Effects of feeding ground or steam-flaked broom sorghum and ground barley on performance of dairy cows in midlactation

The impact of lamb diets containing either barley or corn on growth performance and carcass quality

BACKGROUND AND AIM

Grains, such as barley (BAR) and corn (CORN), are major energy sources for small ruminants. This study aimed to assess the impact of feeding either BAR or CORN-based diets on growth performance and carcass characteristics.

MATERIALS AND METHODS

Awassi male lambs, average body weight of 20.4±0.49 kg, were chosen randomly. Lambs were acclimated for 10 days and assigned to one of two diets (1) BAR and (2) CORN. Feeding continued for 70 days with 60 days of data collection. Daily intake was recorded. Measurements of body weight were taken starting from day 1 then once per week throughout the study period. On day 40, six lambs were randomly chosen from each group and placed in metabolism cages to assess digestibility and N balance. Lambs were slaughtered on the last day of the study to evaluate carcass characteristics and meat quality.

RESULTS

Neutral and acid detergent fiber and ether extract intake were greater (p≤0.05) for lambs fed the BAR diets. Nitrogen loss in feces tended to be greater (p=0.09) for the CORN diet. Eye muscle depth (mm) tended to be greater (p=0.07) for the BAR diet. Nutrient digestibility, daily weight gain, carcass characteristics, and meat quality were not different (p≥0.1) between diets.

CONCLUSION

The results herein demonstrate that feeding BAR grain improved nutrient intake efficiency and consistency and did not affect weight gain and carcass traits. BAR-based diets might be a useful alternative to CORN for feeding growing lambs.

Effects of Dietary Forage Proportion on Feed Intake, Growth Performance, Nutrient Digestibility, and Enteric Methane Emissions of Holstein Heifers at Various Growth Stages

Simple Summary

Enteric methane (CH₄) emission from ruminants is a large source of anthropogenic greenhouse gas production, which is an inevitable by-product when feedstuff is digested and fermented in the rumen, representing approximately 7% of dietary energy loss. Although the Chinese government has committed to reduce CH₄ emissions under the requirement of the Copenhagen Accord (2009), there is lack of accurate CH₄ emission data from young cows as the guideline of IPCC gives little consideration to the variations of geographic conditions, animal physiology stages, and dietary components of dairy production system. Our study investigated the effects of different dietary forage-to-concentrate on feed intake, growth performance, nutrient digestibility, and enteric CH₄ emissions of Holstein heifers under various growth stage, and developed the prediction equations using production and emission data. Our results demonstrated that enteric CH₄ emission was significantly affected by dietary composition and physiological condition; results obtained from the current study will be of great importance for development of regional or national emission inventories and mitigation approaches for heifers at specific growth stage.

Abstract

Enteric methane (CH₄) emissions from young ruminants contribute to a substantial proportion of atmospheric CH₄ accumulation. Development of emission inventory and mitigation approaches needs accurate estimation of individual emission from animals under various physiological conditions and production systems. This research investigated the effect of different dietary concentrate contents on feed intake, growth performance, nutrient digestibility and CH₄ emissions of heifers at various stages, and also developed linear or non-linear prediction equations using data measured by sulphur hexafluoride tracer technique. Increasing dietary concentrate contents increased feed intake and growth rate, enhanced nutrient digestibility, and reduced enteric CH₄ emissions. Heifers at the age of 9, 12, and 15 months with an average weight of 267.7, 342.1, and 418.6 kg produced 105.2, 137.4, and 209.4 g/day of CH₄, and have an average value of CH₄ energy per gross energy intake (Y_m) 0.054, 0.064, 0.0667, respectively. Equations relating CH₄ emission values with animal and feed characteristics were developed with high determination coefficients for heifers at different growth stages. Dietary concentrate contents had significant influence on overall performance of heifers. These data can be used to develop regional or national emission inventories and mitigation approaches for heifers under various production regimes in China.

Cereals level and source effects on rumen fermentation, colostrum and milk properties, and blood metabolites in periparturient ewes

Optimal type and dietary inclusion rates of cereal grains for periparturient sheep are unknown. The objective was to determine effects of feeding diets with high (H) v. low (L) levels of ground corn grain (CN) v. combined ground wheat and barley grains (WB) on intake, rumen fermentation, colostrum and milk properties, and blood metabolites of periparturient sheep. Twenty Afshari×Merino ewes were used in a completely randomized design study from 24 days prepartum through 21 days postpartum. Ewes were kept indoors in individual boxes and received once daily at 0900 h total mixed rations. Treatments were mixed rations containing either (1) H or (2) L concentrate based on either (1) 100% CN or (2) 50 : 50 ratio of ground wheat : ground barley grains in a 2×2 factorial arrangement. Each treatment group had five ewes including two twin-lamb ewes and three single-lamb ewes. Postpartal dry matter intake (DMI) increased by feeding high CN v. high and low WB, while high v. low CN improved postpartum DMI. The DMI during lambing tended to increase with the high v. low WB. Feeding CN v. WB, and feeding both CN and WB at L v. H level increased fecal pH. Postpartal rumen pH was lower with the high v. low WB (5.7 v. 6.2). Rumen concentrations of propionate were lower and of acetate were higher with L v. H grain levels. Increased dietary grain reduced urine pH for WB (7.24 v. 7.83) but not for CN (7.63 v. 7.52) prepartum. Colostrum properties, postpartal urine pH, lamb weight at birth and 21 days of age, and placental weight and expulsion time were unaffected. Milk yield increased and milk fat yield tended to increase by H v. L grain diets. Plasma glucose was increased by feeding high v. low WB, whereas CN v. WB tended to reduce peripartal plasma non-esterified fatty acids (NEFA) and increased insulin to NEFA ratio. In conclusion, more cereal grains can be included in periparturient sheep diets and CN instead of WB may be fed to periparturient sheep to improve energy status. Findings suggest opportunities to optimize periparturient ewe physiology and performance through feeding certain cereals and avoiding high levels of WB.

Evaluation of panicle residue from broom sorghum as a feed ingredient in finishing diets for lambs

Sorghum panicle residue (SPR), a by-product of Sorghum vulgare, obtained in the manufacture of brooms and wisks, has potential as a partial substitute for grain in growing-finishing diets for feedlot lambs. Accordingly, 48 Pelibuey×Katahdin lambs (initial weight=16.2±4.3 kg) were used in an 84-d growth-performance trial to evaluate its comparative feeding value. Lambs were blocked by weight and assigned within weight groupings to 12 pens (4 lambs per pen). The SPR was finely ground before it was incorporated into the diet. The basal diet contained 60% whole grain sorghum (WGS; DM basis). Dietary treatments consisted in the replacement of WGS with 0, 50, or 100% SPR. Replacement of WGS with SPR decreased (linear effect, P=0.04) average daily gain (ADG), and tended to increase (linear effect, P=0.06) dry matter intake (DMI). Replacement of WGS with SPR decreased (linear effect, P<0.01) gain efficiency (ADG : DMI), and observed dietary net energy (NE), as well as hot carcass weight, dressing percentage, kidney-pelvic-heart fat, and back fat thickness (linear effect, P⩽.05) Other carcass characteristics and wholesale cuts as a percentage of cold carcass weight were not affected by dietary treatments. It is concluded that SPR is a palatable feed ingredient for inclusion in finishing diets for feedlot lambs. The comparative NE values for SPR are 1.50 and 0.91 Mcal/kg for maintenance and gain, respectively, 75% the NE value of WGS. These NE values reflect the greater fiber content of SPR. To the extent that dietary energy density limits energy intake (and hence daily weight gain), appropriate constraints on level of SPR incorporation is warranted.

Effects of inclusion of graded amounts of soya bean hulls on feed intake, chewing activity and nutrient digestibility in dairy cows

Twelve multiparous Holstein dairy cows were used in a replicated 4 × 4 Latin square changeover design to evaluate the effects of graded inclusion of soya bean hulls (SHs) in replacement of diet forages at 0%, 10%, 20% and 30% of dietary dry matter (DM) basis on peNDF > 8 and peNDF > 1.18 contents of diets and their resulting effects on chewing activity, nutrient digestibility and milk production of dairy cattle. The control diet contained 50% forage, 50% concentrate and no SH. In the other three diets, SH was substituted for alfalfa hay, corn silage and wheat bran to supply 10%, 20% and 30% of the dietary DM. Increasing SH concentration in the diets resulted in decreasing concentrations of forage neutral detergent fibre (NDF), physically effective NDF (peNDF) and mean particle size (p < 0.01). Chewing activity per kilogram of daily dry matter intake (DMI) was not affected by the different diets tested. However, chewing activity significantly decreased for kilogram intake of NDF, but increased for peNDF > 1.18 when SH was included in the diets (p < 0.01). Total tract apparent digestibility of nutrients significantly increased for DM, organic matter (p < 0.05) and NDF (p < 0.01) but decreased for crude protein (p < 0.05) as the proportion of SH was increased in the diets. Rumen pH value of cattle was not influenced by the diets. Including medium and high amounts of SH in the diets decreased DMI of the animals (p < 0.05) without any significant effect on their daily milk or 4% fat-corrected milk production. In conclusion, the results of this study showed that the NDF from a non-forage fibre source like SH had a lower potential for stimulating chewing activity than did forage NDF. Despite this, the small size of dietary particles increased not only the chewing activity per kilogram of peNDF intake but also saliva secretion as well as the potential for rumen to neutralize acids. The findings of this study demonstrate the greater differences in peNDF > 8 among the diets and that these differences are better reflected in terms of DMI, chewing activity and nutrient digestibility, but not in rumen pH.

Dietary ratios of maize silage to lucerne hay affect feed intake, chewing activity and milk production of dairy cows

The present study investigated the effects of substitution of chopped lucerne hay (LH) for maize silage on feed intake, rumen pH and fermentation, digestibility, milk production and feed efficiency of dairy cows. Fifteen Holstein dairy cows in early lactation (37 ± 10 days in milk) were randomly assigned to three dietary treatments in a completely randomised design. The experiment lasted for 80 days, with 10 days of adaptation and 70 days of data collection. Treatment diets consisted of 60% concentrate and 40% forage, comprising 30 : 10 (MS30), 20 : 20 (MS20) or 10 : 30 (MS10) of maize silage (MS) to LH ratio (MS : LH). Cows were fed ad libitum as total mixed ration. Water was added daily to adjust the moisture content of the feed to be similar across diets. Decreasing the ratio of MS : LH resulted in linear and quadratic decreases of DM intake and physically effective neutral detergent fibre, without affecting apparent digestibility in the total digestive tract. Decreasing MS : LH also linearly reduced total chewing time and tended to reduced chewing index (min/kg DM intake), but had limited effects on rumen pH and fermentation characteristics. Increasing the substitution of LH for MS decreased milk production (33.1, 31.7, and 29.8 kg/day for MS30, MS20, and MS10, respectively), and tended (P = 0.06) to decrease 4% fat-corrected milk and fat yield. However, milk content of protein (2.70%, 2.77% and 2.77%) and fat improved, and tended to improve by decreasing the MS : LH ratio, respectively. The efficiency of milk production, expressed as either milk yield/kg DM intake or 4% fat-corrected milk/kg DM intake, was not affected by the treatments. Results indicated that under the current feeding conditions, decreasing the ratio of MS : LH was not recommended to maintain milk production and DM intake.

Prepartal wheat grain feeding improves energy and calcium status of periparturient Holstein heifers

Wheat grain (WG) is unique in possessing extensive starch and nitrogen fermentation (i.e. >85% in ground and steam-processed WG), low cation-anion difference and high-intake properties, making it a potentially useful prepartal dietary choice. The objective was to determine the effects of WG provision to pre-partum first-calf heifers on metabolic, health and productive criteria during the transition period. WG replaced barley grain that was commonly used earlier. Fifteen Holstein heifers at 31 ± 6 days pre partum were blocked based on expected calving date and assigned to three treatments or feeding totally mixed rations containing either (i) barley grain (13.8%) and wheat bran (6.1%), (ii) 10% WG (WG10) or (iii) 18% WG (WG18; dry matter (DM) basis) from 31 days pre partum until calving. In replacing WG for barley grains, some changes in WG use and slight changes in soybean and cottonseed meals use were made to properly formulate balanced rations for net energy for lactation, CP, calcium and P. Prepartal diets contained no supplemental anionic salts. Cows were monitored until 21-day post partum and received the same early lactation diet. The prepartal provision of WG and related dietary changes reduced urine pH at 7-day pre partum, and elevated blood calcium and glucose at 7-day pre partum and at 3-day post partum. Milk fat and protein yields were increased during the 21 days post partum by prepartal WG provision and related diet changes. Blood albumin, globulins, total proteins and urea concentrations were similar among treatments. Feeding diets with WG did not affect body condition score, calving difficulty, calf weight, placenta weight and the time interval from calving to placenta expulsion. It is suggested that prepartal provision of WG with necessary dietary changes led to simultaneous improvements in energy and calcium status of the heifers experiencing their first periparturient phase without compromising parturition status.

Barley grain for ruminants: A global treasure or tragedy

Barley grain (Hordeum vulgare L.) is characterized by a thick fibrous coat, a high level of ß-glucans and simply-arranged starch granules. World production of barley is about 30 % of that of corn. In comparison with corn, barley has more protein, methionine, lysine, cysteine and tryptophan. For ruminants, barley is the third most readily degradable cereal behind oats and wheat. Due to its more rapid starch fermentation rate compared with corn, barley also provides a more synchronous release of energy and nitrogen, thereby improving microbial nutrient assimilation. As a result, feeding barley can reduce the need for feeding protected protein sources. However, this benefit is only realized if rumen acidity is maintained within an optimal range (e.g., > 5.8 to 6.0); below this range, microbial maintenance requirements and wastage increase. With a low pH, microbial endotoxines cause pro-inflammatory responses that can weaken immunity and shorten animal longevity. Thus, mismanagement in barley processing and feeding may make a tragedy from this treasure or pearl of cereal grains. Steam-rolling of barley may improve feed efficiency and post-rumen starch digestion. However, it is doubtful if such processing can improve milk production and feed intake. Due to the need to process barley less extensively than other cereals (as long as the pericarp is broken), consistent and global standards for feeding and processing barley could be feasibly established. In high-starch diets, barley feeding reduces the need for capacious small intestinal starch assimilation, subsequently reducing hindgut starch use and fecal nutrient loss. With its nutritional exclusivities underlined, barley use will be a factual art that can either matchlessly profit or harm rumen microbes, cattle production, farm economics and the environment.

Ground wheat grain for midlactation cows: challenging a common wisdom

The objective was to determine the effects of ground wheat grain (GW) inclusion rate, grinding extent (GE), and their interaction on lactating cow performance. Eight midlactation cows in 3 × 4 m individual boxes were used in a 4 × 4 replicated Latin square design study with 4 21 d periods. GW was fed at either 10% or 20% of diet dry matter (DM), as either finer or coarser particles. DM intake increased and net energy for lactation (NE(L)) intake tended to increase when GW was fed at 10% instead of 20% of diet DM. Milk energy yield, milk solids content and yield, and urine pH were unaffected. Fecal pH tended to increase at 20% versus 10% GW. Total tract apparent NDF, but not DM, digestibility tended to be greater for coarsely than finely GW and tended to be greater at 10% versus 20% GW. GW at 10% versus 20% of diet DM decreased blood BHBA and increased blood concentrations of total proteins and albumin. Data provide novel evidence that both finely and coarsely ground WG can be safely fed up to 20% midlactation cows. Commercial accessibility and cost will determine feeding preference of wheat grain to dairy cows.

Effect of replacing barley with corn or sorghum grain on rumen fermentation characteristics and performance of Iranian Baluchi lamb fed high concentrate rations

The present study, conducted in Iran, was aimed to evaluate the effects of partial substitution of barley with corn or sorghum (slowly fermenting grains) on in situ dry matter (DM) and starch degradability and in vivo digestion characteristics and performance in finishing Iranian Baluchi lambs. In the first experiment, samples of ground barley (B), corn (C), sorghum (S) and their combinations [%: 70 barley : 30 corn (LC), 70 barley : 30 sorghum (LS), 30 barley : 70 corn (HC) and 30 barley : 70 sorghum (HS)] were incubated in nylon bags in rumen of three fistulated Holstein steers. Effective degradability (ED) for DM and starch were different (P < 0.05) among treatments. In both cases, ED was higher (P < 0.05) for B than that for C, S, HC and HS. Results of the present study confirmed previous reports that ruminal degradability of barley is higher than that of corn and sorghum, and further suggested that there may be benefits in replacing barley with ~70% of corn or sorghum. In Experiment 2, 30 Iranian Baluchi male lambs weaned at 65 days of age (BW 32 ± 2.3 kg) were divided into five equal weight groups (6 animals per group) in a complete randomised design. Lambs received a mixed diet in the form of total mixed rations (TMR), consisting of 32.5% alfalfa hay [89% DM, 43% natural detergent fibre (NDF) and 16% crude protein (CP) in diet DM basis] and 67.5% of the respective concentrates. The five iso-caloric (10.73 MJ ME/kg) and iso-nitrogenous (14% CP/kg DM) concentrates with different sources of starch used in the study were (1) barley, as the control cereal source for starch, and in the other treatments barley substituted with (2) 30% corn (LC), (3) 30% sorghum (LS), (4) 70% corn (HC) and (5) 70% sorghum (HS). Lambs in HC and HS diets recorded increases of 20 and 50 g/day in average daily gain, respectively, compared with lambs in B. Substitution of B with 70% C and S significantly (P < 0.01) improved ruminal pH and, presumably, resulted in higher starch outflow for post-ruminal digestion, as reflected by a higher blood glucose concentration, particularly for lambs in the HS diet. Results of the present study reaffirmed the advantages of feeding a mixture of grains with differing fermentation rates and, as previously reported, also suggested that the inclusion rate of slowly degradable grains should be ~70% so as to enhance animal performance.

Chromium improves production and alters metabolism of early lactation cows in summer

Metabolic demands of early lactation introduce enormous challenges to dairy cows when coincided with environmental stresses. The objective of this study was to determine effects of a chromium (Cr) supplement on feed intake and blood indicators of nutrient metabolism in early lactation cows in summer. Fifteen Holstein cows at 38±6 days in milk were grouped based on parity and randomly assigned to three supplemental doses of 0, 0.05 and 0.10 mg Cr/kg of BW(0.75) . Cows received a basal mixed ration with a forage to concentrate ratio of 57.7:42.3, twice daily at 09:00 and 16:00 h for 9 weeks. The first 2 weeks were for adaptation, and the following 7 weeks were for weekly sampling and data collection. The Cr supplement (a Cr-methionine product with 10% Cr and 90% Met from a compound containing one atom of Cr and three molecules of Met) was mixed with 100 g of ground corn and top dressed with the morning feed. The average ambient temperature-humidity index was 77.7 units during the study. Dry matter intake increased from 21.8 to 24.2 and 23.7 kg/day when 0.05 and 0.10 mg Cr/kg BW(0.75) was provided respectively. Milk output of energy, fat, protein and total solids increased by providing Cr at 0.05 mg but not 0.10 mg/kg BW(0.75) . Both doses of Cr increased milk protein content, but the higher Cr dose reduced feed efficiency compared with control. While rectal temperature and body condition score were unaffected, cows receiving 0.05 mg and not 0.10 mg Cr/kg BW(0.75) tended to have greater respiration rate than control cows. Blood insulin and non-esterified fatty acids concentrations and the insulin to glucagon ratio decreased, and serum albumin increased when cows received 0.05 mg of Cr/kg BW(0.75) . Blood glucose, glucagon, insulin-like growth factor-1, total protein, globulins, urea, BHBA, triglycerides, cholesterol, cortisol, progesterone, and high- and very low-density lipoproteins were not affected. Therefore, supplemental Cr supply at 0.05 and 0.10 mg/kg BW(0.75) improved feed intake, only at 0.05 mg/kg BW(0.75) increased milk secretion, and mainly at 0.05 mg/kg BW(0.75) altered peripheral nutrient metabolism in early lactation Holstein cows under high ambient temperatures.

Ground versus steam-rolled barley grain for lactating cows: a clarification into conventional beliefs

Our objective was to compare the effects of grinding versus steam-rolling of barley grain at 30 or 35% of diet dry matter on feed intake, chewing behavior, rumen fermentation, and milk production in high-producing lactating cows. Eight multiparous Holstein cows (85 +/- 9 d in milk) were used in a replicated 4 x 4 Latin square design experiment with four 21-d periods. Each period included 14 d of adaptation and 7 d of sampling. Treatments included grinding (GB) or steam-rolling (SB) of barley grains at either 35 or 30% of dietary dry matter. Diets were prepared as a total mixed ration and delivered twice daily at 0730 and 1600 h. Neither processing method nor dietary barley grain inclusion rate affected dry matter intake, daily eating, ruminating and chewing times, rumen pH and major volatile fatty acid molar percentages, or milk percentages and yields of fat and protein. Energy-corrected milk yield increased for SB compared with GB at 35% but not at 30% barley grain. Feed efficiency was increased by SB, but was unaffected by dietary barley grain level. Results suggest that at 30% dietary barley grain, GB resulted in similar lactation performance as SB and that SB did not affect productivity when dietary barley grain increased from 30 to 35%. Regardless of barley grain level, grinding effectively maintained dry matter intake and rumen pH at 4 h postfeeding, whereas steam-rolling increased feed efficiency. Increasing barley grain from 30 to 35% of diet dry matter did not improve feed intake and milk production.