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1.
J Anim Sci ; 84(6): 1415-21, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16699098

RESUMEN

Two studies were conducted to determine the effect of increasing the valine:lysine (V:L) ratio in diets of lactating sows above the minimum proposed by the NRC (1998). The first experiment involved 189 PIC, Camborough product sows (parity 1 to 4) that were allotted to 1 of 3 dietary treatments. Diets were formulated to achieve total dietary V:L ratios of 0.90, 1.05, or 1.25:1, respectively, and were corn and soybean meal-based. The second experiment involved 279 PIC, Camborough sows (parity 1 to 5) that were allotted to 1 of 4 treatments. Diets 1 and 3 were formulated using corn and a fixed inclusion of soybean meal (16.7%), with 0.27% L-lysine HCl. The V:L ratios in diets 1 and 3 were 0.73 and 1.25:1, respectively. Diets 2 and 4 were typical corn-soybean meal diets containing 0.05% L-lysine HCl, with a fixed inclusion of soybean meal (22.7%). The V:L ratios in diets 2 and 4 were 0.86 and 1.25:1, respectively. In both experiments, each litter was standardized to a minimum of 10 pigs, which achieved litter growth rates of 2.22 and 2.56 kg/d in Exp. 1 and 2, respectively. In Exp. 1, increasing the dietary V:L ratio beyond 0.90:1 did not improve (P > 0.10) the number of pigs weaned, survival rate, or piglet growth rate, even though sows were nursing more than 10 pigs per litter for 19 d. In Exp. 2, total lysine intake was similar among treatments and ranged from 52.1 to 55.3 g/d. Valine intake increased as the diet valine concentration increased (diet 1 vs. 3 and diet 2 vs. 4, P < 0.001), ranging from 40.0 to 66.1 g/d. Litter gain tended to improve (P = 0.14) when the 0.27% L-lysine HCl control (0.73 V:L) was supplemented with valine to achieve a 1.25:1 V:L ratio. In contrast, no aspect of sow or litter response was improved when the practical control diet containing 0.05% L-lysine HCl (0.86 V:L) was supplemented with valine to achieve a 1.25:1 V:L ratio. Collectively, this research shows that a V:L ratio in excess of 0.86 does not conserve maternal tissue loss or improve piglet growth rate, but a V:L ratio of 0.73 may compromise litter growth rate.


Asunto(s)
Lactancia/metabolismo , Porcinos/metabolismo , Valina/metabolismo , Alimentación Animal , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Dieta , Proteínas en la Dieta , Femenino , Lisina/metabolismo , National Academy of Sciences, U.S. , Necesidades Nutricionales , Estados Unidos
2.
J Anim Sci ; 82(9): 2601-9, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15446476

RESUMEN

Two experiments were conducted to evaluate the effect of lysolecithin on performance and nutrient digestibility of nursery pigs and to determine the effects of fat encapsulation by spray drying in diets fed in either meal or pelleted form. In Exp. 1, 108 pigs (21 d of age; 5.96 +/- 0.16 kg BW) were allotted to one of four dietary treatments (as-fed basis): 1) control with no added lard, 2) control with 5% added lard, 3) treatment 2 with 0.02% lysolecithin, and 4) treatment 2 with 0.1% lysolecithin in a 35-d experiment. Added lard decreased ADG (P = 0.02) and ADFI (P < 0.06) during d 15 to 35 and overall. Lysolecithin improved ADG linearly (P = 0.04) during d 15 to 35 and overall, but did not affect ADFI or G:F. Addition of lard decreased the digestibility of DM (P = 0.10) and CP (P = 0.05) and increased (P = 0.001) fat digestibility when measured on d 10. Lysolecithin at 0.02%, but not 0.10%, tended to improve the digestibility of fat (P = 0.10). On d 28, digestibilities of DM, fat, CP, P, (P = 0.001), and GE (P = 0.03) were increased with the addition of lard, and lysolecithin supplementation linearly decreased digestibilities of DM (P = 0.003), GE (P = 0.007), CP, and P (P = 0.001). In Exp. 2, 144 pigs (21 d of age, 6.04 +/- 0.16 kg BW) were allotted to one of six treatments in a 3 x 2 factorial randomized complete block design. Factors included 1) level (as-fed basis) and source of fat (control diet with 1% lard; control diet with 5% additional lard; and control diet with 5% additional lard from encapsulated, spray-dried fat) and 2) diet form (pelleted or meal). Addition of lard decreased feed intake during d 0 to 14 (P = 0.04), d 15 to 35 (P = 0.01), and overall (P = 0.008), and improved G:F for d 15 to 35 (P = 0.04) and overall (P = 0.07). Encapsulated, spray-dried lard increased ADG (P = 0.004) and G:F (P = 0.003) during d 15 to 28 compared with the equivalent amount of fat as unprocessed lard. Pelleting increased ADG (P = 0.006) during d 0 to 14, decreased feed intake during d 15 to 35 (P = 0.01), and overall (P = 0.07), and increased G:F during all periods (P < 0.02). Fat digestibility was increased (P = 0.001) with supplementation of lard, and this effect was greater when diets were fed in meal form (interaction, P = 0.004). Pelleting increased the digestibility of DM, OM, and fat (P < 0.002). Results indicate that growth performance may be improved by lysolecithin supplementation to diets with added lard and by encapsulation of lard through spray drying.


Asunto(s)
Alimentación Animal , Grasas de la Dieta/administración & dosificación , Digestión/efectos de los fármacos , Ingestión de Alimentos/efectos de los fármacos , Lisofosfatidilcolinas/administración & dosificación , Porcinos/crecimiento & desarrollo , Aumento de Peso/efectos de los fármacos , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Grasas de la Dieta/farmacología , Suplementos Dietéticos , Relación Dosis-Respuesta a Droga , Composición de Medicamentos/veterinaria , Implantes de Medicamentos , Emulsiones , Femenino , Manipulación de Alimentos/métodos , Lisofosfatidilcolinas/farmacología , Masculino , Distribución Aleatoria , Porcinos/metabolismo , Destete
3.
J Anim Sci ; 80(2): 494-501, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11881933

RESUMEN

A study was conducted with 20 weaned barrows (14 d, 4.98 +/- .21 kg) to determine the effect of spray-dried plasma (SDP) on the pig's immune response to a lipopolysaccharide (LPS) challenge. After weaning, pigs were fed a diet containing 0 or 7% SDP for 7 d. On d 6 postweaning, all pigs were fitted with a jugular catheter. On d 7 postweaning, the pigs were given an i.p. injection of either saline or LPS (150 microg/kg BW) followed by a 3-h blood collection every 15 min. Following blood collection, all pigs were killed and tissue was collected for mRNA analysis. Additionally, the small intestine was collected for measurement of villus height, crypt depth, and villus height:crypt depth ratio (VCR) at three sites (25, 50, and 75% of the total length). Feeding SDP resulted in reduced (P < 0.05) mRNA expression of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) mRNA in the adrenal gland, spleen, hypothalamus, pituitary gland, and liver. Additionally, expression of IL-6 mRNA was reduced (P < 0.05) in the spleen and pituitary gland for pigs fed SDP. For pigs fed the diet with SDP, LPS administration did not affect (P > 0.10) cytokine mRNA expression, whereas LPS reduced expression of TNF-alpha mRNA in the spleen and IL-1beta mRNA in the adrenal gland, spleen, and thymus for pigs fed the diet without SDP. For pigs fed the diet with SDP, LPS caused serum TNF-alpha to increase 150-fold compared to a 60-fold increase for pigs fed the diet without SDP. Similarly, interferon-gamma (IFN-gamma) increased 110-fold for pigs fed the diet with SDP compared to a 16-fold increase for pigs fed the diet without SDP. For pigs fed the diet with SDP, LPS caused major villus atrophy, whereas for pigs fed the diet without SDP, LPS had no effect on intestinal morphology. These results demonstrate that the basal activation of the immune system appears to be less for pigs fed the diet with SDP compared to pigs fed the diet without SDP after weaning. Additionally, for pigs fed the diet with SDP, there appeared to be an overresponse of the immune system following LPS administration, which resulted in major damage to the mucosa of the gastrointestinal tract.


Asunto(s)
Intestino Delgado/efectos de los fármacos , Lipopolisacáridos/farmacología , Porcinos/inmunología , Glándulas Suprarrenales/efectos de los fármacos , Glándulas Suprarrenales/inmunología , Animales , Cateterismo/veterinaria , Hipotálamo/efectos de los fármacos , Hipotálamo/inmunología , Inyecciones Intraperitoneales/veterinaria , Interferón gamma/metabolismo , Interleucina-1/metabolismo , Intestino Delgado/patología , Lipopolisacáridos/inmunología , Hígado/efectos de los fármacos , Hígado/inmunología , Masculino , Hipófisis/efectos de los fármacos , Hipófisis/inmunología , ARN Mensajero/metabolismo , Distribución Aleatoria , Bazo/efectos de los fármacos , Bazo/inmunología , Timo/efectos de los fármacos , Timo/inmunología , Factor de Necrosis Tumoral alfa/metabolismo , Destete
4.
Domest Anim Endocrinol ; 16(3): 145-8, 1999 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10343916

RESUMEN

Early growth is an important determinant of gain and efficiency in growing pigs. A major limiting factor of piglet growth is feed intake. Orexins, newly discovered neuropeptides, may be important regulators of appetite. The orexin gene, which encodes orexin-A and -B, was recently identified in rodents and man. The objectives of this study were to clone the cDNA for porcine orexin, utilize the cDNA sequence information to produce synthetic hormone, and evaluate the effect of orexin administration on feed intake in weanling pigs. Oligonucleotide primers were designed for reverse transcription polymerase chain reaction production of porcine orexin cDNA. The polymerase-chain-reaction products were cloned, sequenced, and found to be 88.5% homologous to the human orexin sequence. Predicted translation of porcine orexin cDNA revealed orexin-A and -B amino acid sequences that were 100% and 96% homologous to the known human peptides, respectively. Porcine orexin-B was synthesized according to the predicted sequence. Twenty-six cross-bred piglets were utilized in three replicates (n = 8-10/replicate). Piglets were weaned between 2-3 wk of age. One week after weaning, equal numbers of animals in each replicate received intramuscular (i.m.) injections of orexin-B (3 mg/kg body weight) or vehicle (sterile water). Feed intake was monitored from -24 to 24 h relative to injection (time 0). The orexin-injected pigs ingested an additional meal at 12 h when compared with the control animals (P = 0.02). Cumulative feed intake was increased by orexin-B administration from 12 to 24 h postinjection (P < or = 0.05). Total feed intake at 24 h was improved by 18% in orexin-treated pigs (P = 0.05). The ability to stimulate appetite during critical periods of early growth, particularly following weaning, could result in significant improvements in swine-production efficiency.


Asunto(s)
Clonación Molecular , Ingestión de Alimentos/efectos de los fármacos , Péptidos y Proteínas de Señalización Intracelular , Neuropéptidos/administración & dosificación , Neuropéptidos/genética , Precursores de Proteínas/genética , Porcinos/fisiología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Proteínas Portadoras/química , Proteínas Portadoras/genética , ADN Complementario/química , ADN Complementario/genética , Humanos , Inyecciones Intramusculares , Datos de Secuencia Molecular , Neuropéptidos/química , Orexinas , Homología de Secuencia , Destete
5.
J Anim Sci ; 76(5): 1437-42, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-9621951

RESUMEN

We conducted an experiment to determine the proportion of the lysine requirement of lactating sows that can be met using L-lysine x HCl. A total of 247 Pig Improvement Company (PIC) sows (parity one to four) were randomly allotted to one of five experimental diets containing .79% apparently digestible lysine. The first four diets contained 0, .075, .150, and .225% L-lysine x HCl replacing the intact lysine, primarily derived from soybean meal. Dietary crude protein was reduced from 17.9 to 16.9, 15.8, and 14.8% respectively. The fifth diet contained .174% L-lysine x HCl (15.5% CP) with added synthetic methionine, threonine, and tryptophan to restore the ratios of these amino acids to lysine to those in the control diet with no synthetic amino acids. The average lactation length was 15.7 +/- .3 d. Diet did not affect ADFI, sow backfat loss, sow loin eye area loss, or weaning-to-mating interval. Sows consumed an average of 4.6 kg/d and were provided 36 g/d of digestible lysine. Replacing soybean meal with increasing levels of L-lysine x HCl did not affect sow weight change. The number of pigs weaned decreased and preweaning mortality increased linearly (P = .08) with increasing levels of L-lysine x HCl. Litters from sows fed the .174% L-lysine x HCl with added methionine, threonine, and tryptophan grew slower and had a higher mortality rate than litters from sows fed no synthetic amino acids (P < .05). The addition of synthetic methionine, threonine, and tryptophan to the .174% L-lysine x HCl diet did not improve litter growth rate, but it did increase preweaning mortality (P = .05) and decrease the number of pigs weaned (P = .06) compared to the .15% L-lysine x HCl with no additional synthetic amino acids. These additions also resulted in an increased sow weight loss (P = .10). These results suggest that when more than .075% L-lysine x HCl is used to meet the lysine requirement preweaning mortality is increased and the number of pigs weaned is decreased. Supplementation with methionine, threonine, and tryptophan failed to ameliorate the negative response associated with L-lysine x HCl, which suggests that other amino acids may be limiting.


Asunto(s)
Alimentación Animal/normas , Dieta/veterinaria , Lactancia/fisiología , Lisina/administración & dosificación , Porcinos/fisiología , Animales , Animales Lactantes/crecimiento & desarrollo , Dieta/normas , Ingestión de Alimentos , Femenino , Lisina/síntesis química , Metionina/administración & dosificación , Metionina/síntesis química , Porcinos/crecimiento & desarrollo , Treonina/administración & dosificación , Treonina/síntesis química , Triptófano/administración & dosificación , Triptófano/síntesis química , Aumento de Peso
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