Zusammenfassung Die Post Valve T‐Caecum Kanulierungstechnik beim Schwein zur Bestimmung der Verdaulichkeit von Aminosäuren Es wird die Post Valve T‐Caecum (PVTC) Technik als Kanülierungstechnik zur Bestimmung der ilealen Verdaulichkeit beschrieben. Ein Verdaulichkeitsversuch mit PVTC‐fistulierten Schweinen wurde durchgeführt, um diese Technik anzuwenden. Die PVTC Kanüle ist direkt gegenüber der Ileocaecalklappe plaziert. Da die Kanüle in das Colon gesetzt wird, ist der Einfluß auf die Motilität des Ileums minimiert. PVTC fistulierte Schweine können über einen längeren Zeitraum genutzt werden, ohne daß Anzeichen von Unbehagen auftreten. Die Chymussammlung mit PVTC fistulierten Schweinen ist annähernd quantitativ, dennoch ist ein Marker notwendig. Es wurde ein Verdaulichkeitsexperiment mit drei in ihren Rohfasergehalten unterschiedlichen Futtermitteln durchgeführt: Mais 1,8%, Erdnußextraktionsschrot 12,7%, Sonnenblumenextraktionsschrot 23,6%. Die Ergebnisse der ilealen Verdaulichkeit, des Rohproteins und der nicht essentiellen Aminosäuren dieser drei Futtermittel wurden mit Daten der Literatur verglichen. Bei Erdnußextraktionsschrot variierten die Verdaulichkeiten zwischen den Versuchen. Bei Mais war die Anzahl der Beobachtungen begrenzt. Die in diesem Experiment und den aufgeführten Untersuchungen dargestellten Ergebnisse für die Verdaulichkeit des Rohproteins und der nicht essentiellen Aminosäuren in Sonnenblumenextraktionsschrot bestand eine gute Übereinstimmung.

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Two experiments were conducted to determine apparent ileal DM and crude-protein (CP) digestibilities in rations fed to pigs. An evaluation was made of Cr,O, and HC1-insoluble ash as digestive markers. In addition, the effects of body weight (BW) on apparent ileal DM and C P (N x 625) digestibilities were studied. In Expt 1, thirteen barrows averaging 35 kg BW were fitted with post-valve T-caecum (PVTC) cannulas to determine the apparent ileal DM and C P digestibilities of a wheat glutepbran ration (B2) and a soyabean-meal ration (El). Immediately after morning feeding ileal digesta samples were collected on an hourly basis for a total of 12 h. Subsequently, N and marker contents were determined in the samples. The postprandial patterns of N and Cr passage were more similar than those of N and HClinsoluble ash. Therefore Cr,O, is more suitable as a marker than HC1-insoluble ash. The apparent ileal C P digestibility coefficient of ration B2 derived using Cr,O, as a marker was significantly (P < 0.05) higher by 0.018 compared with the value obtained using HCI-insoluble ash. The corresponding values for ration E2 obtained using Cr,O, and HC1-insoluble ash were both 0.825. In Expt 2, apparent ileal DM and C P digestibilities were determined in eighteen rations using twelve barrows also fitted with PVTC cannulas (BW from 40 to 100 kg). The protein sources for these rations were from different groups of feedstuffs. In four and three of the rations apparent ileal DM and C P digestibilities respectively were significantly different (P < 0.05) when assessed using the two markers. The digestibility coefficients were not systematically higher or lower for either marker. Absolute differences were < 0.049 on average. Significant effects of live weight on apparent ileal CP digestibilities were found.

A review of experiments on the effect of energy and protein intake on fertility in gilts suggested that a high energy intake shortly before oestrus (flushing) increased ovulation rate. Although high energy intake gave more ovulations than low energy intake, embryonic mortality was greater. The most suitable sequence during rearing, flushing and early pregnancy seemed to be low, high and low energy, respectively. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Twelve crossbred sows were used in an energy balance study to estimate energetic efficiency of milk production from feed. Balances were made from 7 to 14 d and from 18 to 25 d of lactation. Two feeding levels were applied (high and low). The low level (L) was meant to supply energy slightly above maintenance, with energy needed for milk to be derived from body reserves. The high level (H) was meant to supply sufficient energy for maintenance and for milk production. The low-level animals received 2.5 to 2.6 kg of feed/d and the high level animals 4.8 to 6 kg/d. The loss of weight of sows during lactation depended more on feeding level than on stage of lactation. A high level of feeding to sows resulted in heavier piglets compared with the low feeding level (significant after 10 d). At 24 d of age piglets with the high-feeding-level sows weighed 7.5 kg and those with the low-level sows, 5.7 kg. At the high level, animals excreted 1,200 to 2,800 kcal more milk energy per day than the low-level animals. Energy for milk from feed was produced with an efficiency of 67 to 69% with a maintenance requirement of 112 to 125 kcal metabolizable energy (ME) X W-.75 X d-1. Efficiency of milk production from feed was calculated as 62% and the maintenance requirement was 68 kcal. In this calculation, milk was corrected toward zero energy balance. Another way of calculating this efficiency after correcting feed toward zero energy balance resulted in estimates of 68% for efficiency and of 88 kcal ME X W-.75 X d-1 for maintenance requirement. From these data it was derived that, for each piglet, the sow needed to receive .5 to .6 kg of extra feed (ME content 3,000 kcal/kg) per day to cover milk production. Level of metabolic rate for nursing piglets was estimated as 97 kcal ME X W-.75 X d-1 for maintenance and, in addition, .195 kcal/kcal extra of milk intake above maintenance.