Forage source (alfalfa hay vs wheat straw) and rumen undegradable to degradable protein ratio: Effects on growth performance, microbial protein yield, digestibility, blood metabolites, and behavior of Holstein dairy calves

Aim of the study: The effects of forage source (alfalfa hay; AH vs. wheat straw; WS) with rumen undegradable to degradable protein ratio [low ratio (LR) = 28:72; high ratio (HR) = 36:64] were evaluated in young dairy calves.Area of study: Arak, Iran.Material and methods: Forty-eight 3-d old female Holstein dairy calves (44.5 kg of BW) were allocated in four treatments: (1) AH with low dietary RUP:RDP ratio (AH-LR); (2) AH with high dietary RUP:RDP ratio (AH-HR); (3) WS with low dietary RUP:RDP ratio (WS-LR); and (4) WS with high dietary RUP:RDP ratio (WS-HR), being RDP and RUP rumen degradable and undegradable proteins, respectively. The calves weaned on d 53 of the experiment and remained in the study until d 73 of age.Main results: The average daily gain and feed efficiency were improved in dairy calves receiving HR diets compared to LR diets during the post-weaning period (p<0.05). The fecal score (p=0.03) and neutral detergent fiber digestibility (p=0.04) were improved when calves fed WS diets compared to AH diets. Feeding HR diets increased allantoin (p=0.04) and microbial protein yield, and reduced blood urea nitrogen concentration (p=0.03) compared to LR diets. Assessing the interaction effects of the experimental factors resulted that the greatest BW, wither height, and blood beta-hydroxybutyrate, and the lowest urinary N concentration were observed in the WS-HR treatment (p<0.05).Research highlights: Feeding WS with high RUP:RDP ratio is recommendable in dairy calves due to the improvement in gain and N efficiency

Growth performance, nutrient digestibility, and ruminal fermentation of dairy calves fed starter diets with alfalfa hay versus corn silage as forage and soybean oil versus palm fatty acids as fat source

The present study was intended to evaluate the effect of forage source (alfalfa hay; ALF vs. corn silage; CS) along with a supplemental fat source (soybean oil; SO vs. rumen-inert palm fatty acids; PF) on growth performance, nutrient digestibility, and ruminal fermentation in dairy calves. Forty-eight new-born Holstein female calves (3 d old) were assigned to one of 4 treatments: (1) alfalfa hay with soybean oil (ALF–SO); (2) alfalfa hay with palm fatty acids (ALF–PF); (3) corn silage with soybean oil (CS–SO); (4) corn silage with palm fatty acids (CS–PF). Starter diets had equal amounts of forage (100 g/kg dry matter; DM) and fat source (30 g/kg DM). Calves were fed a constant amount of milk (d 1 to 63) and had ad libitum access to water and starters (d 1 to 83). The lowest and greatest starter intakes during the preweaning period occurred in ALF–SO and CS–PF, respectively. This coincided with forage × fat source interaction for average daily gain (ADG) during preweaning. The forage source affected total DM intake and ADG over the entire period, body weight (BW) at weaning, and final BW with greater values in calves that received CS compared with ALF. The concentrations of total short-chain fatty acids and butyrate were increased, whereas concentration of acetate and acetate:propionate ratio were decreased in the rumen of calves fed CS compared with ALF. Feeding CS increased urinary excretion of allantoin and, as a trend, total purine derivatives (PD) and estimated microbial protein synthesis in comparison with ALF. The fat source affected starter intake, ADG, and BW postweaning with the highest values in PF. The digestibility of neutral detergent fiber, crude protein and, as a trend, organic matter were higher in calves fed PF compared with SO. Calves fed PF had lower ruminal ammonia-N concentration and urinary N excretion and greater urinary excretion of allantoin and total PD. Calves receiving SO had a lower ruminal protozoa population. In conclusion, supplementing starter diets with CS and PF is superior to ALF and SO. Interaction of the positive effects of CS and PF on performance underlines that concurrent supplementation of CS with PF is especially recommendable in young calves before weaning

Grain grinding size of cereals in complete pelleted diets for growing lambs: Effects on ruminal microbiota and fermentation

[EN] Lambs from intensive dairy sheep production systems are sold out either after weaning as milk-fed lambs or after a fattening characterized by high intakes of concentrate feeds (mainly cereals) which can lead to ruminal disorders. Therefore, it is essential to explore different feeding alternatives in order to reach a balance between economic or productive benefits and animal welfare. Twenty weaned male lambs (6–8 weeks age, 14.8 ± 0.16 kg body weight) were allocated randomly to one of two different groups (n=10 per group) to study the effect of feeding a complete pelleted diet (CPD) in which cereal grains were ground at two different sieve sizes (either 2-mm with 13.5% dry matter (DM) of the particles>1.7mm or 6-mm with 47.1% DM of particles>1.7 mm) on DM intake, nutrient digestibility, ruminal microbiota and fermentation. Lambs were fed the corresponding CPD ad libitum and slaughtered when they reached 27 kg. DM intake was greater in the lambs fed 2-mm grains than in those fed 6-mm grains (P < .05). Feeding 2-mm grains in comparison to 6-mm grains resulted in darker colour of ruminal mucosa (100 vs. 127, from a scale where 0 is black and 256 white; SED=9.8; P=.017) and thicker stratum corneum (45.3 vs. 30.9 μm; SED=3.67; P=.001), suggesting more severe acidotic conditions in the rumen with the smaller cereal particle size. Analysis of microbial communities revealed that the presence of ruminal bacteria such as Prevotella and Quinella was increased in the digesta of animals fed the 2-mm diet. These data were corroborated by the odd- and branched-chain fatty acid profile of ruminal contents, which would indicate a shift from cellulolytic to amylolytic bacteria in the rumen of lambs fed the 2-mm diet. In conclusion, feeding 6-mm in comparison to 2-mm ground cereal grains included in CPD formulated for growing lambs is an alternative strategy that may reduce ruminal acidosis through changes in the microbiota.wSICSIC ( (Proyecto Intramural Especial; Project 201540E084)Ministerio de Economía y Competitividad (España

Does providing metabolizable protein in excess of requirement prior to calving improve nitrogen balance and cow-calf performance?

The objective of this experiment was to evaluate the effect of over-feeding metabolizable protein (MP) during late gestation on prepartum N balance, and postpartum cow BW and skeletal muscle catabolism, colostrum composition, and milk yield (MY) and composition. Twenty-four (14 cannulated, 10 non-cannulated) crossbred Hereford cows were assigned to a control treatment designed to meet (CON = 100% MP, n =12) or exceed (HMP = 133% MP, n = 12) MP requirements. Cows consumed a common lactation (103% MP) diet postpartum. One HMP and 1 CON cow-calf pair were removed due to dystocia, while 1 CON cow was removed due to aggression at parturition. Heifers were housed and fed individually from d -55 to d 33 relative to parturition and then group-housed until 112 d post-partum. Dry matter intake was measured throughout the study and summarized by week. Cow BW was recorded on d -55 ± 3.7, -41 ± 3.7, -28 ± 3.6, -8 ± 3.9, 7 ± 1.0, 13 ± 2.0, 28 ± 2.9, 57 ± 3.6, 82 ± 5.1, and 112 ± 2.9 relative to parturition. Total fecal and urinary collections were conducted over a period of 6 d starting on d -33 and -15 to measure N balance, and total tract digestibility. Urine samples from the prepartum collections and postpartum spot samples (starting d 7 and 28) were composited and analyzed for 3-methylhistidine (3-MH) and creatinine as indicators of muscle turnover. Digesta samples were collected and ruminal ammonia-N concentration was measured on d -33 ± 5.3, -15 ± 4.4, 7 ± 0.9, and 28 ± 2.9. Blood samples were collected from cows via jugular venipuncture on d -34 ± 5.3, -17 ± 4.4, 7 ± 0.9, 28 ± 2.9, 70 ± 3.2 and 112 ± 2.9 and analyzed for plasma glucose, urea-N, and insulin, and serum NEFA and BHBA. Calf BW and frame measurements were conducted at birth and on d 7 ± 0.9, 28 ± 2.9, 57 ± 3.6, 82 ± 5.1, and 112 ± 2.9. At parturition, colostrum samples were collected and analyzed for nutrient composition and IgG concentration. Milk yield was measured on d 7 ± 0.9, 12 ± 0.9, 28 ± 2.9, 33 ± 2.9, 70 ± 3.2, and 112 ± 2.9 relative to parturition. Milk samples were analyzed for the concentration of fat, crude protein, lactose, urea-N (MUN) and somatic cell count (SCC). Data for the prepartum and postpartum periods were analyzed separately. All data were analyzed as a randomized complete block design using the MIXED procedure of SAS. Fixed effects included treatment, time, and the two-way interaction of treatment and time, while cow nested in block was considered as the random effect. Time (day or week) was analyzed as a repeated measure when appropriate. Prepartum BW did not differ among days for CON. Whereas, HMP cows increased BW as parturition approached (treatment × day, P < 0.01). While not differing by treatment, dry matter intake (% BW) increased (P < 0.01) by 18% on week -2 compared to -8, but then decreased (P <0.01) by 8.0% during week -1. Nitrogen intake, apparent digestion, excretion, and retention (g/d) were all greater (P < 0.01) for HMP heifers than CON. Heifers fed HMP had improved (P < 0.01) DM, OM, and NDF digestibility relative to CON heifers. Concentration of urinary 3-MH and the 3-MH:creatinine ratio did not differ (P ≥ 0.23) between treatments. Maximum ruminal pH and the total concentration of short-chain fatty acids were not affected by treatment. Prepartum ruminal ammonia-N decreased (treatment × day, P < 0.01) as parturition approached for HMP (10.1 to 8.7 mg/dL) whereas, ammonia-N was not affected for CON (1.0 to 1.3 mg/dL). Plasma urea-N was greater (P < 0.01) for HMP heifers (15.0 vs. 7.5 mg/dL). Postpartum BW did not differ (P 0.30) by treatment, day, or the interaction of treatment and day, but rump fat decreased (P = 0.011) as lactation progressed. Dry matter intake decreased during wk 2 and 3 compared to 1 and 4, whereas ruminal pH was less during wk 2, 3, and 4 relative to wk 1. Colostrum fat concentration was less (P = 0.003) for HMP than CON, but milk production and milk component concentrations were not affected by treatment. Milk yield was greatest from d 7 to 33 and decreased thereafter (P < 0.001). Plasma and serum metabolites were not affected by treatment, but NEFA was greater (P < 0.001) on d 7 and 28 relative to d 70 and 112. Urinary 3-MH and the 3-MH:creatinine ratio did not differ by treatment, day, or the interaction of treatment and day (P ≥ 0.22). Calf growth was not affected by treatment. Over-feeding MP prepartum may improve prepartum heifer BW, NDF and OM digestibility and N balance, but might decrease colostrum fat concentration without affecting lactation or postpartum metabolic indicators of energy balance or protein turnover

Evaluation of lighter density fraction from dried distillers grains with solubles as a feedstuff for ruminants

The objective of this study was to evaluate the lighter fraction of DDGS as a possible feedstuff for cattle. To accomplish this, a digestion trial was performed to determine nutrient digestibility and crude protein retention by steers consuming the lighter fraction of DDGS. Steers received L, a diet containing the lighter fraction of DDGS, D, a diet containing whole DDGS, or C, a control diet. Steers receiving L consumed less DM than steers receiving D and C. CP retention and digestibilities of DM, OM, ash, NDF, ADF, HC, and energy did not differ among steers in different treatment groups. Fat digestibility was greatest for steers consuming L and D. Steers consuming L digested more CP than steers receiving C, with steers consuming D being in between. These data suggest that the lighter fraction of DDGS can be effectively fed to cattle without adversely affecting digestibility

Growth performance and rumen microbial loads of west african dwarf rams fed diet containing garlic (Allium sativum) meal

The study investigated the effects of Garlic (Allium sativum) on growth performance and rumen microbial loads of West African Dwarf (WAD). Twenty-five (25) WAD rams with an average live weight of 17.38±0.04&nbsp;kg were used in a completely randomized design for 16&nbsp;weeks. Five concentrate diets containing varying levels (0, 0.5, 1.0, 1.5 and 2.0&nbsp;%) of Allium Sativum were formulated while Panicum maximum was fed as a basal diet. Rumen fluid was collected at the end of feeding trial to determine rumen microbial loads. Data collected were subjected to one-way Analysis of Variance (ANOVA). Results showed the daily dry matter grass intake was found to be higher at 2&nbsp;% inclusion level (348.51&nbsp;g/day) and lowest at 0.5&nbsp;% inclusion which were significantly affected (p&lt;0.05) by inclusion levels of garlic meal. The best feed conversion ratio (FCR) was obtained (8.54) at 1&nbsp;% inclusion compared to rams fed meal at 0&nbsp;% which has 10.97 feed conversion ratio (FCR). The total bacterial values ranged from 2.87x107&nbsp;cfu/ml to 4.47x107&nbsp;cfu/ml in rams feed containing 1.0&nbsp;% garlic meal which were significantly affected (p&lt;0.05) by inclusion levels of garlic meal. The highest total protozoan counts 5.00x105&nbsp;cfu/ml was obtained with rams fed diets containing 1.0&nbsp;% garlic meal while the lowest total protozoan count 2.67x105&nbsp;cfu/ml was recorded with diets containing 0.0&nbsp;% garlic meal which was significantly affected (p&lt;0.05) by inclusion levels. It was therefore concluded that Allium sativum meal can be incorporated into the diets of rams at 1&nbsp;% for effective rumen fermentation and better nutrient utilization of West African Dwarf rams without any adverse effects on the health status of experimental ram

The effect of malic acid supplementation on diet digestibility and methane production by beef cattle fed a forage diet

This project was conducted to determine the effect of malic acid (MA) supplementation to a forage diet on ruminal fermentation and methane (CH4) production by beef cattle. Four ruminally fistulated animals were fed at maintenance a 75% bluegrass straw and 25% alfalfa hay basal diet at 0700 and 1900 h. Malic acid treatment levels were 0, 196.6, 409.5, and 607.7 g/d and were supplemented via the rumen fistula in two equal portions. Ruminal fluid samples were collected at 0, 4, 8, 12, 16, and 20 h after feeding and immediately analyzed for pH. Bluegrass straw and alfalfa hay dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), and organic matter (OM) in situ digestibilities were determined at 0, 8, 16, 24, and 48 h after feeding. Methane emissions were determined twice daily. The mean ruminal fluid pH level was 6.4 ± 0.04 and was unaffected by MA treatment. Bluegrass straw in situ NDF, ADF, and ash disappearance were unaffected by MA treatment, though there was a trend towards reduced DM and OM disappearance with increasing MA supplementation. An effect of time on disappearance was observed for BGS DM, NDF, ADF, and OM disappearance. An interaction between treatment and time was observed for all BGS disappearance measurements. These interactions indicate a suppression of BGS DM, NDF, ADF, and OM disappearance over time as MA treatment level increases. An effect of time on disappearance was observed for alfalfa hay DM, NDF, ADF, and OM disappearance. However, alfalfa hay DM, NDF, ADF, and OM disappearance was unaffected by MA treatment. Methane emissions averaged 299.1 ± 0.11 g/d and were not affected by treatment. In addition, CH4 loss as a percent of gross energy intake was not affected by treatment and averaged 7.6% across all treatments. Consequently, MA treatments added directly to ruminal contents at these levels was ineffective at reducing CH4 emissions

Oat Grain Rations for Growing and Finishing Cattle

Mechanical processing to alter physical and possibly chemical properties is one attempt to improve the value of a feedstuff. Processing methods such as grinding and rolling reduce particle size. These methods may result in an increase in rate of passage through the digestive tract but with more total efficiency in utilization of nutrients. This has been shown for roughages where grinding of hay resulted in improved daily gain and feed efficiency over those obtained with unprocessed hay. Reduction in particle size of concentrates has not shown the response in daily gain as that for roughages. Rather, the main advantage for processing of concentrates has been improved feed efficiency. Excessively fine grinding of concentrates may induce more frequent cases of rumenitis and other gastrointestinal upsets which are important. factors to consider when processing· such feedstuffs. A wide variety of concentrates is used in beef cattle finishing rations. Many have been subject ed to several methods of processing to investigate the possibility of improving animal performance. Some of the more conventional grains for finishing cattle are corn, sorghum and barley. Traditionally, oats have been used in limited amounts for starting cattle on feed, wintering breeding flocks and herds, creep feeds and growing type rations. However, oats are a major crop in South Dakota and availability may make the grain an appropriate alternative as a major feed grain under favorable economic conditions. As a cattle feed, less supplemental protein is necessary when feeding oats due to the higher protein content. But, the energy value of oats is substantially lower than for corn, primarily due to the high percentage of hulls. Lightweight oats are composed of a higher proportion of hulls, therefore more fiber, which is why the variability in oat test weight can play a major role in feeding value. A ration of oat grain is approximately equivalent to one composed of 60 parts whole corn grain and 40 parts alfalfa hay in crude fiber and total digestible nutrients. In view of this, oats must be considered as a substitute not only for concentrate but also for roughage. Oats are the fourth largest grain crop globally and South Dakota ranks first in oat production in the United States. These facts, coupled with poorer performance from animals fed all-oat rations, indicated a need to try to improve the feeding value of oats and to more accurately describe the place of oats in growing and finishing rations for cattle. Therefore, these experiments were conducted to study whole, rolled and ground and pelleted oats as the sole grain without added roughage for feedlot steers. The experiments included feeding trials along with studies on digestibility, nitrogen balance and rumen fermentation