Ultrasonographic examination of the reticulum, rumen, omasum and abomasum during the first 100 days of life in calves.

The goal of this study was to examine the development of the reticulum, rumen, omasum and abomasum in six calves from birth to 100 days of age by means of six serial ultrasonographic examinations. The examinations were carried out in standing animals using a 5 MHz-transducer as described previously. The calves were primarily fed milk until examination 4 and then they were weaned. The reticulum was assessed for its shape and contractility, the rumen for its size and content, the omasum for its size, content and motility and the abomasum for its size and content before and after the ingestion of milk. The reticulum was seen in all calves starting at examination 2 and had biphasic and triphasic contractions; the latter were associated with eructation. The rumen was always imaged in all calves as early as Day 1 and its visible size increased progressively in all intercostal spaces (ICSs) during the study period. The omasum was best imaged in the 8th or 9th ICS; it was seen medial to the liver dorsally and usually medial to small intestines ventrally. Its visible size in these two ICSs increased progressively but omasal motility was not apparent. In newborn calves the abomasum was the largest compartment and dominated the abdominal cavity. It was visible from the 5th ICS to the flank. Except for examination 2, the mean visible abomasal length was significantly larger after feeding than before. Lateral abomasal extension to the left was greater than to the right at examinations 1-4, but was much smaller than to the right at examinations 5 and 6 because of progressive expansion of the rumen. Abomasal extension into the right hemiabdomen changed little during the study period.

Effects of nutritional conditions around weaning on carbonic anhydrase activity in the parotid gland and ruminal and abomasal epithelia of Holstein calves.

Thirty-two male Holstein calves were used to investigate the effects of nutritional conditions around weaning and aging on carbonic anhydrase (CA) activity in the parotid gland and epithelium from the rumen and abomasum. We fed calf starter and lucerne hay as well as milk replacer (group N) or fed milk replacer either with (group S) or without (group M) administration of short-chain fatty acids (SCFA) through polypropylene tubing into the forestomach until 13 weeks of age. The diets were fed at 1000 hours and 1600 hours, and SCFA were administrated after milk replacer feeding at 1600 hours. Slaughter and tissue sampling were carried out between 1300 hours and 1430 hours at 1, 3, 7, 13, and 18 weeks of age. Tissue samples from five adult (1.5-2.0 years-old) Holstein steers were obtained from a local abattoir. In group N, CA activity in the parotid gland gradually and significantly increased toward the adult value, whilst in the epithelium from the rumen and abomasum, adult values were reached at 3 and 7 weeks of age, respectively. At 13 weeks, the activity for group N was significantly higher than that for the other two groups in the parotid gland, but there was no significant difference in the epithelium from the rumen and abomasum. The concentration of the carbonic isozyme VI in the parotid gland also changed with age but, in contrast to CA activity, had not reached adult levels by 13 weeks of age. In groups M and S, parotid saliva did not show any change toward an alkaline pH or toward a reciprocal change in the concentrations between Cl(-) and HCO(3)(-), even at 13 weeks of age. From these results we conclude that a concentrate-hay based diet around weaning has a crucial role in CA development in the parotid gland, but not in the epithelium of the rumen and abomasum.

Degradation of fresh ryegrass by methanogenic co-cultures of ruminal fungi grown in the presence or absence of Fibrobacter succinogenes.

The ability of five ruminal fungi in syntrophic co-culture with the methanogen Methanobrevibacter smithii to degrade perennial ryegrass ( Lolium perenne) stem fragments and leaf blades was studied to determine the susceptibilities of non-autoclaved fresh tissues to fungal degradation. Autoclaving did not significantly increase fungal degradation of stem fragments but strongly increased degradation of leaf blades by a species of Caecomyces. In methanogenic co-cultures, non-autoclaved stem fragments were degraded more extensively by Neocallimastix frontalis and Piromyces isolates than by Caecomyces isolates. The N. frontalis and Piromyces isolates showed the greatest rates of stem degradation. When interactions between Fibrobacter succinogenes and methanogenic co-cultures of fungi growing on ryegrass stem were investigated, N. frontalis inhibited F. succinogenes. This has not been observed previously. In contrast, a Caecomyces species interacted positively with F. succinogenes to increase stem degradation, suggesting that F. succinogenes and Caecomyces spp. may have complementary fibrolytic activities. All five fungi tested failed to grow on fresh non-autoclaved leaf blades. In a repeat experiment with leaves from a separate harvest, leaf blades were degraded by N. frontalis but not by a Caecomyces species. We suggest that ryegrass leaf blades may contain natural anti-fungal compounds. Our results confirm the superiority of fungi in the degradation of intact stem and indicate that in vitro studies with non-autoclaved forage tissues may yield new information on forage factors affecting rumen microbes.

The provision of solid feeds to veal calves: I. Growth performance, forestomach development, and carcass and meat quality.

Growth performance, forestomach development, and carcass and meat quality of veal calves fed a milk replacer diet (Control) were compared to those obtained from calves fed the same liquid diet plus 250 g x calf(-1) x d(-1) of dried beet pulp or wheat straw. Three groups of 46 Polish Friesian calves, balanced according to initial BW, were assigned to the three dietary treatments in a fattening trial, which lasted 160 d. The provision of either solid feed did not affect the milk replacer intake. However, calves' ADG was increased (P < 0.01) only by feeding the beet pulp diet. The administration of both solid feeds improved calves' health status; calves fed solid feeds required fewer iron treatments for low hemoglobin and needed less medical treatments for respiratory or gastrointestinal diseases. In comparison to the Control calves, the provision of wheat straw and beet pulp increased iron intake throughout the fattening period by 41 and 130%, respectively. However, only calves fed beet pulp showed higher levels of hemoglobin and plasma iron concentrations (P < 0.05), whereas the same blood parameters were similar between Control calves and those fed wheat straw. At slaughter, both solid feeds led to empty forestomach weights heavier than those of Controls without reducing dressing percentage. The reticulorumen was heaviest in calves fed beet pulp, whereas wheat straw promoted omasal development. The administration of beet pulp resulted in a better carcass conformation than did the Control diet or wheat straw, but it had a detrimental effect on carcass color, which was graded as the darkest (P < 0.001). Consistent with this result, meat color of calves fed beet pulp was darker than that of Control calves and those fed wheat straw, because of the higher hematin concentration measured at the muscle level. No differences in carcass and meat color were observed between Control calves and calves fed wheat straw. The administration of solid feeds for welfare purposes does not always prevent the production of veal meat fulfilling the color standards required by the market. There is not a straight-forward relationship between a solid feed's iron content and the "redness" of veal meat, which should be related to the capability of the calves to use the iron provided by the roughage.

Anatomical subdivisions of the stomach of the Bactrian camel (Camelus bactrianus).

Twenty stomachs of Bactrian camels (Camelus bactrianus) were studied by gross dissection. Based on the configuration of the stomach and the structure of the mucous membrane, the stomach was divided into three ventricles that differ from the arrangement described for ox and sheep. The first and second ventricles of the proventriculus of camel form one stomach rather than two different stomachs. These ventricles of the proventriculus do not correspond to the rumen and reticulum of ox and sheep. The third ventricle appears to be the abomasum. One part of the abomasum has reticular mucosal folds that indicate it is not the reticulum. A second part of the abomasum has longitudinal mucosal folds suggesting it is not the omasum. Three glandular sac areas associated with the preventriculus and abomasum are also described.

Pituitary adenylate cyclase-activating polypeptide (PACAP) stimulates exocrine pancreas in conscious preruminating calves.

The effects of new hypothalamic peptides, PACAP-27 and PACAP-38, and secretin and VIP on the interdigestive pancreatic secretion and duodenal myoelectric activity during the asecretory phase of the pancreatic interdigestive cycle, compared with the milk ingestion phase, were examined in five calves. Peptides were infused for 5 min into the external jugular vein (0, 3, 10, 30 and 100 pmol/kg body wt during the asecretory phase of the pancreatic interdigestive cycle, and the pancreatic secretory response was compared with that obtained during milk ingestion. Intravenous infusion of PACAP-27 caused dose-related stimulation of pancreatic juice flow and bicarbonate and protein output; this effect was identical to infusion of secretin. The effect of PACAP-38 was less pronounced, and that of VIP was the weakest. Pancreatic juice volume and bicarbonate responses during milk ingestion were similar to responses obtained with the highest doses of hypothalamic peptides and secretin, whereas postprandial protein secretion was much greater than the secretion stimulated with peptides. It was concluded that PACAP from the VIP/secretin family may stimulate pancreatic exocrine secretion in conscious calves and a part of the pancreatic response to food intake can be mediated by PACAP.

Growth, body composition, and visceral organ mass and metabolism in lambs during and after metabolizable protein or net energy restrictions.

Three trials were conducted to assess effects of metabolizable protein and NE deficiencies on changes in body composition, organ mass and metabolism, and animal growth performance during restriction and realimentation. Growth of lambs was restricted to achieve no change in BW for periods of 5 to 6 wk by limiting intake of metabolizable protein or NE. In Trial 1, changes in body composition and visceral organ mass and metabolism during restriction were compared to unrestricted controls using 36 lambs. Trial 2 was designed to investigate changes in growth, body composition, and visceral organs during restriction and realimentation periods using 44 lambs. Trial 3 was limited to evaluation of differences in performance and carcass characteristics of previously restricted and unrestricted ram lambs (15 total). Results of Trial 1 indicated that liver weights were decreased with nutrient restrictions. Body protein mass was conserved in energy-restricted (ER) lambs and lost in protein-restricted (PR) lambs. Fat was mobilized at similar rates for PR and ER lambs. In Trial 2, liver and intestinal weights, as well as in vitro oxygen consumption by liver slices, were decreased with nutrient restrictions. The reductions persisted after 2 wk of realimentation, yet no compensatory growth was observed. Feed intakes were increased gradually during the first 2 wk of realimentation. Composition of gain during the realimentation period was similar to that of unrestricted lambs. In Trial 3, neither gain nor feed efficiency during realimentation was enhanced as a result of previous nutrient deficiencies. Absence of compensatory growth in Trial 3 is possibly attributable to differences in gastrointestinal fill. Lambs subjected to short-term PR and ER seem to have similar recuperative capacity.

Preruminant calf nutrition.

This article has attempted to give the reader an outline of the principles involved in preruminant calf nutrition together with a practical understanding of milk replacers and their use for raising calves. While the nutrient requirements of the preruminant calf are reasonably well understood, the complex interactions occurring when attempting to replace milk proteins with high levels of nonmilk proteins are clearly not well understood. Further, the management and environmental interactions on nutrition are profound and far from elucidated.

[SEM study on the mucosa of the pre-stomach in Bubalus buffalus]. / Studio al SEM sulla mucosa dei prestomaci in Bubalus buffalus.

Morpho-structural features of pre-stomach mucosa in the first period of post-natal life in Bubalus buffalus have been studied by SEM. The rumen presents a well defined morpho-structural architecture from 10 to 100 days of life, while in reticulum and in omasum numerous morphological variations have been noticed. During the development, in fact, in these organs the establishment of a typical morphological pattern has been observed.

[Weight characteristics of digestive tissues and contents of weaned calves, in the case of 2 feed concentrates differing in the nature of nitrogenous components]. / Caractéristiques pondérales des tissus et des contenus digestifs du veau sevré, dans le cas de deux rations concentrées différant par la nature des matières azotées.

Feeding dairy calves for 13 weeks on concentrate diets differing in nitrogen degradability (pea vs soya bean meal) did not affect the fresh weight of digestive tissues and digesta at a slaughter age of 20 wk.

Factors influencing growth of rumen, liver, and other organs in kids weaned from milk replacers to solid foods.

From pooled data of many feeding trials with kids fed various types of solid foods from 37 days of age and slaughtered thereafter, relationships between such independent variables as age, cumulative intake of solid food, weight gain, and/or final body weight and such dependent variables as weights and such dependent variables as weights of stomach-compartments, heart, liver, kidneys, and spleen were analyzed. Growth of forestomachs, and especially rumen mucosa, relative to body weight was stimulated only in feeding periods of solid foods. Gain, intake of solid food, and final body weight were the best predictors for growth of forestomach-compartments, liver, and heart, respectively. Correlations were large between ruminoreticulum weight and liver weight and among weights of forestomach-compartments. Second degree polynomials were fitted to predict the curvilinear relationships between solid-food intake and either ruminoreticulum weight or rumen mucosal weight, and a linear equation was fitted to predict the relationship between solid-food intake and liver weight. Feeding of roughage increased rumen muscular and omasal weights. Growth of the rumen under stimulation of solid-food intake may be regulated by the same biological factors contributing to increased growth rate of the whole animal. In this situation, growth of the rumen may be correlated closely with growth of the liver.