Transition Diet Research Articles

Radiocarbon and Stable Isotope Evidence of Dietary Change from the Mesolithic to the Middle Ages in the Iron Gates: New Results from Lepenski Vir

A previous radiocarbon dating and stable isotope study of directly associated ungulate and human bone samples from Late Mesolithic burials at Schela Cladovei in Romania established that there is a freshwater reservoir effect of approximately 500 yr in the Iron Gates reach of the Danube River valley in southeast Europe. Using the δ15N values as an indicator of the percentage of freshwater protein in the human diet, the 14C data for 24 skeletons from the site of Lepenski Vir were corrected for this reservoir effect. The results of the paired 14C and stable isotope measurements provide evidence of substantial dietary change over the period from about 9000 BP to about 300 BP. The data from the Early Mesolithic to the Chalcolithic are consistent with a 2-component dietary system, where the linear plot of isotopic values reflects mixing between the 2 end-members to differing degrees. Typically, the individuals of Mesolithic age have much heavier δ15N signals and slightly heavier δ13C, while individuals of Early Neolithic and Chalcolithic age have lighter δ15N and δ13C values. Contrary to our earlier suggestion, there is no evidence of a substantial population that had a transitional diet midway between those that were characteristic of the Mesolithic and Neolithic. However, several individuals with “Final Mesolithic” 14C ages show δ15N and δ13C values that are similar to the Neolithic dietary pattern. Provisionally, these are interpreted either as incomers who originated in early farming communities outside the Iron Gates region or as indigenous individuals representing the earliest Neolithic of the Iron Gates. The results from Roman and Medieval age burials show a deviation from the linear function, suggesting the presence of a new major dietary component containing isotopically heavier carbon. This is interpreted as a consequence of the introduction of millet into the human food chain.

Effects of Different Transition Diets on Dry Matter Intake, Milk Production, and Milk Composition in Dairy Cows

The primary objective of this study was to evaluate the effect on dry matter intake (DMI), milk yield, milk composition, body weight (BW), and body condition score (BCS) change of cows offered diets differing in energy density in the last 4 wk of gestation and in the first 8 wk of lactation. Three diets (grass silage:straw, 75:25 on a dry matter basis (SS), grass silage (S), and grass silage + 3kg concentrate daily (C)) precalving, and two diets (4kg [LC] or 8kg [HC] concentrate daily + grass silage ad libitum) postcalving were combined in a 3×2 factorial design. Sixty Holstein-Friesian cows entering their second lactation were blocked according to expected calving date and BCS into groups of six and were then allocated at random to the treatments. Individual feeding started 4 wk prior to the expected calving date and measurements were made until the end of the 8th wk of lactation. Mean DMI differed between each of the precalving treatments (7.4, 8.1, and 9.9kg/d for SS, S, and C, respectively) in the precalving period. The DMI also differed between SS and C for wk 1 to 8 (13.5 and 14.2kg/d) postcalving. Postcalving, milk (24.2, 26.2, and 28.2kg/d), fat (933, 1063, and 1171g/d), and protein (736, 797, and 874g/d) yields differed between SS, S, and C, respectively. The BCS changes differed between SS and C (−0.09 and 0.12 of a BCS) in the precalving period and between SS and S compared with C (0.02, 0.06, and −0.26 of a BCS) for wk 1 to 8 postcalving. The BW change differed between SS and S compared with C in both wk 1 to 4 (−0.23, −0.37, and −1.25kg/d) and wk 1 to 8 (0.18, 0.10, and −0.58kg/d) postcalving. The BW and BCS were lower at calving for cows on SS compared with C. The greater amount of concentrate supplement postcalving increased DMI, yields of milk, fat, and protein and decreased BW loss in the first 8 wk of lactation. In conclusion, these results indicate that a greater energy density diet in the final 4 wk of the dry period improves cow production in early lactation.

Effects of different transition diets on energy balance, blood metabolites and reproductive performance in dairy cows

The objective of this study was to evaluate the effect of diets differing in energy density (ED) in the last 4 weeks of the dry period and in the first 8 weeks of lactation on energy balance (EB), blood metabolites and reproductive performance. Three diets (grass silage:straw 75:25 on a dry matter basis (SS), grass silage (S) and grass silage+3 kg/day of concentrates (C)) pre-calving and two diets (4 kg (LC) or 8 kg/day of concentrates (HC)+grass silage ad libitum) post-calving were combined in a 3×2 factorial design. Sixty second-lactation Holstein–Friesian cows were blocked according to expected calving date and body condition score into groups of six and were then allocated at random to the treatments. Individual feeding started on average 34 days prior to parturition and measurements were made until the end of the 8th week of lactation. Net energy (NE) intake increased (5.6, 6.5 and 9.0 UFL/cow per day; (standard error of the difference (S.E.D.)=0.22) and EB improved pre-calving as the ED of the diet increased. Post-calving, milk energy output was significantly different between pre-calving treatments at 10.5, 11.6 and 12.7 UFL/day (S.E.D.=0.48) for SS, S and C respectively. Cows on the highest ED diet pre-calving (C) had a greater degree of negative energy balance (NEB) than cows on the lowest ED diet pre-calving (SS) for 7 of the first 8 weeks of lactation. At calving, cows on C had a lower plasma urea concentration than those on S and cows on SS had a lower plasma bile acid concentration than those on S. At week 2 post-calving, C had a higher plasma β-hydroxybutyrate concentration than SS and a higher plasma protein concentration than SS or S. Post-calving, cows receiving HC had higher NE intakes averaged over the first 8 weeks of lactation and lower NEB in each of the first 8 weeks of lactation than those on LC. Plasma glucose and bile acid concentrations were higher on HC compared to LC at week 2 post-calving. Plasma urea concentrations were lower ( P<0.05) on HC compared to LC.

Relationships between transition period diet, metabolic parameters and fertility in lactating dairy cows

Cows in severe negative energy balance after calving have reduced fertility, mediated by metabolic signals influencing the reproductive system. We hypothesised that transition diet could alter metabolic status after calving, and thus influence fertility. Multiparous dairy cows were assigned to four transition groups 6 weeks pre-calving and fed: (a) basal control diet ( n=10); (b) basal diet plus barley (STARCH, n=10); (c) basal diet plus Soypass (high protein, HiPROT, n=11); or (d) no transition management (NoTRANS, n=9). All cows received the same lactational diet. Blood samples, body weights and condition scores (BCS) were collected weekly. Fertility parameters were monitored using milk progesterone profiles and were not affected by transition diet. Data from all cows were then combined and analysed according to the pattern of post-partum ovarian activity. Cows with low progesterone profiles had significantly lower insulin-like growth factor-I (IGF-I) and insulin concentrations accompanied by reduced dry matter intakes (DMIs), BCS and body weight. Cows with prolonged luteal activity (PLA) were older and tended to have lower IGF-I. Analysis based on the calving to conception interval revealed that cows which failed to conceive (9/40) also had reduced IGF-I, BCS and body weight. Fertility was, therefore, decreased in cows which were in poor metabolic status following calving. This was reflected in reduced circulating IGF-I concentrations and compromised both ovarian activity and conception. There was little effect of the transition diets on these parameters.

Effects of Transition Diets Varying in Dietary Energy Density on Lactation Performance and Ruminal Parameters of Dairy Cows

Forty cows and twenty heifers were used to study the effects of dietary energy density during late gestation and early lactation on lactation performance and ruminal parameters. A 2×2 factorial arrangement of treatments was used. During prepartum (−28 d to calving), animals were fed a low energy density diet [DL; 1.58 Mcal of net energy for lactation (NEL)/kg, 40% neutral detergent fiber (NDF) and 38% nonfiber carbohydrate (NFC)] or a high energy diet (DH; 1.70 Mcal NEL /kg, 32% NDF and 44% NFC). After calving, half of the cows from each prepartum treatment group were assigned to a low energy density diet (L; 1.57 Mcal NEL /kg, 30% NDF and 41% NFC) or a high energy density diet (H; 1.63 Mcal NEL /kg, 25% NDF and 47% NFC) until d 20 postpartum. After d 20, all cows were fed H until d 70. Animals fed DH had 19.8% greater dry matter intake (DMI; % of body weight) and 21.5% greater energy intake than animals fed DL prepartum and the response was greater for cows compared to heifers. Animals fed DH had lower ruminal pH compared to animals fed DL, but no major changes in volatile fatty acid concentrations were observed. Effects of dietary energy density during prepartum on postpartum production responses were dependent on parity. Primiparous cows fed DL had higher 3.5% fat-corrected milk yield and milk fat production and percentage during the first 10 wk of lactation than those fed DH. Prepartum diet did not affect lactation performance of multiparous cows. Cows fed H had higher DMI and energy intake for the first 20 d of lactation compared to cows fed L. Diets did not affect DMI after the third wk of lactation. Milk production increased faster for cows fed H compared to cows fed L. Animals fed DL-L sequence of treatments tended to have the lowest energy intake during the first 10 wk of lactation. Prepartum treatments did not affect ruminal fermentation characteristics postpartum. Cows fed H had lower ruminal pH and higher propionate concentrations than cows fed L. No prepartum×postpartum interactions were observed for ruminal fermentation parameters. The effects of DH on prepartum DMI did not carry over to the postpartum period or influence early postpartum production. Increasing concentrate content of the diet immediately postpartum instead of delaying the increase until d 21 postpartum is associated with a higher rate of increase in milk production and higher DMI.

Effects of increasing dietary lysine in transition diets on nursery pig growth performance (2003)

A total of 1,400 weanling pigs (initially 13.6 lb) was used in a 9 d growth assay (d 4 to 13 postweaning) to determine the effects of increasing lysine in the transition diet on nursery pig growth performance. All pigs were fed a common SEW diet until d 4 after weaning. Pigs were then switched to experimental diets with total dietary lysine levels of 1.40, 1.50, 1.60, 1.70 or 1.80%. All diets were formulated to contain 20% soybean meal, with increasing amounts of synthetic amino acids to achieve desired amino acid concentrations in the diets. From d 4 to 9 postweaning, increasing lysine increased ADG (linear, P<0.03) and improved feed efficiency (linear, P<0.001), but ADFI was not affected. Overall (d 4 to 13 postweaning), pigs fed diets containing increasing dietary lysine had improved ADG (linear, P<0.03) and feed efficiency (linear, P<0.001), with no differences in ADFI. Although responses to increasing dietary lysine were linear, there was little improvement either ADG or F/G above 1.7% lysine. There was no difference in average pig weight at the end of the trial, probably because of the short duration of the study. In conclusion, increasing dietary lysine up to 1.7% in transition diets (13 to 19 lb) for nursery pigs maximized growth performance.; Swine Day, 2003, Kansas State University, Manhattan, KS, 2003

Effects of increasing dietary lysine in phase ii diets (15- to 25-lb) on nursery pig growth performance (2003)

A total of 1,260 weanling pigs (initially 18.6 lb) was used in a 19 d growth assay (d 10 to 29 after weaning) to determine the effects of increasing lysine in Phase II diets on nursery pig growth performance. All pigs were weaned and fed 1.2 lb per pig of a SEW diet, then switched to a transition diet until day 10 after weaning. Pigs were then weighed and switched to experimental diets containing true digestible lysine levels of 1.22, 1.32, 1.42, 1.52, and 1.62%, corresponding to approximately 1.36, 1.47, 1.56, 1.65, and 1.75% total lysine. All diets were formulated to contain 30% soybean meal, with increasing amounts of synthetic amino acids to achieve desired amino acid concentrations in the diets. From d 10 to 17 after weaning, increasing lysine increased ADG (quadratic, P<0.04) and improved feed efficiency (quadratic, P<0.01), with both appearing to be maximized at 1.52% true ileal digestible lysine. From d 17 to 24 and 24 to 29, ADFI and F/G improved (linear, P<0.05) with increasing true ileal digestible lysine. For the overall study, (d 10 to 29 after weaning), increasing true ileal digestible lysine increased ADG (quadratic, P<0.07) and improved feed efficiency (quadratic, P<0.001). In conclusion, 1.52% true ileal digestible lysine maximized both ADG and F/G early in the study, but the lysine requirement appeared to decrease to 1.42% from d 17 to 24. Results of two recent studies conducted at the University of Missouri with similar lysine levels fed to 15- to 25-lb pigs suggest a requirement estimate between 1.32 and 1.42% true ileal digestible lysine, slightly lower than the requirements observed in the present study.; Swine Day, 2003, Kansas State University, Manhattan, KS, 2003

Energy Levels in Transition Diets

Dry matter intake may decrease 10 to 30% during the period three weeks prior to calving. During the last 3 weeks prior to calving it is recommended that the energy density be in the range of 1.5 to 1.6 Meal NE/kg dry matter (DM), crude protein (CP) in the range of 13-14%, nonfiber carbohydrate between 33 and 38% and neutral detergent fiber (NDF) 32-50%. More information is needed regarding the metabolizable protein and energy needs of the fetus, placenta, fetal fluids, uterus and mammary gland during the dry period. Proper formulation of rations for protein, energy density, fiber and nonforage fiber carbohydrates will help to increase intake prior to calving. Management of body condition and cow comfort are also critical to assure an excellent transition program.

Effect of liquid feeding weaned pigs on growth performance to harvest.

Four experiments were undertaken to examine the effect of feeding postweaning diets as dry pelleted feed, fresh liquid feed, acidified liquid feed, and fermented liquid feed on pig performance from weaning (26 d) to harvest. In Exp. 1 (n = 12 replicates) and 2 (n = 10 replicates), the treatments were 1) dry pelleted feed and 2) fresh liquid feed. In Exp. 1, 2 kg of starter diet (16.7 MJ of DE/kg and 1.6% lysine) per pig and 5 kg of transition diet (16.7 MJ of DE/kg and 1.5% lysine) per pig followed by a weaner diet (14.0 MJ of DE/kg and 1.36% lysine) were offered to 27 d after weaning. In Exp. 3 (n = 8 replicates), the treatments were 1) dry pelleted feed, 2) fresh liquid feed, and 3) acidified liquid feed. In Exp. 4 (n = 8 replicates), the treatments were 1) dry pelleted feed, 2) acidified liquid feed, and 3) fermented liquid feed. In Exp. 2, 3, and 4, 3 kg of starter diet (16.1 MJ of DE/kg and 1.74% lysine) per pig and 6 kg of transition diet (15.3 MJ of DE/kg and 1.5% lysine) per pig followed by a weaner diet (14.0 MJ of DE/kg and 1.36% lysine) was offered to 27 d after weaning. All treatments were balanced for boars and gilts and diets were offered for ad libitum consumption. Acidified liquid feed was produced by adding lactic acid to the liquid feed so that its pH was decreased to 4.0. Fermented liquid feed was produced by adding an inoculum of Lactococcus lactis subsp. cremoris 303 (1.3%, vol/wt) to the first mix. In Exp. 1, ADG from weaning to d 27 after weaning was 338 and 286 g/d (SEM = 10; P < 0.01) and DM gain/feed in the same period was 888 and 594 g/kg (SEM = 23.1; P < 0.001) for dry pelleted feed and fresh liquid feed, respectively. In Exp. 2, ADG was 391 and 352 g/d (SEM = 6.4; P < 0.01) and DM gain/feed was 856 and 642 g/kg (SEM = 9.9; P < 0.001) for dry pelleted feed and fresh liquid feed, respectively, during the period from weaning to d 27 after weaning. In Exp. 3, ADG was 408, 416, and 433 g/d (SEM = 12.7; P > 0.05) and DM gain/feed was 865, 755, and 789 g/ kg (SEM = 14.5; P < 0.001) for dry pelleted feed, fresh liquid feed, and acidified liquid feed, respectively. In Exp. 4, ADG was 361, 389, and 347 g/d (SEM = 13.2; P = 0.11) and DM gain/feed was 888, 749, and 733 g/ kg (SEM = 15.8; P < 0.001) for dry pelleted feed, acidified liquid feed, and fermented liquid feed, respectively, during the period from weaning to d 27 after weaning. It is concluded that although feeding acidified liquid feed may have some merit in the first 27 d after weaning, this benefit is lost in the subsequent period. No benefit arose from feeding fresh liquid feed or fermented liquid feed. Growth performance from d 28 after weaning to harvest was not improved by any liquid feed treatment.

Effects of anionic salts in a pre-partum dairy ration on calcium metabolism.

The effects of anionic salts in the transition diet on serum and urine calcium at calving and on peripartal health, subsequent milk production and fertility performance were studied in a well-managed, high-producing Friesland dairy herd. Over a period of a year, approximately 21 days before the expected date of calving, 28 pre-partum heifers and 44 multiparous dry cows were randomly allocated within parity to 1 of 2 transition diets, designated control and experimental anionic diets. The anionic diet contained the same quantities of the basic transition ration fed to the control group as well as a standard anionic salt mixture containing 118 g NH4Cl, 36 g (NH4)2SO4 and 68 g MgSO4 (total 222 g) per animal per day. This reduced the DCAD to -11.68 mEq/100 g dietary dry matter compared to +13.57 for the control diet. Blood and urine were randomly sampled from 7 to 8 animals within each category within 3 hours post-partum. Serum calcium (total and ionised) and creatinine, urine calcium and creatinine and the fractional clearance of calcium were assessed. Relevant clinical, milk production, and fertility data were collected. The total serum calcium (2.07 versus 1.60 mmol/l), serum ionised calcium (1.12 vs 1.02 mmol/l), urine calcium (0.92 vs 0.10 mmol/l) and the fractional clearance of calcium (1.88 vs 0.09%) were significantly higher(P <0.01) at calving for multiparous cows fed the anionic diet compared to those fed the control diet. In the primiparous cows there were no significant differences in serum calcium levels. However, the urine calcium (1.07 vs 0.43 mmol/l) and the fractional clearance of calcium was higher (1.75 vs 0.45%) in cows fed the anionic diet (P <0.05 and 0.01 respectively). These results illustrated that there were benefits, although no differences were demonstrated with respect to health, milk production or fertility. The supplementation of diets with anionic salts in the last 2-3 weeks before calving has the potential to significantly improve parturient calcium homeostasis.

The Establishment of a “Transition Diet”

The Establishment of a “Transition Diet”

Meat enhances nonheme iron absorption in pigs

Human subjects absorb heme iron (Fe) more efficiently than nonheme Fe under most conditions. Meat enhances nonheme Fe absorption from most diets. It is not known whether these effects also occur in the pig, a promising model for human Fe absorption studies. The objective of this study was to compare Fe bioavailability from diets containing nonheme Fe (NHI), nonheme Fe with meat (NHI/M) and heme Fe (HI) in the weanling pig. Iron bioavailability was measured by hemoglobin (Hb) repletion assay. Diets were formulated to contain 150 mg Fe/kg diet. Nonheme Fe was supplied as ferric citrate and heme Fe as dried animal red blood cells. Pigs were made anemic by reducing the standard Fe injection at birth to 30 mg and feeding a low Fe transition diet post-weaning until age 41 days. At 41 days of age, pigs were assigned to 3 groups of 8 animals such that mean Hb concentration and body weight of each group were nearly equal. Groups were randomly assigned to 1 of 3 repletion diets. After 7 days feeding, Hb repletion efficiency (HRE) was 21.8% in pigs fed the NHI/M diet compared to 11.2% and 9.1% in pigs fed the NHI or HI diets, respectively. The results presented here demonstrate that, in Fe-deficient weanling pigs, meat increases nonheme Fe bioavailability from corn-based diets while heme Fe, supplied by dried animal red blood cells, is no more bioavailable than Fe from ferric citrate. The results of this study provide further evidence of the validity of the pig model for studying food Fe bioavailability.

Effects of high-grain or high-roughage transition diets on finishing performance of cattle previously fed high-concentrate growing diets (2000)

Three hundred twenty-eight crossbred beef steers previously fed high-concentrate growing diets had ad libitum access to one of two transition diets prior to initiation of the finishing phase. Transition diets consisted of 58% steam-flaked corn and 30% alfalfa hay or of 23% steamflaked corn and 65% alfalfa hay (DM basis). Average daily gains, dry matter intakes, and feed efficiencies during the transition phase were greater for steers fed the high-grain diet than for steers fed the high-roughage diet (P .20).

Evaluation of spray-dried animal plasma and select menhaden fish meal in transition diets of pigs weaned at 12 to 14 days of age and reared in different production systems.

We conducted two experiments with pigs weaned at 12 to 14 d of age to evaluate the effects of adding spray-dried animal plasma (SDAP) and select menhaden fish meal (SMFM) to the diets fed from 5 to 19 (Exp. 1) and 7 to 21 d (Exp. 2) after weaning. This 14-d period represents the transition from the nutrient-dense diet fed to all pigs after weaning to the simpler corn-soybean meal-based diet fed to all pigs for an additional 14 (Exp. 1) or 7 d (Exp. 2) after the experimental period. Pigs averaged 5 kg at the start of the experimental period. In Exp. 1, pigs had a high health status and were weaned to an off-site nursery (SEW) and fed 12 experimental diets in a 3 (0, 2.5, or 5% SDAP) x 4 (0, 2.5, 5, or 7.5% SMFM) factorial arrangement. Diets were formulated to contain 1.6% lysine and contained 20% dried whey, 5% soybean oil, and 2.5% spray-dried blood meal. The SDAP and(or) SMFM replaced corn and soybean meal on an equal lysine basis. Average daily gain and ADFI were not affected by treatment during any period of the experiment. Gain:feed was improved by the addition of SDAP (linear, P < .05) and SMFM (linear, P < .07) during the period from 5 to 19 d. Over the 33-d experiment, SDAP and SMFM improved (linear, P < .05) gain:feed. In Exp. 2, pigs were weaned on-site to an all-in/all-out by room nursery and fed diets identical to those fed in Exp. 1, with 0 or 2.5% SDAP and 0, 2.5, or 5% SMFM in a 2 x 3 factorial arrangement. The addition of 2.5% SDAP improved ADG and gain:feed during the period from 7 to 14 d (P < .05) and 0 to 28 d (P < .10), but not over the period from 7 to 21 d. The addition of SMFM did not affect ADG during any period, but it resulted in a quadratic improvement in gain:feed during the periods from 7 to 14 (P < .05) and 7 to 21 (P < .10) d. These results suggest that high-health SEW pigs respond less to SDAP and SMFM in the transition diet than pigs with a lower health status reared in an on-site nursery. The data further suggest that formulation of transition diets should consider the type of production system if pig performance and diet cost are to be optimized.

Practical approaches to feeding the high producing cow

The feeding period 30 days prepartum to 30 days postpartum is critical for optimum milk yield, health, and reproduction. Two dry cow rations (traditional and transitional) can minimize metabolic disorders, adjust body condition scores, and shift the rumen physiology. Feeding strategies in the transitional diet include higher levels of undegraded protein, added trace minerals and vitamins, anionic salts, yeast culture, niacin, and propylene glycol. Dry matter intake can be 10–18% below target levels achieved later in lactation. Weight loss must be managed to avoid ketosis, maintain fertility, and minimize fatty liver syndrome. Recommended feeding groups would include traditional dry cow group, transition dry cow group, fresh cow group, early lactation group, and first lactation group.

Combinations of select menhaden fish meal and spray-dried plasma protein in the transition diet (11 to 15 lb) for the early-weaned pig (1995)

Combinations of select menhaden fish meal and spray-dried plasma protein in the transition diet (11 to 15 lb) for the early-weaned pig (1995)

Impact of changes in organic nutrient metabolism on feeding the transition dairy cow.

Pregnancy, decreased feed intake during late gestation, lactogenesis, and parturition have dramatic effects on metabolism in dairy cows during the transition period from 3 wk before calving to 3 wk after calving. Increases in plasma NEFA occur during the 10 d before calving and may precede the decrease in feed intake. Plasma NEFA concentrations are highest at calving and decrease rapidly after calving. Plasma glucose concentration decreases during the transition period except for a transient increase associated with calving. Hepatic glycogen is reduced and lipid is increased during the transition period. Feed intake is usually decreased 30 to 35% during the final 3 wk prepartum, but negative energy and protein balances are not as severe as during the week following parturition. Prepartum feed intake is positively correlated to postpartum feed intake; therefore, efforts to maximize feed intake should begin before calving. Overconditioned cows may be more susceptible to a prepartum decrease in feed intake. Increasing nutrient density of the diet during the transition period may enhance feed intake. Feeding more fermentable carbohydrate during the prepartum transition period may acclimate the microbial population to lactation diets, promote development of ruminal papillae, increase absorptive capacity of the rumen epithelium, and reduce lipolysis by delivering more glucogenic precursor to the liver and enhancing blood insulin. Supplementing fat to transition diets does not seem to alleviate health problems associated with negative energy balance. Enhancing amino acid absorption by the prepartum cow may improve lactation performance and health, although mechanisms of action have not been identified.

Dietary lysine requirements of segregated early-weaned pigs (1994)

A total of 320 (160 barrows and 160 gilts) 14- to 18-d-old pigs (initially 10.2 ± 2.2 lb) was used to determine the optimal level of dietary lysine needed for the segregated early-weaned pig. Two diet formulation methods were used with six dietary lysine levels within each formulation method, resulting in a 2 X 6 factorial arrangement of treatments. The first formulation method consisted of a basal diet that contained 1.95% lysine. Increasing levels of cornstarch replaced L-lysine to achieve the other five dietary treatments (1.2, 1.35, 1.50, 1.65, and 1.80% dietary lysine). All other amino acids in each diet were maintained at the same level as in the 1.95% lysine treatment. The second formulation method consisted of a basal diet (1.2% lysine) with the live additional treatments achieved by adding synthetic lysine and other essential amino acids to maintain an ideal amino acid ratio, relative to lysine. All diets contained 20% dried whey, 10% lactose, 7.5% spray-dried porcine plasma, 5.0% spray-dried wheat gluten, 5.0% select menhaden fish meal, 5.0% soybean oil, and 1.75% spray-dried blood meal. No lysine x formulation method interactions occurred for average daily gain (ADG) or average daily feed intake (ADFI) throughout the 28 d period. However, lysine x formulation method interactions were observed for feed efficiency (F/G) from d 0 to 7, d 0 to 14, and d 0 to 28. From d 0 to 7 postweaning, ADG was improved quadratically as dietary lysine increased and appeared to be maximized at 1.65% dietary lysine. Feed efficiency was lowest for pigs fed 1.80% lysine for the first diet formulation method and for pigs fed 1.95% lysine for the second diet formulation method. From d 0 to 14 postweaning, ADG and F/G were improved by increasing dietary lysine, with both response criteria maximized in pigs fed approximately 1.65% dietary lysine. However, ADFI was not affected during the 28-d experiment. These data suggest that segregated early-weaned pigs require approximately 5.2 and 6.2 g/d of lysine from d 0 to 7 and d 0 to 14 postweaning, respectively, to optimize growth performance. Based on these results, the diet for pigs < 11 lb needs to be formulated to contain at least 1.7% lysine. The transition diet (11 to 15 lb) should be formulated to contain approximately 1.5 to 1.6% lysine.; Swine Day, Manhattan, KS, November 17, 1994

Optimal dietary sequence in a nursery-phase feeding program for segregated early-weaned (9±1 d of age) pigs (1993)

Two hundred forty weanling pigs (initially 7.2 lb BW and 9 + 1 d of age) were used to compare four dietary sequences of three diets in a 21-d growth trial. Diet A was formulated to contain 1.7% lysine and contained 7.5% spray-dried porcine plasma and 1.75% spray-dried blood meal. Diet B was formulated to contain 1.4% lysine and contained 2.5% spray-dried porcine plasma and 2.5% spray-dried blood meal. Diet C was formulated to contain 1.25 % lysine and contained 2.5% spray-dried blood meal. The four dietary sequences were as follows AAB, AAC, ABB, and ABC, with each letter indicating the diet fed from d 0 to 7, d 7 to 14, and d 14 to 21 postweaning, respectively. Pigs fed diet B from d 7 to 14 postweaning had numerically lower average daily gain (ADG) than pigs remaining on diet A. However, pigs fed diet B from d 14 to 21 postweaning had higher ADG compared to pigs fed diet C. Pigs fed dietary sequences AAB or ABB were 11% heavier on d 21 postweaning than pigs fed dietary sequences AAC or ABC. In conclusion, dietary sequences AAB and ABB provided identical performance from d 0 to 21 postweaning; however, utilization of a transition diet (B) from d 7 to 14 postweaning substantially reduced feed cost per lb of gain for pigs weaned at 9 d of age.; Swine Day, Manhattan, KS, November 18,1993

Techniques for hand‐rearing tree‐shrews (Tupaia belangeri) from birth

AbstractIn captivity, Tupaia belangeri (Thailand tree‐shrew) frequently show aberrant patterns of maternal care which result in the death of offspring. In order to maximize the potential of the tree‐shrew as an animal resource for experimental studies we have developed a program for hand‐rearing tupaiidae from birth. Newborn tree‐shrews were removed from mothers with a history of poor parental care to a nursery maintained under conditions of controlled relative humidity (70 ± 10%) and temperature (25 ± 1°C) on a 12 h dark: 12 h light cycle. The young tree‐shrews were fed on a liquid formula until the eyes opened (Day 18–23) and for the subsequent 10 days on a transitional diet until they could feed themselves on solid food. Our hand‐rearing protocol appears to conform to the natural weaning pattern of tupaiids. Food consumption during the liquid diet phase was linearly related to age and the increase in body weight in both sexes. The initial growth rate of male and female hand‐reared tree‐shrews was slower than that of maternally reared animals during the liquid diet phase. The growth rate accelerated subsequently and the body weight of hand‐reared tree‐shrews eventually reached that of maternally reared animals of the same sex. Various developmental changes occurred during the same period in artificially and naturally reared animals. In both hand‐reared and maternally reared groups, the growth rate of male tree‐shrews exceeded that of females from about Day 40 onward. The accelerated growth rate of male tree‐shrews was in apparent association with an increase in androgen secretion at the onset of puberty. The high fecundity of tree‐shrews in captivity reinforced with a program for hand‐rearing the young make T belangeri a potential alternative to more conventional laboratory species in specific areas of biomedical research.