Empty Rumen Research Articles

Preweaning Megasphaera elsdenii Supplementation in Dairy-Beef Calves: Impact on Performance, Behavior, and Rumen Development

This study evaluates the effects of an oral probiotic capsule containing a live culture of M. elsdenii NCIMB 41125 on performance, feeding behavior, rumen pH VFA, and development of dairy-beef crossbred calves. Thirty-one male dairy-beef crossbred calves (Holstein x Angus; mean ± SD; 45.3 ± 7.1 kg; 8.2 ± 2.0 d old) were enrolled in a blinded, 76-d randomized trial. Calves were randomly assigned to one of 3 treatments: placebo, probiotic capsule administration on d 15, or probiotic capsule on d 15 plus a second capsule on d 39 of the study. Calves were housed individually with ad libitum access to water and calf starter and were fed 7L/d of milk replacer (1050g of powder/d) in 2 meals until d 41, then 3.5L/d in 2 meals until weaning on d 56. Behavioral observations were recorded in 1-min intervals using a wall-mounted camera. Rumen fluid samples were collected on d 14, 35, 49, 58, and 70, and analyzed for pH and VFA. Upon euthanasia on d 77, forestomach weights were recorded, and rumen papillae dimensions were measured. Mixed linear models were used for statistical analysis. Probiotic treatment resulted in greater daily solid feed DMI and ADG, particularly during weaning and postweaning periods. Additionally, probiotic treated calves spent more time drinking water and tended to have lower rumen pH compared with control. Empty rumen weight and papillae area were greater in calves supplemented with the probiotic capsule on d 15 compared with the other treatments. These findings suggest that preweaning M. elsdenii supplementation enhances performance and rumen development in dairy-beef crossbred calves. However, the impacts of timing and number of capsule applications on rumen development and calf performance should be further investigated. Further research should also investigate the probiotic's impact on the rumen microbiome and fermentation dynamics throughout the rearing period using detailed microbiome analysis.

Aspectos clínicos, ultrassonográficos e anatomopatológicos do teratoma ovariano em uma novilha

ABSTRACT: Teratomas rarely occur in domestic species, especially in cattle. These tumors originate in fetal life and are characterized by rapid growth, which justifies their frequent detection in young animals. This study reported a case of ovarian teratoma in a heifer. On physical examination, the main signs identified were apathy, abdominal distention and tension, empty rumen, and mushy diarrhea. During rectal palpation, a mass was identified in the pelvic region, which was suggestive of cysts on ultrasound examination. The animal underwent laparotomy, followed by euthanasia due to a poor prognosis. At necropsy, a 54 x 43 x 52 cm (length x width x thickness) tumor was observed in the right ovary with multiple cystic areas, in addition to masses associated with multiple adhesions of the intestinal loops and peritonitis. On histopathology, muscle, cartilage, bone, nervous and epithelial tissue, glands, hair with follicles, were identified in the affected ovary. There was mixed inflammation and foci of necrosis observed with a complete absence of ovarian architecture in both the ovaries. Infiltrations were identified in the lymph nodes and mesenteric vessels. Glandular ducts were seen from the serosa to the intestinal mucosa. A locally infiltrative and expansile ovarian teratoma was diagnosed accordingly. It is considered that this kind of tumor can induce abdominal distension and absence of estrus in previously healthy, non-pregnant heifers.

Rumen Development of Artificially-Reared Lambs Exposed to Three Different Rearing Regimens.

Simple SummaryYoung ruminants possess an undeveloped rumen when first born. Encouraging good rumen development in early life is vital for young ruminants as they transition to a solid feed diet, to ensure optimum growth post-weaning. This study aimed to investigate the effect of three different rearing regimens on rumen development in lambs reared artificially. Weaning of lambs at 42 d of age improved rumen fluid n-butyric content and also resulted in a thicker rumen dorsal wall. Feeding lambs pellets with low fibre and weaning them early increased rumen fluid n-valeric content. Papillae width, density, and rumen wall muscle thickness were affected by rearing treatment. Empty rumen weight, rumen volume, papillae development, and rumen fluid iso-butyric and iso-valeric content had positive associations with dry matter intake and nutrient intakes from solid feed. The majority of volatile fatty acids in the rumen fluid had a positive association with papillae height on the rumen dorsal wall. These results suggest that lamb diet and age at weaning influenced rumen function and physical development. Further studies examining how rumen microbial composition and rumen gene expression are influenced by rearing regimens are required.The objective of this study was to examine the effect of three different rearing regimens on rumen development in lambs reared artificially. Romney ram lambs were randomly allocated to one of three treatments: commercial milk replacer fed to 57 d of age and high fibre concentrate pellets (HFP57); commercial milk replacer, high fibre concentrate pellets, and early weaning from milk replacer at 42 d of age (HFP42); high protein milk replacer from 2–16 d of age followed by commercial milk replacer, low fibre concentrate pellets, and early weaning from milk replacer at 42 d of age (LFP42). Lambs were slaughtered at 57 d of age. Volatile fatty acid content in rumen fluid at slaughter was analysed and rumen tissue samples were collected for histological examination. The rumen n-butyric content was greater (p < 0.05) in both LFP42 and HFP42 treatment lambs compared to HFP57 lambs. The n-valeric content was greater (p < 0.05) in LFP42 lambs compared to both HFP57 and HFP42 treatment lambs. Thickness of the rumen dorsal wall determined by ultrasound scanning at 49 d was greater (p < 0.05) in both HFP42 and LFP42 lambs compared to HFP57 lambs. There was an interaction (p < 0.05) between treatment and site of rumen tissue sampling on papillae width, density, and rumen muscular layer thickness. Collectively, early weaning and the provision of a low fibre pellet leads to improved rumen function and physical development.

Growth and Body Composition of Artificially-Reared Lambs Exposed to Three Different Rearing Regimens.

Simple SummaryOptimum lamb growth and cost-effective artificial lamb rearing are important to maximise farm profit. In addition to milk feeding, supplementation of a solid feed with balanced nutrients and an adequate level of fibre will aid rumen development, allowing for a smooth transition from a liquid to a solely solid diet. This study aimed to determine the effect of pellet fibre level, milk replacer composition and early milk weaning at 42 days of age, on the growth and body composition of lambs reared artificially to 57 days of age. Results demonstrate that lamb growth rate to 57 days of age was not affected by early weaning or pellet fibre level. Early milk weaning increased pellet intake and empty rumen weight. Early weaning resulted in leaner carcasses due to reduced fat deposition and lower total feed costs compared to lambs offered milk to 57 days of age. Overall, feeding lambs either low or high fibre pellets and weaning early (42 days of age) was shown to be beneficial, as growth was similar to unweaned lambs, but leaner carcasses and reduced feed costs were observed.This study was designed to investigate the influence of pellet fibre level, milk replacer composition and age at weaning on growth and body composition of lambs reared artificially. Romney ram lambs were randomly allocated to one of three rearing treatments; HFP57: commercial milk replacer to 57 days of age, and high fibre concentrate pellets; HFP42: commercial milk replacer with early weaning at 42 days of age, and high fibre concentrate pellets; LFP42: high protein milk replacer from 2–16 days of age followed by commercial milk replacer with early weaning at 42 days of age, and low fibre concentrate pellets. Lambs were slaughtered at 57 days of age. Overall average daily liveweight gain of lambs did not differ (p > 0.05) between treatments. Dressing out percentage, carcass weight, empty small intestine and omental fat were higher (p < 0.05) in HFP57 than in both HFP42 and LFP42 lambs. HFP42 and LFP42 lambs had heavier (p < 0.05) empty rumen weights. Whole body protein content was higher (p < 0.05) in HFP42 lambs compared to both HFP57 and LFP42 lambs. Fat content and daily fat deposition were greater (p < 0.05) in HFP57 lambs than HFP42 and LFP42 lambs. Weaning lambs at 42 days of age with provision of either low or high fibre concentrate pellets, resulted in similar growth rates, reduced whole body fat deposition and was a more cost-effective rearing regimen.

Repeated Inoculation of Young Calves With Rumen Microbiota Does Not Significantly Modulate the Rumen Prokaryotic Microbiota Consistently but Decreases Diarrhea.

The complex rumen microbiota exhibits some degree of host specificity. The undeveloped simple rumen microbiota is hypothetically more amendable. The objective of this study was to investigate if the rumen prokaryotic microbial assemblage of young calves can be reprogrammed by oral inoculation with rumen microbiota of adult cows. Twenty newborn male calves were randomly assigned to four groups (n = 5 per group), with two groups being orally inoculated with rumen microbiota (fresh rumen fluid) collected from two lactating dairy cows, while the other two groups receiving autoclaved rumen fluid collected from another two donor cows. Each calf was orally drenched with 100, 200, 300, 400, and 500 mL of the rumen fluid at d3, d7, d21, d42, and d50, respectively, after birth. The inoculation with rumen microbiota did not affect (P > 0.05) feed intake, average daily gain (ADG), heart girth, or feed conversion ratio but significantly (P < 0.01) lowered instance of diarrhea. At the age of 77 days (27 days post-weaning), all the calves were slaughtered for the sampling of rumen content and determination of empty rumen weight. Rumen fermentation characteristics were not affected (P > 0.05) by the inoculation. Rumen prokaryotic microbiota analysis using metataxonomics (targeting the V4 region of the 16S rRNA genes) showed that the calf rumen prokaryotic microbiota differed from that of the donors. Two Succinivibrionaceae OTUs, two Prevotella OTUs, and one Succiniclasticum OTU were predominant (relative abundance > 2%) in the donors, but only one Succinivibrionaceae OTU was found in the calves. On the other hand, five other Prevotella OTUs were predominant (>3%) in the calves, but none of them was a major OTU in the donors. No correlation was observed in relative abundance of major OTUs or genera between the donor and the calves. Principal coordinates analysis (PCoA) based on weighted UniFrac distance showed no significant (P > 0.05) difference in the overall rumen prokaryotic microbiota profiles among the four calf groups, and principal component analysis (PCA) based on Bray-Curtis dissimilarity showed no significant (P > 0.05) difference in functional features predicted from the detected taxa. Nor the calf rumen microbiota showed any clustering with their donor’s. Repeated oral inoculation with rumen microbiota probably has a limited effect on the development of rumen microbiota, and the rumen microbiota seems to develop following a program determined by the host and other factors.

Hair Cortisol in Sheltered Cows and Its Association with Other Welfare Indicators.

Simple SummaryHair cortisol concentrations are measured for the assessment of long-term stress in animals. The objective of this study was to assess the levels of stress in retired, abandoned and unproductive cows housed in traditional shelters through the measurement of their hair cortisol levels. The study further aimed to explore the association of the hair cortisol concentrations with other cow and resource-based welfare indicators. High hair cortisol levels were associated with dung lying in the sheds, low dry bulb temperature and shelters having little access to the yards. At the cow level, high hair cortisol levels were associated with injuries on the joints and body, dehydration, old age, and low body hair loss level. The study concluded that hair cortisol is an effective tool to assess stress levels in cows under field conditions.India, the country with the largest population of dairy cows in the world, has a policy of retiring abandoned and non-lactating cows in shelters, but the level of provision for their welfare in these shelters is unclear. Cows in 54 shelters across India were assessed for historic evidence of physiological stress, through determination of hair cortisol in 540 samples from 10 cows in each shelter by enzyme immunoassay. Animal-based and shelter resource-based welfare measures were recorded and correlations with the hair cortisol investigated by multivariable analysis. High hair cortisol concentrations were associated with dung in the lying area of the cowshed, a low dry bulb temperature there and little cow access to yards, as shelter-based variables. At a cow level, high hair cortisol concentrations were associated with dirty flanks, hock joint ulceration, carpal joint injuries, body lesions, dehydration, an empty rumen, old age, and low levels of body hair loss. Hair cortisol level promises to be an effective biomarker of stress in cows when conducting studies under field conditions.

The effect of adding fennel (Foeniculum vulgare) seed powder to the diet of fattening lambs on performance, carcass characteristics and liver enzymes

The objective of this research was to investigate the effects of adding fennel (Foeniculum vulgare) seed powder (FSP) to the diet on dry matter intake (DMI), live weight gain and carcass characteristics in fattening male lambs. Thirty lambs (27.5 ± 0.45 kg body weight (BW) at eight months of age) were allotted to three experimental diets in a completely randomized design. Experimental diets were 1) control diet (no FSP); 2) diet containing 0.75% FSP and 3) diet containing 1.5% FSP. The ratio of forage to concentrate in diets was 40:60 (dry matter basis). The lambs were allocated to three groups with equal animals and fed the diets for 80-days. At the end of the experiment, all animals were slaughtered on the same day. The day before slaughter blood samples were taken 3 h after morning feeding. Lambs fed the 1.5% FSP diet had greater (P < 0.05) DMI, final BW, live daily gain, the weights of warm and cold carcass, lean meat, loin, leg, gallbladder, testis and eye muscle area than those fed control diet. The best feed conversion (FC) was achieved in lambs fed 1.5% FSP diet (P < 0.05). Adding FSP to the diet of lambs decreased (P < 0.05) the liver and cooled shrink weights. The back fat depth and weight of empty rumen in lambs fed 0.75% FSP were lower in comparison to other diets (P < 0.05). Adding FSP increased the concentration of blood testosterone (P < 0.05). The lower concentrations of liver SGPT and SGOT in lambs fed 0.75% FSP compared with other diets were observed. Results of this research showed that adding 1.5% FSP to the diet of fattening lambs increased their finishing performance and muscle tissue yield, and improved FC.

Infusion of sodium butyrate promotes rumen papillae growth and enhances expression of genes related to rumen epithelial VFA uptake and metabolism in neonatal twin lambs.

The objective of this study was to evaluate the effect of sodium butyrate (SB) infusion on rumen papillae growth and volatile fatty acid (VFA) uptake and metabolism in neonatal lambs. Seven pairs of newborn twin lambs were used. Within each pair, lambs were assigned to receive an oral infusion of SB at 0.36 g/kg body weight (BW) (SB, n = 7) or the same volume of saline (Con, n = 7). Treatments were administered from 10 to 49 d of age, when all lambs were slaughtered. Results showed that the average daily feed intake (ADFI) of starter, average daily gain (ADG), BW of lambs at ages of 5 and 6 wk in SB group were greater (P < 0.05) than those in Con group. Infusion of SB increased (P < 0.05) the concentrations of acetate, butyrate, and total VFA in the rumen fluid and elevated (P < 0.05) the levels of β-hydroxybutyrate acid (BHBA), insulin-like growth factor-1 (IGF-1), and insulin in plasma. Infusion of SB promoted rumen papillae growth, depicted by higher emptied rumen weight, larger rumen papillae length, width, and surface area, and greater thickness of stratum corneum and total epithelium. Sodium butyrate infusion upregulated (P < 0.05) mRNA expression of cyclin A2, cyclin D1, and cyclin-dependent kinases 6 (CDK6), and downregulated (P < 0.05) mRNA expression of caspase-3 and Bcl-2-associated X protein (Bax) in the rumen epithelia. Moreover, SB infusion also upregulated (P < 0.05) mRNA expression of insulin-like growth factor-1 receptor (IGF-1R), and insulin-like growth factor-binding protein 5 (IGFBP-5), and downregulated (P < 0.05) mRNA expression of insulin-like growth factor-binding protein 3 (IGFBP-3) in the rumen epithelia. Sodium butyrate infusion also enhanced (P < 0.05) gene expressions of monocarboxylate transporter isoform 1 (MCT1), downregulated in adenoma (DRA), 3-hydroxy-3-methylglutaryl-CoA synthase isoform 2 (HMGCS2), and 3-hydroxy-3-methylglutaryl-CoA lyase (HMGCL), while depressed (P < 0.05) mRNA expression of sodium/proton exchanger isoform 2 (NHE2) in the rumen epithelia. Our results suggest that the SB infusion can improve animal performance, promote the ruminal papillae growth, and enhance expression of genes related to ruminal epithelial VFA uptake and metabolism in preweaning twin lambs. These findings provide a better understanding of the molecular mechanism of SB promoting rumen epithelial development and function in preweaning lambs.

Cow responses and evolution of the rumen bacterial and methanogen community following a complete rumen content transfer

AbstractUnderstanding the rumen microbial ecosystem requires the identification of factors that influence the community structure, such as nutrition, physiological condition of the host and host–microbiome interactions. The objective of the current study was to describe the rumen microbial communities before, during and after a complete rumen content transfer. The rumen contents of one donor cow were removed completely and used as inoculum for the emptied rumen of the donor itself and three acceptor cows under identical physiological and nutritional conditions. Temporal changes in microbiome composition and rumen function were analysed for each of four cows over a period of 6 weeks. Shortly after transfer, the cows showed different responses to perturbation of their rumen content. Feed intake depression in the first 2 weeks after transfer resulted in short-term changes in milk production, methane emission, fatty acid composition and rumen bacterial community composition. These effects were more pronounced in two cows, whose microbiome composition showed reduced diversity. The fermentation metrics and microbiome diversity of the other two cows were not affected. Their rumen bacterial community initially resembled the composition of the donor but evolved to a new community profile that resembled neither the donor nor their original composition. Descriptive data presented in the current paper show that the rumen bacterial community composition can quickly recover from a reduction in microbiome diversity after a severe perturbation. In contrast to the bacteria, methanogenic communities were more stable over time and unaffected by stress or host effects.

Survey of Rumen Impaction in Goat from Katsina Metropolis, Katsina State, Nigeria

The study was conducted to investigate rumen impaction in goats slaughtered at Katsina Metropolitan Abattoir by administering 147 questionnaires and making weekly visits to the abattoir for information retrieval for eleven weeks. In addition, live-weights of sampled animals, weight of rumen contents and empty rumen were determined. The data indicated that 60% of the animal keepers allow their animals to scavenge on refuse and majority (93%) of the respondents observed some effects of rumen infection, which include death of the animals (34%). The result revealed that the problem was more common among the age range of 16 and 18 months of age and that sex also has effect on the rate of impaction occurring more in females. Types and quantity of non-degradable materials in the affected animals were identified and polythene materials occurred more. Frequency of non-degradable materials was also observed in goats. The study recommends cleanup of the environment in that, it will substantially reduce foreign bodies syndrome in goats, proper feeding, addition of mineral constituents in the diet, hence there is need for state legislature to enforce proper disposal of non-degradable synthetic polythene materials to make the environment safe for ruminants.

Effects of forage type and age at which forage provision is started on growth performance, rumen fermentation, blood metabolites and intestinal enzymes in Holstein calves

The aim of this study was to determine the effects of two forage sources supplemented either from Day 3 or Day 15 of age on growth performance, rumen fermentation, blood metabolites, intestinal enzymes and incidence of diarrhoea in Holstein bull calves. Forty neonatal male Holstein calves (40.6 ± 5.8 kg BW) were randomly assigned to five treatments, with eight replicates each, including calves fed starter feed without any forage provision (Control; CON), and the same starter plus either chopped alfalfa hay started fed from Day 3 (AE) or Day 15 of age (AL) or chopped oat hay fed from Day 3 (OE) or Day 15 of age (OL). The study finished when all calves were weaned at 56 days of age. During the experimental period average daily gain, starter intake and total dry matter intake were similar among calves fed either of five dietary treatments (P &gt; 0.05). Empty rumen weight (proportional to bodyweight) was greater in CON calves than in OL calves (P &lt; 0.05). The AL calves had a lighter small intestine compared with CON, OL and AE calves, but similar to OE. Frequency of diarrhoea was not affected by dietary treatment (P &gt; 0.05). Rumen concentration of total volatile fatty acids and pH were similar among dietary treatments (P &gt; 0.05). Control calves had a lower molar proportion of acetate compared with OL calves, but similar to the other calves (P &lt; 0.05). Forage-fed calves had similar molar proportion of butyrate to CON calves. Acetate to propionate ratio was higher in OL-fed calves than in those fed CON and AE diets (P &lt; 0.05). Rumen concentration of NH3-N tended to be higher (P = 0.059) in CON calves than in forage-fed calves. During experimental period, serum concentrations of globulin, total protein, glucose and total cholesterol were similar among dietary treatments. Calves fed OE had lower serum concentration of albumin than those fed other diets (P &lt; 0.01). Serum concentration of triglycerides (P &lt; 0.05) was greater in calves fed AE followed by those fed AL and then those fed CON, OL and OE. The AL-fed calves had a higher serum lactate dehydrogenase compared with AE and OE fed calves, but similar to calves fed OL and CON. Duodenum amylase concentration was greater (P &lt; 0.05) in AE-fed calves compared with CON-fed calves, but similar to calves fed AL, OL and OE. Calves fed OL had greater (P &lt; 0.05) ileum lipase concentration than those fed OE, but similar to calves fed AL, AE and CON. In conclusion, provision of chopped alfalfa or oat hay to calves either from Day 3 or Day 15 of age resulted in similar starter intake and total dry matter intake and feed efficiency and physical development of the reticulorumen compared with calves fed the CON diet, which justifies the supply of forage to young calves, even at an early age, as forages are generally cheaper than starter concentrates.

602 The impact of time on feed and partial replacement of high-moisture corn with a high-lipid high-fiber pellet on steer performance, visceral organ weight, fat deposition, and carcass composition

The objective of this experiment was to determine the impact of time on feed and the partial replacement of starch with a high-fat, high-fiber by-product based pellet. Angus crossbred steers (n = 97; initial BW 469.3 ± 45.8 kg) were randomly assigned to one of two isocaloric dietary treatments: control (CON; n = 48) steers were fed a finishing diet consisting of 10% haylage, 77% high-moisture corn, 11% soybean meal, and 2% of a salt, vitamin, and mineral pre-mix including monensin; or high-fat, high-fiber pellet (HLHF; n = 49). The HFHF contained 29.8% wheat shorts, 26.2% corn DDGS, 18.8% soy hulls, 19.2% corn gain, and 6% tallow and replaced 30% (DM basis) of the high moisture corn in CON. Steers were randomly assigned to pens equipped with Insentec feeders to record individual feed intake. Steers were randomly split into two blocks in order to facilitate sample collection at the abattoir. On d 1 of the feeding period and every 6 wk thereafter, 10 steers from each treatment were selected at random and slaughtered. Organ and visceral fat weights were recorded, and rib sections were cut into muscle, fat, and bone in order to estimate carcass composition. Data were analyzed as a randomized complete block using PROC MIXED in SAS and included the fixed effects of diet, time on feed, and random effects of pen and block. Contrasts between diet and linear effects of time on fed were used for mean separation and significance was declared at P ≤ 0.05. Steer initial BW did not differ (P ≥ 0.43); however, final BW increased linearly (P < 0.001), but did not differ with dietary treatment (P = 0.55). Overall ADG did no differ with dietary treatment (P = 0.63), but decreased linearly with increasing time on feed (P = 0.015). Empty rumen mass was 12.4 and 11.4 ± 0.24 for CON and HLHF (P = 0.004). Abomasum weight tended to be heavier for HLHF than CON steers (P = 0.06). Carcass traits did not differ with dietary treatment (P > 0.51). Rib dissection indicated that rib section weights of lean, bone, intermuscular, body and subcutaneous fat did not differ with dietary treatment (P ≥ 0.24). Overall these data indicate that partially replacing starch with a high-lipid, high-fiber pellet had limited impacts on growth performance and carcass traits and energy partitioning in steers.

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.

Effect of electronic identification with ruminal bolus on growth parameters and stomach development in young goat kids

Although most of the European goat farms are dairies, there are a significant number of herds dedicated to meat production as the main product. Due to the current policy of food safety in European Union, the traceability, particularly the electronic identification, is taken into consideration; however, the effect of this electronic identification has not been studied on goat kids for fattening. For this reason, the effect of the ruminal bolus on the growth of goat kids and the development of their stomachs were studied. At 16 kg, animals were randomly assigned in two groups: control (n=23) and bolus (n=27), the latter identified with Inoxeramic Bolus. Both of them were slaughtered at 24 kg. Statistical differences in growth parameters and stomach development were not observed, except in the reticulum-omasal orifice diameter, which was bigger in the bolus group. Moreover, when the breed was taken into account (Majorera, Palmera and Tinerfeña), interbreed differences were found in orifice diameter and empty rumen–reticulum weight, due to treatment (P<0.05).

Short communication: Effect of breed on performance and carcass characteristics of Mexican hair sheep

To determine the effect of breed on growth performance and carcass characteristics in Mexican hair sheep, 48 lambs (average 38.9 &plusmn; 1.56 kg body weight, BW) were used in a completely randomized experimental design. The breed types assessed were 16 Pelibuey (PB), 16 Pelibuey x Katahdin (PB-KT) crossbred and 16 Pelibuey x Dorper (PB-DP) crossbred lambs. The lambs were fed a maize grain-based diet (88% concentrate and 12% forage) containing 155 g CP and 12.13 MJ ME/kg DM. The growth performance trial lasted 45 days. The average daily gain was significantly higher for the PB breed than for the PB-KT and PB-DP cross-breds. Feed intake in the PB and PB-KT was significantly higher than in the PB-DP. The feed conversion ratio was lower for the PB than for PB-KT and PB-DP lambs. Hot carcass dressing and leg perimeters were significantly lower for the PB than for the PB-DP lambs, and similar to that of the PB-KT lambs. The lowest dorsal fat values were measured in the PB breed, compared with both the PB-KT and PB-DP cross-breds. Mesenteric fat (as % of BW) in the PB was significantly higher than in PB-KT and PB-DP lambs. Empty rumen and small intestine weights (as % of BW) in the PB lambs were significantly higher than in the PB-DP lambs, but their large intestine was significantly smaller than in the other two breeds. It was concluded that the PB lambs have a better growth performance and carcass characteristics than the PB-DM lambs, but similar to that of the PB-KT lambs.Keywords: Dressing percentage, longissimus dorsi, organ weights, lambs, Pelibuey, Katahdin, Dorper

FATORES RELACIONADOS AO RENDIMENTO DE CARCAÇA DE NOVILHOS OU NOVILHAS SUPERJOVENS, TERMINADOS EM PASTAGEM CULTIVADA

The objective of the experiment was to study the body factors related to the variation of dressing percentage in castrated males or non-pregnant females, slaughtered at fourteen months of age. The animals were finished with energetic supplementation on cultivated pasture. Twelve contemporary animals of each sex were used, all crossbred Nellore (3/8) x Hereford (5/8) from the same herd. Farm live weight, slaughterhouse live weight and hot carcass weight were superior in males, being 365.8; 350.4 and 203.4 kg, respectively, while the females showed 310.3; 294.5; and 168.6 kg, in the same order. Males also showed higher hot carcass dressing percentage in relation to farm live weight (55.6 vs 54.4%) and in relation to slaughterhouse weight (58.1 vs 57.2%) than females. The lower female dressing percentage was a result of the higher hide (9.03 vs 7.96%), inguinal fat in the udder of heifers or cod fat of steers (1.02 vs .67%), full digestive tract (19.35 vs 16.84%), empty rumen plus reticulum (2.34 vs 1.91%) and empty intestine (2.54 vs 2.11%) percentages. There was no significant difference between sexes in heart, liver, lungs, kidneys and spleen percentages, being, respectively, 0.40, 0.93, 1.01, 0.22 and 0.35% in males and 0.41, 0.98, 1.02, 0.22 and 0.30% in females, cited in the same order. KEY WORDS: braford, hide, organs, rumen, sex.

Increased blood concentration of isopropanol in ketotic dairy cows and isopropanol production from acetone in the rumen

To evaluate acetone and isopropanol metabolism in bovine ketosis, the blood concentrations of isopropanol, acetone, plasma 3-hydroxybutyrate (3-HB) and other metabolites were analyzed in 12 healthy controls and 15 ketotic dairy cows including fatty liver and inferior prognosis after laparotomy for displaced abomasum. In ruminal fluid taken from 6 ketotic cows, ruminal isopropanol and acetone were also analyzed. Ketotic cows showed higher concentrations of isopropanol, acetone, 3-HB and nonesterified fatty acid, and higher activities of aspartate transaminase and gamma-glutamyl transferase than control cows. Blood samples had higher concentration of isopropanol accompanied by increased acetone. In the ketotic cows, acetone was detected not only in blood but also in ruminal fluid, while higher ruminal isopropanol did not necessarily accompany its elevation in the blood. Using 2 steers with rumen cannula, all ruminal content was emptied and then substituted with artificial saliva to evaluate the importance of ruminal microbes in isopropanol production. Under each condition of intact and emptied rumen, acetone was infused into the rumen and blood isopropanol was analyzed. The elevation in the blood isopropanol concentration after acetone infusion was markedly inhibited by the emptying. Here, increased blood concentrations of isopropanol and acetone were observed in ketotic cows, and the importance of ruminal microbes in isopropanol production was confirmed.

Performance at slaughtering of Marchigiana beef cattle

On a 766 heads sample of Marchigiana bullocks slaughtered in 2004-2006 at Senigallia’s Slaughterhouse main performance at slaughtering were recorded: identity, personal data, live weight, right hoof, right fore and hind limbs, head, tongue, skin, head skin, gross stomachs, empty rumen, gross intestines, stomach fat, thickness of skin, carcass and half weights, limb girth, SEUROP carcass and fatness scoring (using 3 subclasses). Avarage daily gain (ADG) and percentages were computed. All statistics were performed on 726 males: means, correlations, multivariate analysis, variance components, heritability. Average slaughtering data were: age 598.8 ± 78.6 d, live weight 681.6 ± 81.1 kg, live ADG 1.154 ± 0.175 kg/d, carcass weight 424.9 ± 54.9 kg, gross dressing 62.29 ± 2.08%, net dressing 68.89 ± 1,89%, carcass ADG 0.719 ± 0.116 kg/d. Phenotypic correlations of live weight with SEUROP carcass evaluation and fatness have been equal to 47% and 26% while the correlations between ADG, SEUROP and fatness carcass evaluation have been equal to 41% and 37%. Following heritabilities were estimated: carcass weight 0.29, skin 0.62, head 0.34, SEUROP carcass evaluation 0.48.

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.

Effect of rumen emptying on biting rate of cows grazingBrachiaria brizanthaat three stocking rates in Yucatán, México

SummaryThe experiment was carried out in the east of Yucatán, in pastures ofB. brizantha. It was of three months duration during the end of the rainy season. Four rumen cannulated cows with an average weight of 442 kg were used at all of three stocking rates: Low (2LU/ha), Medium (4LU/ha) and High (6LU/ha), to evaluate the effect of an empty rumen on the rate of biting, which was measured as the time taken to take 20 uninterrupted bites on ten occasions. The measurements were made on two sequential days at 09.00 h, the first under normal conditions, the second with an empty rumen. There was no effect (P&lt;0.050 of rumen emptying on the rate of biting which was 24 bites per minute when the animals were normal, and 25 bites a minute when the rumen was empty. On the other hand, there was a reduction of 8% in the rate of biting for the animals at the high stocking rate compared with the low and medium stocking rates. The finding that bite rate was not affected by an empty the rumen is evidence which gives confidence in the use of cannulated animals as collectors of representative samples of forage under grazing conditions.