Effect of replacing corn with brown rice in a total, mixed, ration silage on milk production, ruminal fermentation and nitrogen balance in lactating dairy cows

The Energy Contents of Broken Rice for Lactating Dairy Cows

This study aimed to evaluate (1) the net energy for lactation of broken rice in dairy cows and (2) the effects of broken rice substituting in diets on feed intake, nutrient energy utilization, and milk production. An energy metabolism experiment was conducted using a respiration chamber system in four multiparous Holstein crossbred cows (88.6% Holstein × 11.4% Native Thai; body weight of 438 ± 16.0 kg; 70 ± 31 days in milk) according to a 4 × 4 Latin square design with four 21-d periods. The four dietary treatments included a basal diet substitution with broken rice at 0%, 12%, 24%, and 36%. Increasing the substitution rate of broken rice in the diet resulted in unaffected feed intake, milk yield and composition, and energy balance (p > 0.05); however, a linear increase in the digestibility of dry matter, organic matter, and neutral detergent fiber (p < 0.05). The estimated net energy for lactation of broken rice was 8.68 MJ/kg. The net energy requirement for maintenance was estimated at 504 kJ/kg of metabolic body weight. Our results indicated that broken rice is a good energy-feed resource and that increasing the proportion in the diet up to 36% had no adverse effect on dairy cows' production performance.

Effects of the Use of Rice Grain on Growth Performances, Blood Metabolites, Rumen Fermentation, and Rumen Microbial Community in Fattening Hanwoo Steers

This study aimed to assess the influence of rice grain in the total mixed ration (TMR) on the growth performance, blood metabolites, rumen fermentation, and rumen microbial community of fattening Hanwoo steers. Two experimental diets were prepared: (i) a TMR containing 33% dry matter (DM) corn grains (Corn TMR) and (ii) a TMR containing 33% DM rice grains (Rice TMR). Twenty-two Hanwoo steers (body weight [BW], 498 ± 32 kg; months, 17 ± 0.5) were distributed into two treatment groups in a completely randomized block design according to BW. The Rice TMR group had a higher final BW and DM intake (DMI) compared to those in the Corn TMR group (p < 0.01). However, no difference was observed in the average daily gain (ADG) and feed conversion ratio (FCR) between the two treatments. For the rumen fermentation parameters, the molar portion of butyrate in the Rice TMR was higher than in the Corn TMR (p < 0.01). Streptococcus bovis tended to be higher in the Rice TMR (p = 0.09). The results of this study suggest that using rice grain as the primary starch source in TMRs may be an alternative option for fattening Hanwoo steers.

Improvement of Fermentation Quality in the Fermented Total Mixed Ration with Oat Silage

The use of the fermented total mixed ration (FTMR) is a promising approach for the preservation of homogeneous feed, but changes during fermentation and links with the bacterial community of FTMR are not fully understood. This study investigated the effects of adding oat silage (OS) to the fermented total mixed ration (FTMR) in terms of fermentation, chemical composition, and the bacterial community. The fermentation quality of FTMR with 22% OS was greatly improved, as demonstrated by decreases in the butyric acid concentration, a lower lactic acid/acetic acid ratio, a larger population of lactic acid bacteria (LAB), and quicker spoilage yeast death. Further examination of the effects of various ensiling days on nutritive values showed stable crude protein and nonprotein nitrogen (NPN) contents. The concentrations of acetic acid, propionic acid, and ammonia-nitrogen (NH₃-N) were increased following all FTMR treatments after 15 d, while the concentration of water-soluble carbohydrates (WSC) was decreased. More heterofermentative LAB, such as Lentilactobacillus buchneri, Lentilactobacillus brevis, and Companilactobacillus versmoldensis were found after adding 11% and 22% OS. Moreover, the addition of 22% OS caused a marked increase in both bacterial richness and diversity, dominated by the Lactobacillus genus complex. Among species of the Lactobacillus genus complex, the occurrence of Loigolactobacillus coryniformis was positively correlated with lactic acid, NPN, and NH₃-N concentrations, suggesting its potential role in altering the fermentation profiles.

Broken rice in a fermented total mixed ration improves carcass and marbling quality in fattened beef cattle

Objective

This study aimed to determine the effects of replacing cassava chips with broken rice in a fermented total mixed ration diet on silage quality, feed intake, ruminal fermentation, growth performance, and carcass characteristics in the final phase of fattening beef cattle.

Methods

Eighteen Charolais-Thai native crossbred steers (average initial body weight: 609.4±46 kg; average age 31.6 mo) were subjected to three ad libitum dietary regimes and were maintained in individual pens for 90 d before slaughter. The experimental design was a randomized complete block design by initial age and body weight with six replicates. The dietary regimens used different proportions of broken rice (0%, 16%, and 32% [w/w] of dry matter [DM]) instead of cassava chips in a fermented total mixed ration. All dietary treatments were evaluated for in vitro gas production and tested in in vivo feeding trials.

Results

The in vitro experiments indicated that organic matter from broken rice was significantly more digestible than that from a cassava-based diet (p<0.05). Silage quality, nutrient intake, ruminal fermentation characteristics, carcass fat thickness, and marbling score substantially differed among treatments. The ruminal total volatile fatty acids, propionate concentration, dietary protein intake, and digestibility increased linearly (p<0.05) with broken rice, whereas acetate concentration and the acetate:propionate ratio decreased linearly (p<0.05) with broken rice (added up to 32 g/kg DM). Broken rice did not influence plasma metabolite levels or growth performance (p>0.05). However, the marbling score increased, and the carcass characteristics improved with broken rice.

Conclusion

Substitution of cassava chips with broken rice in beef cattle diets may improve fattened beef carcass quality because broken rice increases rumen fermentation, fatty acid biosynthesis, and metabolic energy supply.

Substitution effects of rice for corn grain in total mixed ration on rumen fermentation characteristics and microbial community in vitro

This study determined the substitution effects of rice for corn as the main grain source in a total mixed ration (TMR). In vitro rumen fermentation characteristics and microbes were assessed using two experimental diets. Diets included 33% dry matter (DM) of either corn (Corn TMR) or rice grains (Rice TMR). In a 48-h in vitro incubation, DM digestibility (IVDMD), neutral detergent fiber degradability (IVNDFD), crude protein digestibility (IVCPD), volatile fatty acids (VFAs), pH and ammonia nitrogen (NH₃-N) were estimated. Gas production has been calculated at 3, 6, 12, 24 and 48 h. Our results indicate that the gas production, VFAs, IVDMD, and IVNDFD of Rice TMR were higher than those of Corn TMR (p < 0.05). Ruminal pH and total fungi were significantly higher in Corn TMR (p < 0.05) than in Rice TMR; however, NH₃-N and IVCPD were not affected by treatment type. In conclusion, substituting rice for corn at 33% DM in TMR appears to have no negative effects on in vitro rumen fermentation characteristics. Therefore, rice grains are an appropriate alternative energy source in early fattening stage diets of beef cattle.

Replacement of corn with rice grains did not alter growth performance and rumen fermentation in growing Hanwoo steers

OBJECTIVE

This study was realized to evaluate the nutritional value of rice grains as a replacement for corn grains in the diet of growing Hanwoo steers.

METHODS

Two experimental diets were prepared: i) Corn total mixed ration (TMR) consisting of 20% corn grains and ii) Rice TMR consisting of 20% rice grains, in a dry matter (DM) basis. These treatments were used for in vitro rumen fermentation and in vivo growth trials. In the rumen fermentation experiment, the in vitro DM digestibility (IVDMD), in vitro crude protein digestibility (IVCPD), in vitro neutral detergent fiber digestibility, pH, ammonia nitrogen, and volatile fatty acids (VFA) were estimated at 48 h, and the gas production was measured at 3, 6, 12, 24, and 48 h. Twenty four growing Hanwoo steers (9 months old; body weight [BW]: 259±13 kg) were randomly divided into two treatment groups and the BW, dry matter intake (DMI), average daily gain (ADG), and feed conversion ratio (FCR) were measured.

RESULTS

The in vitro experiment showed that the IVDMD, IVCPD, and VFA production of the Rice TMR were higher than those of the Corn TMR (p<0.05). The growth trial showed no differences (p>0.05) in the final BW, ADG, DMI, and FCR between the two TMRs.

CONCLUSION

The use of rice grains instead of corn grains did not exhibit any negative effects on the rumen fermentation or growth performance, thereby rice grains with a DM of less than 20% could be used as a starch source in the diet of growing steers.

Effects of rumen-protected methionine on milk production in early lactation dairy cattle fed with a diet containing 14.5% crude protein

We evaluated the influence on milk production of feeding early lactation cows a diet that included 14.5% crude protein (CP) and that did not meet methionine (Met) requirements or that met them by supplying rumen‐protected Met (RPMet). Thirty‐nine multiparous Holstein cows were allocated into two groups. For 15 weeks after calving, each group was fed one of the two total mixed rations, Control (n = 20) or Treatment (n = 19). The Treatment group received added RPMet at 0.034% (8 g/day) of the Control diet on dry matter basis. The adequacies of Met for the Control and Treatment groups were 96% and 106%, respectively, and for other amino acids, >110%. The CP level (14.5%) was 1 percentage point lower than that recommended by the Japanese Feeding Standard (2006). No between‐group differences were found in milk yield (40 kg/day), milk composition, plasma profile, rumen fermentation, nitrogen balance, or cow health. Met intake and the amount of rumen‐undegradable feed Met were higher in the Treatment group (p < 0.05). Microbial Met and total metabolizable Met did not differ between groups. Supplying RPMet in a 14.5% CP diet during early lactation did not dramatically affect milk production, because the amount of total metabolizable Met was unchanged.

The effect of pelleting on in situ rumen degradability of compound feed containing brown rice for dairy cows

This study was conducted to determine the effect of pelleting on in situ dry matter degradability of pelleted compound feed containing brown rice for dairy cows. Mash feed of the same composition was used as a control and the in situ study was conducted using three non-lactating Holstein steers fitted with a rumen cannula. The feeds contained 32.3% brown rice, 19.4% rapeseed meal, 11.4% wheat bran and 10.6% soybean meal (fresh weight basis). Except for moisture content, the chemical composition of the feed was not affected by pelleting. In situ dry matter disappearance of the feed increased from 0 to 2 h and after 72 h of incubation with pellet processing. Integration of the dry matter disappearance values over time revealed that degradability parameter a (soluble fraction) increased with pellet processing, whereas parameter b (potentially degradable fraction) decreased. Parameter c (fractional rate of degradation) and effective degradability (5% passage rate) were not affected by pellet processing. We concluded that pellet processing promotes rumen degradability at early incubation hours when the pelleted feed contains brown rice.

Effects of ruminally degradable starch levels on performance, nitrogen balance, and nutrient digestibility in dairy cows fed low corn-based starch diets

OBJECTIVE

This trial was performed to examine the effects of ruminally degradable starch (RDS) levels in total mixed ration (TMR) with low corn-based starch on the milk production, whole-tract nutrient digestibility and nitrogen balance in dairy cows.

METHODS

Eight multiparous Holstein cows (body weight [BW]: 717±63 kg; days in milk [DIM]: 169±29) were assigned to a crossover design with two dietary treatments: a diet containing 62.3% ruminally degradable starch (% of total starch, low RDS) or 72.1% ruminally degradable starch (% of total starch, high RDS). Changes to the ruminally degradable levels were conducted by using either finely ground corn or steam-flaked corn as the starch component.

RESULTS

The results showed that dry matter intake, milk yield and composition in dairy cows were not affected by dietary treatments. The concentration of milk urea nitrogen was lower for cows fed high RDS TMR than low RDS TMR. The whole-tract apparent digestibility of neutral detergent fiber, acid detergent fiber and crude protein decreased, and that of starch increased for cows fed high RDS TMR over those fed low RDS TMR, with no dietary effect on the whole-tract apparent digestibility of dry matter and organic matter. The proportion of urinary N excretion in N intake was lower and that of fecal N excretion in N intake was higher for cows fed high RDS TMR than those fed low RDS TMR. The N secretion in milk and the retention of N were not influenced by the dietary treatments. Total purine derivative was similar in cows fed high RDS TMR and low RDS TMR. Consequently, estimated microbial N flow to the duodenum was similar in cows fed high RDS TMR and low RDS TMR.

CONCLUSION

Results of this study show that ruminally degradable starch levels can influence whole-tract nutrient digestibility and nitrogen balance in dairy cows fed low corn-based starch diets, with no influence on performance.

Short communication: Evaluation of nitrogen excretion equations from cattle

Nitrogen excretion in dairy manure is a precursor for N2O and NH3 formation in livestock housing, manure storage facilities, and after manure is applied to land. Nitrous oxide is a major contributor to greenhouse gas emissions, and reducing N output from dairy production facilities can reduce the amount of anthropogenic N2O entering the atmosphere. The objective of the study was to conduct a comprehensive evaluation of extant prediction models for N excretion in feces and urine using extensive literature data. A total of 45 N excretion equations were evaluated for lactating cows, heifers, and nonlactating cows and steers. These equations were evaluated with 215 treatment means from 69 published studies collected over 20 yr from 1995 to 2015. Two evaluation methods were used: the root mean square prediction error and the concordance correlation coefficient. Equations constructed using a more rigorous development process fared better than older extant equations. Equations for heifers and nonlactating cows had greater error of prediction compared with equations used for lactating cows. This could be due to limited amount of data available for construction and evaluation of the equations. Urinary N equations had greater prediction errors than other forms of excretion, possibly due to high variability in urinary N excretion and challenges in urine collection. Fecal N equations had low error bias and reached an acceptable level of precision and accuracy.

Effect of ensiling process of total mixed ration on fermentation profile, nutrient loss and in situ ruminal degradation characteristics of diet

This experiment aimed to determine the changes in chemical composition, fermentation profile, in situ disappearance characteristics, and nutrient losses of ensiled total mixed ration (TMR) containing steam-flaked corn or brown rice (BR) during storage. TMRs for dairy cows, containing either steam-flaked corn or BR at 31.9% with 15.2% rye silage, 40.5% alfalfa silage, 5.0% beet pulp and 7.0% soybean meal, were prepared (dry matter (DM) basis). Each TMR was placed in a plastic drum silo, stored at 23°C in an air-conditioned room and sampled 0, 7, 14, 30, 90 and 210 days after preparation. In both grain sources, the fermentation products increased, while DM and starch storage losses increased and starch content greatly decreased during storage. The rapidly degradable fraction and effective ruminal degradability of DM, crude protein and starch increased during storage. These changes of dietary characteristics were large during 30 days of storage, but small after 90 days of storage. Replacing corn with BR led to increased fermentation products, starch loss and effective ruminal degradability of the ensiled TMR. These results indicate that the ensiling process of TMR changes the dietary characteristics and replacing corn with BR in TMR had a large impact on these dietary characteristics.

Changes in nutrient composition and in vitro ruminal fermentation of total mixed ration silage stored at different temperatures and periods

BACKGROUND

Total mixed ration (TMR) is widely used for dairy cattle and needs to be prepared daily because it deteriorates rapidly. Ensiling TMR allows preservation and saves labour at the farm; however, silage fermentation may influence various nutritional components. The objectives of this study were to evaluate nutritional changes and in vitro rumen fermentation of TMR silage that was stored at different temperatures and durations on a laboratory scale in comparison with those of typical TMR before ensiling.

RESULTS

No distinct changes in crude protein (CP), neutral detergent fibre and non-fibrous carbohydrate contents were observed during silage fermentation. However, clear changes were observed in the soluble CP and soluble sugar fractions; solubilisation of the CP fraction in TMR silage was enhanced by prolonged storage and higher storage temperatures, and most soluble sugars were lost during ensiling. Short-chain fatty acid concentrations in the in vitro rumen from TMRs before and after ensiling were not significantly different; however, throughout incubation, NH3 -N concentrations from TMR silages were significantly higher than those from TMR before ensiling.

CONCLUSION

A higher ruminal NH3 -N concentration from TMR silage may be a result of a shortage of fermentable sugars and enhanced deamination of CP. Feeding TMR ensiled under a high temperature must be investigated to balance proteins and carbohydrates for rumen fermentation.

Lactation and digestion in dairy cows fed ensiled total mixed ration containing steam-flaked or ground rice grain

The objective of this experiment was to investigate the effect of feeding ensiled total mixed ration (TMR) containing steam-flaked (SF) or ground brown rice (Oryza satira L.; BR) on feed intake, lactation performance, digestion, ruminal fermentation and nitrogen (N) utilization in dairy cows. Eight multiparous Holstein cows were used in a crossover design with two dietary treatments: diets containing either SF or fine ground (FG) BR at 24% of dietary dry matter. Dietary treatment did not affect dry matter intake or milk yield and composition. The whole-tract digestibility of organic matter and fiber decreased, and the digestibility of starch increased with the replacement of SF with FG in ensiled TMR, but these differences were small between diets. Crude protein digestibility was not different between diets. The processing method of BR did not affect ruminal pH, total volatile acid concentration, or volatile fatty acid proportion in cows. The N intake, milk N secretion, fecal and urinary N excretion and N retention were not influenced by dietary treatment. These results show that feeding ensiled TMR containing FG instead of SF reduces fiber digestibility but has little impact on lactation and N utilization when diets contained 24% on a dry matter basis.

Effects of dietary combination of corn and rice as whole crop silage and grain sources on carbohydrate digestion and nitrogen use in steers

Four Holstein steers were used to evaluate the combination effects of whole crop corn (Cs) or rice (Rs) silage with steam-flaked corn (Cg) or rice (Rg) grain (four dietary treatments) on ruminal carbohydrate digestion, duodenal nitrogen (N) flow and plasma essential amino acid (EAA) concentration. The ruminal digestibility of starch and nonfiber carbohydrate (NFC) for Rs and Rg diets compared with Cs and Cg diets was greater, but that of neutral detergent fiber (aNDFom) was less. Because the ruminal disappearance of NFC plus aNDFom was similar across four dietary treatments, microbial N flow was not affected by the diets. There was an interaction of methionine (Met) flow by silage and grain sources: greatest for CsRg and least for RsRg diet, and blood plasma concentration of Met after feeding was lower for Rg than Cg diets. Postprandial reduction degree of plasma EAA varied with the diets and individual EAA. The Cs diets compared with the Rs diets tended to be greater in N retention because of greater digestible organic matter (OM) intake. These results suggest that silage source combined with corn or rice grain affects N use in steers through the digestible OM intake, and the kinds of limiting AA may differ among the combination of silage and grain sources.