Rumen Weight Research Articles

Rumen development and blood metabolites of Criollo kids under two different rearing systems

This study compared rumen development and blood metabolite concentrations of Criollo kids under two different rearing systems. Forty goat kids were reared by their dams, suckling goat milk from birth until weaning at 45 (TR, traditional rearing system, n=20) or 30 days of age (AR, alternative rearing system, n=20). Goat kids in the AR group were offered a solid starter diet ad libitum from birth until 45 days of age and a growing diet (80% alfalfa hay and 20% ground corn) from 30 to 90 days of age. The TR group was fed a growing diet (without starter diet) between 30 and 90 days of age. Blood samples were analyzed for serum concentration of glucose, total protein, blood urea nitrogen (BUN), <beta>-hydroxybutyrate (<beta>HB), and non-esterified fatty acids (NEFA). Five kids from each group were slaughtered at 21, 45, 70 and 90 days of age to determine rumen variables. AR kids consumed 32.7 % less goat milk than TR kids throughout the trial. Body weight of AR kids at 45–60 days of age was lower than the traditional market weight. Rumen weight (as % of body weight) was higher (P<0.01) in AR kids than in TR kids at 21 and 45 days of age. Furthermore, rumen weight (as % of weight of all compartments) was higher in AR kids compared to TR kids at 21, 45 and 70 days of age. Rumen papillae of AR kids tended (P<0.10) to be longer than those of TR kids at 21 and 45 days of age. Blood glucose concentration decreased with increasing age of kids, indicating a shift from glucose to short-chain fatty acids as primary energy source. Serum <beta>HB and BUN concentrations at 30 and 45 days of age were higher (P<0.05) in AR kids than in TR kids. The higher serum concentrations of BUN and <beta>HB were attributed to early development of rumen microbial fermentation activity and to greater metabolic development of the rumen epithelium of AR kids compared to TR kids. In conclusion, the alternative rearing system improves the physical and metabolic development of the rumen and promotes the transition of kids from pre-ruminant to ruminant. In dry periods with shortage of forage, the alternative rearing system could be used, but these goat kids should be reared above the traditional age to enable them to achieve an appropriate weight for marketing.

Morfologia dos pré-estômagos e de papilas ruminais de cordeiras Santa Inês em crescimento submetidas a dois planos nutricionais

Para se avaliar o efeito do plano nutricional e crescimento sobre a massa dos pré-estômagos, morfologia e quantificação de papilas ruminais, trinta e seis cordeiras da raça Santa Inês foram submetidas a dois planos nutricionais (ad libitum ou restrito) sendo abatidas em diferentes pesos vivo (20, 30 ou 40 kg de peso vivo), em um delineamento inteiramente casualizado balanceado em arranjo fatorial 2x3. Feito o abate, as vísceras foram pesadas livres de seu conteúdo em seguida mediu-se o volume de repleção do rúmen e retículo. Amostras do tecido ruminal oriundas dos sacos cranial e ventral foram coletadas para posteriormente serem realizadas com auxílio de lupa estereoscópica as medidas morfométricas das papilas ruminais, altura, largura da base, área, papilas por cm² e área absortiva por cm². Os resultados obtidos foram submetidos a análise de variância e as médias resultantes por tratamento foram comparadas por meio de teste de Student Newmann Keuls. Os diferentes planos nutricionais não influenciaram a massa das vísceras rúmen, retículo e omaso (P&gt;0,05), no entanto, observou-se crescimento dessas vísceras em função do aumento do peso ao abate. O volume dessas vísceras foi afetado pelo peso ao abate, e observou-se menores volumes para animais com alimentação ad libitum (P&lt;0,10). O número de papilas por cm² foi reduzido com o aumento do peso ao abate, sendo que altura e área foram aumentadas quando em pesos maiores. O plano nutricional afetou apenas a área e altura das papilas ruminais oriundas do saco cranial. A área absortiva não foi afetada pelos tratamentos. Plano nutricional e diferentes pesos vivos influenciam a morfologia dos pré-estômagos de cordeiras da raça Santa Inês.

Effects of roughage source, amount, and particle size on behavior and gastrointestinal health of veal calves

The European Union 1997 Directive, stipulating that veal calves should be fed a minimum of 50 to 250g of fibrous feed from 8 to 20wk of age, is vague. A fibrous feed ration maximum of 250g has been implicated in welfare issues, namely the occurrence of abnormal oral behaviors and poor gastrointestinal health. Past research suggests that this amount is insufficient to prevent the development of abnormal oral behaviors and enabling good rumen development. Different sources and particle sizes of roughage could lead to very different welfare outcomes. In a 3×2 × 2 factorial design, 240 group-housed calves (10±1d; 46.1±0.1kg) were fed different roughage sources (straw, maize silage, or maize cob silage; the latter 2 were dried and provided no extra moisture compared with straw) in 2 amounts (250 or 500g of dry matter per day), and 2 particle sizes (chopped or ground). Roughage was supplemented to milk replacer (MR) from 2wk after arrival. In addition, 60 calves were fed 1 of 3 additional control treatments: MR only (n=20), MR plus an iron supplement (n=20), or MR plus ad libitum hay (n=20). Oral behaviors were recorded using instantaneous scan sampling at 2-min intervals for 2h in 3 periods per day, at 12 and 22wk of age. Calves were slaughtered at 24wk of age and rumen and abomasal health parameters were recorded. Limited provision of straw resulted in behavior comparable with that from unlimited provision of hay, with reduced tongue playing and oral manipulation of the environment, as well as increased chewing compared with diets with no roughage supplement. Straw prevented ruminal hairballs, but impaired rumen development and increased abomasal damage. A higher ration of roughage increased chewing (12wk), decreased oral manipulation of the trough (12 and 22wk) and the pen (22wk), and increased rumen weight. However, more roughage led to increased abomasal damage for certain parameters. Longer feed particles had no obvious benefits for behavior, but decreased hairball prevalence. Overall, unlimited hay had the highest benefit for both behavior and gastrointestinal health. Adding iron to the MR did not alter behavior or gastrointestinal health compared with MR without iron supplement. This study demonstrated that different roughage sources, amounts, and particle sizes have different effects on veal calf behavior and gastrointestinal health, and hence on veal calf welfare.

Effects of a mixture of steam-flaked corn and extruded soybeans on performance, ruminal development, ruminal fermentation, and intestinal absorptive capability in veal calves1

This study investigated the effects of a mixture of steam-flaked corn and extruded soybeans on performance, ruminal development, ruminal fermentation variables, and intestinal absorptive capability in Holstein male calves (n = 39). Calves were assigned to 1 of 3 treatments (13 calves per treatment): 1) milk replacer (MR), 2) one-half of the amount of MR in treatment 1, plus a mixture of 62.1% steam-flaked corn and 30.5% extruded soybeans provided ad libitum (HMCS), or 3) a mixture of 62.1% steam-flaked corn and 30.5% extruded soybeans provided ad libitum (CS). All the calves were started at 2 ± 1 d of age and studied for 150 d. Each 30 d was defined as 1 period. Dry matter intake and growth were measured daily and monthly, respectively. All calves were harvested at 150 d of age, after which rumen fluid was collected. Rumen and intestine samples were gathered. Calves fed MR exhibited greater BW (P = 0.001) and ADG (P < 0.001), compared with calves fed HMCS and CS from period 2 to 3; however, from period 4 to 5, CS calves had greater (P < 0.04) ADG than MR calves. The treatments did not differ in final BW (P = 0.72) and ADG (P = 0.20) from period 2 to 5. Compared with HMCS and MR calves, CS calves had the greatest DMI (P < 0.001) and the least feed efficiency (P < 0.001) from period 2 to 5. For ruminal fermentation parameters, CS calves had decreased (P = 0.04) rumen pH than MR calves. The NH3 concentrations were greater (P = 0.03) in calves fed HMCS than calves fed MR and CS. Total VFA concentrations were greatest in CS calves (P = 0.02). Calves fed CS had the greatest molar concentrations of propionate, butyrate, and valerate (P < 0.002), and calves fed HMCS had the greatest molar concentrations of isobutyrate (P = 0.001) and isovalerate (P = 0.001). The CS calves exhibited greater empty rumen weight (P = 0.001), papillae length (P < 0.001), papillae width (P < 0.001), rumen wall thickness (P = 0.012), and papillae density (P = 0.003). The greatest villus heights in the jejunum (P = 0.04) and ileum (P = 0.005) were observed in CS calves. Compared with HMCS calves, calves fed CS had greater villus:crypt ratios in the duodenum (P = 0.001) and jejunum (P = 0.001). Results indicate that CS improves ADG in period 4 to 5 and positively contributes to ruminal development, ruminal fermentation, and intestinal absorptive capability in veal calves.

Effects of early rumen development and solid feed composition on growth performance and abomasal health in veal calves

The experiment was designed to study the importance of early rumen development and of the composition of solid feed intake on growth performance and abomasal health in milk-fed veal calves. One hundred and six Holstein-Friesian male calves were included in the experiment, and studied during 2 successive 12-wk periods (period 1 and period 2). In a 2 × 2 factorial arrangement, effects of partially replacing milk replacer by solid feed during period 1 and partially replacing dry matter (DM) intake from maize silage and barley straw by concentrate during period 2 were tested. Solid feed during period 1 consisted of maize silage, barley straw, and concentrate (25:25:50 on a DM basis). Solid feed during period 2 consisted of maize silage and barley straw (50:50 ratio on DM basis) for the nonconcentrate groups, and maize silage, barley straw and concentrates (25:25:50 on a DM basis) for the concentrate groups. At the end of period 1 (n=16) and at the end of period 2 (n=90), parameters of animal performance, rumen development, rumen fermentation, ruminal drinking, and abomasal damage were examined. Partially replacing milk replacer by solid feed during period 1 resulted in early rumen development (ERD) at the end of period 1, characterized by increased rumen weight, and an increased epithelial and absorptive surface area. Both ERD and partially replacing roughage by concentrates in period 2 increased the rumen development score at the end of period 2. Although ERD calves consumed more solid feed and less milk replacer during period 1 and 2 than non-ERD calves, carcass weight gains at 25wk were identical, and utilization of the solid feed provided appeared similar to that of milk replacer. Partially replacing roughage by concentrates in period 2 increased dressing percentage and warm carcass weight. Plaque formation at the rumen mucosa was unaffected by ERD or partially replacing roughage by concentrates and generally low in all calves. The prevalence of large scars in the abomasum in ERD calves was decreased compared with non-ERD calves. This may indicate that ERD provided protection against abomasal lesions. In conclusion, early compared with late rumen development improves feed utilization and may be beneficial for abomasal health.

A dose-response of cinnamaldehyde supplementation on intake, ruminal fermentation, blood metabolites, growth performance, and carcass characteristics of growing lambs

The objective of this study was to determine the effect of different doses of cinnamaldehyde on feed intake, gain, feed efficiency, ruminal fermentation parameters, blood metabolites, carcass yield, and meat quality of lambs fed barley-based diets. Forty-eight ewe lambs were stratified by live weight (LW) and randomized among treatments (n=4) at weaning (LW=20.4±1.12kg). Animals had ad libitum access to pelleted diets (140g CP/kg of DM; 309g NDF/kg of DM) and water over 18-week period. There were four treatments with 12 animals each: 1) Control (no cinnamaldehyde); 2) cinnamaldehyde at 100mg/kg of dry matter (DM); 3) cinnamaldehyde at 200mg/kg of DM; 4) cinnamaldehyde at 400mg/kg of DM. Dry matter intake (DMI), average daily gain (ADG) and feed conversion (DMI/ADG) were not affected by cinnamaldehyde supplementation. Ruminal pH, total VFA concentrations, molar proportions of individual VFA (acetate, propionate and valerate) and ammonia concentration were similar between lambs fed cinnamaldehyde and those fed the control diet. For blood metabolites, except urea nitrogen concentration which was higher (P=0.05) in lambs fed cinnamaldehyde at 200mg/kg compared to those fed the control diet, no changes were observed for non-esterified fatty acids (NEFA), cholesterol and triglycerides concentrations. The addition of cinnamaldehyde to the diet had no effect on carcass characteristics [liver and rumen weights, hot carcass weight, dressing percent, back fat thickness (grade), quality grade, saleable meat yield (as primal cuts)] and fatty acid (FA) composition of back fat and liver. Overall, sensory attributes of sirloins were not altered although off-flavor intensity was higher (P<0.01) for sirloins from lambs fed cinnamaldehyde at 100 and 400mg/kg of DM compared to the control. Results from this study suggest that cinnamaldehyde may have limited potential to improve feed efficiency and growth in lambs fed concentrate-based diets.

Gastrointestinal development of dairy calves fed low- or high-starch concentrate at two milk allowances

The objective was to study the effect of type of concentrate with varying starch and fibre content on growth and gastrointestinal development in preweaned dairy calves. Thirty-two newborn Danish Holstein male calves were allocated to four treatment groups in eight blocks of four calves. An experimental low-starch, high-molasses, high-fibre (EXP) concentrate or a traditional high-starch (TRA) concentrate were fed either at a high (HIGH; 2 × 3.2 kg/day) or a low (LOW; 2 × 1.6 kg/day) whole milk allowance in a 2 × 2 factorial design. TRA contained 350 and EXP 107 g starch/kg dry matter (DM), whereas the NDF content was 136 and 296 g/kg DM, respectively. Metabolizable energy (ME) was 11.2 and 12.2 MJ ME/kg DM in EXP and TRA, respectively. All calves had free access to artificially dried grass hay (9.8 MJ ME/kg DM). Four calves were culled during the experiment. The calves were euthanized either at 38 (12 calves) or 56 days (16 calves) of age. Evaluated across both slaughter ages, there was no difference between TRA and EXP in concentrate and hay intake, rumen weight and papillation. EXP resulted in increased villi number in duodenum and jejunum compared with TRA. Concentrate intake and reticulo-rumen weight was higher for LOW compared with HIGH milk allowance, whereas live weight gain was 20% lower. The results show that a low-starch, high-molasses, high-fibre concentrate with 8% lower ME content tended to reduce daily gain compared with a traditional calf starter concentrate, but resulted in similar ruminal development in preweaned calves both on a high and a low milk allowance fed along with grass hay. Furthermore, the results suggest that the experimental concentrate stimulated intestinal villi growth over that of the traditional concentrate.

ORIGINAL ARTICLE: Description of development of rumen ecosystem by PCR assay in milk-fed, weaned and finished lambs in an intensive fattening system

This study examined the reticulo-rumen characteristics of the microbial community and its fermentative characteristics in milk-fed, at weaning and finished lambs in a conventional fattening system. Five lambs were assigned to each of three groups: milk-fed lambs slaughtered at 30 days (T30), weaned lambs slaughtered at 45 days (T45) and 'finished lambs' slaughtered at 90 days (T90). At slaughter, rumen size, fermentation parameters (pH, volatile fatty acids and microbial enzyme activity) and protozoal counts were recorded. Quantitative PCR was used to quantify the genes encoding 16S and 18S ribosomal DNA of the rumen bacterial and protozoal populations, respectively, and the sequential colonization of the rumen by cellulolytic (Ruminococcus albus, Ruminococcus flavefaciens) and amylolytic (Prevotella ruminicola, Streptococcus bovis) bacteria, and protozoa (Entodinium sp.). Denaturing gradient gel electrophoresis was used to study the development of rumen microbiota biodiversity. Intake of solid food before weaning caused a significant increase in rumen weight (p < 0.0001) and bacterial DNA (p < 0.05) and volatile fatty acid analysis concentration (p < 0.01), whereas pH declined. In milk-fed lambs, cellulolytic bacteria were evident after 30 days. Thereafter, in the 45-day and 90-day groups, the proportions of R. flavefaciens decreased and R. albus increased. Amylolytic bacteria were present in milk-fed lambs; the proportion of P. ruminicola increased in fattening lambs and S. bovis was the least abundant species. Protozoal concentrations were irregular; milk-fed lambs had a significant number of protozoa species from Entodinium and subfamily Isotrichiidae, but they disappeared at weaning. Lamb rumen were refaunated in some individuals at 90 days (Entodinium and subfamily Diplodiniinae spp.), although individual concentrations were variable.

The Kinetic of Biogas Production Rate from Cattle Manure in Batch Mode

In this study, the kinetic of biogas production was studied by performing a series laboratory experiment using rumen fluid of animal ruminant as inoculums. Cattle manure as substrate was inoculated by rumen fluid to the anaerobic biodigester. Laboratory experiments using 400 ml biodigester were performed in batch operation mode. Given 100 grams of fresh cattle manure was fed to each biodigester and mixed with rumen fluid by manure : rumen weight ratio of 1:1 (MR11). The operating temperatures were varied at room temperature and 38.5 o C. The cumulative volume of biogas produced was used to measure the biodigester performance. The research showed that the rumen fluid inoculated to biodigester gave significant effect to biogas production (P<0.05). Rumen fluid inoculums caused biogas production rate and efficiency increase two to three times in compare to manure substrate without rumen fluid. With the rumen fluid inoculums, gave the kinetic parameters of biogas production i.e biogas production rate constants (U), maximum biogas production (A), and minimum time to produce biogas (λ) are 3.89 ml/(gVS.day); 172.51 (ml/gVS); dan 7.25 days, respectively. While the substrate without rumen fluid gave the kinetic parameters U, A, and λ are 1.74 ml/(gVS.day); 73.81 (ml/gVS); dan 14.75 days, respectively. The future work will be carried out to study the dynamics of biogas production if both the rumen inoculums and manure are fed in the continuous system.

Órgãos internos e trato gastrintestinal de novilhos de gerações avançadas do cruzamento rotativo entre as raças Charolês e Nelore terminados em confinamento

Foram avaliados os efeitos de heterose e de grupo genético nos órgãos internos e no trato gastrintestinal de novilhos puros (Charolês - C e Nelore - N) e cruzados da segunda (G2) (3/4C 1/4N e 3/4N 1/4C), terceira (G3) (5/8C 3/8N e 5/8N 3/8C) e quarta (G4) (11/16C 5/16N e 11/16N 5/16C) gerações de cruzamento terminados em confinamento e abatidos com 23 meses de idade. Os animais cruzados da G2, G3 e G4 foram, respectivamente, 14,95; 17,25 e 18,46% superiores aos puros quanto ao peso de corpo vazio (PCVZ). A heterose para o rendimento de carcaça fria em relação ao PCVZ (RCFCVZ) foi positiva em todas as gerações. Os mestiços apresentaram menor peso relativo (ao PCVZ) de coração, pulmões e rins, de modo que a heterose foi significativa para peso de coração (-18,29%) e rins (-14,29%) na G3 e para pulmões (-13,45%) na G4. Novilhos mestiços apresentaram valores inferiores à média dos puros para todos os componentes do trato gastrintestinal quando o peso destes componentes foi expresso em relação a 100 kg de PCVZ ou de peso vivo ao abate (PVA), com exceção do rúmen na G2. A heterose retida foi positiva e significativa para PCVZ, RCFCVZ e para peso absoluto do fígado. Entretanto, foi negativa para a quantidade de sangue para os pesos de coração, intestino delgado + grosso e trato gastrintestinal quando expressos em relação a 100 kg de PCVZ e de PVA. Entre os animais puros, os novilhos Nelore tiveram maior RCFCVZ (57,09 vs 61,64%). O peso absoluto de rúmen, abomaso, intestino delgado + grosso e o trato gastrintestinal foram maiores nos novilhos Charolês em relação aos Nelore, o que também foi observado quando estes componentes foram expressos em relação ao PCVZ e PVA, com exceção para o intestino grosso + delgado. Estas diferenças explicam, em parte, o maior rendimento de carcaça dos novilhos Nelore.

Effects of Supplementing Concentrates Differing in Carbohydrate Composition in Veal Calf Diets: II. Rumen Development

The objective of this experiment was to examine the effects of concentrates in feed, differing in carbohydrate source, on the rumen development of veal calves. For this purpose, 160 male Holstein Friesian×Dutch Friesian crossbred calves were used in a complete randomized block design with a 5×2 factorial arrangement. Dietary treatments consisted of 1) a milk replacer control, 2) a pectin-based concentrate, 3) a neutral detergent fiber-based concentrate, 4) a starch-based concentrate, and 5) a mixed concentrate (equal amounts of the concentrates in treatments 2, 3, and 4). Concentrate diets were provided as pellets in addition to a commercial milk replacer. Calves were euthanized at either 8 or 12 wk of age. Plasma acetate and β-hydroxybutyrate (BHBA) were measured as indicators of rumen development. Empty rumen weight was determined, and wall samples were taken at slaughter. In most calves, a poorly developed rumen mucosa was observed. Coalescing rumen papillae with embedded hair, feed particles, and cell debris were found in all calves fed the concentrate diets. Calves fed concentrates had significantly heavier rumens than calves fed the control diet. In the dorsal location of the rumen, calves fed concentrate diets showed an increased ratio of mucosa to serosa length compared with calves fed the control diet, whereas in the ventral location only, calves fed the pectin and mixed diets showed larger ratios of mucosa to serosa length. Mucosa thickness and muscle thickness were greater in the ventral and dorsal locations of the rumen, respectively. In both locations, the NDF diet resulted numerically in the lowest mucosa thickness and highest muscle thickness among the concentrate treatments. At 8 wk, calves fed the concentrate diets had higher plasma acetate concentrations than calves on the control treatment. However, at 12 wk, only NDF-fed calves showed significantly higher plasma acetate concentrations. The plasma BHBA concentrations of calves at 8 wk of age fed the pectin and mixed diets were higher than those of the control diet-fed calves. At 12 wk, no differences in BHBA concentrations were observed among treatments. Results of a principal component analysis indicated that, in addition to rumen volatile fatty acid concentrations, other factors were likely to affect rumen development, and that the relationships between rumen development and individual types of volatile fatty acids present in the rumen liquor were similar. Also, variations in rumen development coincided with variations in plasma acetate and BHBA concentrations.

GASTROINTESTINAL MORPHOLOGY OF FEMALE WHITE-TAILED AND MULE DEER: EFFECTS OF FIRE, REPRODUCTION, AND FEEDING TYPE

We assessed variation in length, width, density, and surface enlargement factor of papillae; rumen and intestinal digesta weight; intestinal length; and intestinal tissue weight of reproductive and nonreproductive female whitetailed (Odocoileus virginianus) and mule deer (O. hemionus) using similar burned and unburned habitat. Deer were collected from study areas in Custer and Pennington counties, South Dakota, in and adjacent to a wildfire burn. Length of papillae and enlargement factor of papillae surface of white-tailed deer and mule deer were greater in burned than unburned habitat, and dry weight of rumen digesta of white-tailed deer was greater in unburned than burned habitat. Papillae surface enlargement factor, papillae length and width, and dry weight of rumen and intestinal digesta were greater for lactating than nonlactating white-tailed deer. Papillae density, intestinal digesta dry weight, and intestinal length were greater in mule deer than white-tailed deer. The mosaic pattern of the burned habitat was beneficial at the mucosal level for white-tailed and mule deer within 3 years postfire. Enhanced papillae morphology of lactating compared with nonlactating and pregnant deer was attributed to high nutritional demands associated with reproductive status. Papillae density may be more important in mule deer because of feeding strategy (concentrate selector‐intermediate feeder) compared to white-tailed deer (concentrate selector), whereas greater rumen digesta dry weight and intestinal length may be directly associated with size.

Growth, Feed Efficiency, Behaviour, Carcass Characteristics and Meat Quality of Goats Fed Fermented Bagasse Feed

The effects of long-term feeding of diets based on bermudagrass hay supplemented with lucerne hay cube (LH) or fermented bagasse feed (FBF) on the growth rate, feed efficiency, behaviour, gut development, carcass characteristics and meat quality of goats were investigated. Six spring-born 8-month-old male crossbred (Japanese Saanen×Tokara native goats) bucks weighing mean 21.6 kg were allotted to 2 treatment groups (3 animals each) and each animal had ad libitum access to feeds, i.e. bermudagrass hay (basal diet)+LH or FBF throughout the experiment. The FBF was produced by the solid-state fermentation of substrates containing dried sugarcane bagasse mixed with wheat bran in a ratio of 1:3 (w/w DM) with Aspergillus sojae. The live body weight, final weight and average daily gain were not different between treatments. Average basal diet intake of goats fed FBF diet was significantly higher than that fed LH diet (p<0.05), but average dry matter intake (DMI; g/day and g/W 0.75 ), feed conversion ratio, digestible crude protein (DCP) and total digestible nutrients (TDN) intake of experimental diets were not significantly different between treatments. Goats fed on LH and FBF diets had similar eating, rumination, resting and drinking behaviours, and blood constituents except for phosphorus content. Slaughter and carcass weights, net meat percentage ((total meat/carcass weight)×100), loin ratio ((loin/total meat)×100) and rib-eye area were not different between treatments. However, goats fed FBF diet had lower dressing percentage and higher bone/muscle ratio compared with goats fed LH diet (p<0.01). Empty gut and guts fill of goats fed FBF diet were significantly greater (p<0.05 and p<0.01, respectively) than those fed LH diet. The weights of rumen and abomasum were also significantly heavier in goats fed FBF diet (p<0.05), but the length and density of papillae of rumen in goats were not different between treatments. Although meat composition of loin was not different in both groups, the meat of goats fed FBF diet was superior to that of LH diet in flavor, aroma and overall quality of loin (p<0.01). In conclusion, the nature of the diet consumed voluntarily did not affect subsequent growth, nutrient intake and behaviour of goats but had an influence on carcass traits and sensory evaluation of meat partly, when either of LH or FBF was fed with bermudagrass hay. (Asian-Aust. J. Anim. Sci. 2005. Vol 18, No. 11 : 1594-1599)

Performance and ruminal morphologic characteristics of Saanen kids fed ground, pelleted or extruded total ration

The aim of the present study was to determine feed intake and average weight gain and to evaluate the ruminal morphologic characteristics of Saanen kids slaughtered at 30, 45 and 60 days of age, according to a completely randomized design. Thirty-six non-castrated male Saanen kids were fed ground total ration, pelleted total ration, or extruded total ration. Feed intake and refusals were controlled daily and the animals were weighed at birth and then once a week. Newborn kids received a milk replacer and were weaned at 45 days. Immediately after slaughter, the animals were eviscerated, the entire digestive apparatus was removed from the carcass. The reticulo-rumen was separated, emptied, washed and weighed. Samples were collected from the dorsal sac, pillar area and ventral sac of the rumen, fixed for about 24 h in Bouin's solution, dehydrated, embedded in Histosec and cut into 5 μm sections. Results showed that dry matter intake (DMI) at weaning and post-weaning and weight gain were higher ( P < 0.05) in animals that received the pelleted total ration. The weight of the reticulo-rumen accompanied body development and was heavier in these animals. Histologically, after weaning ruminal papillae were more developed in animals that received pelleted total ration. Length of papillae increased with increase of age. The ratio of papillary height to papillary width increased with age in the ventral sac and until weaning ( P > 0.05). We conclude that the pelleting process of the total ration favored increased intake, with a 46.7% increase in weight gain and increase in rumen weight and papillae length, suggesting that best results are obtained with this processing. In general, no difference was observed between the results obtained with extruded and ground total ration, although animals fed extruded total ration showed an increase in rumen weight and papillae width.

Effects of type of liquid feed and feeding frequency on calf performance

ABSTRACT The effects of liquid feed and feeding frequency on concentrate mixture intake, rumen fermentation and rearing performance were investigated in 24 bull calves divided into 2 groups, receiving milk or milk-replacer once or three times a day. VFA concentration was estimated in the rumen fluid at 36 and 90 days of age. The liquid feed did not influence the concentrate intake (P>0.05). The calves receiving milk were characterized by the higher concentration of butyric acid in the rumen fluid (P≤0.02) and higher daily weight gains (P≤0.02) compared with those fed milk-replacer. The increasing feeding frequency during the period from 7 to 36 days of age was reflected in the lower daily intake of concentrate mixture (P=0.02). KEY WORDS: calves, liquid feed, feeding frequency, performance INTRODUCTION The changes in milk-replacer formulas led to the replacement of dried skim milk with plant products, which in nonruminant calves decrease nutrient utilization (Montagne et al., 2003). The negative effects on performance of calves is also exerted by the once daily feeding system (Strzetelski et al., 2001). When the daily diet is divided into more portions calves are characterized by the homeostasis of blood metabolites, which is beneficial for calf’s growth (Kaufhold et al., 2000). The effects of liquid feed composition and frequency of feeding on the rearing performance of calves are not really recognized.

Effect of Sodium Laurate on Ruminal Fermentation and Utilization of Ruminal Ammonia Nitrogen for Milk Protein Synthesis in Dairy Cows

A crossover design trial with 4 ruminally and duodenally cannulated lactating dairy cows was conducted to study the effect of sodium laurate on ruminal fermentation, nutrient digestibility, and milk yield and composition. The daily dose of sodium laurate (0, control or 240 g/cow, LA) was divided in 2 equal portions and introduced directly into the rumen through the cannula before feedings. Ruminal samples (29 in 114h) were analyzed for fermentation variables and protozoal counts. Sodium laurate had no effect on ruminal pH and total and individual volatile fatty acids concentrations. Ruminal ammonia concentration, ammonia N pool size, and the irreversible loss of ammonia N were unaffected by treatment. Compared to control, protozoal counts were reduced by 91% by LA. Carboxymethylcellulase and xylanase activities of ruminal fluid were decreased (by 40 and 36%, respectively), and amylase activity was not affected by LA compared with control. Flow of microbial N to the duodenum was reduced by LA. Dry matter intake and apparent total tract digestibility of dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber were not different between the 2 treatments. Milk yield, fat-corrected milk yield, milk fat and protein concentrations and yields, and milk urea N content were not affected by treatment. Sodium laurate did not affect transfer of ruminal ammonia-15N into bacterial or milk protein. In conclusion, LA at approximately 0.3% of the rumen weight reduced ruminal protozoal population and had a negative effect on fibrolytic activities of ruminal fluid and microbial protein flow to the intestine. Treatment had no other significant effects on ruminal fermentation, total tract digestibility, or transfer of ruminal ammonia-15N into milk protein.

Quantification of energy expenditures of the gastrointestinal tract of steers fed three diets at two levels of intake

Forty eight yearling Holstein steers [257 ± 7.7 kg body weight (BW)] were fed switchgrass hay plus 10% soybean meal (diet S), orchard grass silage (diet O) and alfalfa silage (diet A) at 65 or 90 g DM kg–0.75 BW for 155 to 164 d in a 2 × 3 factorial experiment designed to evaluate the effects of dietary composition and level of feed intake on patterns of O2 consumption in gastrointestinal tract (GIT) tissues. At the end of the growth period, steers were stunned, exsanguinated and eviscerated. The various GIT components were then emptied of their contents and weighed. Ventral sac rumen, jejunal and large intestinal tissue samples were quickly acquired and placed in oxygenated M199 media. Mucosa and muscularis weights of these tissues were determined along with their total O2(TO2), ouabain-sensitive O2 (OSO2) and ouabain-insensitive O2 (OIO2) consumption. Oxygen consumption parameters were determined polarographically using a YSI Clark-style electrode. Total weights of rumen (P &lt; 0.001), small intestine (P &lt; 0.001) and large intestine (P &lt; 0.05) were higher in steers fed the high level of intake compared to those fed the low level of feed intake. In all GIT tissues studied, increasing the level of feed intake (P &lt;0.05) elevated mucosa and muscularis dry weights. Steers fed diet S had lower (P &lt; 0.05) GIT tissue weights compared to those fed diets O and A. Weight-specific (i.e., expressed per unit tissue weight) TO2, OSO2 and OIO2 consumption for rumen, small intestine and large intestine were not affected by dietary composition and level of feed intake (P &gt; 0.05), except for OSO2 consumption, which was higher (P &lt; 0.05) in ruminal mucosa of steers fed diets S and A compared to those fed diet O. It is concluded that level of feed intake and dietary composition altered GIT O2 consumption via changes in visceral organ mass, rather than changes in weight-specific O2 consumption. Key words: Na+, K+-ATPase, gastrointestinal tract, Holstein steers

Influence of chlortetracycline and dietary protein level on visceral organ mass of growing beef steers.

Thirty-two beef steers (285 +/- 3 kg BW) were used to determine the effects of chlortetracycline and dietary protein level on visceral tissue mass, chemical composition, intestinal morphology, and proliferation rate indices. Steers were allotted randomly by weight to a factorial arrangement of dietary treatments consisting of either 10 or 13% CP diets top-dressed with a corn meal carrier (500 g/d) containing either 0 or 350 mg of chlortetracycline. After 84 d, steers were slaughtered and visceral organs removed and separated. Rinsed wet tissue mass was recorded; total RNA, total DNA, tissue DM, and tissue N content were determined; and tissue sections were prepared for immunohistochemical analysis. Thin tissue sections were evaluated to determine crypt depth and villus height as well as proliferation rate by immunohistochemical detection of the nuclear antigen Ki67. Rumen and abomasum weights and small intestinal length were greater (P < 0.04) in steers fed the 13% CP diet than in those fed the 10% CP diet on both an absolute weight basis and a percentage of empty BW. Chemical composition of the small intestinal and ruminal segments were largely unaffected by increased dietary protein. Increasing the dietary CP also increased the villus height in duodenal (P = 0.02) and the crypt depth of jejunal (P = 0.03) sections. Dietary administration of chlortetracycline decreased (P < 0.01) small intestinal weight both on absolute and empty BW bases. Nitrogen and RNA concentrations of the small intestinal segments were unaffected (P > 0.1) by dietary administration of subtherapeutic levels of chlortetracycline; however, because of increases (P < 0.05), or tendencies for an increase (P < 0.1), in the tissue content of DNA, the ratio of N to DNA was decreased (P < 0.05) or tended to be decreased (P < 0.1) in the small intestinal segments of the chlortetracycline-treated animals. The observed decrease in small intestinal epithelial mass does not appear to be due to alterations in cell proliferation rate but rather cell size. Consistent with this finding, cell proliferation, as determined by Ki67 antigen staining, was not affected by dietary treatment. Chlortetracycline administration decreased small intestinal mass that may be a result of decreased cell size.

Performance and carcass traits of early-weaned steers receiving either a pasture growing period or a finishing diet at weaning.

A 2-yr study was conducted to evaluate 1) steers fed ad libitum high concentrate after weaning (CONC), or 2) steers grown on pasture for 82 d, followed by high-concentrate finishing (PAST), on the performance and carcass traits of 74 early-weaned (117 d of age) steers. Potential breed differences were evaluated using crossbred steers of three types: 1) 3/4 Angus x 1/4 Simmental (BRI), 2) 3/4 Simmental x 1/4 Angus (CON), and 3) 1/2 Wagyu x 1/4 Angus x 1/4 Simmental (WAG). Steers were randomly assigned within breed to the two treatments. There was no interactions (P > .10), so the data were pooled over years. The CONC steers had an ADG that was .17 kg/d higher (P = .0001), intake 1.09 kg/d lower (P = .0001), and gain:feed ratio .013 unit better (.190 vs .177, P = .008) than PAST steers overall. Growing treatment did not affect total concentrate consumed (P = .97). The BRI steers required 31 d less than did CON steers (P = .008), and 23 d less than WAG steers (P = .05) when fed to a constant fat end point (1.1 cm). The BRI steers exhibited an ADG .16 kg/d higher (P = .0003), tended (P = .07) to have an ADG intake .49 kg/d higher, and exhibited gain:feed .01 unit better (.189 vs 180) than WAG steers. When compared with CON steers, BRI steers consumed 310 kg less total concentrate (P = .0003). No differences (P > .38) were observed between growing treatments for carcass characteristics or sensory attributes except that CONC steers tended (P = .11) to improve percentage of steers grading Average Choice or higher by 47% over PAST steers. The WAG steers had a 76-unit higher marbling score (1,000 = Small00, 1,100 = Modest00) (P = .006) than BRI steers, resulting in 19% more (P = .09) steers grading > or = Choice and 82% more (P = .03) grading > or = Average Choice. Liver (P = .15) and rumen (P = .01) weights as a percentage of hot carcass weight were reduced for CONC steers. The CONC steers had higher gain, lower intake, better efficiency, reduced liver and rumen weights, and consumed the same amount of total concentrate when compared with PAST steers. The BRI steers had less finishing days and lower daily intake compared with CON steers. The WAG steers had more days finishing, lower gain, lower intake, more undesirable efficiencies, consumed the same amount of total concentrate, and improved quality grades compared with BRI steers.

The influence of oral niacin doses during different dietary protein levels on indexes of rumen fermentation, blood parameters and fattening performance of young bulls

The influence of added niacin (0, 0.5 or 1 g per animal per day) and different crude protein contents (9.2 to 12.0% of DM) or the supply of various N-sources (urea, rape seed meal, soya bean meal, fish meal) were investigated on rumen fermentation, blood parameters, feed intake, weight gain and dry matter (DM) intake per weight gain in three individual feeding experiments with 156 growing bulls weighing between 175 and 300 kg per animal. Niacin supplementation did not significantly influence (P > 0.05) investigated parameters of rumen fermentation and blood. Ruminal propionate concentration increased insignificantly (from 18.9 to 19.5 moles per 100 moles on the average), inorganic P of blood serum somewhat decreased (from 2.98 to 2.82 mmol per 1) when niacin was added (P > 0.05). Protein level did not significantly influence rumen fermentation and blood parameters except an increased urea concentration in the blood of cattle fed with diets richer in protein. The DM intake of control bulls and niacin supplemented animals amounted to 6.35 and 6.46 kg per animal per day on average. Influence of niacin on DM intake varied in dependence on protein source. The daily weight gain increased from 1003 (control) to 1040 g per animal per day (+ niacin, P > 0.05). Niacin increased weight gain of bulls of urea (+ 43 g) and rape seed or soya bean meal added rations (+ 60 g per animal per day), but did not influence the weight gain in fish meal added rations. Increased weight gain resulted from ruminal and metabolic effects (about 2/3) as well as enhanced feed intake of bulls (about 1/3). Feed efficiency mostly improved.