 x 2 factorial arrangement. Treatments were plane of nutrition [control, 100% of requirements vs. restricted, 60% of controls] and dietary Se [adequate Se, ASe (6 microg/kg of BW) vs. high Se, HSe (80 microg/kg of BW)] from Se-enriched yeast. Selenium treatments were initiated 21 d before breeding and dietary restriction began on d 64 of gestation. Diets contained 16% CP and 2.12 Mcal/kg of ME (DM basis) and differing amounts were fed to control and restricted groups. On d 135 +/- 5 (mean +/- range) of gestation, ewes were slaughtered and visceral tissues were harvested. There was a nutrition x Se interaction (P = 0.02) for maternal jejunal RNA:DNA; no other interactions were detected for maternal measurements. Maternal BW, stomach complex, small intestine, large intestine, liver, and kidney mass were less (P < or = 0.01) in restricted than control ewes. Lung mass (g/kg of empty BW) was greater (P = 0.09) in restricted than control ewes and for HSe compared with ASe ewes. Maternal jejunal protein content and protein:DNA were less (P < or = 0.002) in restricted than control ewes. Maternal jejunal DNA and RNA concentrations and total proliferating jejunal cells were not affected (P > or = 0.11) by treatment. Total jejunal and mucosal vascularity (mL) were less (P < or = 0.01) in restricted than control ewes. Fetuses from restricted ewes had less BW (P = 0.06), empty carcass weight (P = 0.06), crown-rump length (P = 0.03), liver (P = 0.01), pancreas (P = 0.07), perirenal fat (P = 0.02), small intestine (P = 0.007), and spleen weights (P = 0.03) compared with controls. Fetuses from HSe ewes had heavier (P < or = 0.09) BW, and empty carcass, heart, lung, spleen, total viscera, and large intestine weights compared with ASe ewes. Nutrient restriction resulted in less protein content (mg, P = 0.01) and protein:DNA (P = 0.06) in fetal jejunum. Fetal muscle DNA (nutrition by Se interaction, P = 0.04) concentration was greater (P < 0.05) in restricted ewes fed HSe compared with other treatments. Fetal muscle RNA concentration (P = 0.01) and heart RNA content (P = 0.04) were greater in HSe vs. ASe ewes. These data indicate that maternal dietary Se may alter fetal responses, as noted by greater fetal heart, lung, spleen, and BW.  相似文献   

16.
The aim of this study was to investigate whether dietary protein intake of gilts during gestation below (50%) or above (250%) recommendations affects body composition, carcass and meat quality, and properties of skeletal muscle and subcutaneous adipose tissue (SCAT) in offspring at d 83 and 188 of age. German Landrace gilts were fed isoenergetic gestation diets (~13.7 MJ of ME/kg) containing a low (LP, 6.5%; n = 18), an adequate (AP, 12.1%; n = 20), or a high (HP, 30%; n = 16) protein content from mating until farrowing. Within 48 h of birth, offspring were cross-fostered to sows fed a standard diet. On d 83 of age, no effects of the LP diet on BW and body composition were detected, whereas HP pigs showed a slight growth delay (P = 0.06) associated with increased relative weights of small intestine (P < 0.01) and brain (P = 0.08), and reduced relative thymus weight (P < 0.01). On d 188 of age, BW was not different among the dietary groups. However, the carcass of LP pigs contained less (P = 0.01) lean and more (P = 0.07) fat compared with AP and HP pigs, which was only pronounced in pigs originating from large litters (P < 0.05). Like skeletal muscles (P = 0.06), the heart muscle weighed less (P = 0.02) in LP than AP pigs. Compared with AP pigs, LP pigs exhibited a fewer (P = 0.09) total number of myofibers in semitendinosus muscle plus LM both at d 83 and 188 of age, whereas total muscular DNA was less (P = 0.02) at d 188 only. The mRNA abundance of IGF2 measured on d 188 was reduced in SCAT (P = 0.03) and LM (P = 0.07) of LP compared with AP pigs. No changes in muscular fiber type frequency, capillary density, or creatine kinase activity, as well as SCAT adipocyte size and number, were observed at either stages of age. Meat quality characteristics remained unchanged at d 83, whereas Warner-Bratzler shear force value in LM was decreased (P = 0.03) in LP compared with AP pigs on d 188 of age. The results suggest that the maternal LP diet impairs prenatal myofiber formation, reduces the potential of postnatal lean growth related to reduced IGF2 mRNA expression and myonuclear accumulation, and consequently changes carcass quality toward reduced lean proportion and improved tenderness at market weight. In contrast, except for a slight transient growth delay, excess dietary protein during gestation seems to have little effect on the fetal programming of postnatal muscle and adipose tissue phenotype of the progeny.  相似文献   

17.
Two experiments evaluated the ability of maternal fatty acid supplementation to alter conceptus and endometrial fatty acid composition. In Exp. 1, treatments were 1) the control, a corn-soybean meal diet; 2) flax, the control diet plus ground flax (3.75% of diet); and 3) protected fatty acids (PFA), the control plus a protected fish oil source rich in n-3 PUFA (Gromega, JBS United Inc., Sheridan, IN; 1.5% of diet). Supplements replaced equal parts of corn and soybean meal. When gilts reached 170 d of age, PG600 (PMSG and hCG, Intervet USA, Millsboro, DE) was injected to induce puberty, and dietary treatments (n = 8/treatment) were initiated. When detected in estrus, gilts were artificially inseminated. On d 40 to 43 of gestation, 7 gilts in the control treatment, 8 gilts in the PFA treatment, and 5 gilts in the flax treatment were pregnant and were slaughtered. Compared with the control treatment, the flax treatment tended to increase eicosapentaenoic acid (EPA: C20:5n-3) in fetuses (0.14 vs. 0.25 +/- 0.03 mg/g of dry tissue; P = 0.055), whereas gilts receiving PFA had more (P < 0.05) docosahexaenoic acid (DHA: C22:6n-3) in their fetuses (5.23 vs. 4.04 +/- 0.078 mg/g) compared with gilts fed the control diet. Both the flax and PFA diets increased (P < 0.05) DHA (0.60, 0.82, and 0.85 +/- 0.078 mg/g for the control, flax, and PFA diet, respectively) in the chorioallantois. In the endometrium, EPA and docosapentaenoic acid (C22:5n-3) were increased by the flax diet (P < 0.001; P < 0.05), whereas gilts receiving PFA had increased DHA (P < 0.001). The flax diet selectively increased EPA, and the PFA diet selectively increased DHA in the fetus and endometrium. In Exp. 2, gilts were fed diets containing PFA (1.5%) or a control diet beginning at approximately 170 of age (n = 13/treatment). A blood sample was collected after 30 d of treatment, and gilts were artificially inseminated when they were approximately 205 d old. Conceptus and endometrial samples were collected on d 11 to 19 of pregnancy. Plasma samples indicated that PFA increased (P < 0.005) circulating concentrations of EPA and DHA. Endometrial EPA was increased (P < 0.001) for gilts fed the PFA diet. In extraembryonic tissues, PFA more than doubled (P < 0.001) the EPA (0.13 vs. 0.32 +/- 0.013 mg/g) and DHA (0.39 vs. 0.85 +/- 0.05 mg/g). In embryonic tissue on d 19, DHA was increased (P < 0.05) by PFA (0.20 vs. 0.30 +/- 0.023 mg/g). Supplementing n-3 PUFA, beginning 30 d before breeding, affected endometrial, conceptus, and fetal fatty acid composition in early pregnancy. Dynamic day effects in fatty acid composition indicate this may be a critical period for maternal fatty acid resources to affect conceptus development and survival.  相似文献   

18.
A possible management strategy to alter fetal development and enhance sow productivity and progeny performance was examined by maternal administration of porcine somatotropin during early gestation. Eighteen crossbred gilts were bred naturally to boars of similar genetics, and pregnancy was confirmed between Days 21 and 24 of gestation by ultrasound. All animals were allowed ad libitum consumption of a 16% CP gestation diet through Day 21 of gestation and 3.0 kg/d for the remainder of gestation. Gilts were injected twice daily with 0 (n = 10) or 15 μg/kg body weight (BW) (n = 10; total, 30 μg/kg BW per d) pituitary-derived porcine somatotropin (pST) during Days 28 to 40 of gestation. Data were collected postmortem during embryonic, neonatal, and market-weight phases. At 41 d of gestation, pST treatment increased embryonic survival (87.9 versus 77.0%; P < 0.05) and embryo crown rump lengths (77.96 versus 65.14 mm; P < 0.01), but embryo weight was not altered (10.15 and 9.03 g; P > 0.10). Pigs from pST-treated gilts had increased (P < 0.01) crown rump lengths at birth (31.5 versus 30.4 cm) and 21 d (50.9 versus 48.4 cm). However, no differences were observed in birth or 21-d weights as a result of pST treatment (P > 0.10). Neonatal carcasses of progeny (20 kg BW) from the pST-treated gilts had heavier semitendinosus muscles (76.1 versus 66.0 g; P < 0.10), larger longissimus muscle cross-sectional area (10.1 versus 8.2 cm2; P < 0.05), longer sides (51.2 versus 47.9 cm; P < 0.001), and decreased 10th rib backfat (6.67 versus 8.64 mm; P < 0.001) compared with those of controls. Carcasses of market-weight progeny (100 kg BW) from pST-treated gilts had larger longissimus muscle cross-sectional area (P < 0.10), heavier trimmed loins (P < 0.10), and longer carcass sides (P < 0.05). Data are supportive of a hypothesis that mechanisms during early embryonic development are sensitive to manipulation through selected management strategies of the sow and that modifications of this strategy may serve as a model for the examination of molecular and cellular events controlling early embryonic growth.  相似文献   

19.
A total of 144 barrows and gilts (initial BW = 44 kg) were used in an 82-d experiment to evaluate the effects of dietary fat source and duration of feeding fat on growth performance, carcass characteristics, and carcass fat quality. Dietary treatments were a corn-soybean meal control diet with no added fat and a 2 × 4 factorial arrangement of treatments with 5% choice white grease (CWG) or soybean oil (SBO) fed from d 0 to 26, 54, 68, or 82. At the conclusion of the study (d 82), pigs were slaughtered, carcass characteristics were measured, and backfat and jowl fat samples were collected. Fatty acid analysis was performed, and iodine value (IV) was calculated for all backfat and jowl fat samples. Pigs fed SBO tended to have increased (P = 0.07) ADG compared with pigs fed CWG. For pigs fed SBO, increasing feeding duration increased (quadratic, P < 0.01) ADG and G:F. For pigs fed CWG, increasing feeding duration improved (quadratic, P < 0.01) G:F. For pigs fed SBO or CWG, increasing feeding duration increased carcass yield (quadratic, P < 0.04) and HCW (quadratic, P < 0.02). Dietary fat source and feeding duration did not affect backfat depth, loin depth, or lean percentage. As expected, barrows had greater ADG and ADFI (P < 0.01) and poorer G:F (P = 0.03) than gilts. Barrows also had greater last-rib (P = 0.04) and 10th-rib backfat (P < 0.01) and reduced loin depth and lean percentage (P < 0.01) compared with gilts. Increasing feeding duration of CWG or SBO increased (P < 0.10) C18:2n-6, PUFA, PUFA:SFA ratio, and IV in jowl fat and backfat. Pigs fed SBO had greater (P < 0.01) C18:2n-6, PUFA, PUFA:SFA ratio, and IV but decreased (P < 0.01) C18:1 cis-9, C16:0, SFA, and MUFA concentrations compared with pigs fed CWG in jowl fat and backfat. Barrows had decreased (P = 0.03) IV in jowl fat and backfat compared with gilts. In summary, adding SBO or CWG increased the amount of unsaturated fat deposited. Increasing feeding duration of dietary fat increases the amount of unsaturated fatty acids, which leads to softer carcass fat.  相似文献   

20.
A total of 120 pigs [Duroc × (Landrace × Large White); initial average BW: 100.3 ± 2.5 kg] were used to investigate the effects of sex (barrows and gilts) and dietary total Lys restriction (7.0, 6.5, and 6.0 g·kg(-1)) on growth performance and carcass, meat, and fat characteristics. Pigs were intended for high-quality dry-cured ham from Spain (called Teruel ham), and a minimum fat thickness at the gluteus medius muscle (GM) is required (16 mm) for carcasses to be acceptable. Animals were slaughtered when they reached 129.0 ± 3.6 kg of BW. There were 6 treatments arranged factorially (2 sexes × 3 dietary Lys concentrations) and 4 replicates of 5 pigs per treatment. Barrows consumed more feed (P = 0.001) and tended to have less G:F (P = 0.06) than gilts. Carcasses from barrows were fatter (P = 0.001) and had heavier main trimmed lean cuts (P = 0.008) than gilts. A greater proportion of final acceptable carcasses for Teruel ham (P = 0.001) was observed in barrows than in gilts because of the greater percentage of carcasses that fulfill the minimum fat depth at GM required (P = 0.001). Meat from barrows had greater content of intramuscular fat (P = 0.02) than meat from gilts. Also, subcutaneous fat from barrows had less proportion of PUFA than fat from gilts (P = 0.02). A reduction in dietary Lys concentration decreased ADG (P = 0.004) and ADFI (P = 0.001) in pigs. In addition, backfat depth (P = 0.007) and fat at GM (P = 0.07) increased as dietary Lys decreased. The proportion of carcasses that fulfilled the minimum fat depth at GM required for Teruel ham increased as dietary Lys decreased in feed, but this effect was greater in gilts than in barrows (sex × Lys, P = 0.02). Meat and fat quality was not influenced by dietary treatment. We conclude that different feeding programs with different dietary Lys concentrations may be needed for barrows and gilts intended for production of dry-cured hams where a minimum carcass fat depth is required.  相似文献   

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