Effects of deoxynivalenol in a wheat ration fed to growing lambs

A wheat diet containing deoxynivalenol (vomitoxin) at 15.6 mg/kg was fed to crossbred lambs for 28 days. Feed consumption, weight gain, and feed efficiency of deoxynivalenol-treated lambs did not differ (P less than 0.05) from those values of controls. Group differences were not noted for hematologic or serum biochemical variables, and gross or microscopic lesions were not observed in treated lambs.     

The metabolic profile of growing lambs fed diets rich in unsaturated fatty acids

The effect of two diets enriched with unsaturated fatty acids – one containing the addition of dried distillers grains with solubles (DGS) and the other the addition of false flax – Camelina sativa cake (CS) – on some metabolic parameters and hormone concentration in growing lambs was determined in this experiment. A total of 21 ram lambs of the Polish Whiteheaded mutton sheep were divided into three groups (the control, receiving DGS and CS). The diets were administered to animals for 6 weeks. During the experiment, peripheral blood was collected. Glucose (GL), total cholesterol (CH), triglycerides (TG), free fatty acids (FFA), insulin (IN), leptin (LE), triiodothyronine (T3) and thyroxine (T4) were assayed in serum. The age‐dependent reduction in CH and TG limited by both experimental diets were observed. A significant increase in FFA concentration was observed in samples collected in the last, that is, third, time period. This was most probably caused by a 12‐h pre‐slaughter fasting period. A significantly lower dynamic of FFA increase in that experimental period was found in animals receiving the experimental feed. Insulin concentration in DGS‐receiving lambs was increased, in contrast to the CS‐receiving lambs, in which it was lower when compared to the control. LE concentration was decreased by both experimental diets, more markedly in the DGS‐receiving animals. No differences between the experimental groups and the control were observed in T3 and T4 concentrations. The effect of 12‐h pre‐slaughter fasting was statistically highly significant for the levels of examined blood markers and hormones, except for TG and IN in the group of lambs receiving the experimental diet with CS.     

Limiting amino acids for growing lambs fed a diet low in ruminally undegradable protein

Ruminally cannulated Rambouillet wether lambs were used in three 6 x 6 Latin square experiments (n = 6/experiment) to determine which essential AA limit N retention. Lambs (BW = 36.9 +/- 1.9 kg for Exp. 1, 35.1 +/- 1.4 kg for Exp. 2, and 46.0 +/- 1.3 kg for Exp. 3) were housed in metabolism crates and limit-fed (DMI = approx. 1.8% of BW daily) twice daily a soybean hull-based diet low in ruminally undegradable protein. Treatments for Exp. 1 were continuous abomasal infusions of a solution (500 mL/d) containing 1) no AA (CON), 2) a mixture of 10 essential AA and 2 nonessential AA (10EAA), 3) 10EAA with Met removed, 4) 10EAA with Lys removed, 5) 10EAA with His removed, and 6) 10EAA with Thr removed. Treatments for Exp. 2 were abomasal infusions of 1) CON, 2) 10EAA, 3) 10EAA with Leu, Ile, and Val removed (-BCAA), 4) 10EAA with Arg removed, 5) 10EAA with Phe removed, and 6) 10EAA with Trp removed. Treatments for Exp. 3 were abomasal infusions of 1) CON, 2) 10EAA, 3) -BCAA, 4) 10EAA with Leu removed, 5) 10EAA with Ile removed, and 6) 10EAA with Val removed. All lambs received continuous infusions of acetate and propionate into the rumen and dextrose into the abomasum to supply additional energy. Periods were 7 d: 3 d for adaptation to abomasally infused treatments and 4 d for fecal and urinary collections. Blood samples were collected 3 h after feeding on d 7. In all 3 experiments, N retention was greater (P < 0.10) for lambs receiving 10EAA vs. CON, demonstrating that the basal AA supply from CON was limiting. Removal of each of the essential AA from 10EAA decreased (P < 0.10) their concentrations in plasma (except for Trp), indicating that 10EAA supplied these AA in excess of the animal's requirement. In Exp. 1, N retention (g/d) decreased (P < 0.10) in response to the removal of Met and Thr, but was not affected by removal of Lys and His from 10EAA. In Exp. 2, N retention decreased (P < 0.10) in response to removal of all 3 branched-chain AA, Arg, and Trp, whereas the removal of Phe from 10EAA did not affect N retention. In Exp. 3, N retention decreased (P < 0.10) in response to removal of branched-chain AA and Val, but was not affected by the omission of Leu and Ile from 10EAA. The results of this research demonstrated that Met, Thr, Arg, Trp, and Val limited N retention of lambs fed a diet low in ruminally undegradable protein.     

Net energy of oat bran,wheat bran,and palm kernel expellers fed to growing pigs using indirect calorimetry

The objectives of this experiment were to (a) determine the effects of fiber increase in diets on heat production (HP), (b) determine the net energy (NE) of oat bran (OB), wheat bran (WB), and palm kernel expellers (PKE) fed to growing pigs using indirect calorimetry (IC). Twenty‐four growing barrows (29.2 ± 2.6 kg) were randomly allotted to one of four diets with six replicate pigs per diet. Diets included a corn‐soybean meal basal diet and three test diets containing 30% OB, WB or PKE, respectively. During each period, pigs were individually housed in metabolism crates for 20 days, including 14 days to adapt to the diets. On day (d) 15, pigs were transferred to the open‐circuit respiration chambers for determination of daily total HP and were fed one of the four diets at 2.3MJ ME/kg body weight (BW)^0.6/day. Total feces and urine were collected for the determination of digestible energy (DE) and metabolizable energy (ME) and daily total HP was measured from d 15 to d 19 and fasted on day 20 for the measurement of fasting heat production (FHP). The apparent total tract digestibility (ATTD) of dry matter (DM), gross energy (GE), and organic matter (OM) were greater (p < 0.01) in pigs fed the basal diet compared with those fed the test diets. The ATTD of neutral detergent fiber (NDF) was lower (p < 0.01) in pigs fed the WB diet compared with those fed the basal, OB, or PKE diets. The ATTD of ether extract (EE) in pigs fed the PKE diet was greater (p < 0.01) compared with those fed the other diets. The average total HP and FHP in pigs fed the four diets were 1261 and 787 kJ/kg BW^0.6/d, respectively, and were not significantly affected by diet characteristics. The NE:ME ratio for diets ranged from 78.1 to 80.9%. The NE contents of OB, WB, and PKE were 10.93, 7.47, and 8.71 MJ/kg DM, respectively.     

Effects of malate on diet digestibility, microbial protein synthesis, plasma metabolites, and performance of growing lambs fed a high-concentrate diet

The objective of this study was to evaluate the effects of malate supplementation on growth rate, feed efficiency, and diet digestibility in growing lambs. Twenty-four Merino lambs with a mean BW of 15.3 +/- 0.22 kg were divided into 3 homogenous groups. Each group was randomly allocated to 1 of 3 malate (16% disodium malate:84% calcium malate) levels: 0 (control), 4 (MAL-4), or 8 (MAL-8) g/kg of concentrate. Lambs were fed concentrate and barley straw ad libitum for 35 d. After a 20-d period, diet digestibility was determined, and microbial N flow at the duodenum was estimated from the urinary excretion of purine derivatives. Blood samples were taken on d 0, 20, and 35. On d 35, lambs were slaughtered and ruminal fluid samples were collected. There were no effects (P = 0.18 to P = 0.95) of malate on concentrate or straw intake, ADG, carcass yield, and apparent digestibility of OM, CP, NDF, or ADF. Malate supplementation did not influence (P = 0.80) the daily urinary excretion of total purine derivatives, and therefore there were no treatment effects (P = 0.77) on estimated microbial N flow at the duodenum. No differences (P > 0.05) among treatments were observed for plasma concentrations of glucose, cholesterol, triglycerides, urea-N, lactate, or VFA, but malate addition increased (P = 0.003) the molar proportion of butyrate in ruminal fluid (4.29, 6.14, and 5.45% of total VFA for control, MAL-4 and MAL-8, respectively). The use of malate as a feed additive under the conditions of the current study did not influence diet intake or digestion, and consequently did not improve lamb performance.     

Effects of dietary iron on performance and mineral utilization in lambs fed a forage-based diet

Twenty-four lambs, averaging 29 kg, were used to determine the effect of supplemental dietary Fe on performance and Cu, P, Zn and Mn utilization. Treatments consisted of supplemental Fe at 0, 300, 600 or 1,200 mg/kg diet as ferrous carbonate. The basal diet contained 154 mg Fe/kg diet and consisted of 90% Coastal bermudagrass pellets, 9.45% group corn, .5% sodium chloride and .05% vitamin mix. Lambs were slaughtered after having ad libitum access to diets for 98 to 121 d. Dietary Fe did not affect lamb gain or feed intake. Supplemental Fe increased Fe concentrations in liver (P less than .01), spleen (P less than .01) and bone (P less than .10), but not in kidney and muscle. Serum Fe concentrations and percentage transferrin saturation in serum were increased (P less than .01) by supplemental Fe at 28 and 84 d, but not at the termination of the study. Plasma Cu was decreased (P less than .01) at 56 d, whereas serum ceruloplasmin activity was reduced (P less than .01) at 28 d in lambs fed 1,200 mg Fe/kg diet compared with lambs fed 600 mg Fe/kg diet. Lower levels of Fe (300 and 600) reduced (P less than .01) ceruloplasmin by 56 d and plasma Cu by 84 d compared with controls. Liver Cu also was decreased (P less than .05) by supplemental Fe. Plasma P was decreased slightly (P less than .10) by 28 d and significantly (P less than .01) at the other sampling dates by supplemental Fe.(ABSTRACT TRUNCATED AT 250 WORDS)     

Beta-glucanase and xylanase activities in stomach and ileum of growing pigs fed wheat bran based diets with and without enzyme treatment.

Pigs were fed diets containing 40% wheat bran incubated with a water: acetic acid mixture (control C) and a cellulase (Cel-i) or xylanase (Xyl-i) preparation or with addition of the cellulase (Cel-a) or xylanase (Xyl-a) preparation immediately before feeding. Stomach and ileal samples were analysed for xylanase and beta-glucanase activities by a standard method based on release of reducing substances and a modified method in which the actual pH of the sample was used. After feeding Cel-treated diets xylanase and beta-glucanase activities were higher in the stomach up to 4 hours after feeding. In the stomach the modified method gave significantly lower xylanase activities than the standard method. Ileal xylanase activity was significantly higher 2-6 hours after feeding Xyl-treated diets and ileal beta-glucanase activity was higher 4-6 hours after feeding Cel-treated diets. In ileal samples, the modified method gave significantly higher xylanase and lower beta-glucanase activities than the standard method. It is concluded that xylanase and beta-glucanase activities can be measured in digesta samples with the methods employed and that the added enzymes were largely inactivated between the feedings. Measuring digesta enzyme activities in conditions (pH) similar to the ones in the gastrointestinal tract may give a more reliable picture of the actual activity of added enzymes.     

Utilisation of dried poultry manure by growing chickens fed on a practical diet

1. Dried poultry manure (DPM) has been tested as a replacement for groundnut cake in poultry diets.

2. Body weight gain, and the efficiency of food conversion were improved when the diet contained 50 g DPM/kg but higher rates of inclusion (100 or 150 g/kg) depressed growth.

3. Birds fed on diets containing 50 g DPM/kg yielded meat of comparable quality to those fed on the control diet whereas those fed on diets containing more DPM yielded meat containing more fat and less water.

4. The percentage moisture in the meat was inversely related to the lipid content.

5. Nitrogen retention was comparable in all groups.     

Metabolic and microbial responses in western crossbred and Meishan growing pigs fed a high-fiber diet

Four Duroc x White composite crossbred (21.8 +/- 1.0 kg BW) and four 12-wk-old Meishan purebred (20.7 +/- 1.6 kg BW) growing barrows were used to determine the relative breed differences in metabolic and microbial responses to a high-fiber diet. The pigs were trained to consume 700 g of a diet containing 35% (as-fed basis) dehydrated alfalfa meal once daily. The pigs' daily intakes of DM, N, GE, NDF, and ADF were 610 g, 16.6 g, 2.64 Mcal, 150 g, and 88 g, respectively. On d 12 after surgical catheterization of the portal vein, ileal vein, and carotid artery, a 3-d total urine and feces collection was conducted. On d 24 after surgery, each pig was placed in an open-circuit calorimeter, and its catheters were connected to a system for simultaneous measurements of oxygen consumption by portal-drained viscera and by whole body, and the net portal absorption of VFA after a 24-h fasting and during a 5-h postprandial period. The VFA measured included acetic, propionic, isobutyric, butyric, isovaleric, and valeric acids. A second 3-d total urine and feces collection was conducted on d 30 after surgery. There were no differences (P = 0.13) between the first and second collections in apparent total-tract digestibility coefficients for nutrients and N retention of pigs. Compared with Duroc x White composite crossbred pigs, Meishan pigs had lower (P = 0.05) apparent digestibility coefficients for DM, N, NDF, hemicellulose, and N retention, but their portal-drained viscera used a greater (P = 0.05) fraction of whole-body oxygen consumption. No differences (P = 0.12) were found between Duroc x White composite crossbred and Meishan pigs in total viable bacteria and cellulolytic bacteria from fecal samples, in vitro digestibility of alfalfa NDF fractions by fecal inocula, whole-body oxygen consumption, net portal absorption of VFA, total energy of absorbed VFA, and the potential of absorbed VFA for meeting the energy needs for whole-body heat production. These results indicate that, in contrast to previous beliefs, the ability of Meishan growing pigs to utilize a high-fiber diet is not superior to that of Duroc x White composite crossbred growing pigs.     

Enhancement of phosphorus utilization in growing pigs fed phytate-rich diets by using rye bran.

Some cereal by-products, such as bran, exhibit a high phytase activity that may enhance phytate P digestibility. This was studied in growing pigs fed a phytase-rich (1,200 IU/kg) diet containing 20% rye bran. The trial involved 12 animals; six were fed a control diet and six were fed a diet containing rye bran for 2 mo. Both diets contained the same levels of energy, protein, Ca (.7%) and total P (.4%). No inorganic P was added; thus, the dietary P was mainly phytic. Pigs fed the control diet, in contrast to those fed the diet containing rye bran, developed a P deficiency, as indicated by hypophosphatemia, hypophosphaturia, hyperhydroxyprolinuria, hypercalcemia, and hypercalciuria. Phosphorus from the rye bran diet was more completely absorbed (55 vs 36%) and retained (50 vs 36%) than that from the control diet. Calcium absorption was equal for the two diets, but Ca retention was higher in pigs fed rye bran than in controls. Pigs fed the rye bran diet showed greater bone density, ash content, and bending moments than controls. In conclusion, high dietary phytase levels or phytase-rich by-products increased phytate P availability and consequently improved bone scores.     

Effect of diet composition and feed intake level on diet digestibility and ruminal metabolism in growing lambs.

Lambs (29 +/- 2.5 kg) were fed three diets at various intakes to determine whether diet composition or level of intake was reflected in changes in diet digestibility or ruminal fluid characteristics. In Exp. 1, a 90% concentrated, pelleted diet or a whole shelled corn diet with a pelleted protein supplement was fed at three levels of intake: ad libitum and 92.5 and 85% of ad libitum (n = 15). Exp. 2 compared the 90% concentrate diet with diets in which the energy density was diluted to 55 or 72.5% concentrate by including alfalfa hay as a possible method of restricting energy intake (n = 6). Lambs were adapted to diets for 13 d; feces were collected for 6 d and ruminal fluid was collected 0, 3, and 6 h after feeding on the day following fecal collection. Restricting intake in Exp. 1 did not affect DM digestibility or digestibility of CP or starch. Digestibility of ADF was increased (P less than .10) by restricting intake. Ruminal fluid pH, ammonia concentration and VFA concentrations were affected little by either restricted intake level. Digestibility of DM was 4% higher (P less than .001) and starch 5% higher (P less than .001) for the whole shelled corn diet than for the pelleted, high-concentrate diet. Ruminal pH of lambs fed the whole shelled corn diet was higher and fluctuated less than the ruminal pH of lambs fed the high-concentrate, pelleted diet. In Exp. 2, diet digestibility was reduced (P less than .01) and ruminal pH was increased (P less than .002) by addition of hay. Restricted feeding of lambs did not seem to increase diet digestibility or alter ruminal conditions.     

Alteration of nitrogen metabolism by alpha-ketoglutarate administration in growing lambs fed high nonprotein nitrogen-containing diets

Two completely randomized design experiments were conducted, using either 10, 38-kg (Exp. 1) or 10, 26-kg (Exp. 2) Hampshire x Western wether lambs, to study the effects of alpha-ketoglutarate (AKG) administration on N metabolism. Lambs were fed 890 and 885 g DM/d in Exp. 1 and 2, respectively, of corn-cottonseed hull basal diets with urea added to attain CP levels of 10.6 and 10.5% in Exp. 1 and 2, respectively. Experiments consisted of 10 d of adaptation followed by 7 d of infusion and excreta collection. Lambs were infused continuously either i.v. (Exp. 1) or abomasally (Exp. 2) with control solutions (CON) or solutions containing 41.3 g AKG/d (AKG). In Exp. 1, fecal and urinary N excretion and N retention were not affected (P greater than .10) by treatment. Compared to CON in Exp. 2, AKG infusion increased (P less than .10) fecal N output (6.6 vs 5.9 g N/d) but did not affect (P greater than .10) the amount of N retained (4.4 vs 3.5 g N/d). Compared to CON, AKG increased (P less than .10) urinary NH3 N excretion in Exp. 1. Serum urea N was lower (P greater than .10) for AKG than for CON in Exp. 1 but was not affected (P greater than .10) by treatment in Exp. 2. In Exp. 1, AKG appeared to reduce activities of several serum enzymes that function in amino N metabolism. In Exp. 1, compared to CON, AKG decreased (P less than .10) aspartate but increased (P less than .10) asparagine in serum.(ABSTRACT TRUNCATED AT 250 WORDS)     

Morphological changes associated with the development of the rumino-reticulum in growing lambs fed different rations

Morphological changes associated with rumino-reticular development was compared in two groups of SA Mutton Merino lambs (n = 12) fed different diets at 3-5 weeks, 17-19 weeks and 31-33 weeks of age. Diet groups were identified as MMH or MHH according to the sequence at which the full-milk replacement (M) or hay (H) diet were fed to the lambs over the three study phases (phases I, II and III) preceding each age period. Prominent differences in the morphology (size and volume) and function (pH, proteolytic activity and microbial population) of the rumino-reticulum were observed in indicator lambs (n = 2) killed at every age period and also between milk-fed and hay-fed lambs. The size of the rumino-reticulum was rudimentary at 3-5 weeks of age and remained underdeveloped in lambs at 17-19 weeks of age which had received a full-milk replacement diet during phase II. One lamb, slaughtered at 3 weeks of age, showed a large distended rumen with severe sloughing of the surface cells of the stratum corneum.The size of the rumino-reticulum increased in size (2 x) in lambs which were fed hay relative to the milk-fed lambs during phase II and reached adult proportions in all lambs at 31-33 weeks of age. Ultrastructural examination showed that rumen papillae were more developed in lambs fed hay during phase II when compared to those of milk-fed lambs. Rumen papillae were best developed in phase III lambs.     

Varying dietary levels of wheat pollard and wheat bran in growing pigs: effect on growth and carcass traits

To study the effect of increasing levels of wheat pollard as a replacement for wheat bran on growth and carcass characteristics of growing pigs, 64 crossbred (Landrace?×?Large white Yorkshire) pigs were fed with diets in which wheat pollard was added back to wheat bran in ratios of 15, 30, 45 and 60 %. The pigs were divided into groups of four, balanced for sex, ancestry and body weight. They were then allotted to the dietary treatments in a completely randomised design with four replications. The trial lasted 4 months and data were collected on feed intake and weight gain. A digestibility trial was carried out on eight male pigs per treatment during the growth period. At the end of the growth period, two pigs per replicate in each treatment (n?=?32) were slaughtered for determination of carcass characteristics. There were significant differences in the rate of gain and efficiency of feed utilisation among treatments. Diet significantly affected weights of the liver, lungs and small intestine (P?<?0.05). The availability of nutrients was not a limiting factor for the growing pigs and that substituting wheat bran by wheat pollard at 60 % improved the pig’s average daily gain and feed efficiency.