Tsunenori Iriki

Effects of nipple or bucket feeding of milk-substitute on rumen by-pass and on rate of passage in calves.

I . Effects of feeding liquid milk-substitute to young calves either by nipple-pail or open-bucket o n the rumen by-pass and on the rate of passage were studied. z. Sixteen Holstein calves, aged I week initially, were used in three experiments in which calves were slaughtered after they were given liquids (milk-substituteand water) containingchromic oxide and SrCI, .6H,O as a tracer either by the nippleor bucket-feeding method, and the distribution of tracers to the rumen, abomasum and the lower alimentary tracts was examined. 3. When the liquid milk-substitute containing tracers was given by the nippleor bucket-feeding method to calves having been trained to the corresponding procedures for the preceding I week, most of the tracers was directed into the omasum and abomasum. There seemed no difference in the functioning of oesophageal groove closure between the two feeding procedures. Even when the liquid milk-substitute containing tracers was given by the nipple-or bucket-feeding method to calves which had been accustomed to different procedures for the preceding week, the majority of tracers were found in the abomasum immediately after administration, though a slightly greater proportion of the tracers entered the reticulo-rumen. 4. Continuing bucket feeding of liquid milk-substitute effected an efficient closure of the oesophageal groove at least up to 16 weeks of age. After calves were accustomed to consume liquid milk-substitute from the bucket from I to 4 weeks of age, drinking warm water from the bucket also caused efficient closure at least up to 16 weeks of age. 5 . When tracers were administered with warm water, Cr,O, and strontium, especially the latter, transferred much more rapidly to the lower gut than when they were administered with liquid milk-substitute, probably reflecting the curd formation of the milk-substitute in the abomasum. When liquid milk-substitute with tracers was fed by the bucket-feeding method, Sr transferred more rapidly to the lower gut than when the milk-substitute was fed by the nipple-feeding method, indicating that the feeding procedure of liquid milk-substitute has an apparent effect on the rate of passage.

Serum osteocalcin in dairy cows: Age-related changes and periparturient variation

We evaluated age-related changes in serum osteocalcin concentrations in non-periparturient cows and variations in serum osteocalcin concentration in periparturient primiparous and multiparous cows. The serum osteocalcin levels were evaluated in 144 non-periparturient Holstein dairy cows aged 11 days to 10 years; these levels were the highest in the youngest cows, appeared to steadily decrease with age until the time of the first calving, and were subsequently maintained at low levels. Between 14 days before calving and 21 days after calving, the serum osteocalcin levels were significantly higher in the primiparous cows than in the multiparous cows. A comparison between age-matched non-periparturient and periparturient cows showed that serum osteocalcin levels were significantly lowered during late gestation in both primiparous and multiparous cows. These results suggest that serum osteocalcin measurement might be useful for the detection of mineral imbalances at the time of parturition in cows.

Mechanism whereby holotrich ciliates are retained in the reticulo-rumen of cattle

The concentrations of holotrichs, reducing sugars and fermentation end-products, and the fluid dilution rates, in the cranial (CR), ventral (V) and caudal (CA) regions of the reticulo-rumen of cows were compared. Additionally, holotrich numbers in fluid and solid digesta samples taken from the dorsal (D) region were determined at different time-intervals. Holotrich numbers expressed per ml fluid at site D were almost twofold those expressed per g solid digesta, and the fluctuation of their numbers in fluid preceded that in solid digesta. Holotrich concentrations at site CR were higher before feeding than after feeding, while those at sites V and CA were lower before feeding than for a few hours after feeding. At sites V and CA, holotrich concentrations fluctuated in good agreement with reducing sugar concentrations, but the increase in the former always preceded that in the latter. The concentration of volatile fatty acids (VFA) tended to decrease from site CA to site CR, while the dilution rate was highest in site CR. The results suggest that migration of holotrichs from the reticulum to the rumen and vice versa are the cause of fluctuation in their numbers, and also the mechanism by which they are retained in the rumen of cattle.

Neonatal diarrhoea in calves given milk-substitutes differing in fat source and fed by different procedures

1. The incidence of diarrhoea, digestibilities of nutrients and the faecal bacterial flora were compared among three groups of Holstein male calves up to 3 weeks of age. Two groups of four calves were given a milk-substitute containing tallow by nipple-pail (group TN) and by open-bucket (group TB). The third group of four calves was nipple-fed a milk-substitute containing soya-bean oil (group SN). Each of the milk-substitutes contained approximately 300 g milk-protein and 100 g fat/kg dry matter (DM)., 2. Mean faecal DM contents (g/kg) were 217, 185 and 112 for groups TN, TB, and SN respectively and the corresponding pH values were 7.21, 7.00 and 6.50. The difference between groups TN and SN was statistically significant (P less than 0.05). 3. No difference was observed between groups TN and SN in the apparent digestibilities of DM, crude protein (CP, nitrogen X 6.25), diethyl ether extract (EE) and total reducing sugars. But in the group TB, the digestibility of EE was significantly lower (P less than 0.05), and that of CP tended to be, though not significantly, lower than in the other two groups. 4. Bacterial flora in faeces showed considerably wide quantitative variations among individual calves, but there was a tendency for increased viable counts of Lactobacilli in faeces of group SN. 5. The present suggested that an appreciable difference in the mechanism would exist between diarrhoea occurring when milk-substitute was offered by bucket and when highly-unsaturated vegetable oils were contained in it. Possible mechanisms were also discussed.

An evaluation of the effect of age and the peri-parturient period on bone metabolism in dairy cows as measured by serum bone-specific alkaline phosphatase activity and urinary deoxypyridinoline concentration.

Various biochemical markers help to evaluate the state of bone turnover in humans and could be used during the peri-parturient period in dairy cows when calcium (Ca) metabolism changes dramatically. To investigate this, the peri-partum characteristics of serum bone-specific alkaline phosphatase (BAP) and urinary deoxypyridinoline (DPD) were investigated. Both serum BAP activity and urinary DPD concentrations were increased and demonstrated wide variability in younger animals, and these findings were consistent with other bone turnover markers. Around the time of parturition, serum Ca concentration and serum BAP activity in multiparous cows were significantly lower than in primiparous cows, but urinary DPD concentration was unchanged. The use of BAP as a bone formation marker appears to be valuable for evaluating bone remodelling status in cows, but the specificity of the test needs to be confirmed. The DPD/BAP ratio around parturition demonstrated a clear difference in bone turnover status between the two parity groups with multiparous cows demonstrating increased signs of bone resorption compared with primiparous cows, corresponding to the Ca requirement for milk production. In future studies, the applicability of the ratio of bone resorption marker to bone formation marker should be evaluated for bone turnover assessment.

Modification of the analysis of parathyroid hormone-related protein in milk and concentrations of this protein in commercial milk and milk products in Japan

Parathyroid hormone-related protein (PTHrP), which causes hypercalcemia associated with malignant tumors, is known to be present in milk. Gene expression of PTHrP in the mammary gland increases markedly during parturition and with the onset of lactation. Even when circulating PTHrP levels are extremely low or below the detection limit, milk PTHrP levels are remarkably high. Parathyroid hormone-related protein derived from the mammary gland is assumed to play a role in maintaining the maternal calcium homeostasis and calcium transport from blood to milk. In previous studies that determined the PTHrP concentrations in milk, the pretreatments and diluent composition were not standardized. Here, we investigated the effect of various pretreatment procedures and diluent constitutions and the consequent PTHrP concentrations in commercial milk and milk products in Japan. Significant differences were found in PTHrP concentrations in raw milk samples subjected to different combinations of pretreatments (mixing, centrifugation, acidification, and heating) and diluents (0pM standard solution of PTHrP, plasma treated with protease inhibitors, and original diluent). We measured the PTHrP concentrations in normal liquid milk, processed milk, milk drinks, formulated milk powders, and skim milk powder by using the appropriate combination of pretreatment (acidification) and diluent (plasma treated with protease inhibitors). The PTHrP concentration in normal liquid milk, processed milk, and skim milk powder was as high as that in raw milk (>5nM), whereas that in milk drinks differed considerably. The PTHrP concentration in infant formulas (<2nM) was lower than that in the other milk products. These results indicate that a certain amount of PTHrP is ingested when milk and milk products are consumed.

Concentrations of ketone body and antidiuretic hormone in cerebrospinal fluid in response to the intra-ruminal administration of butyrate in suckling calves

The aim of the present study was to elucidate the mechanism by which ketone bodies increase antidiuretic hormone (ADH) secretion. Four male Holstein calves (5 weeks of age) were utilized. Four levels of butyrate (0 g, 11 g, 22 g and 44 g) were administrated intra-ruminally in a 4 x 4 Latin square design and cerebrospinal fluid (CSF, six-position lumbar puncture), blood plasma and urine were collected. The concentration of total plasma and CSF protein was 5.5-5.6 g/dL and 27.5-28.3 mg/dL, respectively. CSF concentrations of a specific ketone body, 3-hydroxybutyric acid, were significantly higher in the 22 g and 44 g butyrate groups than in the control group. CSF concentrations of ADH in the 11 g and 44 g butyrate groups were significantly higher than in the control group. Plasma concentration of 3-hydroxybutyric acid was increased by intraruminal administration of butyrate within 15 min in a dose-dependent manner, and it was higher in the 22 g and 44 g butyrate group than in the control group from 15 min to 4 h. With the exception of the 11 g butyrate group, plasma concentrations of ADH also increased in response to butyrate treatment, and it was higher in the 44 g butyrate group than in the 22 g butyrate group from 15 min to 1.5 h. The duration of the elevated plasma concentrations of ADH was shorter than that of the plasma concentration of 3-hydroxybutyric acid. The relationship between the plasma concentrations of ADH and 3-hydroxybutyric acid was statistically significant but the correlation between the two concentrations was not high. Butyrate treatment elevated the plasma concentration of ADH and also resulted in reduced urine volume and increased urine osmolality. Haematocrit (Ht) values, and the osmolality of CSF and plasma were not different among the groups. Our results suggested that the increased ADH secretion observed in suckling calves fed dry feeds was caused by butyrate-derived ketone body that crossed the blood-brain barrier rapidly.

Plasma concentration of anti-diuretic hormone and urine volume in response to intraruminal administration of acetate, propinata and butyrate in suckling calves

Acetate, propionate, and butyrate were intraruminally administered to dry feed-fed suckling calves to evaluate their effects on plasma ketone bodies, anti-diuretic hormone (ADH) concentrations, and urine volume. Four male Holstein calves (5-7 weeks old) were given 1.0 L of warm water or 0.5 mole of one of the acids in 1.0 L of warm water. A 4 x 4 Latin square design was adopted for the experiment. The acetate group showed significantly higher plasma acetate concentrations than the other three groups between 0.25 h and 2.0 h after administration (P < 0.01). Plasma glucose concentrations did not differ markedly among the groups. The butyrate group showed significantly higher plasma ketone body concentrations than the other three groups until the end of the experiment (P < 0.01). Plasma ADH concentrations quickly rose in the butyrate group and remained significantly higher than in the other three groups from 0.25 h to 2.5 h after administration (P < 0.05). In accordance with the elevation of plasma ADH levels, the butyrate group showed decreases in urine volume and increases in urine osmolarity (P < 0.05). Plasma osmolarity and hematocrit values (Ht) were not different among the groups. These results suggest that the administration of acetate and propionate had little effect on ADH secretion.

Identification of Limiting Amino Acids in Calves Receiving Two Levels of a Corn-Soybean Meal Diet above Four Months of Age

早期離乳後も食道溝反射を維持した初体重147kg(16週齢)のホルスタイン種雄子牛8頭を用いて窒素(N)出納試験を実施し,トウモロコシ,大豆粕および稲ワラから成り,現物当たりの粗タンパク質(CP)含量が12.7%の飼料においてメチオニン(Met)またはリジン(Lys)が制限アミノ酸になるか否かを調べた.試験は1区2頭で2週間を1期とする4×4ラテン方格法により行い,基礎飼料は1日に体重kg当たり20および27gの2水準で給与した,両給与水準において1日に体重kg当たり0.111gのDL-Metと0.333gのL-LysHClを食道溝経由で補足した結果,等N量のL-グルタミンを投与した場合と比較して両給与水準ともN出納は改善されなかった.しかし尿中プリン誘導体排泄量は低飼料給与水準において減少し,ルーメン内における微生物態タンパク質合成量は高給与水準よりも少なかったことを示唆した.また,DL-MetとL-LysHClの補足により血漿Metが長時間にわたって高濃度に維持され,血漿側鎖アミノ酸濃度を低下させたが,その傾向も低飼料給与水準の方が顕著であった.以上の結果,この時期の子牛ではMetもLysも供試したトウモロコシ•大豆粕飼料の制限アミノ酸ではなかったか,あるいはDL-Metの過剩により制限アミノ酸が検出されなかった可能性が考えられた.

Altered Calcium Metabolism in Calves after Weaning

11週齢あるいは5週齢で離乳した子牛について離乳がカルシウム(Ca)代謝に及ぼす影響を調べた.5週齢ホルスタイン種雄子牛6頭(平均64.8kg)をそれぞれ3頭ずつ11週齢離乳(L)区あるいは5週齢離乳(E)区に分け,E区の離乳1,6,8,11,19週目にL区とE区のCa出納と腎クリアランスを検討した.E区では離乳直後に若干増体が抑制されたが,その後の増体速度に差がなかったので,試験終了時もE区の方が体重が小さい傾向を示した.1,6週目にはE区で固形飼料摂取量が増加したが,TDN摂取量ではE区の方が低かった.Ca吸収は早期離乳直後に抑制された結果,保持量も減少した.Ca吸収はまたL区の離乳直後にも若干減少した.日数の経過とともに糸球体濾過量が増加し,それに伴って濾過Ca量も増加したが,そのほとんどが尿細管以降で再吸収され,尿中排泄はわずかであった(〈7%),離乳は腎でのCa動態と血中Ca濃度に明確な影響を及ぼさなかった.以上の結果,早期離乳によりとくにCa吸収が変化し,恐らく骨へのCa沈着が減少する可能性が示唆された.