Comparison of growth performance and tissue cobalt concentrations in beef cattle fed inorganic and organic cobalt sources.

Cobalt is an essential trace mineral required for ruminal vitamin B12 synthesis, but sources differ in ruminal microbial utilization, i.e., cobalt carbonate is poorly water soluble, whereas acetate and lactate forms are water soluble. Reports comparing organic cobalt lactate to other cobalt salts are lacking. The study objective was to determine if feeding cobalt lactate at two inclusion rates resulted in similar growth performance and tissue cobalt concentrations as the carbonate and acetate forms used in feeds. One hundred Angus cross bred steers weighing 385 ±â€…20 kg were randomly assigned to one of five treatments. Cattle were fed a basal diet plus: 1) cobalt carbonate to supply cobalt at 30 mg/steer/d, 2) cobalt acetate to supply cobalt at 30 mg/steer/d, 3) cobalt acetate to supply cobalt at 60 mg/steer/d, 4) cobalt lactate to supply cobalt at 30 mg/steer/d, and 5) cobalt lactate to supply cobalt at 60 mg/steer/d. Cattle were fed according to industry standards until body fat deposition was visually deemed to grade USDA Choice, which was 92 and 117 d for each of the 2 blocks, respectively. Steers were harvested and carcass measurements recorded along with sampling of adipose, heart, kidney, liver, and muscle for tissue cobalt concentrations. Three statistical contrasts consisted of: 1: inorganic (cobalt carbonate) vs. organic (cobalt acetate and lactate); 2: cobalt acetate vs. cobalt lactate; and 3: feeding rate of 30 vs. 60 mg/steer/d cobalt. Body weight gains, average daily gains, dry matter intake, and feed conversions were similar (P > 0.10) for steers fed all cobalt sources and feeding rates. Hot carcass weight, yield grade, back fat thickness, and ribeye area were similar (P > 0.10) among steers fed all cobalt sources and inclusion rates. Liver, kidney, muscle, and adipose cobalt concentrations were similar (P > 0.08) for steers fed inorganic vs. organic cobalt sources. Feeding cobalt lactate compared with cobalt acetate did not affect (P > 0.10) liver, kidney, heart, muscle, and adipose tissue cobalt concentrations. Feeding 60 mg/steer/d cobalt compared with 30 mg/steer/d increased (P < 0.01) liver, kidney, heart, and adipose tissue cobalt concentrations, while muscle was a tendency (P < 0.06). The study demonstrated that feeding soluble cobalt lactate, a new cobalt source, resulted in similar growth performance, carcass characteristics, and tissue cobalt concentrations when compared with cobalt acetate and carbonate.

Effects of Essential Oil and/or Encapsulated Butyrate on Fecal Microflora in Neonatal Holstein Calves.

This study was conducted to investigate the effects of feeding oregano essential oil, butyrate, and its mixture on the intestinal microbial diversity of calves. A completely randomized experimental design was used. Sixty-four healthy neonatal Holstein female calves with birth weight ≥ 35 kg were randomly divided into one control and three treatments (16 calves per group). The control group was fed normally, and the treatment group was fed oregano essential oil, butyrate, and their mixture, respectively. The experiment lasted for 70 days, and the lactation period lasted for 56 days. On days 55 and 70, rectal fecal samples from five calves were collected from each group for 16S rRNA amplification and sequencing. The results showed as follows: (1) the three treatments had no significant effects on the intestinal microbial community diversity, community uniformity, and community pedigree diversity of calves (p > 0.05). (2) At the phylum level, Firmicutes, Bacteroidota, Spriochatetota, Actinobacteriota, Firmicutes, and Bacteroidota gates of the main bacteria were detected in feces. (3) At the genus level, the top ten species with relative abundance detected are: norank_ F_Muribaaculaceae, Ruminococcus, unclassified_ F_ Lachnospiraceae, UCG-005, Prevotelaceae_NK3B31_Group, Prevotella, Bacteroides, Rikenellaceae_RC9_Gut_Group, and Faecalibacterium, Alloprevotella. (4) LEfSe analysis results show that the species with significant differences in the control group were f__Lachnospiraceae, o__Lachnospirales, o__Coriobacteriales, and c__Coriobacteriia, g__Megasphaera; in the essential oil group were g__Lachnospiraceae_AC2044_group, o__Izemoplasmatales, g__norank_f__norank_o__Izemoplasmatales, and f__norank_o__Izemoplasmatales; in the sodium butyrate group were g__Lachnospiraceae_NK4A136_group, and g__Sharpea, g__Fournierella; in the mixed group were g__Flavonifractor, and g__UBA1819. (5) The functional prediction analysis of calf gut microbes, found on the KEGG pathway2, shows that essential oil significantly improved membrane transport, Sodium butyrate inhibits lipid metabolism and improves the body's resistance to disease. (p < 0.05). (6) The effects of each treatment on the intestinal microbial structure of calves did not last for 14 days after the treatment was stopped. In conclusion, the addition of oregano essential oil, butyrate, and its mixtures to milk fed to calves can modulate the microbial structure, and it is recommended that oregano essential oil and butyrate be used separately, as a mixture of the two can increase the rate of diarrhea in calves.

The female to male calf sex ratio is associated with the number of services to achieve a calf and parity of lactating dairy cows.

Commercial dairy producers may get frustrated by the lower ratio of female to male calves born because female calves are more valuable than bull calves. Our objective was to determine if parity or stage of lactation at the time of breeding, using conventional semen, influenced the sex of the calf. Data from the University of Illinois and the University of New Hampshire dairy herds were collected and summarized for calf sex, the number of services to achieve a calf and the lactation number when conception of that calf occurred. Logistical regression procedures were used to analyze the dataset via version 9.4 of SAS. The final dataset contained 2,987 calvings, which consisted of 1,406 females and 1,581 males (47.1% and 52.9% for females and males, respectively). The frequency distribution of the number of services to achieve a calf was highest for the first service and progressively declined with increasing services (52.06%, 21.66%, 10.75%, 6.66%, 4.22%, and 4.65% for 1 to 6 services, respectively). The frequency distribution of calvings by lactation number was greatest for first lactation cows becoming pregnant with their second calf and declined with increasing parity (35.49%, 28.22%, 17.01%, 9.61%, 5.02%, 2.51%, 1.14%, 0.70%, and 0.30% for lactation numbers 1 to 9, respectively). Logistic stepwise regression indicated that the number of services to achieve a calf was significant in predicting the ratio of female to male calves. Calculation of odds ratios indicated that as the lactation number increased the likelihood of getting a bull calf decreased. Parity, services, and parity by services interaction were significant for cows having a greater number of parities and cows with a greater number of services yielding more heifer calves. However, an interaction occurred where cows with greater number of services along with greater parities more likely to have a bull calf. These data provide evidence that increasing the number of services to achieve a calf and increasing age of the cow increased the probability of a heifer calf being born. These data indicate that cows with greater parties (lesser cull rate) are more likely to produce heifer calves.

Supplementing additional cobalt as cobalt lactate in a high-forage total mixed ration fed to late-lactation dairy cows.

Cobalt lactate is a highly soluble ruminal Co source. Prior research evaluating higher Co feeding rates demonstrated increased ruminal fiber digestion. Feeding high-forage (>70%) rations to late-lactation dairy cows to enhance income over feed cost could potentially benefit from higher ruminal-soluble Co inclusion rates to enhance ruminal fiber and nutrient digestibility. Twenty-four late-lactation [238 ± 68.8 d in milk (DIM) and 36.4 ± 5.4 kg/d milk] Holstein dairy cows (10 primiparous and 14 multiparous) were blocked by milk yield, DIM, and parity, and randomly assigned to 1 of 2 treatments. Treatments were (1) control, CoCO3 total mixed ration (TMR) containing 12.5 mg/cow per day of cobalt (cobalt carbonate), and (2) cobalt lactate (Co-LAC), same CoCO3 TMR but containing an additional 50 mg/cow per day of Co, via a 1% cobalt lactate product (CoMax, Ralco Inc.). The basal TMR was 70% forage [60% alfalfa baleage and 40% corn silage on a dry matter (DM) basis] and 30% of the respective experimental grain mix on a DM basis. Cows were fed the CoCO3 TMR during the 7-d covariate period, followed by 4 wk of data collection when CoCO3 and Co-LAC TMR were fed. Milk production (26.2 and 25.8 kg/d for CoCO3 and Co-LAC, respectively) and dry matter intake (DMI; 22.9 and 23.1 kg/d) were similar for cows fed both Co treatments. Production of milk fat (1.02 and 1.09 kg/d), milk protein (0.87 and 0.91 kg/d), and lactose (1.17 and 1.26 kg/d) were similar for cows fed both treatments. Body weights (684 and 674 kg) were similar for cows fed both treatments. Rumen ammonia concentrations (15.8 and 12.3 mg/dL) were lower for cows fed Co-LAC compared with cows fed CoCO3 (15.8 mg/dL). Ruminal molar acetate concentrations (59.5 and 61.1%) were greater for cows fed Co-LAC compared with cows fed CoCO3. Feeding additional Co as cobalt lactate in the TMR did not enhance lactational performance (milk production, composition, DMI, or body weight changes) when fed a high-forage TMR but altered ruminal fermentation with decreased ruminal ammonia and increased ruminal acetate concentrations.

Feeding Sheep Cobalt and Oregano Essential Oil Alone or in Combination on Ruminal Nutrient Digestibility, Fermentation, and Fiber Digestion Combined With Scanning Electron Microscopy.

The feeding of Co lactate (Co), an essential oil blend (EO; oregano), or a combination of Co and EO (EOC) may improve nutrient digestion of corn silage-based rations. In four separate studies, Co, EO, or EOC was fed at 0, 4, and 7 g/days to nine rumen fistulated rams arranged in a replicated 3 × 3 Latin square design. The fourth study evaluated the carrier at 0, 4, and 7 g/day. In each ram, fresh ensiled corn silage, leaf, and husk were placed in individual nylon bags inserted through the ruminal cannula and removed after 48 h. Rams fed increasing carrier rates demonstrated similar (P > 0.10) nutrient digestibilities and ruminal pH and volatile fatty acid concentrations. Feeding Co at 4 and 7 g/day increased (P < 0.05) digestibility of DM (59.4, 63.9, and 62.4% for 0, 4, and 7 g/day, respectively), NDF (59.4, 63.9, and 62.4%), and hemicellulose (HC; 56.2, 63.6, and 65.9%) compared with rams fed 0 g/day, while CP digestibility (46.4, 49.9, and 57.8%) was improved (P < 0.05) in rams fed 7 g/day compared with those fed 0 and 4 g/day. Rams fed 4 g/day EO digested greater (P < 0.05) HC (64.1, 71.4, and 69.1%) than rams fed 0 g/day, while rams fed 7 g/day were intermediate and similar (P > 0.10). Rams fed the EOC combination at 4 and 7 g/day demonstrated greater (P < 0.05) digestibilities of DM (57.7, 60.0, and 60.0%), NDF (21.4, 28.8, and 27.7%), and ADF (24.3, 33.3, and 34.4%) than rams fed 0 g/day. The SEM and SM techniques visually demonstrated minor evidence of husk and leaf digestibility in rams across the three experiments when fed 0 g/day of Co, EO, or EOC; rams fed 4 g/day of Co, EO, or EOC exhibited varying visual signs of leaf digestion with some palisade tissue, spongy tissue, and whole vein structure remaining, while in rams fed 7 g/day, only the vein structure remained. Results demonstrated that feeding Co, EO, or EOC at 4 or 7 g/day enhanced ruminal nutrient digestion and fermentation parameters, which was visually confirmed via SEM and SM.

Adaptation and withdrawal of feeding dried Aspergillus oryzae fermentation product to dairy cattle and goats on in vitro NDF digestibility of selected forage sources.

Nutritional fermentation aids [dried Aspergillus oryzae fermentation product (AO)] are used in livestock production to increase nutrient digestion and production efficiency. The objective was to determine AO impact on neutral detergent fiber (NDF) degradation of selected forage sources (FS). A series of in vitro fermentation experiments were conducted using rumen fluid (RF) from rumen fistulated dairy heifers or dairy goats evaluating AO at 0.0, 0.3, or 0.6 g/L inclusion rates. In experiment I, the optimum AO concentration using alfalfa hay (AH), Bermuda grass (BG) hay, and peanut skins (PS) was determined via 48-h in vitro neutral detergent fiber digestion (IVNDFd). In experiment II, 0.0 g/L and 0.3 g/L AO were used to determine in vitro dry matter digestion (IVDMD), in vitro organic matter digestion (IVOMD), IVNDFd, and NDF digestion kinetics. In experiment III, in vivo AO ruminal adaptation (AD) and withdrawal (WD) times were determined for both dairy heifers and goats on IVDMD, IVOMD, IVNDFd, and NDF digestion kinetics. In experiment I, IVNDFd was similar using RF from dairy heifers or goats with IVNDFd being increased 10%, 28%, and 23% for AH, BG, and PS, respectively, at 0.3 g/L of AO compared with 0.0 g/L AO, while adding 0.6 g/L AO reduced IVNDFd among all FS. In experiment II, IVNDFd was greater when adding 0.0 g/L AO compared with 0.3 g/L AO using dairy goat RF (26.7% and 37.6%, respectively) among all FS. The mean retention time and 50% digestion times were greater, while digestion rate was lower for PS compared to AH and BG. In vitro dry matter (DM) and organic matter (OM) digestibilities were greater with AO for AH and BG compared to PS but varied with RF donor source. In experiment III, in vitro DM digestibility increased then decreased with adaptation time, while AO withdrawal increased digestion of DM, OM, and NDF. The NDF digestion kinetics were similar across all FS (AH, BG, and PS), which resulted in no clear determination of AO adaptation and withdrawal times needed for AO efficacy. The optimal AO inclusion rate was determined to be 0.3 g/L for improving in vitro NDF digestion, but subsequent experiments could not confirm that inclusion rate. Inclusion rates greater than 0.3 g/L depressed NDF degradation, which should be avoided due to depression of NDF digestion. Sourcing ruminal fluid from dairy heifers or goats for conducting in vitro fermentations resulted in similar DM, OM, and NDF digestion and NDF degradation kinetics.

Lactobacillus plantarum GB LP-1 as a direct-fed microbial for neonatal calves.

Direct-fed microbial feed additives with potential to enhance growth performance, gut health, and immunity have gained considerable popularity in neonatal calf production. Lactobacillus plantarum GB LP-1 (LP) produced by a proprietary fermentation process could be a viable direct-fed microbial feed for neonatal calves. The hypothesis was that feeding LP may ease transitioning from milk replacer (MR) to calf starter (CS) by improving gut health and appetite, while minimizing health challenges from pathogens and stress to improve growth performance. The experimental objective was to evaluate LP in an MR feeding program at 3 inclusion rates. Fifty-one 2- to 5-d-old Holstein bull calves were randomly assigned to 1 of 3 treatments using a randomized complete block design. Treatments were (1) Control (LP0): LP fed at 0 g/d; (2) LP4: LP fed at 4 g/d; and (3) LP8: LP fed at 8 g/d. Calves were fed MR at 0.57 kg/d for 14 d via bucket, which was increased to 0.85 kg/d until 35 d, and were then fed once daily at 0.425 kg/d with weaning after d 42 of the 56-d experiment. Calves were fed at 0630 and 1800 h in equal allotments, with access at all times to free-choice water and a pelleted CS with 25.5% crude protein. Calves demonstrated a linear growth response to increasing LP inclusion rate: calves fed LP8 gained more body weight (33.0, 36.9, and 37.7 kg for LP0, LP4, and LP8, respectively) than calves fed LP0, with calves fed LP4 being intermediate and similar. The 0-to-42-d (MR feeding phase) average daily gain (ADG; 562.9, 595.9, and 655.7 g/d) and 0-to-56-d ADG (588.6, 658.4, and 673.0 g/d) demonstrated linear responses, with calves fed LP8 having greater ADG than calves fed LP0, and calves fed LP4 being intermediate and similar. Total CS intake was similar among calves fed all treatments (66.3, 69.0, and 72.5 kg/56 d), which resulted in a quadratic response in feed efficiency (0.50, 0.53, and 0.52 kg of gain/kg of dry matter) for calves fed LP4 compared with calves fed LP0, with calves fed LP8 being intermediate and similar. Fecal scores improved linearly with increasing LP inclusion rate. These data demonstrate that feeding Lactobacillus plantarum GB LP-1 to neonatal calves improves gut health to increase growth performance at 4 and 8 g/d, while feed efficiency was greatest at 4 g/d.

Effect of additives and filling methods on whole plant corn silage quality, fermentation characteristics and in situ digestibility.

OBJECTIVE: This project aimed to evaluate the effects of both different additives and filling methods on nutritive quality, fermentation profile, and in situ digestibility of whole plant corn silage. METHODS: Whole plant corn forage harvested at 26.72% dry matter (DM) was chopped and treated with two filling methods, i) fill silos at one time (F1), ii) fill silos at three times (F3), packing samples into one/three silo capacity at the first day, another one/three capacity at the second day, then one/three at the third day, three replicates. For each replicate, samples were treated with three additives, i) control (CTRL, no additive), ii) Sila-Max (MAX, Ralco Nutrition Inc., Marshall, MN, USA), and iii) Sila-Mix (MIX, Ralco Nutrition Inc., USA). With three replicates of each secondary treatment, there were nine silos, 54 silos in total. Each silo had a packing density of 137.61 kg of DM/m3. All silos were weighed and stored in lab at ambient temperature. RESULTS: After 60 d of ensiling, all items showed good silage fermentation under MAX filled one time or three times (p<0.01). Higher silage quality for all additives was obtained at filling one time than that filled three times (p<0.01). The highest DM and lowest DM loss rate (DMLR) occurred to MAX treatment at two filling methods (p<0.01); Digestibility of acid detergent fiber, neutral detergent fiber (NDF), and curde protein had the same results as silage quality (p<0.01). Yield of digestible DM and digestible NDF also showed higher value under MAX especially for filling one time (p<0.05). CONCLUSION: All corn silages showed good fermentation attributes (pH<4.0). The forage filled one time had higher silage quality than that filled three times (p<0.01). MAX with homofermentative lactic acid bacteria enhanced the lactic acid fermentation, silage quality and nutrient digestibility, and so improved the digestible nutrient yield.

Feeding an amino acid-formulated milk replacer for Holstein calves during 2 time periods.

The milk-fed calf has a requirement for essential amino acids (EAA) instead of crude protein (CP). However, most milk replacers (MR) are still formulated to a CP concentration, and although limited amounts of Lys or Met may be added, these MR are not formulated solely on an AA basis. Previous work has demonstrated that feeding a modified MR balanced for specific EAA concentrations of a 24% CP MR, but reducing CP to 22%, resulted in improved growth performance in calves compared with a 24% CP MR. The 56-d objective was to determine if the hypothesis that an EAA MR formulated to the specific EAA concentrations of a 24% CP MR, but reducing CP to 22 (22AA) compared with a standard 22% CP MR would result in similar or enhanced growth performance, while reducing feed costs. Two 56-d studies using forty 3- to 5-d-old Holstein bull calves per study received in 1 lot starting on May 8, 2018 (late-spring cooler) and June 22, 2018 (summer with heat stress) were blocked by body weight (BW) and randomly assigned to 1 of 2 MR treatments. Milk replacer treatments consisted of a standard 22:20 (CP:fat; 22CP) and a 22:20 MR with greater EAA concentrations of a 24% CP MR (22AA). All MR, containing decoquinate and diflubenzuron, were fed at 0.57 kg/d per calf split into 2 feedings at 0630 h and 1800 h for 0 to 14 d via bucket, increased to 0.85 kg/d through 35 d split in 2 feedings, and fed once per day at 0.41 kg/d in the morning with weaning after 42 d. Calves were housed in straw-bedded hutches with ad libitum access to water and 25% CP pelleted calf starter (CS). All data were analyzed as a randomized complete block design with block within study considered random and week as a repeated measurement. Initial BW was similar across all treatments (39.9 ± 2.32 kg). Average daily temperature (i.e., heat stress intensity) tended to be greater for calves in study 2 compared with study 1 (20.5 and 22.9°C for study 1 and 2, respectively). The interaction of study and MR effects were nonsignificant. Calf BW, BW gain, average daily gain, CS intake, total dry matter intake (MR plus CS), feed conversions, and EAA intake (MR plus CS) were similar for calves fed both MR. Study 2 (summer heat stress) resulted in more scours incidences compared with study 1, and 22AA MR formulation tended to increase scours possibly due to synthetic AA addition or greater carbohydrate (lactose) inclusion when AA replaced protein sources. Feed costs as MR and total feed costs were lower for calves fed 22AA MR compared with calves fed 22CP MR. The increased Leu, Lys, Met, Thr, and Val concentrations in the 22AA MR compared with the 22CP MR resulted in similar calf growth performance, but the feed cost was lower for calves fed the 22AA MR, which achieved similar growth performance at a lesser cost under current study conditions, but not enhanced as hypothesized.

Feeding a calf starter containing monensin alone or in combination with an oregano, and cobalt blend to Holstein calves.

Gut health is critically important for growing neonatal calves, and nutritional technologies are needed to prevent disease and stress challenges. Previous work feeding monensin (MON) in combination with an oregano, prebiotic, and cobalt-lactate (EOC) blend had demonstrated improved calf gut health and growth performance. The objective of this study was to evaluate the growth performance of calves fed MON and EOC alone or in combination. Eighty (80) newborn Holstein (37) female and (43) male calves were randomly assigned to one of four treatments arranged in a 2 × 2 factorial (MON and EOC). Treatments were: 1) Control: without MON or EOC added to the calf starter (CS); 2) MON: 50.8 mg/kg CS (Elanco, Greenfield, IN); 3) EOC: 44.1 mg/kg CS (Rum-A-Fresh, Ralco Inc. Marshall, MN); 4) MON + EOC: MON and EOC added to CS. Calves were fed colostrum followed by whole milk through weaning at 42 d, while CS was fed ad libitum through the 70-d experimental period. The MON by EOC interaction was found to be nonsignificant (P > 0.41) for growth performance. Calves fed without or with MON demonstrated similar (P > 0.70) body weight (BW; 68.7 and 68.9 kg without and with MON, respectively), while calves fed EOC demonstrated greater (P < 0.01) BW (67.3 and 70.4 kg without and with EOC, respectively) compared with calves fed without EOC. Calves fed a CS containing MON were similar (P > 0.47) in average daily gain (ADG; 0.88 and 0.91 kg/d) compared with calves fed without MON; however, feeding calves a CS with EOC increased (P < 0.01) ADG (0.84 and 0.95 kg/d) by 13% through the 70-d experimental period compared with calves not fed EOC. Frame measurements indicated that the greater ADG was due to increased (P < 0.10) frame growth for calves fed essential oils (EO) compared with calves fed without EO. A MON by EOC interaction (P < 0.01) for serum propionate concentration demonstrated calves fed MON + EOC and EOC were greater (P < 0.05) compared with calves fed Control, while calves fed MON were intermediate and different (P < 0.05). Feeding calves a CS with EOC increased (P < 0.04) immunoglobulin A, immunoglobulin G, and immunoglobulin M concentrations compared with calves fed without EOC. A MON by EOC interaction was detected (P < 0.01) for total tract starch digestibility for calves fed EOC or MON + EOC demonstrating greater (P < 0.05) starch digestibilities than Control-fed calves. These data demonstrate that EOC and MON fed in combination was not beneficial for enhancing the growth performance, but that calf growth performance can be improved with EOC compared with MON.

Evaluation of essential oils and a prebiotic for newborn dairy calves.

A blend of essential oils (EO) and a prebiotic were combined (EOC) to formulate a colostrum-based liquid birth supplement and a separate feeding supplement (Start Strong and Stay Strong, Ralco Inc., Marshall, MN). These products were designed to promote immunity and stimulate appetite to diminish health challenges and stresses experienced by newborn calves. The hypothesis was that calves supplemented with an oral dose of liquid EOC at birth (10-mL aliquot at birth and 10 mL at 12 h of age) when fed the EOC feeding supplement would result in improved growth performance, health, and immunity. The objective was to determine if an additional feeding of liquid EOC at birth in combination with EOC in the milk replacer (MR) would allow calves to demonstrate improved growth, health, and immunity compare with calves only offered EO in MR. Sixty-one Holstein calves (18 males and 43 females) from a commercial dairy operation were blocked by birth date and randomly assigned to 1 of 3 treatments. Treatments were 1) Control (CON): a 24% crude protein (CP):20% fat (as-fed basis) MR; 2) EP: a 24:20 MR with EOC mixed at 1.25 g/d; or 3) EPC: a 24:20 MR with EOC mixed at 1.25 g/d in addition to calves receiving one 10-mL oral dose of liquid EOC at birth and 10 mL again at 12 h. The 24:20 MR was fed via bucket 2 times per day at a rate of 0.57 kg/calf daily for 14 d, increased to 0.85 kg/calf at 2 times per day until 35 d and was reduced to 0.43 kg at 1 time per day at 36 d to facilitate weaning after 42 d. Decoquinate was added to the MR at 41.6 mg/kg for coccidiosis control. Calves were housed in individual hutches bedded with straw with ad libitum access to a 20% CP-pelleted calf starter and water. All data were analyzed using PROC MIXED as a randomized complete block design. Calves in this study had similar (P > 0.10) average daily gains, body weight, and growth measurements. Calves fed EPC had significantly (P < 0.05) higher IgA titers on day 0 of the trial compared with calves fed EP or CON, which was expected as calves were supplemented with liquid EOC at birth and 12 h later demonstrating an increase in immune response. The use of a liquid EOC product being administrated after birth can improve IgA titers to improve the immune status of the new born calf to fight off potential diseases and pathogens. A formulation error resulted in the EOC being fed at half the rate of the previous experiment of 2.5 g/d, which appears to be below an efficacious dosage.

Plant communities responding to grazing pressure by sheep in an Alpine meadow.

The Chinese grassland ecosystem is an important national asset that not only impacts climate regulation, soil and water conservation, wind protection, and soil carbon and nitrogen fixation but is also an important contributor to maintaining grassland biodiversity while supporting livestock production. Grasslands are a key component contributing to the productivity of grazing animals but also provide basic food production via livestock grazing for herder survival. Grazing is the most basic means of grassland utilization but is considered one of the more important disturbance factors controllable by humans that has a universal and profound impact on the grassland ecosystem due to animal density and over grazing. For Alpine grasslands, it is not clear what grazing intensity (GI) can be achieved to improve plant biodiversity and vegetative nutritional value while improving sheep productivity. This field experiment was conducted for 7 yr comparing the impact of different GI on vegetation community characteristics, nutritional value, and sheep growth performance on the Alpine meadows of the Qinghai-Tibetan Plateau. The GI measured were: Control: 0 sheep/ha; Low: 3.7 sheep/ha; Medium: 5.3 sheep/ha; and Heavy: 7.6 sheep/ha. The grazing experiment started in 2008, but experimental data collection and analyses were collected for the final 4 yr of 2015 through 2018. All grazing intensities >0 sheep/ha reduced (P < 0.05) plant height (27%, 46%, and 48%, respectively, for 3.7, 5.3, and 7.6 sheep/ha), ground coverage (16%, 24%, and 48%), and above ground biomass (2%, 42% and 53%) of the various plant communities while increasing (P < 0.05) the grass community density (individuals/m2) compared to a nongrazed Control. With increasing GI, the community height, coverage, and above-ground biomass decreased (P < 0.05), and the plant community density increased then decreased (P < 0.05) compared to Control. As GI increased, the available community biomass nutritional quality increased (P < 0.05). Comprehensive analysis showed that the community density (quantity) and nutritional quality were the highest when the GI was 5.3 sheep/ha. The higher the GI, the greater the grass's nutritive value with lower above-ground net primary production (ANPP). When GI was the highest, the average daily gain (ADG) per hectare was the highest in the short term, but the highest GI endangers the ANPP and profitability of the grassland grazing ecosystem in the long term. Targeting a moderate GI (5.3 sheep/ha) can provide 78% of the ADG per hectare of the highest GI, which meets the requirement of maintaining a sustainable grazing grassland.

Dietary supplementation with oregano essential oil and monensin in combination is antagonistic to growth performance of yearling Holstein bulls.

Our previous work indicated that feeding oregano essential oil (OEO) in combination with monensin (MON) may not be mutually beneficial to dairy calf growth performance. To evaluate this observation further, a 240-d long-term growth experiment was conducted using 12 young growing Holstein bulls using a 2 × 2 factorial treatment arrangement. Main factors were OEO and MON arranged in 4 individual treatments: (1) ration fed without OEO or MON (control), (2) OEO fed at 26 mg/kg of dry matter (DM), (3) MON fed at 25 mg/kg of DM, and (4) OEO and MON fed in combination (OEO+MON). Holstein bulls were 70 d of age and similar in body weight (BW; 93.3 ± 4.54 kg) and individually fed for 240 d. The targeted feeding rates of OEO and MON were blended into 200 g of concentrate and top dressed each morning to a corn stalklage-based ration. Body weights, frame measurements, and blood samples were collected monthly. Interactions of OEO by MON were detected for BW, BW gain, average daily gain, and a trend for feed conversion. Bulls fed OEO or MON demonstrated greater final BW (368, 385, 381, and 358 kg for control, OEO, MON, and OEO+MON, respectively), and BW gains (278, 292, 285, and 265 kg) and average daily gain (1.16, 1.22, 1.19, 1.11 kg/d) were greatest for bulls fed OEO or MON compared with bulls fed OEO+MON; bulls fed the control were intermediate and similar to bulls fed MON. Intake of DM was greater for bulls fed OEO (6.55, 6.99, 6.60, and 6.42 kg/d) compared with bulls fed remaining treatments. Frame growth gain measurements for heart girth, abdominal girth, withers height, body length, and cannon bone circumference were similar for bulls fed all treatments. Serum triglyceride (0.23, 0.25, 0.28, and 0.24 mmol/L) concentrations were greater for bulls fed MON compared with bulls fed the control and OEO+MON, and bulls fed OEO were intermediate and similar. Cholesterol (2.06, 2.29, 2.20, and 2.07 mmol/L) concentrations were greater for bulls fed OEO compared with bulls fed the control and OEO+MON, and bulls fed MON were intermediate and similar. Serum antioxidant measurements were similar for bulls fed all treatments. Serum IgA, IgG, and IgM concentrations were similar for bulls fed all treatments. Feeding OEO or MON separately can improve growth performance of growing Holstein bulls. We do not know why the combination of OEO and MON is antagonistic to growth performance of Holstein bulls. However, these technologies should not be fed in combination to growing dairy cattle.

Feeding an amino acid formulated milk replacer for Holstein calves.

The milk-fed calf has a requirement for amino acids (AA) instead of crude protein (CP); however, most milk replacers (MR) are still formulated for CP concentrations. Previous work has demonstrated that feeding a modified MR (24:20; CP:fat @ 0.64 kg/d) improved calf growth performance compared with standard (20:20 @ 0.57 kg/d) and accelerated MR (26:16 @ 0.78 kg/d). The 56-d study objective was to determine if feeding an MR formulated using synthetic AA to achieve the AA concentrations of a 24:20 MR while reducing CP results in similar or enhanced growth performance and/or reduce cost compared with standard MR formulations. Eighty 3- to 5-d-old Holstein bull calves received in two lots (40) within the same week were blocked by body weight (BW) and randomly assigned to one of four MR treatments consisting of 20:20 (20), 22:20 (22), 24:20 (24), and a 22:20 having the AA concentrations of the 24, but with reduced CP (22AA). All MR contain decoquinate and were fed at 0.57 kg/calf daily split into 2×/d feeding for 14 d via bucket, increased to 0.85 kg/calf daily in two feedings until 35 d, and then fed 1×/d at 0.41 kg/calf daily with weaning after day 42. Calves were housed in straw-bedded hutches with ad libitum access to water and pelleted calf starter (CS). All data were statistically analyzed as a randomized complete block design with block considered random with week as a repeated measurement. Initial BW was similar (P > 0.10) across all treatments (42.4 ± 2.2 kg). Calves fed 22AA MR demonstrated greater (P < 0.05) BW compared with calves fed the 24 MR, and calves fed the 20 and 22 MR being intermediate and similar (P > 0.10; 78.7, 78.8, 76.5, and 81.8 kg for 20, 22, 24, and 22AA, respectively). CS intake was greater (P < 0.05) for calves fed 22AA (0.74, 0.78, 0.65, and 0.81 kg/d) compared with calves fed the 20 and 24, but similar (P > 0.10) to calves fed 22. Calves fed 24 MR demonstrated the lowest CS intake. This study demonstrates that similar growth performance can be achieved by feeding an AA fortified MR having a lesser CP concentration, which might reduce feed costs.

Study on the correlation between BMPR1B protein in sheep blood and reproductive performance.

Sheep reproductive performance is one of the important economic traits in sheep farming. The bone morphogenetic protein receptor 1B (BMPR1B) gene and protein may play an important role in sheep fertility. This study was to investigate the association of blood BMPR1B protein expression with reproductive performance in sheep. Mongolian sheep with single and twin births and polytocous Small Tail Han sheep were selected due to differences in birth numbers. The BMPR1B mRNA in sheep blood was measured by a reverse transcription-polymerase chain reaction as well as the BMPR1B protein was measured by enzyme-linked immunosorbent assay in blood samples of Mongolian and Small Tail Han sheep. The results demonstrated that blood BMPR1B concentration in Mongolian sheep with twin birth was higher (P < 0.05) than Small Tail Han sheep and Mongolian sheep with single birth. The protein concentration in the anestrus season was higher (P < 0.045) than those in the estrus season for both Mongolian and Small Tail Han sheep. Moreover, BMPR1B concentration in Mongolian sheep increased (P < 0.05) at the age of 6 to 12 mo and that in Small Tail Han sheep increased (P < 0.05) at the age of 3 to 6 mo. The result indicates that the increase in BMPR1B protein concentrations in the blood of Mongolian ewes and Small Tail Han ewes may be beneficial to follicular development, but too high or too low of this blood protein concentration in Mongolian and Small Tail Han sheep is not conducive to ovulation.

Lactational response of early-lactation Holstein cows fed starch or floury corn silage.

The study objective was to evaluate the lactational performance of early-lactation dairy cows fed a total mixed ration (TMR) based on corn silage produced from a standard starch hybrid compared with 2 floury starch hybrids. Twenty-one (6 primiparous and 21 multiparous) high-producing, early-lactation Holstein cows were blocked by calving date and parity and randomly assigned to 1 of 3 experimental corn silages from wk 4 through wk 12 postpartum using a randomized complete block design with wk 3 as a covariate. The Dekalb blend (STA; Monsanto Company, St. Louis, MO), Masters Choice 527 (LF1; Masters Choice, Anna, IL), and Masters Choice 5250 (LF2) treatments were planted and harvested as corn silage using a kernel processor silage harvester, inoculated, and ensiled in individual Ag-Bags (Ag-Bag, St. Nazianz, WI). The TMR were formulated to be isonitrogenous at 17.5% crude protein consisting of 15.9% alfalfa hay, 35.1% concentrate mix, and 48% of the respective experimental corn silage on a dry matter basis. Crude protein content of STA and LF2 was lower than LF1 corn silage. Starch content was higher for STA compared with LF1 and LF2 silage. The TMR digestible fiber (neutral detergent fiber) concentration was lower for STA than LF1 and LF2 (14.0, 15.5, and 17.9% dry matter for STA, LF1, and LF2, respectively). Growing crop year affected corn silage vomitoxin (0.60, 1.45, and 1.56 mg/kg) concentrations, which may have affected lactational performance as STA corn silage was from 2013, whereas LF1 and LF2 were from the 2012 crop year. Dry matter intake (22.9, 23.5, and 22.4 kg/d), milk yield (35.6, 34.8, and 36.1 kg/d), 3.5% fat-corrected milk yield (38.7, 36.5, and 37.6 kg/d), energy-corrected milk yield (38.2, 36.1, and 38.1 kg/d), feed efficiency (1.79, 1.61, and 1.67 kg/kg; 3.5% fat-corrected milk/dry matter intake), milk fat (4.17, 3.94, and 3.71%), milk protein (3.12, 3.09, and 3.03%), lactose (4.93, 4.92, and 4.92%), solids-not-fat (8.96, 8.92, and 8.85%), body weight change (-0.10, -0.06, and -0.08 kg/d), and body condition score change (-0.05, -0.04, and -0.05 score/d) were similar for early-lactation dairy cows fed all corn silage hybrids. Lower ruminal pH and acetate along with higher propionate molar percentages were reported for cows fed STA compared with cows fed LF1 and LF2. Early-lactation dairy cows fed a corn silage with lower starch and higher digestible fiber concentrations resulted in similar milk production compared with cows fed higher starch and lower digestible fiber concentrations.

Effects of oregano essential oil on in vitro ruminal fermentation, methane production, and ruminal microbial community.

Different inclusion rates of oregano essential oil (OEO) were investigated for their effects on ruminal in vitro fermentation parameters, total gas, methane production, and bacterial communities. Treatments were (1) control, 0 mg/L of OEO (CON); 13 mg/L (OEO1); 52 mg/L (OEO2); 91 mg/L (OEO3); and 130 mg/L (OEO4), each incubated with 150 mL of buffered rumen fluid and 1,200 mg of substrate for 24 h using the Ankom in vitro gas production system (Ankom Technology Corp., Fairport, NY). Treatment responses were statistically analyzed using polynomial contrasts. Digestibility of DM, NDF, and ADF increased quadratically with increasing OEO inclusion rates. Digestibility of DM and NDF were highest for OEO2, whereas ADF digestibility was highest for OEO3, compared with CON, with the remaining treatments being intermediate and similar. Ammonia nitrogen concentrations decreased from CON at a quadratic rate with increasing OEO inclusion rates, and OEO2 had the lowest concentration compared with the other groups. Total VFA, acetate, propionate, butyrate, valerate, and isovalerate concentrations linearly decreased with increasing OEO inclusion rates. Total gas production levels by CON and OEO4 were greater than those of OEO1, OEO2, and OEO3 in a quadratic response, and methane production linearly decreased from CON, compared with OEO4, at a decreasing rate with OEO inclusion rates. As determined by 16S rRNA sequencing, the α biodiversity of ruminal bacteria was similar among OEO inclusion rates. Increasing OEO inclusion rates linearly increased the relative abundance of Prevotella and Dialister bacteria. Several bacteria demonstrated different polynomial responses, whereas several bacteria were similar among increasing OEO inclusion rates. These results suggested that OEO supplementation can modify ruminal fermentation to alter VFA concentrations and reduce methane emissions by extensively altering the ruminal bacterial community, suggesting an optimal feeding rate for future animal studies of approximately 52 mg/L for mature ruminants.

Calf starter containing a blend of essential oils and prebiotics affects the growth performance of Holstein calves.

Essential oils extracted from specific plants can exhibit antimicrobial properties that make them potential antibiotic alternatives. The objective was to evaluate an essential oil and prebiotic combination (EOC) on the growth, development, and health status of growing neonatal calves. Forty Holstein newborn calves were blocked by birth date and alternately assigned to 1 of 2 treatments. Treatments were a pelleted calf starter (CS) without (control) or with EOC at 44.1 ppm. Calves were fed the experimental CS for ad libitum consumption from 3 d of age through the end of the 70-d experiment. Calves were fed 2 L of whole milk twice daily to 10 d of age, then 3 L twice daily through d 35, and then fed 3 L once daily with abrupt weaning occurring after 42 d of age. The average daily gain (0.78 and 0.87 kg/d for control and EOC, respectively) was greater for calves fed EOC compared with calves fed the control. Calves fed EOC demonstrated greater dry matter intake (1.63 and 1.74 kg/d) compared with calves fed the control. Feed conversion ratio (0.62 and 0.65 kg of gain/kg of dry matter intake) was greater for calves fed EOC compared with calves fed the control. At 70 d of age, calves fed EOC demonstrated increased body frame measurements (hip height, body length, heart girth, abdominal girth, and pastern) compared with calves fed the control. The incidence of scours score 4 (mild diarrhea) was 3.5 incidences lower for calves fed EOC compared with calves fed the control, whereas the incidence of scours score 5 (severe diarrhea) for calves fed EOC was 0.5 incidences lower than calves fed the control. Blood concentrations of IgG and IgM on d 14, IgA on d 28, and total serum protein on d 42 were all greater for calves fed EOC compared with calves fed the control. The blood volatile fatty acid concentrations were greater for calves fed EOC compared with calves fed the control, which indicated enhanced ruminal development. Total-tract digestibility of dry matter, crude protein, acid detergent fiber, neutral detergent fiber, starch, and many minerals were increased for calves fed EOC compared with calves fed the control. The inclusion of an EOC blend into a CS demonstrates promising benefits for enhancing calf growth, ruminal development, gut health, nutrient digestibility, and immunity. The use of an EOC blend can be a plausible alternative to feeding subtherapeutic antibiotics for improving calf performance, health, and immunity.

Effects of oregano essential oil on the ruminal pH and microbial population of sheep.

Oregano essential oil (OEO), which has antimicrobial properties, may be used for altering the ruminal pH and microbial populations of sheep, as observed by the altered volatile fatty acid patterns. To further elucidate the effects of OEO on ruminal pH and microbial populations of sheep, 3 German merino sheep × local sheep crossbred rams with permanent ruminal fistulas were randomly assigned to a 3 × 3 Latin square design with 12-d periods. The treatments were as follows: control (CON); OEO4: OEO supplied at 4 g•d-1; and OEO7: OEO supplied at 7 g•d-1. Starting on day 11, rumen fluid was collected at 0 h, and at 4, 8, 12, 24 and 48 h after supplying OEO, and then pH values of rumen fluid were immediately measured. The abundance of microbial populations was determined by using qPCR. The ruminal pH values were similar among the sheep from all treatments. The abundance of ruminal fungi was higher for the sheep supplied OEO7 compared with the sheep supplied CON and OEO4, especially at 4 and 12 h. The abundance of ruminal protozoa decreased with supplied OEO, indicating that OEO could inhibit the protozoa. The abundance of the total ruminal bacteria was similar for the sheep from all treatments, but R. flavefaciens, R. albus and F. succinogenes increased in the sheep supplied OEO4 compared with those in the sheep supplied CON, however, the sheep supplied OEO7 had higher abundances of R. flavefaciens than the sheep supplied CON. These results demonstrated that supplying OEO to sheep did not affect the ruminal pH but could shift the rumen microbial population to one with less protozoa. Supplying OEO can preferentially enhance the growth of certain rumen microbial populations, but the shifts were influenced by the supply rate. Therefore, supplying low amount (i.e. 4 g•d-1) of OEO could have positive effects on ruminal microbial populations, whereas supplying elevated doses of OEO could be detrimental to those same ruminal microbial populations.