Cacao bean husk: an applicable bedding material in dairy free-stall barns.

OBJECTIVE: The objectives of the study were to assess the effect of cacao bean husk as bedding material in free-stall barn on the behavior, productivity, and udder health of dairy cattle, and on the ammonia concentrations in the barn. METHODS: Four different stall surfaces (no bedding, cacao bean husk, sawdust, and chopped wheat straw) were each continuously tested for a period of 1 week to determine their effects on nine lactating Holstein cows housed in the free-stall barn with rubber matting. The lying time and the milk yield were measured between d 4 and d 7. Blood samples for plasma cortisol concentration and teat swabs for bacterial counts were obtained prior to morning milking on d 7. The time-averaged gas-phase ammonia concentrations in the barn were measured between d 2 and d 7. RESULTS: The cows spent approximately 2 h more per day lying in the stalls when bedding was available than without bedding. The milk yield increased in the experimental periods when cows had access to bedding materials as compared to the period without bedding. The lying time was positively correlated with the milk yield. Bacterial counts on the teat ends recorded for cows housed on cacao bean husk were significantly lower than those recorded for cows housed without bedding. Ammonia concentration under cacao bean husk bedding decreased by 6%, 15%, and 21% as compared to no bedding, sawdust, and chopped wheat straw, respectively. The cortisol concentration was lowest in the period when cacao bean husk bedding was used. We observed a positive correlation between the ammonia concentrations in the barn and the plasma cortisol concentrations. CONCLUSION: Cacao bean husk is a potential alternative of conventional bedding material, such as sawdust or chopped wheat straw, with beneficial effects on udder health and ammonia concentrations in the barns.

Rumen fermentation, milk production and conjugated linoleic acid in the milk of cows fed high fiber diets added with dried distillers grains with solubles.

The effects of corn dried distillers grains with solubles (DDGS) feeding on rumen fermentation and milk production in cows were evaluated using diets high in neutral detergent fiber (NDF, 45.9-46.6%). The control diet (Control) consisted mainly of hay, corn silage and concentrates. In the experimental diets, the concentrates were replaced with DDGS as 10% dry matter (DM) (10%DDGS) and 20% DM (20%DDGS). Eight cows were used for each 14-day treatment period. Effect of DDGS feeding on DM intake was not significant. Ruminal volatile fatty acids and ammonia-N at 5 h after feeding of 20%DDGS were decreased compared to Control, whereas protozoal count at 2 h after feeding of 20%DDGS was higher than that of 10%DDGS. Milk yield of cows fed DDGS diets was greater than that of Control, although percentages of milk protein and solids-not-fat were decreased by DDGS diets. The proportions of C10:0, C12:0, C14:0 and C16:0 in the milk fat decreased, and those of C18:0, C18:1, C18:2 and cis-9, trans-11 conjugated linoleic acid (CLA) increased markedly with elevated DDGS. Increase in trans-11 C18:1 was observed in the rumen fluid at 5 h after feeding. These findings suggest that DDGS feeding enhanced milk yield, as well as CLA synthesis under a high dietary NDF condition.

Time course of changes in antioxidant activity of milk from dairy cows fed a trehalose-supplemented diet.

This study was to investigate the time course of changes to the antioxidant activity of milk from cows fed a trehalose-supplemented diet, and to determine possible underlying mechanisms for observed changes. Six Holstein cows were used, and subjected to two experimental feeding periods consisting of a 1% trehalose-supplemented diet for 10 days, followed by a basal diet only (no trehalose) for 10 days. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities in milk were gradually increased during the trehalose supplementation period and were highest at the end of the second period. However, trehalose was not detected in the milk and plasma of dairy cows fed a diet supplemented with trehalose for 10 days, indicating that the increased antioxidant activity in the milk of trehalose-fed cows is not due to the direct transfer of trehalose to the milk. Plasma DPPH activities exhibited a similar time course to that seen for milk. Relative superoxide dismutase (SOD) activities in the rumen were higher 3 days after the end of trehalose supplementation than at any other time during the experimental periods. These results suggested that the improved antioxidant activity in milk and plasma of cows fed a trehalose-supplemented diet was due to improved ruminal relative SOD activity.

McrA gene and 16S rRNA gene in the phylogenetic analysis of methanogens in the rumen of faunated and unfaunated cattle.

The influence of rumen protozoa on the composition of rumen methanogens was studied by using seven growing Holstein cattle divided into two groups: four faunated and three unfaunated. 16S ribosomal RNA gene (rDNA) and methyl coenzyme-M reductase (MCR) α subunit (mcrA) gene clonal libraries were constructed. The results of each analysis showed that Methanobacteriales was dominant in the rumen of both groups. By mcrA gene analysis, 22.1% of unfaunated clones were classified into unfaunated group 1, which was not detected from faunated cattle. The 16S rRNA gene analysis showed that the number of operational taxonomic units was higher in unfaunated than faunated cattle, suggesting the diversity of methanogens tended to be higher by the removal of protozoa. The results of the LIBSHUFF program indicated that the 16S rRNA gene and mcrA gene clone libraries for the faunated group differed from those for the unfaunated group (P = 0.001). It was suggested that the presence of protozoa strongly affected the composition of rumen methanogens.

Effect of supplementation of soy sauce oil and Ca salts of fatty acids on rumen fermentation, milk production and conjugated linoleic acid in milk of dairy cows.

Eight cows were used to evaluate the effects of supplementation of soy sauce oil (SO) or Ca salts of fatty acids (FA) on rumen fermentation and milk production. The control diet (CO) consisted mainly of hay, corn silage and a concentrate. In the experimental diets, 400 g/day per cow of SO or FA (soybean oil and rapeseed oil) was supplemented to the CO diet. Experimental period for the three treatments was 14 days, and milk samples were taken during the last 2 days and rumen sample was taken on the last day. Dry matter intake was not affected by the treatments. The number of rumen protozoa at 0 h increased by SO and FA diets. Total volatile fatty acids at 2 h after feeding of SO diet was decreased compared to CO. The milk composition yield did not differ among treatments, although the percentages of fat and protein were decreased by SO and FA diets. The proportions of C8-C16 fatty acids in milk fat decreased, and those of C18 increased by SO and FA diets. The proportion of cis-9, trans-11 conjugated linoleic acid in milk fat by SO and FA diets increased by 120% and 135%, respectively. In spite of the slight suppression of rumen fermentation by SO diet, negative effects on feed intake and milk production were not detected.

Fatty acid composition of ruminal bacteria and protozoa, and effect of defaunation on fatty acid profile in the rumen with special reference to conjugated linoleic acid in cattle.

Objectives of this study were to compare fatty acid (FA) composition of ruminal bacterial (B) and protozoal (P) cells, and to investigate effect of protozoa on FA profile in the rumen of cattle. Three cows were used to prepare ruminal B and P cells. Four faunated and three defaunated cattle (half-siblings) were used to study effect of protozoa on ruminal FA profile. Proportions of C16:0 and C18:0 in total fatty acids in B cells were 20.7% and 37.4%, whereas those in P cells were 33.4% and 11.6%, respectively. Proportions of trans-vaccenic acid (VA) and cis-9, trans-11 conjugated linoleic acid (CLA) in B cells were 3.9% and 1.0%, and those in P cells were 5.5% and 1.6%, respectively, being higher in P cells. Proportions of C18:1, C18:2 and C18:3 in P cells were two to three times higher than in B cells. Proportions of unsaturated fatty acids, VA and CLA in B cells of faunated cattle were higher than those of defaunated. VA and CLA in the ruminal fluid of faunated were also 1.6 to 2.5 times higher than those of defaunated. This tendency was similar for cell-free fraction of ruminal fluid. These results indicate that protozoa contribute greatly in VA and CLA production in the rumen.

Real-time PCR detection of the effects of protozoa on rumen bacteria in cattle.

A real-time PCR approach was used in this study to clarify the populations of major bacterial species in the rumens of faunated and unfaunated cattle. The sensitivity of this novel real-time PCR assay was evaluated by using 10(1) to 10(8) plasmid copies of target bacteria. The numbers of plasmid copies of Ruminococcus albus, Ruminococcus flavefaciens, Prevotella ruminicola, and the CUR-E cluster were higher in the unfaunated than in the faunated rumens. The CUR-E cluster belongs to the Clostridium group. In contrast, Fibrobacter succinogenes was higher in the faunated than in the unfaunated rumens. Although it is well known that an absence of protozoa brings about an increase in the bacterial population, it was clarified here that an absence of protozoa exerted differential effects on the populations of cellulolytic bacteria in cattle rumens (i.e., F. succinogenes, R. albus, and R. flavefaciens). In addition, real-time PCR analysis suggested that the CUR-E cluster was more prevalent in the unfaunated rumens.

Culture-independent analysis of fecal microbiota in cattle.

The phylogenetic diversity of the fecal bacterial community in Holstein cattle was determined by 16S ribosomal RNA gene sequence analysis. The sequences were affiliated with the following phyla: Firmicutes (81.3%), Bacteroidetes (14.4%), Actinobacteria (2.5%), and Proteobacteria (1.4%). The Clostridium leptum subgroup was the most phylogenetically diverse group in cattle feces. In addition, a number of previously uncharacterized and unidentified bacteria were recognized in clone libraries.

The effect of protozoa on the composition of rumen bacteria in cattle using 16S rRNA gene clone libraries.

The effect of the presence of protozoa on the composition of rumen bacteria was investigated in cattle. Seven castrated Holstein cattle were divided into two groups: four faunated and three unfaunated, and 16S ribosomal RNA gene (rDNA) clonal libraries were constructed. A total of 312 clones were sequenced across 1,500 bp. The 151 sequences of the faunated cattle were classified into 98 operational taxonomic units (OTUs) having at least 97% similarity. The sequences derived from the faunated cattle were classified into Firmicutes (59.7%), Bacteroidetes (34.4%), Spirochaetes (2.6%), Actinobacteria (2.0%), and Proteobacteria (1.3%). Bacteroides and Prevotella (34.4%) were the major groups in the faunated cattle. The 161 sequences in the unfaunated cattle were classified into 72 OTUs. The sequences derived from the unfaunated libraries were classified into Firmicutes (65.7%), Bacteroidetes (31.1%), Proteobacteria (1.9%), and Spirochaetes (1.2%). The Clostridium botulinum group and its relatives (36.0%) were the major groups in the unfaunated cattle. An analysis by the computer program LIBSHUFF clarified that the presence of ruminal protozoa markedly affected the composition of rumen bacteria.

Molecular cloning, expression, and characterization of an endo-beta-1,4-glucanase cDNA from Epidinium caudatum1.

An endo-beta-1,4-glucanase gene (epi3) from the rumen ciliated protozoan Epidinium caudatum was cloned from a cDNA library constructed by using the lambda ZAP II vector. The enzymatic activity of the gene product was detected by the Congo red assay, using carboxymethyl cellulose (CMC) as substrate. The nucleotide sequence of epi3 revealed 1,253 nucleotides with an open reading frame for a protein (Epi3) of 356 amino acids (Mr -41,014). Epi3 shows high homology with family 5 endoglucanase genes and with genes from protozoa isolated from sources other than the rumen. The specific activity of Epi3 produced in Escherichia coli was 5.544, 2.754, and 0.295 mmol of glucose min(-1) mg(-1) protein when the substrates used were CMC, beta-glucan, and xylan, respectively. A beta-1,4-linked trisaccharide of glucose was the preferred substrate of Epi3, as determined by analysis with the p-nitrophenyl form of the substrate. To our knowledge, this is the first report of the isolation of an endoglucanase gene from a rumen protozoan.