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The effects of 1-h soaking of a pig diet based on wheat and barley with low (4.1 g P per kg) and high (6.8 g P per kg) total phosphorus (P) content on total tract apparent digestibility and performance in growing-finishing pigs were studied in a balance and a performance trial respectively. Phosphorus bound to inositol penta- and hexaphosphate (IP5-IP6 ) was reduced by proportionately 0.1 in the soaked food. Soaking numerically increased the apparent digestibility of P. The digestibility of P did not differ between the dry high P and the soaked low P. Excretion of P in urine was correlated (R² = 0.84) with the intake of digestible P. The average daily weight gain, final body weight and carcass weight were lower (P < 0.001), and the energy conversion ratio was higher (P < 0.001) in the dry low P treatment than in the other treatments. Pigs on the low P diets had lower levels of inorganic P in serum (P < 0.01) and slightly higher serum Ca values (P < 0.05) and there were no effects of soaking. The density of femur was lower (P < 0.01) in both the low P treatments than in the high P treatments, and soaking of the low P diet improved (P < 0.01) femur density. In conclusion, a 1-h soaking of pig food in water appears to be sufficient to improve P availability and growth performance. [ABSTRACT FROM AUTHOR]

Digestibility and nitrogen (N) balance studies were carried out on the leaves of short-term (ST ) and long-term (LT ) varieties of cassava, preserved by sun-drying and grinding into a meal or by ensiling. The cassava leaf meal and ensiled leaves (471 and 373 g/kg total diet dry matter, respectively ) were mixed with palm syrup and palm oil, to give the experimental diets CLM and CLS, respectively. Four Mong Cai (MC) (17·2 (s.e. 2·61) kg) and four Landrace × Yorkshire ( L×Y ) (41·5 (s.e. 2·12) kg) male castrate pigs were used. The experiment was designed as a 2 × 2 × 2 factorial, with breed, cassava variety and processing method as factors. The hydrogen cyanide (HCN) levels of the fresh cassava leaves of ST (545 mg/kg dry matter (DM)) and LT (408 mg/kg DM) varieties were reduced by proportionately 0·63 and 0·33, respectively, after sun-drying and by 0·78 and 0·77, respectively, after ensiling. Intake was higher for DM, crude protein (CP) and organic matter (OM) ( P <0·001) and neutral- and aciddetergent fibre (NDF and ADF) and crude fibre (CF) (P detergent <0·01) in CLM than in CLS. There was a breed by processing method interaction for CF intake (P <0·05). The coefficient of total tract apparent digestibility (CTTAD) was higher in CLS than in CLM for DM, CP, OM and CF (P <0·001) and NDF and ADF (P <0·01). The MC pigs digested ADF (P <0·01) and CF (P<0·001) more effectively than L×Y pigs but there was no difference (P >0·05) in the digestibility of other nutrients or DM. There was a breed by cassava variety interaction for ADF digestibility and breed by processing method for CF digestibility (P <0·01). Daily N intake and faecal N were higher (P <0·001) in CLM than in CLS. Urinary N was lower in CLS than in CLM ( P <0·05) and in L×Y than in MC pigs ( P <0·001). N utilization (N retained per unit intake) was higher for CLS than CLM ( P <0·001) and in L×Y than in MC pigs ( P <0·001). It is concluded that ensiling is a more effective method than sun-drying for reducing HCN in cassava leaves after 60 days re-growth, and also results in higher digestibility of DM and dietary components than sun-drying. However, the bulkiness of the silage limits intake. The MC pigs digested dietary fibre more efficiently than the L×Y pigs, whereas the L×Y pigs utilized N more efficiently than the MC pigs. [ABSTRACT FROM AUTHOR]

The net absorption of amino acids (AA) in young pigs fed a barley-based control diet (C) and diets where barley was replaced by 200 g/kg fresh weight of dried lucerne (Medicago sativa; L20), white clover (Trifolium repens; W20) or perennial ryegrass (Lolium perenne; PR20) meal was studied. Castrated male pigs were fitted with permanent catheters in the hepatic portal vein and mesenteric artery, and the hepatic portal net absorption of AA was estimated from the porto–arterial plasma concentration differences and the hepatic portal-vein blood flow. In general, the essential AA (EAA) concentrations in the hepatic portal vein reached peak levels 90 min after feeding and thereafter exhibited a transient decline. Maximum porto–arterial differences were reached between 1 and 3 h postprandially for most of the AA. The cumulative net absorption of non-essential AA (NEAA) and EAA did not differ significantly between the barley-based diet and diets W20 and PR20. Due to a lower intake of AA on diet L20, the cumulative net absorption of NEAA and EAA was significantly (P<0·05) lower than diet C. With the exceptions of the EAA arginine, cystine and valine, and the NEAA glutamic acid + glutamine and glycine, there were no significant differences in the absorption coefficients for the EAA and NEAA between the diets. In addition, the pattern of the total EAA in the mixture absorbed postprandially did not differ significantly between the diets. The present study gives support to the contention that the replacement of barley AA with forage meal AA in a barley-based diet for growing pigs should be expected to result in minor differences in the net portal flux of AA. [ABSTRACT FROM PUBLISHER]

Two experiments were performed with post-valve T-cannulated growing pigs, using five animals in each experiment in a change-over design to evaluate the effect of inclusion of four different dried forage meals on ileal crude protein (CP) and amino acid (AA) digestibilities. The control diets (C1 and C2) were barley-based and the experimental diets were formulated by replacing the barley with 100 or 200 g/kg of either lucerne (Medicago sativa) or white clover (Trifolium repens) meal in Expt 1 and red clover (Trifolium pratense) or perennial ryegrass (Lolium perenne) meal in Expt 2. A decrease (P < 0·05) in the apparent ileal digestibility of CP and most of the essential and nonessential AA was found with the inclusion of lucerne, white clover and perennial ryegrass meal in the barley-based diets. When red clover meal was included, only the apparent ileal digestibilities of CP, leucine, phenylalanine, tyrosine and glutamic acid were found to decrease (P < 0·05). The estimated apparent ileal digestibilities of most essential AA in the forage meals were lower than in the barley-based diets. The ileal flow of glucosamine and ornithine was found to increase (P < 0·05) with increasing proportion of fibre in the diet, suggesting an increase in endogenous N secretions and small-intestinal microbial activity. With the minor changes found for ileal essential AA digestibilities with forage meal inclusion in the diet the present data confirm the potential of forage meals as a source of protein in pig diets. [ABSTRACT FROM PUBLISHER]

Ileal digestibility of amino acids in barley-based diets with increasing inclusion of lucerne leaf meal (LLM; 0, 50, 100 and 200 g/kg) was studied in a change-over experiment with post-valve T-caecum cannulated growing pigs. The apparent Heal digestibility of crude protein, as well as of most of the essential (EAA) and non-essential amino acids (NEAA) was not significantly affected by the dietary inclusion of LLM. The exceptions were cystine, methionine, phenylalanine, glutamic acid and serine, all of which showed a significant (P < 0·05) reduction in apparent Heal digestibility with increasing inclusion of LLM. In contrast, the calculated true Heal digestibility of all EAA (with the exception of arginine and lysine) and the NEAA glutamic acid and serine were significantly (P < 0·05) reduced with the inclusion of LLM. Associated with an increased crude protein intake, there was a significant (P < 0·05) increase in the amount of absorbed EAA when the proportion of LLM was increased in the diet. With increasing proportion of fibre in the diet, there was a significant (P < 0·05) increase in the Heal flow of glucosamine.It can be concluded from the present data that the inclusion of LLM in a barley-based diet for growing pigs will result in an improvement in the absorbed amino-acid profile due to a significant increase in the absorption of all of the EAA. [ABSTRACT FROM PUBLISHER]

Growing pigs fitted with simple t-shaped cannulas posterior to the ileal-caecal valve were used in a change-over design experiment (5 × 5) to determine the Heal and total tract apparent digestibility and hindgut disappearance of dietary components and energy in a barley-based diet with increasing inclusion of either red-clover or perennial ryegrass meal (proportionately 0·10 and 0·20). The total tract and Heal apparent digestibilities of organic matter (OM), crude protein (CP), nitrogen-free extractives (NFE) and energy were significantly reduced with increasing inclusion of red-clover and perennial ryegrass meal in the diet (P < 0·05). For all fibrous components (total fibre (TF), neutral-detergent fibre (NDF), acid-detergent fibre (ADF) and crude fibre (CF)), the ileal apparent digestibility was unaffected by level offibre inclusion in the diet. Also the total tract apparent digestibility of TF, NDF and CF were unaffected by red-clover meal inclusion, while in contrast the total tract apparent digestibility of TF, NDF and CF were significantly reduced with perennial ryegrass meal inclusion (P < 0·05). The hindgut disappearance of crude fat, NDF, ADF and CF was not affected by forage meal inclusion, whereas the hindgut disappearance of OM, NFE, TF and energy were significantly lower in the perennial ryegrass meal diets than in both the control diet and the red-clover meal diets (P < 0·05).The total tract apparent digestibility of OM was higher for the control diet compared with the red-clover and perennial ryegrass meal diets. There was also a significantly higher apparent digestibility of OM in the total tract for red-clover meal compared with perennial ryegrass meal (P < 0·05). The Heal apparent digestibility of energy in a barley-based diet with forage meal inclusion decreased proportionately by about 0·014, 0·023 and 0·030 units per unit increase ofTF, NDF and CF in dry matter, respectively. Correspondingly, for the total tract energy apparent digestibility, there was a decrease proportionately by about 0·010, 0·016 and 0·022 units per unit increase of TF, NDF and CF in dry matter, respectively. Digestible energy content was significantly reduced, as measured at the ileum or over the total tract, with increasing inclusion offorage meal (P < 0·05). [ABSTRACT FROM PUBLISHER]

The present study was undertaken to determine the Heal and total tract apparent digestibility and hindgut disappearance of dietary components and energy in a barley-based diet which included either lucerne or white-clover meal (proportionately 0·10 and 0·20). The experiment was conducted as a 5 × 5 change-over design with growing pigs fitted with simple t-shaped cannulas posterior to the ileo-caecal valve. The Heal and total tract apparent digestibilities of organic matter (OM), crude protein, crude fat, nitrogen-free extractives and energy were significantly reduced ivith increasing inclusion of lucerne and white-clover meal in the diet (P < 0·05). The total tract apparent digestibility of total fibre (TF) was significantly reduced with lucerne meal inclusion (P < 0·05), while the Heal apparent digestibility of TF was unaffected by lucerne and white-clover meal inclusion. Hindgut apparent digestibility (proportion of total tract apparent digestibility) of OM and energy was approximately 0·10, 0·70 and 0·70 for barley, lucerne and white-clover meal, respectively.Both the Heal and total tract apparent digestibility of OM and energy were significantly higher for the control diet compared with lucerne and white-clover meal (P < 0·05). There was also a significantly higher apparent digestibility of OM, TF, crude fibre and energy in the total tract for white-clover meal compared with lucerne meal (P < 0·05). For neutral- and acid-detergent fibre a similar pattern was observed, however the effect was not significant.The dietary digestible energy content was significantly reduced (F < 0·05), both at the ileum and over the total tract, with increasing inclusion offorage meal. [ABSTRACT FROM PUBLISHER]