Total Dry Matter Intake Research Articles

Citrus Pulp Replacing Corn in the Supplement Decreased Fibre Digestibility with No Impacts on Performance of Cattle Grazing Marandu Palisade Grass in the Wet-Dry Transition Period.

Simple SummaryDeterioration of forage quality as the dry season approaches has detrimental effects on the performance of cattle grazing tropical grasses unless supplementation strategies are implemented. In this study, corn was replaced by citrus pulp as an energy source to evaluate the effects of supplementation on liveweight performance and metabolic parameters of Bos indicus cattle grazing Urochloa brizantha cv. Marandu in the wet-dry transition period.The wet-dry transition period brings unique challenges to cattle producers in the tropics as the forage quality starts to decrease and animal performance is negatively affected unless supplementation strategies are applied. Two experiments were conducted concomitantly to evaluate the performance and metabolic parameters of cattle supplemented with two different energy sources under a C4 tropical grass continuous grazing system in the wet-dry transition period. In experiment (exp) 1, the liveweight (LW) gain of 42 growing Bos indicus Nellore bulls allocated to 12 paddocks of Uruchloa brizantha cv. Marandu, in a completely randomized block design, was evaluated to compare corn and citrus pulp-based supplements offered at 0.5% LW. Metabolism was evaluated in exp 2 with eight rumen-cannulated Nellore steers in an incomplete replicated Latin square design (RLSD) 4 × 2 (steers × treatment) fed the same two treatments as in exp 1. No differences in animal performance were observed between corn or citrus pulp-based supplements. Rumen pH, ammonia nitrogen, and blood urea nitrogen were lower in the rumen of animals supplemented with citrus pulp. Despite this, there were no differences in total dry matter intake amongst the two energy sources. The neutral detergent fibre digestibility of the diet containing corn decreased, but it neither affected performance nor liveweight gain per area. The findings suggest that corn can be replaced by citrus pulp with neither detrimental effects on animal performance nor indirect effects on pastures productivity.

Effects of supplementation rate of an extruded dried distillers' grains cube fed to growing heifers on voluntary intake and digestibility of bermudagrass hay.

Our objectives were to 1) investigate the difference in chemical composition and disappearance kinetics between loose dried distillers' grains (DDG) and extruded DDG cubes and 2) evaluate the effects of supplementation rate of extruded DDG cubes on voluntary dry matter intake (DMI), rate and extent of digestibility, and blood parameters of growing beef heifers offered ad libitum bermudagrass (Cynodon dactylon) hay. To characterize the changes in chemical composition during the extrusion process, loose and extruded DDG were evaluated via near-infrared reflectance spectroscopy, and dry matter (DM) disappearance kinetics were evaluated via time point in situ incubations. Extruded DDG cubes had greater (P ≤ 0.01) contents of fat, neutral detergent insoluble crude protein, and total digestible nutrients, but lower (P ≤ 0.01) neutral and acid detergent fiber than loose DDG. Additionally, the DM of extruded DDG cubes was more immediately soluble (P < 0.01), had greater (P < 0.01) effective degradability and lag time, and tended (P = 0.07) to have a greater disappearance rate than loose DDG. In the 29-d supplementation rate study, 23 Charolais-cross heifers were randomly assigned to one of four supplemental treatments: 1) control, no supplement; 2) low, 0.90 kg DDG cubes per d; 3) intermediate, 1.81 kg DDG cubes per d; or 4) high, 3.62 kg DDG cubes per d. Titanium dioxide was used as an external marker to estimate fecal output and particulate passage rate (Kp). Blood was collected from each animal to determine supplementation effects on blood metabolites. Indigestible neutral detergent fiber was used as an internal marker to assess the rate and extent of hay and diet DM digestibility (DMD). Increasing supplementation rate increased Kp and total diet DMI linearly (P < 0.01), yet linearly decreased (P < 0.01) hay DMI. Hay DMD decreased quadratically (P < 0.01), while total diet DMD increased linearly (P < 0.01) with increased DDG cube inclusion. Supplemented heifers had greater (P = 0.07) blood urea nitrogen concentrations than control animals 4 h post-supplementation. Intermediate and high rates of supplementation resulted in lower (P < 0.01) serum nonesterified fatty acid concentrations post-supplementation than control heifers. Concentrations of serum glucose and lactate were greatest (P ≤ 0.06) 8 h post-supplementation. Our results suggest that extruded DDG cubes may be an adequate supplement for cattle consuming moderate-quality forage, and further research is warranted.

Performance, structural growth, and digestibility by Holstein calves fed different amounts of milk through step-up/step-down or conventional methods

Early life milk intake can influence the survival and future productivity of replacement heifers. The present study determined the effects of different amounts of milk through step-up/step-down or conventional feeding methods on the performance of dairy calves. Thirty-nine Holstein calves (18 male and 21 female) were used in a completely randomized design. Calves were randomly allocated to 1 of 3 treatments: (1) conventional milk feeding (CONV; 4.5 L/d of milk from d 1 to 50 and 2 L/d of milk at d 51 and 52 of the study; total milk intake = 229 L); (2) low milk intake with step-up/step-down method (L-SUSD, 4 L/d of milk from d 1 to 10, 6 L/d from d 11 to 20, 8 L/d from d 21 to 30, 6 L/d from d 31 to 40, 4 L/d from d 41 to 50, and 2 L/d milk at d 51 and 52 of the study, total milk intake = 284 L); (3) high milk intake with step-up/step-down method (H-SUSD, 6 L/d of milk from d 1 to 10, 8 L/d from d 11 to 20, 10 L/d from d 21 to 30, 8 L/d from d 31 to 40, 6 L/d from d 41 to 50, 4 L/d milk at d 51, and 2 L/d milk at d 52 of the study, total milk intake = 386 L). All calves were weaned at d 52 and followed until d 70. Performance data (every week), skeletal growth (d 52 and 70), and ruminal fermentation parameters and digestibility (d 35, 55, and 70) were analyzed as repeated measurements with PROC MIXED of SAS version 9.3 (SAS Institute Inc.). A treatment × time interaction was observed for total dry matter intake (TDMI) as follows: TDMI differed among all treatments where H-SUSD > L-SUSD > CONV from d 11 to 38 of study, greater for H-SUSD versus other treatments from d 3 to 10 and d 39 to 70 of study. Starter feed intake and average daily gain (ADG) were greater in H-SUSD calves than in CONV calves, and L-SUSD treatment was intermediate for those traits. The H-SUSD calves tended to have greater body weight (BW) and lower feed efficiency than calves fed CONV or L-SUSD treatments. The treatments did not affect structural growth parameters, except for hip width, which tended to be greater in H-SUSD calves than CONV calves. Regardless of treatments, ADG, starter feed intake, BW, and body measurements increased as calves aged, whereas feed efficiency increased from d 1 to 52 of study and decreased from d 52 to 70 of study. The treatments had no effect on digestibility, rumen parameters, or fecal score. Overall, in calves that were weaned at 52 d and fed milk 3 times daily, the high milk intake (386 L) through the SUSD method did not increase diarrhea or decrease digestibility but increased starter feed intake and ADG.

Effect of Feed Supplement Containing Dried Kratom Leaves on Apparent Digestibility, Rumen Fermentation, Serum Antioxidants, Hematology, and Nitrogen Balance in Goats

The objectives of the present study were to examine the influence of supplementation with dried kratom leaf (DKTL) on the performance, hematology, and nitrogen balance in goats. Four 12-month-old male crossbred (Thai Native x Anglo Nubian) goats with an initial body weight (BW) of 24.63 ± 0.95 kg were allocated randomly to receive four different levels of DKTL using a 4 × 4 Latin square design. The DKTL was added to a total mixed ration (TMR) diet with doses of 0, 2.22, 4.44, and 6.66 g/day to investigate the treatment’s efficacy. The DKTL was high in secondary metabolites, including mitragynine, total phenolics, total tannins, flavonoids, and saponins. There were quadratic effects on total DMI in terms of kg/day (p = 0.04), %BW (p = 0.05), and g/kg BW.75 (p = 0.02). DKTL increased apparent digestibility with quadratic effects (DM; p = 0.01, OM; p = 0.01, CP; p = 0.04, NDF; p = 0.01, and ADF; p = 0.01). The pH value was within the rumen’s normal pH range, whereas NH3-N and BUN concentrations were lower with DKTL supplementation, and also reduced cholesterol (CHOL, p = 0.05) and low-density lipoprotein (LDL, p = 0.01). The protozoa population decreased linearly as DKTL levels increased (p &lt; 0.01), whereas Fibrobacter succinogenes increased quadratically at 0 h (p = 0.02), and mean values increased linearly (p &lt; 0.01). The average value of acetic acid (C2) and methane production (CH4) decreased linearly (p &lt; 0.05) when DKLT was added to the diet, whereas the quantity of propionic acid (C3) increased linearly (p = 0.01). Our results indicate that DKTL could be a great alternative supplement for goat feed. We believe that DKTL could provide opportunities to assist the goat meat industry in fulfilling the demands of health-conscious consumers.

Fresh cassava root replacing cassava chip could enhance milk production of lactating dairy cows fed diets based on high sulfur-containing pellet

The experiment objective was to assess the shifting effect from cassava chip (CC) to fresh cassava root (FC) affected feed utilization, rumen metabolism, cyanide-using bacteria, and milk quality in lactating Thai Friesian dairy cows fed diets based on high sulfur-containing pellet (PS). Four lactating Thai Friesian dairy cows of 481.5 ± 31.3 kg BW (about 4 years old were allocated with four treatments in a 4 × 4 Latin square design. The four treatments were: replacement FC for CC at 0%, 60%, 80%, and 100% dry matter (DM), respectively. Feed intakes for four diets in terms of total dry matter intake (kg/day and % BW) was linearly correlated with levels of replacement of FC (p < 0.01). Digestibilities of crude protein (CP), DM, organic matter (OM), amylase-treated neutral detergent fiber (aNDF), and acid detergent fiber (ADF) did not change with increasing levels of FC in the diet (p > 0.05). Moreover, the total bacterial counts and cyanide population utilizing bacteria cubically increased with an increase of FC replacement (p < 0.01). The effect of CC substitution with FC in the PS diet was cubically increased on blood thiocyanate concentrations (p < 0.01). In addition, the propionate (C3) concentration at 0 and 4 h post-feeding changed significantly among treatments (p < 0.01), which were linearly improved with an increasing dose of replacement FC and were highest when FC was replaced at 100%. The yield of 3.5% fat-corrected milk was high in the treatment with the replacement of FC as compared to the control (p < 0.01). The yield of fat and milk fat percentages was high (p < 0.01) in the group with the replacement of FC as compared to feed with no diet replaced. The milk thiocyanate concentration was cubically enhanced when levels of FC replacement increased (p < 0.01) and was the highest when FC was replaced at 100%. As the amount of FC replacement was raised, the somatic cell count in the milk decreased linearly (p < 0.01). In conclusion, the replacement of FC at 100% in PS could enhance the feed intake, microbial populations, total volatile fatty acid (VFA), C3 concentration, milk yield, and milk quality.

Replacement of soybean meal by red yeast fermented tofu waste on feed intake, growth performance, carcass characteristics, and meat quality in Thai Brahman crossbred beef cattle

This study aimed to determine the effect of replacing soybean meal (SBM) by red yeast fermented tofu waste (RYFTO) on feed intake, growth performance, carcass characteristics, and meat quality in Brahman crossbred beef cattle. A total of 12 cattle (1.5-2years old and 275.0 ± 6.1kg of initial body weight) were randomly allotted to three dietary treatments in completely randomized design. There were three dietary treatments as following: Control (SBM), 50%replacing SBM by red yeast fermented tofu waste (RYFTO50), and 100% replacing SBM by red yeast fermented tofu waste (RYFTO100) in concentrate diet raised for 60days. Rice straw was used as roughage source and fed ad libitum. The results found that cattle received the diet with replacing SBM by RYFTO both RYFTO50 and RYFTO100 group affect roughage intake, total dry matter intake, and ADG (P < 0.05) except the digestibility and FCR (P > 0.05). The feed cost of roughage, concentrate, and total feed cost were lowest in RYFTO100 group when compared to the control (P < 0.05). Blood urea nitrogen was deducted when cattle received RYFTO100 when compared to the control and RYFTO50 (P < 0.05). However, the carcass characteristics and meat quality were similar among treatments (P > 0.05). In conclusion, the 100% replacing SBM by RYFTO in concentrate diet affect roughage intake and ADG without negative effect on concentrate intakes, digestibility, carcasses and meat quality. Therefore, RYFTO could be used as a protein source for partial replacement of SBM in the, concentrate diet at 50% which can lower feed cost. This study suggested that the further study should be conducted for longer period to gain the benefits of carotene in red yeast on carcass and meat quality.

36 Inclusion of Different Sources of Ca Salts of Fatty Acids on Productive Responses of Finishing Cattle

Abstract This experiment (d -9 to d 148) evaluated productive responses of feedlot cattle consuming or not different sources of fatty acids (Nutricorp, Araras, SP, Brazil) during the finishing period. Bos taurus-influenced steers (n = 120) were ranked by initial body weight (BW; 410 ± 6 kg) on d -9 and allocated to 1 of 20 pens (6 steers/pen) equipped with Calan gate feeders (American Calan, Northwood, NH) for individual feed delivery. Steers within each pen were randomly assigned to receive a corn-based finishing diet containing or not (CON; n = 30) Ca salts of palm oil (PALM, n = 30), Ca salts of soybean oil (SB, n = 30), or a mixture of Ca salts of palm, soybean, and cottonseed oils (MIX, n = 30) at 2% of the diet (as-fed basis). Within each treatment, 12 steers were shipped to a packing plant on d 93 of the experiment, and the remaining steers on d 148 of the experiment. Steer shrunk BW was recorded on d -9 (initial), and final BW calculated as 63% of hot carcass weight. Initial and final BW were used to calculate average daily gain (ADG). Individual dry matter intake was calculated by measuring dietary weekly offer and refusals. Feed efficiency was measured using steer total body weight gain and total dry matter intake during the experiment. No differences were detected for initial BW (P = 0.99). Final BW, BW gain, and dry matter intake were all greater (P ≤ 0.05) for MIX, PALM and CON compared with SB. Feed efficiency was greater (P ≤ 0.05) for MIX and PALM compared with SB, and also greater (P ≤ 0.05) for MIX compared with CON. Longissimus muscle area was greater (P ≤ 0.05) for MIX and CON compared with PALM. Collectively, inclusion of MIX into a finishing diet increased performance and feed efficiency of feedlot cattle, whereas inclusion of SB was detrimental to these responses.

Subacute ruminal acidosis phenotypes in periparturient dairy cows differ in ruminal and salivary bacteria and in the in vitro fermentative activity of their ruminal microbiota

Both ruminal microbial structure and functionality might play a role in inter-individual variation in susceptibility for subacute rumen acidosis (SARA) observed in dairy cows. The aims of this study were to determine whether differences between cows with distinct SARA susceptibility were reflected in distinct (1) ruminal microbial communities, (2) salivary bacterial communities, and (3) fermentative capacity of ruminal microbiota assessed in vitro. To test this hypothesis, rumen samples were collected via an esophageal tube on 21 d postpartum from 38 multiparous Holstein cows, which were classified into 4 groups differing in median and mean time of reticular pH below 6 as well as area under the curve of pH below 6.0. During the 21 d postpartum, all cows within a group fulfilled following criteria: susceptible (S, n = 10; mean or median ≥180 min/d), moderately susceptible (MS, n = 7; 60 min/d < mean time of pH below 6 < 180 min/d, and median time of pH below 6 <180 min/d), moderately unsusceptible (MU, n = 11; 10 min/d < mean < 60 min/d, and median time of pH below 6 ≤30 min/d), or unsusceptible (U, n = 10; median = 0 min/d, and mean <10 min/d). Groups did not differ in total daily dry matter intake nor in total, roughage, or concentrate intake during daily 6-h time intervals. Rumen bacterial α-diversity did not differ among groups, but β-diversity varied and bacterial 16S rRNA gene copy numbers were lower in S compared with U cows. The relative abundance of genera Streptococcus, Sharpea, Prevotellaceae_YAB2003, Succinivibrionaceae_UCG-001, Ruminococcus, and Ruminococcaceae_UCG-001 were higher in S compared with U cows. In contrast, Lachnospiraceae_ND3007 and Oscillospiraceae_V9D2013 were more abundant in U cows. Although pH-associated, inter-animal differences were also observed in the salivary bacteria, common differences in ruminal and salivary bacterial genera were limited. The functionality of the rumen microbiota was evaluated in vitro through exposure of the microbial inoculum of S and U cows to an anaerobic buffer at pH 5.8 and 6.8, in the presence of sterile supernatant of their own and of dry cows' rumen fluid (2 × 2 design). Generally, the S inoculum produced more volatile fatty acids, except at low pH with dry cows' supernatant, where volatile fatty acid production was completely impaired and lactate accumulation was highest. Compared with the microbes of U cows, microbes of S cows showed less fermentative activity in situations with 2 stress factors (low pH and an unfamiliar environment, i.e., rumen fluid supernatant of dry cows).

Inclusion of Cocoa Bean Shell in the Diet of Dairy Goats: Effects on Milk Production Performance and Milk Fatty Acid Profile

The use of agro-industrial by-products in animal nutrition is a promising strategy to reduce the food-feed competition, the diet cost at farm level and the environmental impact of animal-derived food production. In this study, the suitability of cocoa bean shell (CBS), a by-product of the cocoa industry, as a feed ingredient in the diet of dairy goats was evaluated, with a focus on the related implications on feed intake, milk yield, milk main constituents, and fatty acid (FA) profile of milk fat. Twenty-two Camosciata delle Alpi goats were divided into two balanced groups. All the goats were fed mixed hay ad libitum. The control group (CTRL; n = 11) also received 1.20 kg/head × day of a commercial concentrate, while in the experimental group (CBS; n = 11) 200 g of the CTRL concentrate were replaced by the same amount of pelleted CBS. The total dry matter intake of the goats was reduced by the dietary inclusion of CBS (P ≤ 0.01). The milk yield, as well as the milk fat, protein, and casein contents and yields were unaffected by the treatment. Milk from the CBS-fed goats showed decreased urea content when compared to the CTRL group (P ≤ 0.001). Milk from the CBS group of goats also showed increased concentrations of total branched-chain FA (both iso and anteiso forms; P ≤ 0.001) and total monounsaturated FA (P ≤ 0.05), as well as a decreased ∑ n6/∑ n3 FA ratio (P ≤ 0.05). De novo saturated FA, total polyunsaturated FA, total conjugated linoleic acids, and the majority of ruminal biohydrogenation intermediates remained unaffected by the dietary treatment. These results suggest that CBS can be strategically used as an alternative non-conventional raw material in diets intended for lactating goats, with no detrimental effects on their milk production performance. The use of CBS in goat nutrition may be hindered by the presence of theobromine, a toxic alkaloid. Special attention is needed by nutritionists to avoid exceeding the theobromine limits imposed by the current legislation. Detheobromination treatments are also suggested in literature to prevent toxic phenomena.

Feeding mango wastes to dairy goats: Effects on diet digestibility, ruminal fermentation, and milk yield and composition

The aim of this study was to assess the potential of mango wastes (0.65:0.35 pulp:peels mixture, PP) preserved in multinutrient blocks (MMB) for goats feeding that replaced part of a commercial concentrate for dairy goats, and contained 0.29 of the mango PP. The multinutrient blocks were formulated to have similar protein content than the concentrate. In addition, soybean meal was totally replaced with sunflower meal. Two diets composed of 0.4 of alfalfa hay and either 0.6 of a commercial concentrate (control diet) or 0.4 of concentrate and 0.2 of MMB (MAN diet) were fed to two homogeneous groups of Murciano-Granadina dairy goats of 8 animals each. Feed intake, diet digestibility, milk yield, composition and fatty acid (FA) profile, ruminal fermentation parameters, and urinary excretion of purine derivatives were measured. The daily intake of MMB averaged 83.9 g dry matter (DM) per goat and was accompanied by an average daily decrease of 71.0 g in concentrate intake (P = 0.324) and 41.0 g of increase in alfalfa hay intake. However, there were no differences between groups (P ≥ 0.253) in the intake of total DM, nitrogen and gross energy. Similarly, nutrient digestibility, utilization of both nitrogen (N) and energy, and urinary excretion of purine derivatives were similar (P ≥ 0.103) for both diets. Partial replacement of concentrate with MMB did not affect (P ≥ 0.358) milk yield and composition, but the milk from MAN-fed goats had greater (P = 0.038) saturated FA and lower (P = 0.047) polyunsaturated FA proportions than the milk from goats fed the control diet. Feeding the MAN diet also resulted in greater (P = 0.003) proportions of milk FA with less than 16 carbons and lower (P = 0.009) proportions of FA with more than 16 carbons compared with feeding the control diet. Similar values (P ≥ 0.213) of ruminal pH and concentrations of NH3-N and total volatile fatty acids were registered in both groups of animals, but goats fed the MAN diet had lower (P = 0.003) acetate and greater (P = 0.029) propionate proportions than those fed the control diet. Under the circumstances of the present study, the profit of milk production (€/d) tended (P = 0.056) to be greater for the MAN diet compared with the control diet. Although multinutrient blocks seem to be a feasible option to preserve mango wastes, more studies are needed to increase the intake of MMB by goats.

High-digestible silages allow low concentrate supply without affecting milk production or methane emissions

In this study, we tested a response function comprising responses in milk to changes in organic matter digestibility of silages and concentrate supply. We studied the effect of changes in silage digestibility and concentrate supply on milk yield, feed intake, body weight, and methane production using 60 Norwegian Red cows. The experiment was a complete randomized block design comprising 3 periods. The pre-experimental period lasted 20 d and all the cows were fed a common silage for ad libitum intake and concentrate according to yield. Next, response period 1 lasted 17 d and the cows were divided into 2 treatments, where a low-digestible silage (LDS) was fed to half of the cows, and the other half were fed a high-digestible silage (HDS). Both groups were fed silage for ad libitum silage intake. Concentrate was optimized according to the yield and type of silage offered. In this period, the effect of silage was evaluated using a mixed model, including the results from pre-experimental period, with parity as a covariate and animal as a random effect. In response period 2, which lasted 20 d, the concentrate level was evaluated by dividing the silage digestibility treatments further into 3 subgroups. Concentrate was increased by 2 kg of dry matter (DM) per day, decreased by 2 kg of DM/d, or remained unchanged. In response period 1, silage treatments were optimized to obtain similar yields and resulted in a lower concentrate offer to HDS treatment. However, the HDS treatment showed a 3.0 kg of DM/d higher total feed intake due to a higher than expected silage intake. This resulted in 3.5 kg higher energy-corrected milk (ECM). Methane emissions were similar between silage treatments, but HDS showed lower methane per kilogram of DM due to its higher intake. The effect of concentrate supply level and interaction with silage digestibility was evaluated using mixed models, including the results for response period 1, with parity as a covariate and animal as a random effect. The reduction in concentrate offer by 2 kg/d in response period 2 was compensated for by increased 1.3 kg of DM/d of silage intake for HDS, resulting in similar intake (22.1 kg of DM/d and 21.7 kg of DM/d without and with concentrate reduction, respectively) and ECM yields (29.4 and 29 kg of ECM without and with concentrate reduction, respectively). However, concentrate offer reduction could not be compensated for by increased silage intake for LDS and resulted in lower milk yields (27.5 kg of ECM). Increased concentrate showed a higher marginal ECM response (kg of ECM per kg of additional concentrate intake) for LDS (1.8 vs. 3.3 kg of ECM for HDS and LDS, respectively). Thus, the drop in milk yields could be compensated for by increased concentrate offers if LDS are fed. Total methane production increased with increased concentrate intake, regardless of silage digestibility. Methane emissions per unit of milk were affected by total DM intake rather than by changes in silage digestibility and concentrate level. The results of this study are based on short-term periods and could show differences if study periods were longer; the results should be interpreted accordingly.

Physical and economic performance of dairy cows managed within contrasting grassland-based milk production systems over 3 successive lactations

A diverse range of grassland-based milk production systems are practiced on dairy farms in temperate regions, with systems differing in relation to the proportion of grazed grass, conserved forages and concentrates in diet, calving season, duration of housing, cow genotype, and performance levels. The current study was conducted to examine performance within diverse grassland-based systems of milk production under experimental conditions. This study examined 4 milk production systems over 3 successive lactations (20 cows per system during each lactation). With winter calving-fully housed (WC-FH), Holstein cows were housed for the entire lactation and offered a complete diet consisting of grass silage, maize silage, and concentrates [approximately 50% forage on a dry matter (DM) basis]. With winter calving-conventional (WC-Con), Holstein cows were housed and offered the same diet from calving until turnout (late March) as offered with WC-FH, and thereafter cows were given access to grazing and supplemented with 5.0 kg of concentrate/cow daily. Two spring-calving systems were examined, the former involving Holstein cows (SC-H) and the latter Jersey × Holstein crossbred cows (SC-J×H). Cows on these systems were offered a grass silage-concentrate mix (70% forage on a DM basis) until turnout (late February), and thereafter cows were given access to grazing supplemented with 1.0 kg of concentrate/cow per day. The contributions of concentrates (3,080, 2,175, 722, and 760 kg of DM/cow per lactation), conserved forages (3,199, 1,556, 1,053, and 1,066 kg of DM/cow per lactation), and grazed grass (0, 2,041, 2,788, and 2,692 kg of DM/cow per lactation) to total DMI (6,362, 5,763, 4,563, and 4,473 kg of DM/cow per lactation) with WC-FH, WC-Con, SC-H, and SC-J×H, respectively, varied considerably. Similarly, milk yield (9,333, 8,443, 6,464, and 6,049 kg/cow per lactation), milk fat content (44.9, 43.3, 42.8, and 49.0 g/kg), and milk protein content (34.6, 34.9, 33.6, and 36.3 g/kg) differed between systems (WC-FH, WC-Con, SC-H, and SC-J×H, respectively). The higher milk yields with the WC systems reflect the greater concentrate inputs with these systems, whereas the greater milk fat and protein content with SC-J×H reflect the use of Jersey crossbred cows. Crossbred cows on SC-J×H produced a similar yield of milk solids as Holstein cows on SC-H. Cows on WC-FH ended the lactation with a greater body weight (BW) and body condition score than cows on any other treatment. While Jersey crossbred cows on SC-J×H had a lower BW than Holstein cows on SC-H, cows on these 2 systems were not different for any of the other BW, body condition score, or blood metabolite parameters examined. Cows on WC-FH had a greater interval from calving to conception, a greater mastitis incidence, and a greater locomotion score than cows on the spring calving systems. Whole-system stocking rates and annual milk outputs were calculated as 2.99, 2.62, 2.48, and 2.50 cows/ha, and 25,706, 20,822, 15,289, and 14,564 kg of milk/ha, with each of WC-FH, WC-Con, SC-H, and SC-J×H, respectively. Gross margin per cow was highest with WC-Con, gross margin per hectare was highest with WC-FH, and gross margin per kilogram of milk was highest with SC-J×H. This study demonstrated that diverse grassland-based milk production systems are associated with very different levels of performance when examined per cow and per hectare.

Inclusion of Barley Fodder in Alfalfa/Grass-Based Diets on Milk Production in Goats and Milking Sheep

The purpose of this study was to determine the effect of Barley Sprout Fodder (BSF) on milk production and milk composition of Saanen goats and Friesian ewes. Twenty Saanen does (1-year-old) and twenty East Friesian ewes (1 to 5 years old), were selected for this experiment, where each species was divided into four treatment groups. Goat treatments consisted of 0 (CRTL), 758 (BSF1), 1498 (BSF2) and 2270 (BSF3) g wet BSF/d added to an alfalfa/grass hay mix provided in random order. Sheep treatments were similar, but 0, 454, 908, and 1362 g wet BSF/d. The dry matter content of the fodder was 10.7%. A grain mix was fed to the goats (798 DM g/d) and sheep (400 DM g/d) during morning and evening milking. Treatment periods were fifteen days. Feed consumed was measured and milk yield and samples were collected on days 13 and 14. Milk samples were analyzed for milk fat, protein, and lactose. The cheese was made from day 14 milk and milk and cheese were analyzed for fatty acid composition. Total DM intake was between 2.7 and 2.9 kg/d for does and was different (P<0.05) between BSF treatments, 2.6 to 3.0 kg/d for ewes. Milk yield was not affected by BSF treatment. Goat milk yield averaged 2681 g/d across the treatments, while sheep was 1021 g/d. Milk fat content increased numerically from 77 to 82 g/d for goats and 50 to 58 g/d for sheep. BSF did not affect goat milk protein g/d, but sheep milk protein increased from 46 to 53 g/d. Goat milk lactose was not changed with BSF inclusion, while sheep milk lactose increased from 47 to 54 g/d. Total solids were not different from BSF in the diet for goats but was for sheep increasing from 143 to 164 g/d. There were no differences in cheese fatty acid composition for either species. The CRTL diet cost $0.82/day for goats and $0.72/d for sheep, while the high level of BSF inclusion cost $1.06/d for goats and $0.91/d for sheep. Based on the parameters of this study, the inclusion of BSF had relatively no effect on goat milk parameters but did improve milk solids in sheep milk, with no increase in milk yield.

Replacing concentrates with a high-quality hay in the starter feed in dairy calves: I. Effects on nutrient intake, growth performance, and blood metabolic profile

Concentrate-rich starter feeds are commonly fed to dairy calves to stimulate early solid feed intake and growth performance; yet, starter feeds lacking in forage fiber may jeopardize gut development. This research primarily aimed to test a complete or partial replacement of concentrates with hay of different qualities in the starter feed on nutrient intake, growth performance, apparent total-tract digestibility (ATTD) of nutrients, and blood metabolites in dairy calves. Immediately after birth, 40 Holstein Friesian calves were randomly allocated to 1 of 4 starter diets, which differed in hay quality and concentrate inclusion [MQH = 100% medium-quality hay, 9.4 MJ of metabolizable energy (ME), 149 g of crude protein (CP), 522 g of neutral detergent fiber (NDF)/kg of dry matter (DM); HQH = 100% high-quality hay, 11.2 MJ of ME, 210 g of CP, 455 g of NDF/kg of DM; MQH+C = 30% medium-quality hay + 70% starter concentrate; HQH+C = 30% high-quality hay + 70% starter concentrate]. The concentrate consisted mainly of grains, oilseeds, and mineral supplements (13.5 MJ of ME, 193 g of CP, 204 g of NDF/kg of DM). Calves were used in the experiment from d 1 to 99 of life. During the first 4 wk, all calves were fed acidified whole milk ad libitum, and afterward they were gradually weaned from wk 5 to 12. Calves had ad libitum access to their starter diets and water throughout the experiment. Milk, water, and solid feed intake was recorded daily, live weight was measured once a week, and blood samples were collected on d 1, 3, 7, 21, 49, 77, and 91 and analyzed for selected metabolites. The ATTD was measured in wk 14 of life. Total DM intake and daily weight gain of calves were not affected by the starter feed during the first 8 wk of life. However, from wk 9 to 14, calves fed the MQH diet had lower DM, ME, and CP intake and gained less weight than calves from the other experimental groups. Feeding the HQH diet resulted in similar CP and ME intake and growth performance compared with calves receiving diets containing concentrates. Furthermore, feeding the HQH diet improved the ATTD of NDF, resulting in similar ATTD of organic matter with the HQH+C and MQH+C groups. Interestingly, calves fed the HQH+C diet showed less sorting for concentrate, compared with the MQH+C group. Concentration of blood metabolites, including glucose, lactate, insulin, nonesterified fatty acids, triglycerides, and total protein, did not differ after the first week of life. However, serum β-hydroxybutyrate was higher in calves fed the HQH diet starting from wk 11. Both groups fed the hay-only diets maintained higher cholesterol levels after weaning compared with the groups fed hay-concentrate mixtures. In conclusion, feeding high-quality hay can fully replace starter concentrates in the feeding of dairy calves without adverse effects on performance during the rearing period, while increasing forage fiber intake and utilization, which enhanced ruminal ketogenesis and cholesterogenesis around weaning. Further research is needed to evaluate long-term effects of feeding high-quality hay on health and development of dairy calves, especially in terms of the observed improvements in ruminal ketogenesis and cholesterogenesis around weaning.

Intake and performance of growing lambs supplemented with quebracho tannins.

Tannins can modulate rumen fermentation and increase the bypass protein; however, the use of different doses and sources of condensed tannins (CT) in animal diets has divergent results. The aim of this study was to evaluate the effect of different levels of dietary quebracho extract inclusion, as a CT source, in the performance and carcass characteristics of growing lambs. Forty-eight weaned lambs (Texel, Suffolk, and Hampshire Down crossbred) were homogenously blocked into four groups and supplemented at 0, 10, 30, and 60g tannins/kg dry matter intake (DMI) (CONT, T1%, T3%, and T6%, respectively). The DMI, the roughage to concentrate ratio, the feed conversion rate (FCR), the average daily gain (ADG), and the body condition score (BCS) were evaluated. After the trial, animals were slaughtered, and the cold carcass weight, carcass yield, and subcutaneous fat thickness (SFT) were determined. Higher levels of CT in T3% and T6% reduced (P < 0.001) the total DMI and intake of concentrate without impacting (P = 0.071) the roughage intake (% body weight). ADG was the lowest for T6%, although the total weight gain and BCS were the lowest also for T3% (P < 0.001). FCR was worst for T6% (P < 0.001). Regarding carcass characteristics, T6% had the lowest weight of carcass (P = 0.003) and SFT (P = 0.021) compared to CONT. Carcass yields were similar among all the groups (P = 0.247). T1% did not differ from CONT to any parameter (P > 0.05). Supplementing quebracho CT at a low dose did not show beneficial effects; moreover, higher doses of CT led to detrimental effects in intake and animal performance.

Effect of pre-grazing herbage mass on pasture production and performance of suckler-bred steers during the grazing season and subsequent indoor finishing period

The objective was to determine the effect of pre-grazing herbage mass (PGHM) on herbage production and nutritive value, intake and growth of suckler-bred steers in a rotational stocking system, and the residual effects on intake, growth and carcass traits during subsequent indoor finishing. A total of 108 yearling steers previously offered grass silage indoors over 105 days were assigned to one of two PGHM (1500 – low (L) or 2000 – high (H) kg dry matter (DM)/ha; > 4 cm) treatments. Steers (ca. 345 kg at turnout to pasture in spring) rotationally grazed perennial ryegrass (Lolium perenne) dominant pasture in 12 groups of 9 for 203 days. At the end of the grazing season they were housed indoors and offered either (1) grass silage only or (2) grass silage + 3.17 kg concentrate DM/head daily for 136 days until slaughter at 24 months of age. Annual herbage production was higher (8427 vs. 7542 kg DM/ha, P < 0.01) for H than L, but there was no difference between treatments in surplus herbage removed as silage due to the tendency for H steers to consume more herbage/ha while grazing (7363 vs. 6479 kg DM/ha, P = 0.08). During the grazing season, compared to L, steers grazing H had a greater estimated herbage DM intake (6.59 vs. 5.93 kg DM/ha, P < 0.001), daily live weight gain (0.81 vs. 0.76 kg, P < 0.01), live weight at the end of the grazing season (553 vs. 539 kg, P < 0.01) and live weight gain/ha (1261 vs. 1206 kg/ha). During the indoor finishing period there was no PGHM × finishing diet interaction, and no residual effect of PGHM on daily live weight gain, but carcass weight tended to be heavier for H (359 vs. 354 kg, P = 0.06) than L. Compared to silage only, the silage + concentrates group had a higher (P < 0.001) total DM and energy intake, feed conversion efficiency, live weight gain, carcass weight and carcass conformation and fat score. In conclusion, grazing the lower PGHM reduced herbage production, steer live weight gain at pasture, overall live weight gain/ha and tended to reduce carcass weight; therefore, under the conditions of this experiment grazing a PGHM of 2000 kg DM/ha is recommended. Removing concentrates from the finishing diet reduced carcass weight and fatness, making it more difficult to finish steers at a commercially acceptable carcass (carcass fat score > 6.0, 1 - 15 scale).

Cyberlindnera jadinii yeast as a protein source in early- to mid-lactation dairy cow diets: Effects on feed intake, ruminal fermentation, and milk production

We examined the effects of substituting soybean meal with either yeast protein from Cyberlindnera jadinii or barley in concentrate feeds on feed intake, ruminal fermentation products, milk production, and milk composition in Norwegian Red (NRF) dairy cows. The concentrate feeds were prepared in pellet form as soy-based (SBM; where soybean meal is included as a protein ingredient), yeast-based (YEA; soybean meal replaced with yeast protein), or barley-based (BAR; soybean meal replaced with barley). The SBM contained 7.0% soybean meal on a dry matter (DM) basis. This was replaced with yeast protein and barley in the YEA and BAR concentrate feeds, respectively. A total of 48 early- to mid-lactation [days in milk ± standard deviation (SD): 103 ± 33.5 d] NRF cows in their first to fourth parity and with initial milk yield of 32.6 kg (SD = 7.7) were allocated into 3 groups, using a randomized block design, after feeding a common diet [SBM and good-quality grass silage: crude protein (CP) and neutral detergent fiber (NDF) content of 181 and 532 g/kg of DM, respectively] for 14 d (i.e., covariate period). The groups (n = 16) were then fed one of the dietary treatments (SBM, YEA, or BAR) for a period of 56 d (i.e., experimental period). The concentrate feeds were offered in split portions from 3 automatic feeders using electronic identification, with ad libitum access to the same grass silage. Dietary treatments had no effect on daily silage intake, total DM intake, or total NDF intake. Dietary CP intake was lower and starch intake was higher in the BAR group compared with the other groups. Ruminal fluid pH, short-chain volatile fatty acid (VFA) concentrations, acetate-to-propionate ratio, and non-glucogenic to glucogenic VFA ratio were not affected by dietary treatments. No effects of the dietary treatments were observed on body weight change, body condition score change, milk yield, energy-corrected milk yield, milk lactose and fat percentages, or their yields. In conclusion, yeast protein can substitute conventional soybean meal in dairy cow diets without adverse effect on milk production and milk composition, given free access to good-quality grass silage.

Effect of

Context Spirulina platensis (SP) has been found to be an important dietary supplement for boosting animal growth performance, having a high protein content (60–70% on a dry-matter basis) with minimal toxicity. Aims The effect of Spirulina platensis (SP) supplementation on the growth and performance of two Omani goat breeds (Jabbali and Sahrawi) was investigated. Methods Thirty-six 11-month-old bucks from two Omani goat breeds were studied for 70 days at the Livestock Research Centre, Ministry of Agriculture, Fisheries and Water Resources, Oman. Each breed was divided into three groups (n = 6) and fed one of the following three rations: (1) control (CON): concentrate with 14% crude protein and 11.9% energy (MJ/kg DM); (2) Treatment 1 (T1): the same concentrate with 2 g/head.day SP; and (3) Treatment 2 (T2): the same concentrate with 4 g/head.day SP. Weekly growth, performance and body conformation data collected included live bodyweight (BWT), body condition score (BCS), average daily gain (ADG), chest girth (CG), wither height (WH) and body length (BL). Key results The Jabbali breed had a higher feed conversion ratio for T1 and T2 than did the Sahrawi breed. During the trial, no differences in total DM intake were found between treatments for either breed. T1 and T2 SP supplementation levels significantly (P &lt; 0.05) improved the BWT and ADG of the Sahrawi breed compared with the CON group. Analysis of all traits indicated a significant (P &lt; 0.05) effect of feeding spirulina on all the studied traits except WH and BL. ANOVAs for fixed effects in this study (dam age and kid birth type, i.e. single, twin or triple) were not significant (P &gt; 0.05) for any of the studied traits. However, the breed effect was highly significant (P &lt; 0.001) on BWT, ADG, BCS and treatment effect was significant (P &lt; 0.05) on CG traits. Conclusions Spirulina platensis could be used as a supplement feed to improve growth, performance and morphological traits in Omani goat production. Feeding spirulina to kids led to increased growth, herd performance and buck selection facilitation at an earlier age. Implications These findings will benefit Omani goat producers in managing productivity and product quality.

Effect of Groundnut (&amp;lt;i&amp;gt;Arachis hypogaea&amp;lt;/i&amp;gt; L.) Haulm and Maize Bran Mixture Supplementation on Growth and Carcass Characteristics Performance of Local Sheep Fed Pasture Hay Basal Diet

The experiment was conducted to evaluate the effect of groundnut haulm and maize bran mixture supplementations on feed intake, digestibility, body weight gain and carcass characteristics of local sheep fed hay basal diet at Salga sheep farm in Assosa district, Western Ethiopia. The experiment was laid out in a randomized complete block design (RCBD) with four treatments consisting of six blocks with four animals per block based on their initial body weight of 20.12 ± 0.05 kg (mean ± SD). Treatments comprised of feeding natural pasture hay ad libitum T1 = 0; T2 = 100% maize bran (MB); T3 = 50% MB and 50% Groundnut haulm (GNH), and T4 = 100% GNH. The amount of supplements offered was 300 g/day/animal on DM basis. The daily feed intake, daily body weight gain, feed conversion efficiency, dry matter and nutrient digestibility, and carcass characteristics parameters were measured during the experimental period. The study result indicates that the crude protein (CP) contents were 7.12% and 11.6%, and the neutral detergent fiber (NDF) contents were 67.9% and 57.5% for natural grass hay and groundnut haulm, respectively. The total DM intake was higher (P

Effect of incorporation of sun-dried rumen digesta in the diet on nutrient intake and growth performance of Djallonke sheep

Sun-dried rumen digesta (SDRD) was used as replacement of soybean meal and evaluated its effect on in vitro digestible organic matter, microbial count, nutrient digestibility, blood profile, growth and carcass characteristics of Djallonke sheep. Four S DRD-based concentrate supplements (0, 4, 8 and 12% SDRD) were incubated in a buffered rumen fluid for 24 h and 72 h to estimate the organic matter digestibility and degradation characteristics. Sixteen Djallonke rams (12.4±2.4 kg, 10 to 12 months old) were randomly assigned to four SDRD based concentrates with rice straw as the basal diet and replicated four times in a completely randomized design. They were individually fed over a 63 day period. There was significant difference (p<0.05) in the in vitro digestible organic matter (IVDOM) with the lowest value in 8% SDRD. Lactic acid bacteria were detected in the SDRD-based concentrates. Total dry matter and organic matter intakes were not significantly (p>0.05) affected by the inclusion of SDRD. However, crude protein intake was significantly (p<0.05) lower in 8% SDRD compared to 12% SDRD. Rams fed SDRD-based concentrate had similar final body weight and weight gain as the control. Haematology, serum profile and carcass characteristics of the rams were not significantly (p>0.05) affected by the dietary treatments. It was concluded that sun-dried rumen digesta used in this study can effectively replace soybean meal (up to 12%) without any effect on digestibility and growth performance of sheep.