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1.
J Anim Sci ; 94(12): 5239-5247, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28046168

RESUMO

The AA requirements of reproducing females are likely influenced by genetics, number of embryos and fetuses, and their nutritional needs during development. Hence, it is important to determine the change in AA concentration during development. Fetuses from a total of 26 second-parity sows were used to determine their AA composition at various stages of pregnancy. Yorkshire × Landrace sows were bred to Duroc boars and killed at 45, 62, 80, and 100 d of gestation, and fetal weights were determined. The pigs from 6 litters were killed prior to nursing the sow. The number of fetuses ranged from 10 to 13 pigs/litter. Pigs were combined by litter, ground, and freeze-dried, and AA was determined by gas chromatography. Litter was the experimental unit, and statistics were conducted using the GLM model of SAS with the best fitting regression equation estimates for each AA determined. Individual pigs (average/litter), litter, grams per 100 g total AA, and the ratio of each AA to Lys were statistically determined. Although the regression of individual pigs and litters were significant in a quadratic, cubic, or quartic manner ( < 0.01 to < 0.05), the general trend was a quadratic increase in total essential AA (EAA) and nonessential AA (NEAA) from 45 d to birth. All AA increased rapidly from 80 d of gestation, and more than 50% of total fetal growth occurred from 80 d to birth. Three AA (Arg, Leu, and Lys) constituted more than half of the total EAA from 80 d of gestation to birth compared with the other EAA. Overall, the NEAA increased more rapidly as pregnancy progressed than the EAA, with Pro, Hyp, and Gly increasing at a faster rate. When expressed in a ratio of Lys to the other AA, both Arg and Leu had a greater ratio increase than Lys. These results demonstrated that 50% of the total amount of EAA in the fetal pig increased during the last 2 wk of gestation and that Arg and Leu increased at a greater rate than Lys. The NEAA increased at a faster rate than the EAA throughout pregnancy.


Assuntos
Aminoácidos/análise , Desenvolvimento Fetal , Suínos/fisiologia , Aminoácidos/metabolismo , Animais , Cruzamento , Feminino , Peso Fetal , Feto , Tamanho da Ninhada de Vivíparos , Masculino , Paridade , Gravidez , Reprodução
2.
J Anim Sci ; 93(3): 1149-56, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26020892

RESUMO

Graded levels of a trace mineral premix containing an organic (Bioplex) source of Cu, Fe, Mn, and Zn was evaluated with additional treatments containing organic Zn or Fe. Grower-finisher pigs were fed from 25 to 115 kg BW. The number of pigs in the experiment, the breeding/genetics of the pigs, the management, and the average age of the pigs were previously reported. The experiment was conducted as a randomized complete block design in 7 replicates. Treatments were 1) basal diet without supplemental Cu, Fe, Mn, and Zn; 2) basal diet + 2.5 mg/kg Cu, 50 mg/kg Fe, 1.5 mg/kg Mn, and 40 mg/kg Zn (50% NRC); 3) basal diet + 5 mg/kg Cu, 100 mg/kg Fe, 3 mg/kg Mn, and 80 mg/kg Zn (100% NRC); 4) basal diet + 25 mg Zn/kg; 5) basal diet + 50 mg Zn/kg; and 6) basal diet + 50 mg Fe/kg. Selenium and I were added to all diets at 0.3 and 0.14 mg/kg, respectively. Diets were composed of corn-soybean meal, dicalcium phosphate, and limestone with phytase added to enhance mineral availability. Three pigs per pen were bled at 55, 80, and 115 kg BW and plasma was analyzed for microminerals. When the average replicate BW was 115 kg, 3 pigs per pen of an equal gender ratio were killed. The liver, kidney, and heart were removed and analyzed for microminerals. Liver, duodenum, and jejunal metallothionein and the antioxidant enzymes in the liver containing these microminerals were determined. The results demonstrated that plasma minerals were unaffected at the 3 BW intervals. Liver and duodenum metallothionein protein were greater ( < 0.05) as dietary micromineral levels increased but jejunum metallothionein did not change as microminerals increased. The activity of Cu/Zn superoxide dismutase (SOD) was not affected as the levels of the micromineral increased, whereas the activity of Mn SOD increased slightly ( < 0.05) to the 50% NRC treatment level. Liver Zn (relative and total) increased ( < 0.05) as dietary micromineral levels increased and also when Zn was added singly to the diet. Liver, kidney, and heart Cu and Mn concentrations were similar at the various micromineral levels. The activities of liver enzymes containing graded levels of Zn were not affected by dietary microminerals at 115 kg BW. These results indicate that the supplemental levels of Cu, Fe, and Mn were not necessary for grower-finisher pigs and that these innate microminerals in a corn-soybean meal diet were adequate, whereas a need for supplemental Zn was demonstrated.


Assuntos
Fígado/efeitos dos fármacos , Fígado/enzimologia , Metalotioneína/metabolismo , Minerais/metabolismo , Minerais/farmacologia , Suínos/metabolismo , Animais , Cobre/análise , Cobre/metabolismo , Cobre/farmacologia , Suplementos Nutricionais , Feminino , Intestino Delgado/química , Ferro/análise , Ferro/metabolismo , Ferro/farmacologia , Rim/química , Masculino , Manganês/análise , Manganês/metabolismo , Manganês/farmacologia , Minerais/análise , Miocárdio/química , National Academy of Sciences, U.S. , Superóxido Dismutase/metabolismo , Estados Unidos , Zinco/análise , Zinco/metabolismo , Zinco/farmacologia
3.
J Anim Sci ; 93(1): 185-96, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25568367

RESUMO

Two experiments were conducted to determine the effects of increasing the dietary Zn content on growth performance, carcass characteristics, plasma Zn, and ileal mucosal inflammation mRNA expression of finishing pigs fed diets containing ractopamine HCl (RAC; Elanco Animal Health, Greenfield, IN). In Exp. 1, 312 pigs (327 × 1050; PIC, Hendersonville, TN; 94 kg BW) were used in a 27-d study. There were 2 pigs per pen and 26 pens per treatment. Treatments included a corn-soybean meal diet (control; 0.66% standardized ileal digestible [SID] Lys); a diet (0.92% SID Lys) with 10 mg/kg RAC; and the RAC diet plus 50, 100, or 150 mg Zn/kg from ZnO or 50 mg Zn/kg from a Zn AA complex (ZnAA; Availa-Zn; Zinpro, Eden Prairie, MN). All diets also contained 83 mg Zn/kg from ZnSO4 in the trace mineral premix. Pigs fed the RAC diet without added Zn had increased (P < 0.05) ADG, G:F, HCW, carcass yield, and loin weight compared with pigs fed the control diet. Increasing Zn from ZnO in diets containing RAC tended to increase (linear, P = 0.067) G:F and loin weight (quadratic, P = 0.064). Pigs fed diets with 50 mg Zn/kg from ZnAA tended to have increased (P = 0.057) ADG compared with pigs fed the RAC diet. In Exp. 2, 320 pigs (327 × 1050; PIC; 98 kg BW) were used in a 35-d study. There were 2 pigs per pen and 20 pens per treatment. Treatments included a control diet (0.66% SID Lys); a diet (0.92% SID Lys) with 10 mg/kg RAC; or the RAC diet plus 75, 150, and 225 mg Zn/kg from ZnO or ZnAA. All diets also contained 55 mg Zn/kg from ZnSO4 from the trace mineral premix. Pigs fed the RAC diet had increased (P < 0.05) ADG, G:F, HCW, loin depth, percentage lean, and liver weight compared with pigs fed the control diet. No Zn level or source effects or level × source interactions were observed for growth performance. A Zn level × source interaction (quadratic, P = 0.007) was observed in liver Zn concentrations. This resulted from liver Zn concentrations plateauing at 150 mg Zn/kg when ZnO was supplemented, while there was a linear increase when using ZnAA. Increasing Zn in diets containing RAC increased (linear, P < 0.05) plasma Zn on d 18 and 32. The expression of IL-1ß was increased (P = 0.014) in mucosa of pigs fed the RAC diet compared with those fed the control diet. Expression of IL-1ß decreased (linear, P = 0.026) in the mucosa of pigs fed increasing added Zn. In conclusion, adding Zn to diets containing RAC resulted in a trend for improved growth performance of pigs in 1 of 2 experiments. Also, additional Zn increased plasma Zn and reduced IL-1ß.


Assuntos
Composição Corporal/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Suplementos Nutricionais , Ileíte/metabolismo , Fenetilaminas/farmacologia , RNA Mensageiro/metabolismo , Suínos/crescimento & desenvolvimento , Zinco/farmacologia , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta/veterinária , Íleo/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Mucosa Intestinal/metabolismo , Fígado/metabolismo , RNA Mensageiro/genética , Suínos/metabolismo , Zinco/administração & dosagem , Zinco/metabolismo
4.
J Anim Sci ; 92(10): 4486-93, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25149347

RESUMO

Inclusion of up to 0.38% S in diets that contain 30% distillers dried grains with solubles (DDGS) has no negative effect on growth performance of growing-finishing pigs, but there is no information about the effects of dietary S on accumulation of S in tissues in pigs. Therefore, the objective of this experiment was to determine if the concentration of S in diets containing DDGS affects carcass characteristics, loin quality, or tissue mineral concentrations in growing-finishing pigs. A total of 120 barrows (34.2 ± 2.3 kg BW) were allotted to 3 dietary treatments with 10 replicate pens and 4 pigs per pen in a randomized complete block design. Pigs were fed grower diets for 42 d and finisher diets for 42 d. At the conclusion of the experiment, the pig in each pen with the BW closest to the pen average was slaughtered. The control diet was based on corn and soybean meal and the finisher diet contained 0.14% S, 0.19 mg/kg Se, and 15.3 mg/kg Cu. The DDGS diet was formulated with corn, soybean meal, and 30% DDGS and the finisher diet with DDGS contained 0.16% S, 0.32 mg/kg Se, and 14.0 mg/kg Cu. The DDGS plus S (DDGS-S) diet was similar to the DDGS diet, except that 1.10% CaSO4 (16.2% S) was included in this diet, and the finisher diet with DDGS-S contained 0.37% S, 0.35 mg/kg Se, and 13.8 mg/kg Cu. Results indicated that organ weights and loin quality, 24-h pH, drip loss, loin subjective color, marbling, and firmness did not differ among treatments, but loin a* was greater (P < 0.05) for pigs fed the control diet than for pigs fed the DDGS-S diet. Concentrations of S in hair, liver, heart, loin, and all other tissues did not differ among treatments, but urinary S concentration was greater (P < 0.05) for pigs fed the DDGS-S diet than for pigs fed the other diets. Pigs fed the DDGS diet or the DDGS-S diet had greater (P < 0.01) concentrations of Se in hair, liver, heart, and loin than pigs fed the control diet, but liver concentrations of Cu did not differ among treatments. In conclusion, inclusion of 30% DDGS in diets fed to growing-finishing pigs did not influence carcass characteristics or tissue S concentrations regardless of S concentration in the diet, and excess dietary S was excreted in the urine. However, because of the greater concentration of Se in DDGS than in corn and soybean meal and, therefore, greater concentrations in DDGS-containing diets, tissue concentrations of Se were increased in pigs fed diets that contained DDGS. In contrast, dietary DDGS did not influence liver concentrations of Cu.


Assuntos
Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Dieta/veterinária , Grão Comestível/metabolismo , Enxofre/farmacologia , Sus scrofa/crescimento & desenvolvimento , Tecido Adiposo/efeitos dos fármacos , Animais , Composição Corporal/efeitos dos fármacos , Cobre/metabolismo , Carne , Selênio/metabolismo , Glycine max/química , Suínos , Zea mays/química
5.
J Anim Sci ; 92(4): 1582-94, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24663209

RESUMO

Zinc is the trace element involved in more biological functions than any other micromineral in the nutrition of the newly weaned pig. Its role in growth via protein synthesis and antioxidant defense makes it a key nutrient in the diet of the newly weaned nursery pig for maximum lean tissue growth and health. In this study, 500 pigs (5 pigs/pen) were weaned at approximately 18 d of age and fed 0, 25, 50, 75, or 100 mg/kg of Zn supplied as organic or inorganic Zn or 50 mg Zn/kg combination with 50% Zn from each source. Pigs were killed at 0, 10, and 35 d of the study to determine mineral tissue concentrations and antioxidant activity in the liver and the amount of metallothionein (MT) protein in the liver, duodenum, and jejunum. Growth performance did not differ for the pigs supplemented with Zn but were greater than those fed the basal diet with no added Zn (P ≤ 0.05). Hepatic Zn concentration was numerically maximized with 75 mg/kg of organic Zn, but 100 mg/kg of Zn of inorganic Zn was necessary to achieve a similar concentration. At d 10, Mn superoxide dismutase in pigs fed no supplemental Zn was lower than when pigs were fed organic Zn (P ≤ 0.05). Hepatic MT responded in a linear manner with organic Zn (P ≤ 0.01) and pigs fed the basal diet had less than those supplemented with Zn (P ≤ 0.01). Duodenal MT was greater at d 10 with organic Zn (P ≤ 0.01) than pigs fed the basal diet, and at d 35, there was a linear response to both organic and inorganic Zn (P ≤ 0.01). As expected, jejunal MT was reduced compared to this protein in the duodenum. The provision of Zn at 50 mg/kg from either source resulted in greater jejunal MT than when Zn was fed as a combination of both sources at the same concentration (P ≤ 0.05). Our data indicate that the needs of the nursery pig, that is, Zn requirements for health and well-being, have changed since the data used to establish the 2012 Nutrient Requirements of Swine (NRC, 2012) was published. Organic minerals are shown in this study to be managed biologically in a different manner than inorganic Zn (sulfate) in the young pig. The newly weaned pig, while changing nutritional sources and physical environments, has extremely high biological demand for antioxidant defense. Our data show that to maximize growth, health, and well-being, 75 mg/kg of organic Zn in a complex nursery diet benefits today's fast growing pigs with a very high lean tissue composition.


Assuntos
Suínos/crescimento & desenvolvimento , Zinco/farmacologia , Ração Animal , Animais , Antioxidantes/metabolismo , Dieta/veterinária , Suplementos Nutricionais , Feminino , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Masculino , Necessidades Nutricionais , Suínos/metabolismo , Zinco/administração & dosagem , Zinco/química
6.
Meat Sci ; 96(1): 73-81, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23896139

RESUMO

Forty-eight British cross heifers were used to examine the effects of ovariectomization (OVX v. intact; INT) and ractopamine-HCl inclusion (0 or 0.41 mg/kg of BW day(-1); NORAC or RAC) for the final 31 days on performance, meat yield, and tenderness of select muscles. Ractopamine supplemented heifers had heavier BW (P≤0.05) and greater dressing percent than NORAC. Dressing percent was also greater (P<0.01) for INT v. OVX. LM area tended to be larger for RAC (P=0.07) and was larger for INT (P=0.05). Neither ractopamine inclusion nor sex class affected (P>0.08) organ weights or percent intramuscular fat. Ractopamine inclusion increased (P≤0.05) subprimal weight for the shoulder clod and bottom round. However, ractopamine inclusion and sex class had minimal effects on subprimal yields or slice shear force. Heifers receiving ractopamine had increased BW, DP, carcass weight and select subprimal weights without impacting meat quality. Ovariectomization did not influence the affects of ractopamine supplementation.


Assuntos
Agonistas Adrenérgicos beta/farmacologia , Qualidade dos Alimentos , Carne/análise , Músculo Esquelético/efeitos dos fármacos , Fenetilaminas/farmacologia , Ração Animal/análise , Animais , Peso Corporal , Bovinos , Suplementos Nutricionais , Feminino , Músculo Esquelético/metabolismo , Tamanho do Órgão , Ovariectomia
7.
J Anim Sci ; 91(12): 5680-6, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24249799

RESUMO

The dietary effects of Cu, Fe, Mn, and Zn levels, and the addition of Zn and Fe to a nonfortified, micromineral basal diet were evaluated in grower-finisher pigs. Growth, feed efficiency, hematology, carcass characteristics, and loin quality were assessed in growing-finishing pigs (n = 222; initial BW = 24 kg). Corn-soybean meal diets fortified with limestone and dicalcium phosphate with added phytase constituted the basal diets. A study was conducted with 6 dietary treatments and 7 replicates in a randomized complete block design. Treatments consisted of: 1) basal diet without added Cu, Fe, Mn, and Zn microminerals, 2) basal + 50% NRC Cu, Fe, Mn, and Zn requirements, 3) basal + 100% NRC Cu, Fe, Mn, and Zn requirements, 4) basal + 25 mg Zn/kg, 5) basal + 50 mg Zn/kg, and 6) basal + 50 mg Fe/kg. The microminerals were added as an organic mineral proteinate and all diets incorporated organic Se at 0.3 mg/kg. Diets were fed ad libitum over 3 growth phases. At 55, 80, and 115 kg BW, 3 pigs per pen were bled and hemoglobin (Hb) and percent hematocrit (Hct) were determined. At 115 kg BW, 3 pigs per pen were killed and carcass characteristics and loin quality measurements were determined. The ADG, ADFI, and G:F for each of the 3 dietary phases and overall period were not affected by dietary micromineral treatments. The concentration of Hb and percent Hct did not differ because of the treatment at each of the 3 phases. There were no treatment differences in carcass characteristics (HCW, backfat, or LM area). Loin pH, color (L*, a*, and b*), and drip loss did not differ by dietary treatment. Subjective marbling, color, and firmness scores, and intramuscular fat content of loins did not differ as the micromineral level increased above the 1998 and 2012 NRC requirements. The LM from pigs fed supplemental Fe had greater (P < 0.05) firmness and wetness scores than pigs fed the basal diet. These results indicate that there is sufficient amount of innate microminerals (Cu, Fe, Mn, and Zn) in a typical corn-soybean meal based diet to meet the grower-finisher pig's requirement for growth and hematological measurements. Although there was no detrimental effect by eliminating these microminerals from diets, it would seem that a dietary level of 50% of the NRC requirement for Cu, Fe, Mn, and Zn would be warranted.


Assuntos
Ração Animal/análise , Minerais/farmacologia , Suínos/crescimento & desenvolvimento , Fenômenos Fisiológicos da Nutrição Animal , Animais , Composição Corporal , Cobre/química , Cobre/farmacologia , Dieta , Ferro/química , Ferro/farmacologia , Manganês/química , Manganês/farmacologia , Carne/normas , Minerais/química , National Academy of Sciences, U.S. , Necessidades Nutricionais , Estados Unidos , Zinco/química , Zinco/farmacologia
8.
J Anim Sci ; 91(9): 4216-25, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23893978

RESUMO

Collaborative studies comprising growth performance and metabolism experiments were conducted to reevaluate growth performance and nutrient and energy utilization responses of nursery pigs to dietary lipid sources and levels. Two lipid sources (soybean oil or tallow) were included at the rate of 1%, 3%, or 5% at the expense of cornstarch in a 2 × 3 factorial arrangement for 6 diets, and Lys was added to maintain a constant calorie:Lys ratio. A growth performance experiment (d 0 to 7, d 7 to 21, and d 21 to 35 postweaning) involving a total of 822 crossbred pigs was conducted at 9 research stations. Each station contributed 2 to 7 replicate pens with 4 to 6 pigs per pen, resulting in a total of 28 replicate pens per diet. The initial BW ranged from 5.9 to 7.3 kg, and the final BW ranged from 20.9 to 28.9 kg. Diets fed during d 7 to 21 and d 21 to 35 were evaluated with 120 barrows in 2 metabolism experiments with 10 individually fed barrows per diet to determine digestibility and retention of nutrients and energy. Lipid source and the interaction between lipid level and source did not affect growth performance. Lipid did not affect growth performance from d 0 to 7. There was a quadratic decrease (P < 0.05) in ADG with increasing level of added lipid only during d 7 to 21 postweaning. The ADFI was decreased (P < 0.01) both during d 7 to 21 and d 21 to 35 postweaning with increasing level of lipid supplementation. A linear improvement (P < 0.001) in G:F with increasing level of lipid supplementation occurred during both d 21 to 35 and d 0 to 35 postweaning. There was a linear increase in DE, ME, and nitrogen-corrected ME (MEn) of diets fed during d 7 to 21 postweaning with increasing lipid level regardless of lipid source. For diets fed during d 21 to 35 postweaning, there were interactions (P < 0.05) between lipid source and level for digestibility of DM, N, lipid, and energy and for DE, ME, and MEn of diets. The improved feed efficiency was, perhaps, partly attributable to the increase in ME content of the diets with added lipids. There were interactions (P < 0.05) between lipid source and level for efficiency of energy use for BW gain for diets fed during d 21 to 35. The efficiencies of use of DE, ME, and NE for BW gain were not affected in pigs fed diets containing increasing levels of soybean oil; however, there were linear increases in these response criteria for pigs fed diets containing increasing levels of tallow. These results indicate that the energy values of soybean oil from the 2012 NRC study used in formulating these diets were fairly accurate.


Assuntos
Digestão , Ingestão de Energia , Gorduras/metabolismo , Óleo de Soja/metabolismo , Sus scrofa/crescimento & desenvolvimento , Sus scrofa/metabolismo , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Cromatografia Gasosa/veterinária , Dieta/veterinária , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Gorduras/administração & dosagem , Masculino , Distribuição Aleatória , Óleo de Soja/administração & dosagem , Desmame
9.
J Anim Sci ; 91(4): 1719-27, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23408815

RESUMO

An experiment was conducted to study P digestibility in mature horses because of the growing environmental concerns regarding P runoff and previous equine research focused mostly on young and growing animals or used ponies as a model. Phytase supplementation of swine and poultry diets can result in greater phytate-P digestibility, leading to a decreased need for inorganic P supplementation and a decrease in P excreted to the environment; this, however, has not been demonstrated in the horse. Six mature Arabian geldings were fed 6 diets consisting of pelleted concentrate and alfalfa hay. The concentrates consisted mainly of soybean hulls, ground corn, wheat midds, broken rice, and beet pulp, and phytase was added to the concentrates accordingly before pelleting. There were 3 diet types: control (concentrate and hay), high P (greater P concentrate and hay), and forage only, and each diet type included 1 phytase-supplemented diet and 1 non-phytase-supplemented diet, resulting in 6 total diets. Phytase supplementation for the forage only diet was accomplished by feeding a nominal amount of concentrate formulated solely as a vehicle for the phytase. Horses had unrestricted access to water throughout the experiment. Using a Latin square design, all horses received all diets over a period of 12 wk. In each week, the new diet was fed for 11 d of diet acclimation, which was followed by a 3-d total collection of feces and urine for each horse. There was no effect (P < 0.05) of phytase supplementation on P output in the urine or feces, resulting in no differences in P apparent digestibility. Analysis of the feed and feces for phytate revealed a 93% average disappearance rate of phytate, indicating that horses are highly capable of degrading phytate and that phytase supplementation was not beneficial. Thus, the results indicate that mature horses are able to maintain a near 0 P balance, with adequate P provided in the diet even as phytate, and increased P intakes above requirement may result in increased potentially detrimental outputs to the environment.


Assuntos
6-Fitase/farmacologia , Suplementos Nutricionais , Medicago sativa , 6-Fitase/análise , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Animais , Cálcio/análise , Cálcio/urina , Dieta/veterinária , Suplementos Nutricionais/análise , Digestão/efeitos dos fármacos , Digestão/fisiologia , Ingestão de Alimentos/fisiologia , Fezes/química , Cavalos/metabolismo , Cavalos/fisiologia , Magnésio/análise , Magnésio/urina , Masculino , Fósforo/análise , Fósforo/urina
10.
J Anim Sci ; 90(12): 4408-13, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23100581

RESUMO

An experiment involving 854 crossbred pigs (20 replicate pens of 4 to 8 pigs per pen) was conducted at 8 experiment stations to determine the effects of acids in nursery pig diets and their inclusion amounts on growth performance using diets and weaning ages typical of those used in the United States commercial pork industry. Diets were formulated to have constant a ME and contain 1.45, 1.45, and 1.30% standardized ileal digestible Lys for phases 1, 2, and 3, respectively. The basal diets were supplemented with various types and concentrations of acid at the expense of corn (Zea mays). Treatment diets included 0% acid (control), 0.1 or 0.2% phosphoric acid, 1 or 2% organic acids, and 0.1% phosphoric acid plus 1% organic acids with or without an antibiotic. The organic acids consisted of 50% citric acid and 50% fumaric acid by weight. All but the final diet contained the antibiotic carbadox. All diets contained 3,000 mg of Zn/kg diet from zinc oxide during phases 1 and 2 and had limited acid buffering capacity, ranging from 142, 127, and 122 mEq/kg of feed for phases 1, 2, and 3, respectively. At each participating station, pigs were randomly allotted to dietary treatments on the basis of their initial BW. Sex and ancestry were equally distributed across the treatments. Results indicated that treatment effects on pig performance were observed in phases 1 and 2 but not in phase 3. In phase 1, ADG of pigs fed 0.2% phosphoric acid was greater than that of pigs fed the combination of acids with no antibiotic (P = 0.041). In phase 2, pigs fed treatments containing an antibiotic had a greater ADG than those fed the combination of acids without antibiotic (P < 0.05). Addition of acids to diets did not affect growth performance during any phase or the overall period. Over the 4-wk study, growth rate was slowest on the treatment without antibiotic, with specific differences that were often statistically significant (P < 0.05). In summary, under the conditions of this experiment, the acid treatments had no effect but the antibiotic improved growth performance.


Assuntos
Ácidos/farmacologia , Ração Animal/análise , Dieta/veterinária , Suínos/crescimento & desenvolvimento , Ácidos/química , Fenômenos Fisiológicos da Nutrição Animal , Animais , Soluções Tampão , Cálcio/química , Feminino , Concentração de Íons de Hidrogênio , Masculino , Fósforo/química
11.
J Anim Sci ; 89(10): 3286-99, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21571896

RESUMO

The objective of the study was to evaluate the dietary effects of distillers dried grains with solubles (DDGS) with either inorganic or organic trace mineral sources on air emissions. Three diets were compared: a corn- and soybean meal-based control diet (Con), a diet containing 20% DDGS with inorganic trace mineral sources (20In), and a diet containing 20% DDGS with organic trace mineral sources (20Org). Groups of 6 pigs were allocated randomly to 1 of 12 environmentally controlled rooms for a 98-d experiment. A total of 72 pigs were blocked into 3 light and 3 heavy BW groups to minimize BW variation. Average initial BW for the light and heavy blocks were 22.6 kg and 27.0 kg, respectively. Concentrations and airflow of NH3, H2S, N2O, CH(4), CO2, and nonmethane total hydrocarbons (NMTHC) were measured in the exhaust air from each room. Body weight gain (94 kg per pig; P = 0.36) and G:F (0.39; P = 0.79) were not different as a result of diet, although a reduced feed intake was observed in pigs offered 20Org (P < 0.05). Total daily H2S emission mass was greater (P = 0.03) in rooms where the 20In diet was offered (462.26 mg) compared with rooms where the Con (354.62 mg) and 20Org (323.10 mg) diets were offered. No dietary effect (P = 0.47) was observed when H2S emissions were adjusted for S consumption (14.38 mg of H2S emitted daily per gram of S consumed). Compared with NH3 emitted on the Con diet, the daily mass of NH3 emitted decreased by 7.6% when pigs were fed 20In and increased by 11.0% in rooms where the 20Org was fed (P < 0.05). On a N consumption basis, feeding swine 20In significantly reduced NH3 emissions compared with 20Org and Con, whereas NH3 emissions from pigs fed 20Org were significantly greater than emissions from pigs fed the Con diet (P < 0.01). The NH3 emission mass from rooms offered the Con, 20In, and 20Org diets was 120.1, 109.8, and 142.8 mg/g of N consumed/d, respectively (P < 0.01). Feeding DDGS with either inorganic or organic trace mineral sources increased the daily emission masses of CH4 and NMTHC (P < 0.01), but not N2O emissions. Plasma urea N (P = 0.64), albumin (P = 0.39), globulin (P = 0.75), and total bilirubin concentrations (P = 0.82) were not different between diet groups. Results demonstrated that DDGS will increase H2S, CH4, NH3, and NMTHC emissions from pigs, but organic sources of trace minerals are a promising mitigation strategy to alleviate the adverse effect of DDGS on H2S emissions.


Assuntos
Poluentes Atmosféricos/química , Ração Animal/análise , Grão Comestível/química , Sulfeto de Hidrogênio/metabolismo , Metano/metabolismo , Suínos/fisiologia , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dióxido de Carbono/química , Dióxido de Carbono/metabolismo , Dieta/veterinária , Sulfeto de Hidrogênio/química , Masculino , Esterco/análise , Metano/química , Óxido Nitroso/química , Óxido Nitroso/metabolismo
12.
J Anim Sci ; 89(8): 2440-51, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21454861

RESUMO

Three experiments were conducted to evaluate the effects of increasing dietary Cu and Zn on weanling pig performance. Diets were fed in 2 phases: phase 1 from d 0 to 14 postweaning and phase 2 from d 14 to 28 in Exp. 1 and 2 and d 14 to 42 in Exp. 3. The trace mineral premix, included in all diets, provided 165 mg/kg of Zn from ZnSO(4) and 16.5 mg/kg of Cu from CuSO(4). In Exp. 1, treatments were arranged in a 2 × 3 factorial with main effects of added Cu from tri-basic copper chloride (TBCC; 0 or 150 mg/kg) and added Zn from ZnO (0, 1,500, or 3,000 mg/kg from d 0 to 14 and 0, 1,000, or 2,000 mg/kg from d 14 to 28). No Cu × Zn interactions were observed (P > 0.10). Adding TBCC or Zn increased (P < 0.05) ADG and ADFI during each phase. In Exp. 2, treatments were arranged in a 2 × 3 factorial with main effects of added Zn from ZnO (0 or 3,000 mg/kg from d 0 to 14 and 0 or 2,000 mg/kg from d 14 to 28) and Cu (control, 125 mg/kg of Cu from TBCC, or 125 mg/kg of Cu from CuSO(4)). No Cu × Zn interactions (P > 0.10) were observed for any performance data. Adding ZnO improved (P < 0.02) ADG and ADFI from d 0 to 14 and overall. From d 0 to 28, supplementing CuSO(4) increased (P < 0.02) ADG, ADFI, and G:F, and TBCC improved (P = 0.006) ADG. In Exp. 3, the 6 dietary treatments were arranged in a 2 × 2 factorial with main effects of added Cu from CuSO(4) (0 or 125 mg/kg) and added Zn from ZnO (0 or 3,000 mg/kg from d 0 to 14 and 0 or 2,000 mg/kg from d 14 to 42). The final 2 treatments were feeding added ZnO alone or in combination with CuSO(4) from d 0 to 14 and adding CuSO(4) from d 14 to 42. Adding ZnO increased (P < 0.04) ADG, ADFI, and G:F from d 0 to 14 and ADG from d 0 to 42. Dietary CuSO(4) increased (P < 0.004) ADG and ADFI from d 14 to 42 and d 0 to 42. From d 28 to 42, a trend for a Cu × Zn interaction was observed (P = 0.06) for ADG. This interaction was reflective of the numeric decrease in ADG for pigs when Cu and Zn were used in combination compared with each used alone. Also, numerical advantages were observed when supplementing Zn from d 0 to 14 and Cu from d 14 to 42 compared with all other Cu and Zn regimens. These 3 experiments show the advantages of including both Cu and Zn in the diet for 28 d postweaning; however, as evident in Exp. 3, when 3,000 mg/kg of Zn was added early and 125 mg/kg of Cu was added late, performance was similar or numerically greater than when both were used for 42 d.


Assuntos
Cloretos/farmacologia , Sulfato de Cobre/farmacologia , Cobre/farmacologia , Suínos/crescimento & desenvolvimento , Óxido de Zinco/farmacologia , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Animais , Cloretos/administração & dosagem , Cobre/administração & dosagem , Sulfato de Cobre/administração & dosagem , Dieta/veterinária , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Desmame , Óxido de Zinco/administração & dosagem
13.
J Anim Sci ; 89(4): 1042-55, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21415420

RESUMO

Weanling pigs (n = 160) were used to evaluate dietary essential microminerals (Cu, Fe, Mn, Se, and Zn) on performance, tissue minerals, and liver and plasma enzymatic activities during a 35-d postweaning period. A randomized complete block design with 5 treatments and 8 replicates was used in this study. Organic microminerals were added to complex nursery diets at 0 (basal), 50, 100, or 150% of the requirements of microminerals listed by the 1998 NRC. A fifth treatment contained inorganic microminerals at 100% NRC and served as the positive control. Pigs were bled at intervals with hemoglobin (Hb), hematocrit (Hct), glutathione peroxidase, and ceruloplasmin activities determined. Six pigs at weaning and 1 pig per pen at d 35 were killed, and the liver, heart, loin, kidney, pancreas, and the frontal lobe of the brain were collected for micromineral analysis. The liver was frozen in liquid N for determination of enzymatic activities. The analyzed innate microminerals in the basal diet met the NRC requirement for Cu and Mn but not Fe, Se, and Zn. Performance was not affected from 0 to 10 d postweaning, but when microminerals were added to diets, ADG, ADFI, and G:F improved (P < 0.01) from 10 to 35 d and for the overall 35-d period. Pigs fed the basal diet exhibited parakeratosis-like skin lesions, whereas those fed the supplemental microminerals did not. This skin condition was corrected after a diet with the added microminerals was fed. When the basal diet was fed, Hb and Hct declined, but supplemental microminerals increased Hb and Hct values. Liver catalase activity increased (P < 0.01) when microminerals were fed. The Mn superoxide dismutase activity tended to decline quadratically (P = 0.06) when supplemental microminerals were fed above that of the basal diet. Liver plasma glutathione peroxidase activities were greater (P < 0.01) when dietary organic and inorganic micromineral were fed. Liver concentrations of microminerals increased linearly (P < 0.01) as dietary microminerals increased, indicating that the liver was the primary storage organ. Micromineral tissue concentrations were least in pigs fed the basal diet and increased (quadratic, P < 0.01) to the 50% level of organic microminerals in the various tissues collected. The results indicated that innate microminerals, Cu and Mn, from a complex nursery diet may meet the micromineral needs of the weaned pig, but the need for Fe, Se, or Zn was not met by the basal diet.


Assuntos
Dieta/veterinária , Fígado/enzimologia , Minerais/análise , Plasma/enzimologia , Sus scrofa/fisiologia , Ração Animal/análise , Animais , Feminino , Minerais/metabolismo , Necessidades Nutricionais , Distribuição Aleatória , Sus scrofa/crescimento & desenvolvimento , Desmame
14.
J Dairy Sci ; 93(11): 5309-17, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20965347

RESUMO

Holstein rumen-cannulated cows [n=7; initial body weight (BW) 640.56±71.43 kg] were fed a corn silage basal diet with 1 of 3 concentrates (C=control; P10=10% pigeon peas; P20=20% pigeon peas). Cows were randomly assigned to treatments in a replicated 3×3 Latin square and individually fed using Calan gates. Each experimental period was 21 d with 7 d for adaption and 14 d for sample collection. Ruminal fluid samples were taken the last day of each experimental period and analyzed for pH, ammonia, long-chain fatty acids, and volatile fatty acids (VFA). Consecutive a.m. and p.m. milk samples were taken during the last 2 wk of the 21-d period and analyzed for fat, protein, long-chain fatty acids, and somatic cell count. Dry matter intake (kg/d) was reduced during the second period and was greater for P10 diets. Milk protein was greater for cows fed P20 compared with P10. Energy-corrected milk was greater for cows fed the control diet compared with P10. Treatment had no effect on milk yield. Ruminal fluid pH decreased over sampling times; however, pH remained at or above 5.5. Diets did not affect ruminal fluid pH; however, pH was different for sampling periods. Ruminal ammonia decreased until 8h postfeeding at which time it peaked consistent with changes in ammonia concentrations that usually peak 3 to 5h postfeeding on diets high in plant proteins. Dietary treatments altered ruminal fluid VFA with reduced concentrations of acetate and greater concentrations of propionate for control diet, resulting in reduced acetate:propionate ratio. Isobutyrate exhibited an hour by treatment interaction, in which isobutyrate decreased until 8h postfeeding and then tended to be greater for P10 than for other treatments. Animals fed the P10 diet had greater concentrations of ruminal isovalerate. Ruminal cis-9,trans-11 and trans-10,cis-12 conjugated linoleic acid (CLA) isomers were not affected by dietary treatments. The P10 diet had greatest ruminal synthesis of cis-9,trans-11, but control cows had greatest ruminal synthesis of trans-10,cis-12. Milk CLA isomers were similar among treatments. Trends were observed for greater cis-9,trans-11 and trans-10,cis-12 for the P10 diet. Pigeon peas may be used as a protein supplement in dairy diets without affecting milk production, dry matter intake, or ruminal environment when they replace corn and soybean meal.


Assuntos
Cajanus/metabolismo , Bovinos/fisiologia , Lactação/fisiologia , Rúmen/metabolismo , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos/metabolismo , Suplementos Nutricionais , Feminino , Ácido Linoleico/análise , Leite/química , Leite/metabolismo , Rúmen/química , Silagem , Zea mays/metabolismo
15.
Br J Dermatol ; 162(1): 152-8, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19796179

RESUMO

Background In 2006 a U.K. government White Paper recommended making NHS care in England more accessible by shifting services from secondary care into community settings. There is a shortage of contemporary activity data for U.K. dermatology units to allow benchmarking for service development. This study will not only provide useful comparative data for the future in Wales, but will also serve to highlight the impact of changes made in England. Objective To provide an overview of 1 week's dermatology outpatient activity for the whole of Wales. Methods All dermatology units in Wales collected data for 1 week in early 2007. The case mix, appropriateness of referral, requirement for surgery or second-line therapies and follow-up requirements were all determined. Results A total of 2142 patients were seen. Of new patients, 21% had skin cancer. Seventeen per cent of skin cancers had no diagnosis suggested by the general practitioner (GP) and 10% of basal cell carcinomas, 33% of squamous cell carcinomas and 17% of malignant melanomas were inappropriately diagnosed. In all, 26% of new patients had benign lesions, and this group caused the greatest diagnostic difficulty for GPs. Seventy-one per cent of these patients were diagnosed, reassured and discharged at their first visit without the need for biopsy or surgery. Thirty-seven per cent of new patients required surgery, of which 21% required complex intervention. Twenty-six per cent of follow-up patients were receiving second-line therapies. The new to follow-up ratio varied considerably according to diagnosis, the mean ratio being 1 : 0.21 for benign lesions through to 1 : 5.53 for psoriasis. This highlights the inappropriate nature of a 'one fits all' ratio. The majority of follow-up patients in secondary care required this level of input for monitoring of cancer, complex second-line therapies or surgery. Conclusions This study provides evidence to support logical planning of dermatological services and to assess the impact of proposed changes on different healthcare systems in the U.K.


Assuntos
Atenção à Saúde/normas , Dermatologia/normas , Medicina de Família e Comunidade/normas , Ambulatório Hospitalar , Encaminhamento e Consulta/normas , Dermatopatias/diagnóstico , Carcinoma Basocelular/diagnóstico , Carcinoma de Células Escamosas/diagnóstico , Humanos , Melanoma/diagnóstico , Neoplasias Cutâneas/diagnóstico , País de Gales
16.
J Anim Sci ; 87(14 Suppl): E85-9, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18820153

RESUMO

Before the discovery and elucidation of transporters, mammals were thought to cotransport Cu or Zn as an anionic complex, such as binding with an AA as a chelate or a receptor such as transferrin. In 1995, the first mammalian Zn transporter (ZnT) gene, ZnT1, was identified. However, 2 protein families are now thought to be involved in Zn transport. The ZnT family reduces intracellular Zn by aiding in efflux from the cell or promoting the influx into intracellular vesicles. The mechanism of ZnT transport against a Zn concentration gradient is unknown; however, only ZnT1 appears to be located at the plasma membrane. It has been shown to respond in tissues in a variety of ways to Zn reduction and supplementation. In our laboratory, we have found ZnT1 and metallothionein to work in concert during pharmacological Zn supplementation. The second protein family, Zip proteins, provides Zn transport from extracellular fluid or intracellular vesicles into the cytoplasm and has not been identified in a livestock species. Like Zn, no good indicator of status has been identified for Cu. However, the recent identification of Cu transporters and chaperones gives researchers the opportunity to understand the regulation of Cu trafficking where the proteins are modified by posttranslational mechanisms. Two Cu transporters, Ctr1 and Ctr3, mediate high-affinity Cu uptake. A small cytoplasmic protein, MURR1, has been identified in human hepatic tissue, but its role in Cu metabolism is unknown. The discovery of Cu chaperones that are involved in facilitating Cu absorption into proteins may provide an excellent status indicator. It has been shown that the Cu chaperone for Cu/Zn superoxide dismutase (CCS) is increased in tissue of Cu-deficient rats, induced when moderately high Zn diets are fed. We have recently found CCS in the young pig. Other Cu chaperone proteins that have been identified are COX17 and Atox1. As with CCS, they are involved in making Cu available to apo-enzymes inside the cell. It is essential that these new molecular findings be used to evaluate the bioavailability of and nutritional need for Cu and Zn in livestock.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Proteínas de Transporte de Cátions/metabolismo , Cobre/metabolismo , Zinco/metabolismo , Absorção , Animais , Regulação da Expressão Gênica , Humanos , Metalotioneína/metabolismo
17.
J Anim Sci ; 87(1): 438-46, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18820155

RESUMO

Forage-animal production agriculture is implementing infrastructure changes and management strategies to adjust to increased energy-related costs of fuel, feed grains, fertilizers, and seeds. The primary objectives of this position paper are to assess future research and extension scientific needs in forage utilization, financial support for the discipline, and changing status and number of scientists. A survey questionnaire returned from 25 land-grant universities in the eastern half of the United States rated the top 4 research needs as 1) pasture systems and efficiency of production; 2) interfacing with energy concerns; 3) forage cultivar evaluations and persistence; and 4) environment impacts. Plant-animal future research needs at 11 USDA-ARS regional locations are targeted at sustainable management and improved livestock performance, ecophysiology and ecology of grasslands, environment impacts, and improved technologies for nutritive value assessments. Extension scientists from 17 southern and northeastern states listed the top 3 needs as forage persistence, soil fertility and nutrient management, and pasture systems and efficiency of production. Grant funds currently provide more than 40% of land-grant university research and extension efforts in forage utilization, and scientists estimate that this support base will increase to 55 to 60% of the funding total by 2013. Reduced allocation of state and federal funding has contributed to a reduction in the number of full-time equivalent (FTE) scientists engaged in forage utilization research and extension activities. The current 25 state FTE conducting research number about 2.8 per state. This includes 10 states with >3, 11 states with <2, and 3 states with <1 FTE. Increased interest in cellulosic energy, climate change, and environmental impact may offer new opportunities for these FTE to participate in integrated cross-discipline research Extension programming, and technology transfer methods will change to accommodate reduced funding but with increasing numbers of novice, recreation-oriented landowners.


Assuntos
Agricultura/tendências , Ração Animal , Pesquisa/tendências , Agricultura/economia , Criação de Animais Domésticos/economia , Criação de Animais Domésticos/tendências , Animais , Pesquisa/economia , Estados Unidos , United States Department of Agriculture , Universidades/tendências
18.
J Anim Sci ; 86(1): 112-8, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17878284

RESUMO

Two experiments were completed to determine the potential for using distillers dried grains with solubles (DDGS) in diets with or without phytase to provide available P, energy, and protein to highly productive lactating sows without increasing their fecal P. In Exp. 1, the dietary treatments were as follows: (1) corn and soybean meal with 5% beet pulp (BP) or (2) corn and soybean meal with 15% DDGS (DDGS). Besides containing similar amounts of fiber, diets were isonitrogenous (21% CP, 1.2% Lys) and isophosphorus (0.8% P). Sixty-one sows were allotted to dietary treatments at approximately 110 d of gestation (when they were placed in farrowing crates) based on genetics, parity, and date of farrowing. Sows were gradually transitioned to their lactation diet. On d 2 of lactation, litters were cross-fostered to achieve 11 pigs/litter. Sows and litters were weighed on d 2 and 18. Fecal grab samples were collected on d 7, 14, and 18 of lactation. Dietary treatment did not affect the number of pigs weaned (10.9 vs. 10.8) or litter weaning weight. On d 14, DDGS sows had less fecal P concentration than BP sows (28.3 vs. 32.8 mg/g; P = 0.04). Fecal Ca of sows fed DDGS decreased for d 7, 14, and 18 (55.6, 51.4, and 47.1 mg/g of DM, respectively; P = 0.05) but not for BP sows. In Exp. 2, the dietary treatments were as follows: (1) corn and soybean meal (CON), (2) CON + 500 phytase units of Natuphos/kg diet, as fed (CON + PHY), (3) corn and soybean meal with 15% DDGS and no phytase (DDGS), or (4) DDGS + 500 FTU of Natuphos/kg of diet, as fed (DDGS + PHY). Sows (n = 87) were managed as described for Exp 1. Litter BW gain (46.0, 46.3, 42.1, and 42.2 kg; P = 0.25) and sow BW loss (8.1, 7.2, 7.4, and 6.3 kg for CON, CON + PHY, DDGS, and DDGS + PHY, respectively; P = 0.97) were not affected by dietary treatment. Fecal P concentration did not differ among dietary treatments but was reduced at d 14 and 18 compared with d 7 (P = 0.001). However, fecal phytate P concentration was decreased by the addition of DDGS when DDGS and DDGS + PHY were compared with the CON sows except on d 7 (P < 0.05). Sows fed CON diet had greater fecal phytate P than sows fed DDGS, and sows fed DDGS + PHY had less fecal phytate P than sows fed DDGS with no phytase (P = 0.001). Although these experiments were only carried out for 1 lactation, these results indicate that highly productive sows can sustain lactation performance with reduced fecal phytate P when fed DDGS and phytase in lactation diets.


Assuntos
6-Fitase/farmacologia , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Fezes/química , Lactação/fisiologia , Fósforo/farmacologia , Suínos/metabolismo , 6-Fitase/química , 6-Fitase/metabolismo , Animais , Dieta/veterinária , Feminino , Redução de Peso
19.
J Anim Sci ; 85(10): 2762-71, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17526661

RESUMO

Cow and calf performance was determined in a 2-yr, 2 x 2 factorial, grazing experiment using Coastal or Tifton 85 (T85) replicated Bermudagrass pastures (4 pastures each; each pasture 4.86 ha), without or with aeschynomene creep-grazing paddocks (n = 4, 0.202 ha each, planted in May of each year, 13.44 kg/ha). On June 10, 2004, and June 8, 2005, 96 winter-calving beef "tester" cows and their calves were grouped by cow breed (9 Angus and 3 Polled Hereford/group), initial cow BW (592.9 +/- 70.1 kg, 2-yr mean), age of dam, calf breed (Angus, Polled Hereford, or Angus x Polled Hereford), calf sex, initial calf age (117 +/- 20.1 d, 2-yr mean), and initial calf BW (161.3 +/- 30.4 kg) and were randomly assigned to pastures. Additional cow-calf pairs and open cows were added as the forage increased during the season. Forage mass was similar for all treatment pastures (P > 0.70; 2-yr mean, 6,939 vs. 6,628 kg/ha, Coastal vs. T85; 6,664 vs. 6,896 kg/ha, no creep grazing vs. creep grazing). Main effect interactions did not occur for performance variables (P > 0.10; 2-yr means), and year affected only the initial and final BW of the calves and cows. The 91-d tester calf ADG was greater for calves grazing T85 than Coastal (0.94 vs. 0.79 kg; P < 0.01), and for calves creep grazing aeschynomene compared with calves without creep grazing (0.90 vs. 0.82 kg; P < 0.03). Calf 205-d adjusted weaning weights were increased for calves grazing T85 compared with Coastal (252.9 vs. 240.3 kg; P < 0.01) and for calves with access to creep grazing (249.9 vs. 243.3 kg; P < 0.05). The IVDMD of esophageal masticate from pastures had a forage x creep grazing interaction (P < 0.05; Coastal, no creep grazing = 57.4%; Coastal, creep grazing = 52.1%; T85, no creep grazing = 59.1%; T85, creep grazing = 60.0%), and IVDMD was greater (P < 0.05) for T85 than for Coastal pastures. Cows were milked in August 2004, and in June and August 2005, with variable milk yields on treatments, but increased milk protein (P < 0.05) for cows grazing T85 compared with Coastal pastures in August each year, contributing to increased calf gains on T85 pastures. These results complement previous research with T85 and indicate increased forage quality and performance of cattle grazing T85 pastures. Calf gains on T85 pastures and for calves on creep-grazed aeschynomene paddocks were high enough to influence the efficiency of cow-calf operations.


Assuntos
Ração Animal/análise , Criação de Animais Domésticos/métodos , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Bovinos/crescimento & desenvolvimento , Cynodon , Fabaceae , Aumento de Peso , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Cruzamento , Feminino , Lactação , Masculino , Leite/química , Leite/metabolismo , Proteínas do Leite/análise , Poaceae , Distribuição Aleatória , Estações do Ano , Desmame
20.
J Anim Sci ; 85(9): 2190-7, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17468422

RESUMO

Two experiments were conducted to evaluate dietary fortification levels of a B vitamin pre-mix for starter and grower-finisher pigs on subsequent performance responses. The objective was to determine whether the modern pig requires higher dietary levels of B vitamins than estimated by the NRC (1998). Both experiments added fat-soluble vitamins at the requirement levels (NRC, 1998) in all diets, whereas the B vitamins were added at 0, 100, 200, or 400% of the total NRC (1998) requirement levels for the starter and grower pig. Indigenous vitamin contributions from the feed grains were not included in the estimates. Each station used the same vitamin premixes but incorporated its own grain sources in the diets. The first experiment was conducted across 7 stations (Indiana, Ohio, Oklahoma, Michigan, Missouri, Nebraska, Texas) and involved 660 pigs in a randomized complete block design in 30 replicates. Complex nursery diets were fed in 2 phases. The first phase (0 to 14 d postweaning) and second phase (15 to 35 d postweaning) diets were formulated to Lys (total) levels of 1.50 and 1.30%, respectively. The results demonstrated no performance response to addition of B vitamins from 0 to 14 d post-weaning, but performances increased quadratically (P < 0.01) to the 100% NRC level from 14 to 35 d postweaning and for the overall 35-d period. The second experiment was conducted across 3 stations (Ohio, Nebraska, and South Dakota) and involved 216 pigs in a randomized complete block design in 10 replicates. Corn-soybean meal mixtures were fed in 3 phases formulated to total Lys levels of 1.30% (23 to 55 kg of BW), 1.00% (55 to 85 kg of BW), and 0.78% (85 to 120 kg of BW). Pig performances increased (P < 0.01) to the 100% B vitamin level from 23 to 85 kg of BW, but there was no response to any level from 85 to 120 kg of BW. Carcass measurements demonstrated a greater LM area (P < 0.01) and a lower backfat depth (P < 0.01) to the 100% B vitamin level. One station evaluated an additional treatment (3 replicates) in which each replicate was fed a fifth diet containing the 100% dietary level of B vitamins from 23 to 85 kg of BW whereupon the B vitamins were removed from 85 to 120 kg of BW. This removal did not reduce pig performance responses for the final period or for the overall period. The results demonstrated that supplementation of B vitamins at the 100% total NRC levels for starter and grower pigs was sufficient to meet their needs, and there was no further improvement to or deleterious effect to greater dietary levels.


Assuntos
Composição Corporal/efeitos dos fármacos , Necessidades Nutricionais , Suínos/crescimento & desenvolvimento , Suínos/metabolismo , Complexo Vitamínico B/administração & dosagem , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Animais , Composição Corporal/fisiologia , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Política Nutricional , Desmame , Aumento de Peso
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