Alfalfa Hay Diet Research Articles

Beta-Glucans Improve the Mammary Innate Immune Response to Endotoxin Challenge in Dairy Ewes.

This study evaluated short-term immune responses of dairy ewes supplemented with barley β-glucan (BG) following an intramammary Escherichia coli lipopolysaccharide (LPS) challenge. In the adaptation period, 36 ewes were fed an alfalfa hay diet ad libitum and barley grain cv. Hispanic (3.8% BG). Then, ewes were assigned into three experimental groups: (1) Control (CON), the same previous diet (13.3 g BG/d); (2) high β-glucans barley (HBG), new barley (cv. Annapurna) containing 10% BG (35 g BG/d); (3) intraperitoneally injected (INP) with a 1.4% BG solution dose (2 g BG/ewe). At d 9, all ewes were infused with an E. coli LPS or saline solution in each udder half. After the challenge, rectal temperature (RT), milk yield and composition, somatic cell count (SCC), and plasma interleukins (IL-1α and IL-1β) were monitored daily. The INP treatment revealed a transitory increase in RT and decreased milk yield by 38%. Milk fat, protein, and SCC increased in LPS-treated udders but not by BG treatment. The IL-1α plasma concentration was similar among groups but INP ewes showed a lower IL-1β concentration suggesting a lower inflammatory response. The BG administration appears more effective intraperitoneally than orally, which needs additional study.

PSIX-26 Effectiveness of mineral supplementation during range grazing on mineral status in ewes

Abstract Mineral supplementation in the intermountain west region of the US may be necessary for maintenance of healthy flocks since important trace minerals are deficient in this region. However, rough terrain can make mineral supplementation challenging. The objective of this study was to evaluate the trace mineral status of ewes on range. We hypothesized that ewes with access to a mineral supplement would have decreased risk of mineral deficiency. In this study, ewes (n = 59) grazed four summer pastures on Cedar Mountain near Cedar City, Utah. Ewes between the ages of 1 and 6 yr of age were stratified by initial body weight (BW) = 87 kg ± 13 kg and breed [black face (BLF; Suffolk) and white face breeds (WF; Targhee, Rambouillet, and their crosses)] into two treatment groups 1) trace mineral supplement ad libitum (TRT; n = 7 BLF and 23 WF) or 2) no mineral supplement (CON; n = 15 BLF and 14 WF). All ewes received a diet of mixed alfalfa and triticale hay without mineral supplementation 30 d before the trial began. A SmartFeed (C-lock Inc.) was used to track individual animal mineral intake. Plasma samples were collected via jugular venipuncture at d 0, 34, 77, and 116. A clinical veterinarian from Utah State University performed liver biopsies at d 0 and 116 on a subset of ewes (n = 10). After the grazing season, plasma and liver samples were sent to the Iowa State University Veterinary Diagnostic Laboratory for analysis of Cu, Mn, Se, and Zn. The mixed procedure of SAS was used to analyze plasma mineral content with day as a repeated measure and individual ID as a random variable. The Glimmix procedure of SAS was used to analyze liver mineral content. Plasma Cu and Se increased (P ≤ 0.05) by day in all ewes throughout the grazing season. No differences related to treatment or breed (P > 0.10) were observed for plasma Cu or Se concentrations. Plasma Mn and Zn decreased (P < 0.0001) by 1.5 ppb and 0.4 ppm, respectively, between d 0 and 116 with no treatment effect (P > 0.10). BLF ewes had 0.3 ppm (P = 0.01) greater plasma Mn concentrations than WF ewes, with no difference (P = 0.6) observed due to treatment. Hepatic Cu and Se increased (P ≤ 0.05) by 114 ppm and 1 ppm, respectively, between d 0 and 116. Hepatic Mn concentrations did not differ (P > 0.10) by day or treatment. Hepatic Zn concentrations tended to increase by day (P = 0.07), 23 ppm between d 0 and 116. CON ewes had 28 ppm greater (P = 0.04) hepatic Zn concentrations than TRT ewes. Additional research is warranted to understand why CON had greater hepatic Zn concentrations than TRT, which may indicate that diverse rangeland forages may provide sufficient concentrations for sheep production in summer months.

The effect of replacing conventional alfalfa hay with lower-lignin alfalfa hay on feed intake, nutrient digestibility, and energy utilization in lactating Jersey cows

Lower-lignin (LoL) varieties of alfalfa (Medicago sativa L.) have been developed in recent years, and have the potential to positively impact animal performance. The objective of this study was to evaluate the effects of increasing the proportion of LoL alfalfa hay in diets fed to lactating dairy cows. Research plots were planted with a conventional variety (CON; Dairyland Hybriforce 3400), and 2 LoL varieties (LLG; 54HVX42 and LLB; Aflorex HiGest 460). After harvest, the LoL varieties were blended in equal proportions for feeding. Twelve multiparous Jersey cows (100 ± 4 d in milk) were used in a 3 × 3 Latin square with 3 periods of 28 d. Cows were assigned to 3 diets containing 0 (CNTRL), 16.1 (MdLL), and 32.2% (HiLL) of the diet DM as LoL alfalfa hay, which replaced CON. The CON alfalfa had average CP, NDF, and lignin contents (DM basis) of 20.5 ± 1.15, 42.1 ± 1.37, and 6.81 ± 0.57%, respectively, while the LoL alfalfa averaged 19.8 ± 0.75, 39.9 ± 1.56, and 6.07 ± 0.28%, respectively. No difference was observed in DMI (20.4 ± 0.61 kg/d). No difference in milk yield was observed, averaging 31.0 ± 1.02 kg/d across treatments. Similarly, no difference was observed in ECM yield (averaging 36.2 ± 1.43 kg/d). Feed conversion (ECM/DMI) tended to increase linearly with LoL alfalfa inclusion (1.74 to 1.80 ± 0.03). No difference was observed for milk fat yield and content (1.39 ± 0.075 kg/d and 4.51 ± 0.219%) or milk protein yield and content (1.06 ± 0.041 kg/d and 3.43 ± 0.096%). Total methane production quadratically decreased from CNTRL to MdLL then increased to HiLL (441, 389, 412 ± 18.2 L/d, respectively). No differences were observed on total-tract digestibility of DM (averaging 67.2 ± 0.55%) and NDF (averaging 50.9 ± 1.56%). No difference was observed in the concentration of DE, ME or NEL was observed averaging 2.82 ± 0.021, 2.51 ± 0.027, and 1.72 ± 0.030 Mcal/kg respectively. Our results suggest that replacing CON alfalfa with LoL alfalfa has no effects on milk production, milk composition, or nutrient digestibility but may improve feed efficiency.

Effects of grain processing (cracked vs. steam-flaked) and forage sources (alfalfa hay and wheat straw) as a free-choice provision on growth performance, rumen fermentation, blood metabolites, and behavior of dairy calves

The aim of this study was to investigate the interaction between physical form of starter (PFS) and forage source (FS) with free access to forage on feed intake, growth performance, rumen fermentation, blood metabolites and behavioral traits of dairy calves. A total of 48 7-day-old Holstein calves were randomly assigned to one of four treatments in a 2 × 2 factorial arrangement, with FS [alfalfa hay (AH) and wheat straw (WS)] as free-choice supply and PFS diets (cracked vs. steam-flaked) as main effects. Feeding treatments included (1) starter diet with steam flaked corn (SFC) and free access to AH (SFC-AH), (2) starter diet with SFC and free access to WS (SFC-WS), (3) starter diet with cracked corn (CRC) and free access to AH (CRC-AH) and (4) starter diet with CRC and free access to WS (CRC-WS). The calves were weaned on day 58 and remained in the experiment until day 70. All calves had free access to water and starter feed. The results showed that there was no interaction between PFS and FS in terms of starter intake, forage intake, dry matter intake (DMI), average daily gain (ADG), body weight (BW) or feed efficiency (FE). Calves fed CRC consumed more dry matter, TMR and forage than calves fed SFC diets. Regardless of the PFS diet, weaning weight, total weight and total ADG were higher in calves fed WS, while forage intake was higher in calves fed AH. Calves fed CRC-AH had the lowest rumen pH at day 68 compared to the other groups (except SFC-WS at day 70). An interaction between PFS diets and FS affected rumen proportion of propionate on day 35, since calves, which were fed CRC-AH had the highest molar percentage of propionate than calves fed other diets (except for SF-WS). At day 65, calves fed SFC starter feed had higher plasma glucose concentrations than calves fed CRC. It was found that PFS feed and FS had an interaction effect on BUN at day 65, with calves fed CRC-AH having the highest BUN. Compared to the other groups, calves fed CRC-WS had the highest BHB at day 33 and throughout the period (days 35 and 65). An interaction between PFS diets and FS affected lying time and forage eating time, with CRC-AH calves exhibiting the longest lying time and lowest forage eating time. The time spent on NNOB tended to be longer in SFC-fed calves than in CRC-fed calves, regardless of the forage source. Compared to calves fed SFC, calves fed CRC with high levels of fine particles consumed more dry matter, TMR, and forage while spending less time on NNOB. Furthermore, feeding calves chopped WS instead of AH increased weaning weight, total weight, and total ADG, although forage intake was higher in calves fed AH. In summary, a combination of cracked corn starter with free access to wheat straw appears to provide the best growth outcomes for dairy calves.

Effects of Leymus chinensis hay and alfalfa hay on growth performance, rumen microbiota, and untargeted metabolomics of meat in lambs.

The objective of this study was to compare the effects of Leymus chinensis hay and alfalfa hay as the roughage on the rumen bacterial and the meat metabolomics in lambs. Fourteen male lambs were randomly assigned to two dietary treatments (one group was fed with concentrate and Leymus chinensis hay; another was fed with concentrate and alfalfa hay) with seven replicates per treatment. The feeding experiment lasted for 60 days. Lambs were slaughtered at the end of the feeding experiment. Growth performance, carcass performance, and weights of various viscera were determined. The longissimus dorsi and rumen contents were collected for untargeted metabolomics and 16S rDNA amplicon sequencing analysis, respectively. The lambs fed with alfalfa hay showed a significantly increased in average daily gain, carcass weight, dressing percentage, loin-eye area, and kidney weight. Feeding Leymus chinensis hay and alfalfa hay diets resulted in different meat metabolite deposition and rumen bacterial communities in the lambs. The relative abundance of phyla Fibrobacteres, Bacteroidetes, and Spirochaetes were greater in the Leymus Chinensis hay group, while, the relative abundance of Firmicutes, Proteobacteria, Fusobacteria, and Verrucomicrobia were greater in the alfalfa hay group. Based on untargeted metabolomics, the main altered metabolic pathways included alanine, aspartate and glutamate metabolism, D-glutamine and D-glutamate metabolism, phenylalanine metabolism, nitrogen metabolism, and tyrosine metabolism. Several bacteria genera including BF31, Alistipes, Faecalibacterium, Eggerthella, and Anaeroplasma were significantly correlated with growth performance and meat metabolites. Alfalfa hay improved growth performance and carcass characteristics in lambs. Leymus chinensis hay and alfalfa hay caused different meat metabolite deposition by modifying the rumen bacterial community. These findings will be beneficial to future forage utilization for sheep growth, carcass performance, and meat quality improvement.

376 Effects of Mineral Supplementation During Range Grazing on Ovine Performance

Abstract Western US sheep production systems are dependent on rangeland forages to meet nutritional needs for animal production. While many native rangeland soils and forages are deficient in minerals like Cu, Se, and Zn, it is unknown whether ewes will alter forage selection if they receive a mineral supplemented diet and if alternative forages will affect performance on range. The objectives of this study are to quantify the effects of mineral supplementation on ewe forage selectivity on rangeland, range utilization, and animal performance. We hypothesized ewes who receive a trace mineral supplement will have a more diverse diet, greater rangeland utilization, and improved performance characteristics than their non-supplemented contemporaries. In this study, (n = 59) ewes were grazed across four summer pastures on Cedar Mountain near Cedar City, Utah. Ewes between the ages of 1 and 6 with an average weight of 87 Kg ± 13 Kg were stratified by initial weight and breed into one of two different treatment groups: 1) trace mineral supplement ad libitum (TRT; n = 30), or 2) no mineral supplement (CON; n = 29). Ewe breed types consisted of black face type breeds (BLF; Suffolk) and white face type breeds (WF; Targhee, Rambouillet, and their crosses). All ewes received a similar diet of alfalfa hay and triticale without access to ad libitum mineral supplementation 30 days before the start of the trial. A solar powered C-lock inc. pro was used to track individual animal mineral intake. Back fat (BF) and loin eye depth (LED) were measured at day 0 and day 116 of the trial via ultrasound. Additionally, fecal samples were collected and used for fecal metabarcoding (fDNA) at approximately 30% pasture utilization, which measures the proportion of plant DNA in the feces to determine forage species consumed. Plant species were sorted into functional groups (forbs, grass likes, grasses, shrubs, and trees). The GLM procedure of SAS was used to analyze BF, LED, and fDNA. The mixed procedure of SAS with day as a repeated measure was used to analyze percentage change in body weight. Control ewes had greater BF by 0.08 cm (P = 0.02). No difference in BF was observed by breed (P = 0.8). Loin eye depth was greater by 0.2 cm (P = 0.01) in BLF ewes than WF ewes. Supplemented ewes maintained 1% more of their initial body weight than CON ewes (P = 0.01). No forage selection differences were observed by treatment or breed (P> 0.2). The current study results indicate that mineral supplementation on range may not affect forage selectivity but can benefit animals by maintaining body weight over the grazing season.

PSVI-2 Economic Evaluation of Forage-Fed vs Concentrate-Fed Beef Finishing Systems

Abstract The objective of this study was to determine the price points at which it is more economical to finish beef animals on forage-based or concentrate-based diets. To accomplish this, Hereford steers (n = 21; BW = 444 ± 10 kg) were fed out on one of three diets: a long-stemmed grass hay (HAY, 10.8% CP, 2.11 Mcal ME/kg DM), an alfalfa hay diet (ALF, 20.5% CP, 2.85 Mcal ME/kg DM) or a mixed ration consisting of 30.0% corn silage, 28.0% DDGS, 30.0% rolled corn, 10.5% soybean meal, and 1.5% mineral supplement (CON, 22.0% CP, 2.90 Mcal ME/kg DM). The data were analyzed in SAS v9.4. Animals were evaluated on intake, growth, and performance measures during a 35-day feeding trial. Average daily gain (ADG) and hot carcass weight differed significantly (P < 0.05) between treatments with CON steers gaining 1.47 kg/d with a hot carcass weight of 394.8 kg, ALF steers gaining 0.77 kg/d with a hot carcass weight of 334.7 kg, and HAY steers gaining 0.1 kg/d with a hot carcass weight of 237.4 kg. Dressing percentage was significantly different between all treatments (P < 0.05). The dressing percentage was 58.2%, 54.3%, and 50.6% for CON, ALF, and HAY, respectively. The HAY diet rendered significantly lower marbling scores than ALF or CON (P < 0.05). It was concluded based on carcass quality data that there was no difference in the high-quality forage (ALF) and the concentrate diet (CON) other than diet cost and growth rate. Price per kilogram of gain was $1.42, $1.23, and $14.80 for CON, ALF, and HAY, respectively. Results of this trial are expected to indicate at what price point it becomes more economically effective to finish animals on a high-quality forage or a concentrate-based diet.

PSVI-4 The Influence of Diet Type on Beef Cattle Performance and Meat Quality Characteristics

Abstract The objective of this study was to determine the effect of diet type on feed intake in yearling steers. Hereford steers (n = 21; BW = 444 ± 10 kg) were assigned to one of three drylot pens based on initial BW. Each drylot pen was assigned to one of three diets: a long-stemmed grass hay (HAY, 10.8% CP, 2.11 Mcal ME/kg DM), an alfalfa hay diet (ALF, 20.5% CP, 2.85 Mcal ME/kg DM) or a mixed ration consisting of 30.0% corn silage, 28.0% DDGS, 30.0% rolled corn, 10.5% soybean meal, and 1.5% mineral supplement (CON, 22.0% CP, 2.90 Mcal ME/kg DM). Animals were fed daily at 0700 and 1700 h and weighed weekly at 0630 h. For the duration of the trial, animals were housed in drylot pens with ad libitum access to feed and water and had shade structures in each pen. Following a 14-day adaptation period, feed intake was recorded for 35 days. Body weight gain for diets HAY, ALF, and CON were 0.1, 0.77, and 1.47 kg/day, respectively. After the intake portion of the study was completed, an animal from each pen was slaughtered and evaluated for meat quality. Hot carcass weights for diets HAY, ALF, and CON were 237.4, 334.7, and 394.8 kg, respectively. Following 14 days aging, samples from the ribeye area were collected from each animal and subjected to sensory analysis and other assessments of quality. Data were analyzed as a completely random design in SAS v9.4. There was not a significant difference between the ALF diet and the CON diet based on assessment from Warner-Bratzler shear force, carcass yield, marbling score, and sensory assessment (P < 0.05). It was concluded that high-quality forage can achieve similar carcass quality without detrimental effects on meat quality when compared with a high concentrate diet.

Can banana peel and sweet potato vines serve as efficient feed ingredients in diets for growing rabbits?

This study aimed to evaluate the use of banana peel (BP) and sweet potato vines (SPV) as a replacement for maize and alfalfa hay in diets for rabbits. Animal performance, economic analyses, meat composition, and color were evaluated for 49 days in a total 50 New Zealand White rabbits weaned at 35 days with an average body mass of ± 614 g. The animals were allotted, in a completely randomized design, having five dietary groups: control diet (0), without banana peels and sweet potato vines, or experimental diets, 25, 50, 75, and 100-with 25%, 50%, 75%, and 100% of banana peels and sweet potato vines in substitution to maize and alfalfa hay, respectively. The data were analyzed using ANOVA, while the means were compared by Tukey test (p < 0.05). The results indicate that daily feed intake, mass gain, and feed conversion were not statistically different from one another in the test groups compared to the control group treatment. In addition, the study shows no differences were observed in centesimal compositions and muscle color. The replacement of maize and alfalfa hay by the combination of BP and SPV resulted in reduction in feed costs, reaching 50% in the experimental diet with 100% of substitution the ingredients. It can be concluded, based on the results on animal performance, meat/color composition, and economic analyses, that BP and SPV may be used as a substitute for maize and alfalfa hay up to 100% in diets for growing rabbits.

Evaluating the inclusion of alfalfa hay in diets fed to multigravid Holstein cows in their transition to early lactation

The objectives of this study were to determine the dry matter intake (DMI), urine pH, Ca concentration in blood, Ca output in urine, and frequency of hypocalcemia in pregnant and nonlactating dairy cows consuming diets containing different hays and acidogenic products during the prepartum period. Eighty pregnant and nonlactating Holstein cows approaching their second or greater calving were fed 1 of 4 experimental diets according to a 2 × 2 factorial arrangement of treatments during the prepartum period (21 d before calving). Diets included either grass hay (GH) or alfalfa hay (AH) and calcium chloride (CL) or polyhalite (PO) as the acidogenic products. All diets had a dietary cation-anion difference (DCAD) below -190 mEq/kg of dry matter (DM). Grass hay contained 75 g/kg crude protein, 749 g/kg neutral detergent fiber, 3.6 g/kg Ca, 0.9 g/kg Na, 18.8 g/kg K, 3.8 g/kg Cl, 1.5 g/kg S, and a cation-anion difference equal to 290 mEq/kg of DM. Alfalfa hay contained 196 g/kg crude protein, 456 g/kg neutral detergent fiber, 15.2 g/kg Ca, 1.6 g/kg Na, 25 g/kg K, 7.7 g/kg Cl, 3.2 g/kg S, and a cation-anion difference equal to 292 mEq/kg of DM. Cows consuming GH tended to consume more DM than cows consuming AH (11.6 vs. 10.8 kg/d) but DMI did not differ between acidogenic products. Urine pH decreased below 6.5 for all diets, although cows consuming the GHPO diet had the highest urine pH. The concentration of Ca in plasma decreased substantially around calving but neither hay type nor acidogenic product affected it. Urinary Ca output was lowest for cows consuming the GHPO diet. No associations existed between dietary treatments and the frequencies of normocalcemia and hypocalcemia. Under the conditions of this study, in which alfalfa and grass hays had similar cation-anion differences, we concluded that the inclusion of alfalfa hay in prepartum diets does not necessarily increase the frequency of hypocalcemia. The cation-anion difference of the alfalfa hay, more than the concentration of potassium alone, may be a key determinant of whether alfalfa hay fits in a prepartum feeding program for prepartum dairy cows. Further research should explore this relationship.

Dairy goats fed sunflower hay intercropped with chickpea in small-scale systems. Part I: Animal performance

Background: Small-scale livestock systems provide quality food for a growing demand of animal protein worldwide. Although these systems help to improve rural living standards and reduce the environmental footprint new feeding strategies should be tested to improve animal productivity. Sunflower -which is native to México- and chickpea -also common in the study area- may be used as feed alternatives for dairy goats. Objective: To evaluate the effect of substituting corn straw with sunflower-chickpea hay on yield and nutrient composition of goat milk. Methods: In this participatory study, a total of 28 multiparous Saanen dairy goats were randomly assigned to two treatments (14 goats each) during a 30-day experiment in a small farm. Two weeks prior to the experiment all goats received an adaptation diet. One treatment (MZST) received a conventional diet of lucerne hay (200 g/goat/day) and concentrate (400 g/goat/day), plus 600 g/goat/day (50% of the ration) of corn straw. The second treatment (SFCPT) contained the same lucerne and concentrate content with 600 g/goat/day of sunflower-chickpea hay. Milk yield and composition, and live weight and body condition of the goats were recorded for each treatment. Results: SFCPT significantly increased milk yield, protein, and solids content, but no difference was observed in milk fat. Conclusion: Dietary supplementation of goats with sunflower and chickpea hay increases milk production, protein, and total solids content compared with corn hay.

Effects of Heat Stress in Dairy Cows Offered Diets Containing Either Wheat or Corn Grain during Late Lactation.

Simple SummaryA common nutritional strategy to reduce heat stress on dairy cows is to provide a more slowly degradable starch source that reduces the amount of heat generated during digestion. The aim of this experiment was to investigate the responses of late lactation dairy cows to cereal grain-based diets in a short-term heat challenge. Cows were offered a diet of alfalfa hay supplemented with either wheat grain (fast rumen degradable) or corn grain (slow rumen degradable). Individual cow measurements of feed intake, milk yield and composition, respiration rate, and body temperature were taken daily before, during and after a 4-day heat challenge, during which the cows were in individual controlled-climate chambers and exposed to air temperature up to 33 °C with 50% relative humidity. While exposed to the heat challenge during late lactation, cows that were offered corn grain had greater feed intake and tended to produce more energy-corrected milk but had lower respiration rates and similar body temperature to the cows offered wheat grain. The economic impact of feeding corn in place of wheat grain needs to be assessed before any comparative value of feeding corn grain or wheat grain can be determined.Cereal grains that differ in the rate and extent of ruminal fermentation differ in heat increment and may be used to improve thermoregulation during heat stress. This experiment investigated the responses of dairy cows in late lactation to a heat challenge when offered wheat-grain or corn-grain. Eighteen lactating cows, 220 ± 94 (mean ± standard deviation) days in milk, 3.7 ± 0.17 years of age and 558 ± 37 kg bodyweight, were allocated treatments containing 6 kg dry matter (DM)/day of wheat grain or 6 kg DM/day corn grain (9 per treatment) plus 14 kg DM/day of alfalfa hay. Measurements were made during a 7-day pre-challenge period at ambient conditions in individual stalls, during a 4-day heat challenge (temperature humidity index of 74 to 84) in individual controlled-climate chambers, then during a 7-day recovery period at ambient conditions in individual stalls. During the heat challenge, cows offered corn had lower respiration rates (p = 0.017) and greater feed intake (p = 0.021) but energy-corrected milk (p = 0.097) was not different to that of cows offered wheat. Feeding corn grain to dairy cows during a heat challenge reduced some of the negative impacts of heat stress, enabling the cows to consume more forage compared with supplementing with wheat grain.

Partial Substitution of Alfalfa Hay by Stevia (Stevia rebaudiana) Hay Can Improve Lactation Performance, Rumen Fermentation, and Nitrogen Utilization of Dairy Cows.

The objective of this study was to determine the effect of replacing isonitrogenous and isoenergetic basis alfalfa hay (AH) with stevia (Stevia rebaudiana) hay in dairy cow diets on nutrient digestion, milk performance, rumen fermentation, and nitrogen (N) utilization. In this study, 24 healthy Holstein lactating dairy cattle with a similar milk yield of 33.70 ± 2.75 (mean ± SD) kg, days in milk 95.98 ± 23.59 (mean ± SD) days, and body weight 587.75 ± 66.97 (mean ± SD) kg were selected and randomly allocated into three groups. The constituents of the three treatments were (1) 30.0% AH, and 0% stevia hay (SH) for the AH group; (2) 24.0% AH, and 6% SH for the 6% SH group; (3) 18.0% AH, and 12% SH for the 12% SH group. The substitution of AH with SH did not affect dry matter intake (DMI), gross energy (GE), and other nutrients intake but increased the digestibility of neutral detergent fiber (NDF) and acid detergent fiber (ADF). Compared with the AH diet, the cows fed the 6% SH diet had a higher milk yield and concentration of milk fat. Fecal and urinary nitrogen (N) were lower in cows fed a 6% SH diet than in cows fed the AH diet. Milk N secretion and milk N as a percentage of N intake were higher in cows fed a 6% SH diet than in cows fed AH diets. The concentration of ruminal volatile fatty acids, acetic acid, and ammonia-N were higher in cows fed a 6% SH diet than in cows fed an AH diet. By comparison, the 12% SH group did not affect milk yield, milk composition, N utilization, and rumen fermentation compared with the AH and 6% SH groups. In conclusion, it appears that feeding 6% SH, replacing a portion of AH, may improve lactation performance and N utilization for lactating dairy cows.

Gentiana straminea supplementation improves feed intake, nitrogen and energy utilization, and methane emission of Simmental calves in northwest China.

ObjectiveNative plants can be used as additives to replace antibiotics to improve ruminant feed utilization and animal health. An experiment was conducted to evaluate the effects of Gentiana straminea (GS) on nutrient digestibility, methane emissions, and energy metabolism of Simmental calves.MethodsThirty-two (5-week-old) male Simmental clves, with initial body weight (BW) of 155±12 kg were fed the same basal diet of concentrates (26%), alfalfa hay (37%), and oat hay (37%) and were randomly separated into four treatment groups according to the amount of GS that was added to their basal diet. The four different groups received different amounts of GS as a supplement to their basal diet during whole experiment: (0 GS) 0 mg/kg BW, the control; (100 GS) 100 mg/kg BW; (200 GS) 200 mg/kg BW; and (300 GS) 300 mg/kg BW.ResultsFor calves in the 200 GS and 300 GS treatment groups, there was a significant increase in dry matter (DM) intake (p<0.01), average daily gain (ADG) (p<0.05), organic matter intake (p<0.05), DM digestibility (p<0.05), neutral detergent fibre (NDF) digestibility (p<0.05), and acid detergent fibre (ADF) digestibility (p<0.05). Dietary GS supplementation result in quadratic increases of DM intake (p<0.01), ADG (p<0.05), NDF intake (p<0.05), and ADF intake (p<0.05). Supplementing the basal diet with GS significantly increased nitrogen (N) retention (p<0.001) and the ratio of retention N to N intake (p<0.001). Supplementing the basal diet with GS significantly decreased methane (CH4) emissions (p<0.01), CH4/BW0.75 (p<0.05) and CH4 energy (CH4-E) (p<0.05). Dietary GS supplementation result in quadratic increases of CH4 (p<0.01) and CH4/DM intake (p<0.01). Compared with 0 GS, GS-supplemented diets significantly improved their gross energy intake (p<0.05). The metabolizable energy and digestive energy intake were significantly greater for calves in the 100 GS and 200 GS calves than for 0 GS calves (p<0.05).ConclusionFrom this study, we conclude that supplementing calf diets with GS could improve utilization of feed, energy, and N, and may reduce CH4 emissions without having any negative effects on animal health.

Effect of the Short-Term Incorporation of Different Proportions of Ensiled Artichoke By-Product on Milk Parameters and Health Status of Dairy Goats

The use of local agricultural by-products for animal feed is an alternative that reduces livestock production costs and allows food production of greater environmental sustainability. The aim of this experiment was to study the effect of the inclusion in the dairy goat ration of artichoke by-product silage (ABS) at three levels (25%, 40% and 60%, on a dry matter basis) on the milk yield, composition and quality, and on the metabolic profile of dairy goats. Thirty-six Murciano-Granadina dairy goats in mid-lactation were divided into four groups with homogeneous characteristics. Each group was assigned a diet: a control treatment (C) that consisted of a conventional diet of alfalfa hay and concentrate, and three other treatments that included 25, 40 and 60% ABS: ABS25, ABS40 and ABS60. Small differences were observed in the milk yield and quality and the health status of the animals. Only ABS60 presented a slightly lower milk yield (−20% compared to control group), without relevant differences in the milk composition and mineral profile. Regarding the lipid profile, ABS40 was the treatment with the best milk quality, due to a higher content of polyunsaturated fatty acids (4.37%) and lower atherogenicity (1.90) and thrombogenicity indices (3.05), without differences from C. It was concluded that the maximum inclusion level of ABS in dairy goats’ diet should be equal to 40%.

Determination of maintenance energy requirement and responses of dry ewes to dietary inclusion of lucerne versus concentrate meal

An accurate value for metabolizable energy (ME) requirement for maintenance (MEm) is essential to enable sheep husbandry practice to reach its potential. The objectives of the study were to use calorimetry chamber data of dry ewes (Hu × thin-tail Han F1 crossbred) to develop updated MEm, examine effects of substituting concentrate feed with lucerne hay on energy partitioning, and explore the relationships between energy utilization and fasting heat production (FHP). Data were collected from three experiments. In Exps. 1, 2a and 2b, lucerne hay was used to replace concentrates in three levels (0:40%, 15:25% and 30:10%), with diets containing 60% maize stover (Exp. 1), fresh rye forage (Exp. 2a) or dry rye forage (Exp. 2b). Within each experiment, diets were isoenergetic (digestible energy, DE) and isonitrogenous. Exp. 3 aimed at evaluating effects of three BW levels on nutrient utilization of dry ewes offered diets containing 60% maize stover, 15% lucerne hay and 25% concentrates. Energy metabolism data were measured using the respiration calorimeter chamber technique in all three experiments, followed by the measurement of FHP in Exps. 1, 2b and 3. The MEm derived from the linear regression between energy balance (EB) and ME intake was 0.440 MJ/kg BW0.75. The average FHP was 0.326 MJ/kg BW0.75. The fasting metabolism, net energy requirement for maintenance (NEm) and MEm were estimated to be 0.336, 0.359 and 0.511 MJ/kg BW0.75, respectively, through adjustment of FHP using fasting urinary energy output, activity allowance and efficiency of ME use for maintenance. The FHP was negatively correlated to EB/metabolic BW, ME/gross energy (GE), ME/DE, EB/GE intake and EB/ME intake, while positively correlated to HP/GE intake, HP/ME intake and CH4-E/GE intake. Compared to zero lucerne hay diet, the 15% lucerne hay intake decreased HP (MJ/d), and had no negative effects on EB (MJ/d) or energy utilization efficiencies. The results indicate that nutrient requirement standards currently used across the world are likely to underestimate MEm for dry ewes, and the selection of low FHP ewes for breeding has the potential to improve sheep production efficiency.

The Effect of a High-Grain Diet on the Rumen Microbiome of Goats with a Special Focus on Anaerobic Fungi.

This work investigated the changes of the rumen microbiome of goats switched from a forage to a concentrate diet with special attention to anaerobic fungi (AF). Female goats were fed an alfalfa hay (AH) diet (0% grain; n = 4) for 20 days and were then abruptly shifted to a high-grain (HG) diet (40% corn grain, 60% AH; n = 4) and treated for another 10 days. Rumen content samples were collected from the cannulated animals at the end of each diet period (day 20 and 30). The microbiome structure was studied using high-throughput sequencing for bacteria, archaea (16S rRNA gene) and fungi (ITS2), accompanied by qPCR for each group. To further elucidate unclassified AF, clone library analyses were performed on the ITS1 spacer region. Rumen pH was significantly lower in HG diet fed goats, but did not induce subacute ruminal acidosis. HG diet altered prokaryotic communities, with a significant increase of Bacteroidetes and a decrease of Firmicutes. On the genus level Prevotella 1 was significantly boosted. Methanobrevibacter and Methanosphaera were the most abundant archaea regardless of the diet and HG induced a significant augmentation of unclassified Thermoplasmatales. For anaerobic fungi, HG triggered a considerable rise in Feramyces observed with both ITS markers, while a decline of Tahromyces was detected by ITS2 and decrease of Joblinomyces by ITS1 only. The uncultured BlackRhino group revealed by ITS1 and further elucidated in one sample by LSU analysis, formed a considerable part of the AF community of goats fed both diets. Results strongly indicate that the rumen ecosystem still acts as a source for novel microorganisms and unexplored microbial interactions and that initial rumen microbiota of the host animal considerably influences the reaction pattern upon diet change.

Effects of replacing alfalfa hay with malt sprouts and corn stover on milk production and nitrogen partitioning in dairy cows

The aim of this investigation was to study the effect of replacing alfalfa hay with malt sprouts and corn stover on feed intake and apparent digestibility, rumen fermentation, milk production and composition, and N partitioning in dairy cows. Six multiparous Holstein dairy cows were used a replicated 3 × 3 Latin square design with each period lasting 27 d. The cows were assigned randomly to one of three treatment groups: (1) 0 g/kg malt sprouts and 0 g/kg corn stover (0MS), (2) 49.1 g/kg malt sprouts and 34.4 g/kg corn stover (5MS), and (3) 133 g/kg malt sprouts and 49.1 g/kg corn stover (13MS). The diets were isonitrogenous and contained identical corn silage and concentrate mixtures, but different proportions of corn stover and malt sprouts. The in situ effective degradability of dry matter, neutral detergent fiber and crude protein were higher in cows fed 13MS or 5MS diets than in those fed the 0MS diet. The respective intake and total-tract apparent digestibility of dry matter, crude protein, neutral detergent fiber, and acid detergent fiber were greater for 13MS than for 5MS or 0MS. Cows fed the 13MS diet had greater milk production, energy-corrected milk, milk protein and lactose yields and percent milk protein than cows fed other diets, but fat yield, percentage of milk fat, lactose, somatic cell count, milk urea nitrogen concentration and feed efficiency were similar for the three treatments. Compared with the 0MS diet, cows fed 5MS or 13MS diets had higher rumen ammonia nitrogen and total volatile fatty acids concentration, PD to creatinine ratio. Moreover, the cows that consumed a MS diet had a higher rate of manure excretion. Thus, it appeared that the combination of malt sprouts and corn stover effectively replaced a portion of alfalfa hay in diets without affecting the performance of dairy cows.

The n-alkane technique does not accurately predict the nutrient digestibility of mixed diets fed to horses

This study was conducted to determine the fecal recovery rate of n-alkanes and compare the precision and accuracy of the n-alkane technique and the conventional total fecal collection method in estimating the apparent nutrient digestibility of mixed hay diets fed to horses. Six castrated male adult horses (361 ± 12 kg body weight) were fed diets composed of different proportions of Tifton 85 bermudagrass (Cynodon dactylon) hay and alfalfa (Medicago sativa) hay in a 6 × 6 Latin square design. Treatments were as follows: T100, 100% Tifton hay; T80, 80% Tifton hay and 20% alfalfa hay; T60, 60% Tifton hay and 40% alfalfa hay; T40, 40% Tifton hay and 60% alfalfa hay; T20, 20% Tifton hay and 80% alfalfa hay; and T0, 100% alfalfa hay. The n-alkane detected at the greatest (P < 0.05) mean concentration in feed was n-hexatriacontane (C36H74), followed by n-hexacosane (C26H54), n-heptacosane (C27H56), n-nonacosane (C29H60), n-hentriacontane (C31H64), n-tritriacontane (C33H68), and n-pentatriacontane (C35H72). A strong correlation (r = 0.91, P < 0.001) was found between carbon chain length and fecal recovery. The n-Hentriacontane, n-tritriacontane, n-pentatriacontane, and n-hexatriacontane had the greatest fecal recovery (mean = 0.91, P < 0.05) and were therefore used to estimate nutrient digestibility. None of the n-alkanes provided consistent results. Fecal recovery was incomplete, and fecal recovery rates above 100% were obtained regardless of the proportion of Tifton and alfalfa hay in diets. Dry matter, crude protein, neutral detergent fiber, acid detergent fiber, and mineral matter digestibility estimated using n-alkanes differed (P < 0.05) from digestibility values obtained by the reference method (total fecal collection). The simplest explanation for these results would be that horses preferred one type of hay over the other and had an uneven intake of each diet. Because Tifton and alfalfa hay differ greatly in composition, their uneven intake makes estimation of nutrient digestibility by fecal recovery of n-alkanes unreliable. Even after correction for fecal recovery, n-alkanes were inaccurate markers of nutrient digestibility.

368 Effects of average temperature, wind speed, and solar radiation on daily water intake of beef bulls in winter and early spring in Eastern South Dakota

Abstract Few studies have estimated effects of weather on water intake in beef cattle, and most of these studies estimated effects during summer months. Our objective was to estimate effects of temperature, wind speed, and sunlight on daily water intake (DWI) of beef bulls in winter and early spring. Angus and SimAngus® bulls (n = 36; average starting BW = 369.5 ± 81.8 kg) were sampled from the South Dakota State University Cow-Calf Education and Research Facility (CCERF, Brookings, SD) from December 22, 2017 through April 5, 2018 (104 d total). Bulls were fed a diet (51.97% DM, 14% CP, and 1.08 Mcal NEg/kg DM) of high-moisture corn, corn silage, alfalfa hay, and supplement pellet. Individual feed and water intake were measured with an Insentec RIC system (Hokofarm, Marknesse, The Netherlands). Weather data, including average temperature, wind speed, and solar radiation were obtained from a Mesonet station located 3.9 km from the CCERF. Body weights were collected before feeding at four time points: December 13-14 (averaged), January 23, February 20, and April 2. Average daily gain was calculated from BW and used to predict BW on each day of the trial. Daily water and feed intakes were summed across all bulls each day; total DWI for all 36 bulls was the dependent variable. Average DWI per bull was 17.8 ± 7.05 kg/d and average total DWI per bull (including feed) was 28.9 ± 10.1 kg/d. Effects of average temperature, wind speed, and solar radiation were estimated with a linear model including a covariate of ADFI as percent predicted BW. Increased average temperature (P &lt; 0.001) and solar radiation (P = 0.032) were associated with increased DWI, while increased average wind speed was associated with decreased DWI (P = 0.009). Temperature, wind speed, and amount of sunlight were associated with water intake of beef bulls fed from December until early April in Eastern South Dakota.