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Highlights • Intact bulls perform better than heifers, especially on more energy-rich rations and swards. • Crossbreds give higher carcass yield compared to pure bred bulls, even if the crossbreds comprise 50% bulls and 50% heifers. • Carcass fatness and colour are ideal for premium cuts of heifers but generally not acceptable for premium cuts of the two bull groups when slaughtered from pasture. Abstract When crossbreeding with beef breeds in organic dairy herds, the use of non-sexed semen will results in both male and female offspring to be used for beef production. The objective of the present study was to compare growth and carcass characteristics of 15 Danish Holstein bull (HB) calves, 15 beef x Danish Holstein crossbred bull (CB) calves and 15 beef x Danish Holstein crossbred heifer (CH) calves reared under organic settings. As beef bred sire a high-merit bull of the Limousine breed was used. Furthermore, the study should generate knowledge which can support future organic beef production. Forty-five Spring-born calves were purchased at 10 private farms at approximately 20 days of age with an average initial body weight of 52.9, 58.2 and 56.1 (s.e.m. 2.6) kg for HB, CB and CH, respectively. Calves were housed indoors in groups of five until weaning off cows' milk at 3 months of age. Calves were gradually introduced to a grass-silage based ration from 3 to 4 months of age. From 4 to 7 months calves were kept on mixed grass pasture of ryegrass and white clover. From 7 to 13.5 months calves were housed indoor in groups of 5 and fed a mixed ration with low-moderate energy content. From 13.5 months of age, the established groups of 5 animals grazed in a rotational paddock system until slaughter at 17 months. There was no difference between HB, CB and CH in average daily gain (ADG) from birth to weaning, from weaning until turn-out and during pasture from 4 to 7 months. The ADG indoor from 7 to 13.5 months, and during pasture from 13.5 to 17 months differed between treatment groups. The CB had greater ADG than CH for both periods with HB being intermediate (P < 0.02–0.001). The ADG indoor from 7 to 13.5 months were 1.06, 1.10 and 0.97 (s.e.m. 0.02) kg d −1, and ADG during pasture from 13.5 months until slaughter were 0.88, 1.11, and 0.64 (s.e.m. 0.07) kg d −1 for HB, CB, and CH, respectively. Final body weights were heavier for CB, intermediate for HB, and lowest for CH (575, 534, and 480 (s.e.m. 12.1) kg, P < 0.01). Overall, ADG from arrival to slaughter was 21% higher for CB than CH (P < 0.001), and the average ADG of the combined heifer and bull crossbreds ((CB+CH)/2) was not different from that of HB. Crossbreeding improved EUROP conformation markedly in both CH (5.3) and CB (7.0) compared with HB (3.0) (P < 0.001), and carcass weight was 4% higher for crossbreds ((CB+CH)/2) compared with HB. There was no difference in EUROP fatness between HB and CB which was low (1.0–1.2), whereas CH had an acceptable fatness (2.9). Carcass lean:fat color (assessed using a Danish 1–5 scale) was high for the bulls (3.9–4.0) but acceptable for CH (3.3, P < 0.01). It is concluded that improvements in carcass conformation and carcass weight coupled with similar overall growth of the combined heifer and bull crossbreds support the efficiency of beef x Holstein crossbreds of both sexes compared with purebred Holstein bulls within an organic system with summer grazing. Furthermore, it proved difficult to finish intact bulls on pasture to fulfill a premium beef cut market that requires higher fatness and less dark meat color than obtained herein. [ABSTRACT FROM AUTHOR]

Emerging knowledge shows the importance of preweaning nutrition on programming the gastrointestinal microbiome and development of the gut barrier function. The aim of this study was to assess the effects of supplementing cow milk with either intact dried Ulva sp., Ascophyllum nodosum , or Saccharina latissima on growth performance and several gut health parameters of preweaning dairy calves. Forty male Holstein calves were selected based on birth weight (41 ± 4 kg) and plasma Brix percentage (≥8.7%) at d 2 of life. From d 2 to d 42 of life, the control calves (n = 10) were fed with cow milk (8 L/d) without seaweed supplementation, and the experimental calves were fed with cow milk (8 L/d) supplemented with either Ulva sp. (n = 10), A. nodosum (n = 10), or S. latissima (n = 10) at a concentration of 50 g/8 L of cow milk per day (i.e., 5% on a dry matter basis). Calves were weighed every week, and body weight gain and calf starter intake were monitored weekly. At d 42 ± 3 of life, calves were slaughtered. The organ weights and digesta pH from the reticulorumen, mid- and end small intestine, and mid-colon were recorded. A tissue sample (5 cm) collected from the mid-small intestine was analyzed for histomorphology. Digesta from the mid-small intestine and mid-colon were analyzed for lactobacilli, Escherichia coli , and Enterobacteriaceae , and short-chain fatty acid profile. Weight gain of the calves was not affected by seaweed supplementation. Proportional organ weights were not affected by seaweed supplementation except for reticulorumen weight, which was higher in calves fed Ulva sp. Both the mid-small intestinal and mid-colonic digesta populations of lactobacilli, Enterobacteriaceae , and E. coli , as well as the mid-small intestinal histomorphology in seaweed-supplemented calves were not different from control calves. However, acetic acid proportion in mid-colonic digesta was increased in calves fed Ulva sp. and A. nodosum , whereas butyric acid proportion was decreased compared with the control calves. Digesta pH in mid- and end small intestine and mid-colon were not affected, whereas ruminal pH was increased in calves fed Ulva sp. compared with the control calves. In conclusion, intact dried seaweed supplementation did not improve the growth or selected gut health parameters (i.e., histomorphology, digesta pH, bacteria, and short-chain fatty acids) in preweaning Holstein calves. [ABSTRACT FROM AUTHOR]

The present in vitro experiments were carried out in order to study whether variations in the bovine growth hormone (bGH)/insulin-like growth factor (IGF)-I axis induced by plane of nutrition and bGH treatment of heifer calves caused variations in serum-induced proliferation of C2C12 myoblasts. Serum was obtained from two groups each of six heifer calves (195 ± 8 kg) before (d −1) and after treatment with 15 mg/day of bGH for 6 days (d 6) fed either a low (GHL) or a high plane (GHH) of nutrition. Preceding the experiment all 12 heifer calves were fed at the low plane of nutrition. At d 6, serum concentrations of insulin and IGF-I were increased while that of IGF-binding proteins (IGFBP)-2 was decreased in GHH, but unchanged in GHL calves. Serum-induced proliferation of C2C12 myoblasts, was elevated at d 6 by GHH treatment. Especially human IGFBP-3 but also bovine IGFBP-2 added to cell cultures inhibited the rate of proliferation of C2C12 myoblasts stimulated by human IGF-I. The present results showed that GH treatment causes changes in the GH/IGF axis, which leads to changes in serum-induced growth of C2C12 muscle cells dependent on the plane of nutrition that mimic in vivo effects of GH treatment, which indicate an endocrine contribution of the IGF system. However, drawbacks of this suggestion are discussed. [ABSTRACT FROM AUTHOR]

Intact seaweed or seaweed extracts are used as feed supplements to improve the gut microbiome in young animals. Seaweeds provide functional polysaccharides, and they are a good source of vitamins, minerals, and phenolic compounds, all of which are relevant for immune system development. However, literature on the effects of dried seaweed supplementation on immune system development is limited, especially in calves. This experiment aimed to study the effect of feeding milk supplemented with Ulva lactuca , Ascophyllum nodosum , or Saccharina latissima on the systemic immune status of preweaning dairy calves. Forty male Holstein calves with birth body weight 41 ± 4 kg and plasma Brix percentage ≥8.7% at d 2 after birth were used in this study. Calves were fed 4 L of cow milk twice a day (total 8 L/d). From d 2 to d 28, calves in the control group (n = 10) received milk without seaweed supplementation. Over the same period, experimental calves received milk supplemented with Ulva lactuca (SW1; n = 10), Ascophyllum nodosum (SW2; n = 10), or Saccharina latissima (SW3, n = 10). Dried and ground seaweeds were offered at a daily allowance of 50 g/8 L of milk (i.e., approximately 5% inclusion rate on a dry matter basis). Blood samples were collected from a jugular vein on d 2, 4, 7, 14, 21, and 28 after birth. Plasma concentrations of total protein, albumin, immunoglobulins, and acute-phase proteins (i.e., serum amyloid A, fibrinogen, and haptoglobin) were measured. We detected no differences in average daily gain, plasma immunoglobulins, albumin, or total protein. However, the contrast analysis revealed that plasma concentrations of fibrinogen (SW1 and SW2) and serum amyloid A (SW2 and SW3) were significantly higher in the seaweed groups compared with the control group. We also found a tendency for high plasma haptoglobin in the seaweed groups (SW1 and SW2) compared with the control group. Differences in acute-phase protein concentrations could be partially explained by the large differences in micromineral intake between control and seaweed-supplemented calves. Feeding milk supplemented with dried seaweed increased plasma concentrations of variables related to the innate immune response in preweaning dairy calves. [ABSTRACT FROM AUTHOR]

Traditional starch-rich concentrates for milk-fed calves induces an acidotic ruminal environment even with small daily intakes. A new feeding regimen including use of low-starch concentrate was formulated and tested for impact on ruminal environment and -development in 2 to 10 wk old calves. Eight Holstein calves (48 ± 1 kg BW at birth) implanted with ruminal cannulaes (20 mm ID) at d 7 ± 1 of age were allocated to one of two feeding regimens. Calves on control treatment (CON) had free access to a barley-based concentrate (319 g starch/kg) from wk 1. Calves on alternative treatment (ALT) had no access to concentrate until wk 4 when they got free access to a low-starch concentrate (68 g starch/kg). All calves had free access to artificiallydried grass hay, and water and were fed skim-milk-based milk-replacer (4.6 L/d in wk 1 to 2, 6.4 L/d in wk 2 to 7, and 3.2 L/d in wk 7 to 8). Every wk, 8 ruminal samples/calf were collected from 0730 to 2400. There were no treatment effects on ADG (802 ± 35 g/d) or total solid feed DMI (concentrate + hay; 78 ± 4 kg). On ALT compared with CON, average ruminal pH was higher (6.39 vs. 6.04 ± 0.09, P < 0.05) and minimum ruminal pH was higher (6.14 vs. 5.57 ± 0.09, P < 0.01). A relatively large treatment x wk interaction was found for all VFA data. Especially from wk 2 to 4 the butyrate profile and the ruminal butyrate concentration was smaller (P < 0.001) for ALT (1 to 3 ± 1 mmol/L) compared with CON (6 to 9 ± 1 mmol/L). However, when concentrate was introduced to ALT calves ruminal butyrate increased to a higher (P < 0.001) level (12 to 19 ± 1 mmol/L) compared with CON (8 to 13 ± 1 mmol/L). No differences between treatments in ruminal mass, length, shape and aggregation of ruminal papillae were detected at wk 10. Our results show that it is possible to formulate rumen-friendly low-starch concentrates without compromising growth or ruminal development in milk-fed calves. [ABSTRACT FROM AUTHOR]

• Seaweeds contain low levels of digestible nutrients for non-ruminants. • High ash and fiber concentrations in intact seaweeds may limit inclusion in feed. • Seaweeds may provide essential minerals. • Protein and fat fraction contain high EAA and EFA proportions. • Diverse monosaccharides in seaweed fibers indicate varying bioactive potential. This study aimed to discuss the chemical composition of three seaweed species commonly found in Nordic countries and its potential use in feed rations for pigs and calves. Two brown seaweeds Ascophyllum nodosum , Saccharina lastissima and a green seaweed Ulva sp. harvested from Danish and Icelandic waters were analyzed for proximate, amino acids, minerals, fatty acids and non-starch polysaccharides composition. All studied seaweeds contained low protein concentrations (i.e. 11.4–15.9 g/100 g DM). The ratio of essential amino acids (EAA) to non-essential amino acids (NEAA) was similar in all studied seaweeds (0.81−0.87). Ulva sp. had the highest ash concentration (48.2–54.4 g/100 g DM), followed by S. latissima (39.9 g/100 g DM) and A. nodosum (29.5 g/100 g DM). The most abundant macrominerals in the seaweeds were Ca, K and Na. Iodine was the most abundant micromineral in brown seaweeds (1.4–2.1 g/kg DM). Moreover, Ulva sp. had the highest Fe (5.1–8.0 g/kg DM), Mn (10.5 g/kg DM) and inorganic As (0.008 g/kg DM) concentrations. Ascophyllum nodosum had the highest crude fat concentration (3 g/100 g DM) and the highest concentration of polyunsaturated fatty acids (FAs) (37.9 g/100 g FA). Eicosapentaenoic acid (EPA) concentration was the highest in A. nodosum (7 g/100 g FA) followed by S. latissima (5 g/100 g FA) and Ulva sp. (2 g/100 g FA). Furthermore, concentration of α-linolenic acid, a precursor for EPA, was the highest in Ulva sp. (6.2–14.6 g/100 g FA). Total dietary fiber concentration was higher in the brown seaweeds (27.8–42.6 g/100 g DM) compared to the green seaweeds (17.9–21.5 g/100 g DM), where S. latissima had the highest soluble dietary fiber concentration. The high concentrations of ash and fiber may limit inclusion levels of the analyzed whole seaweeds in feed rations, mainly due to dilution of other nutrients in the feed, reduced digestibility of the feed and possible toxicities (i.e. high inorganic As). On the other hand, high concentrations of essential and valuable microminerals including I, Cu, Fe, Mn, Se were also detected in the studied seaweeds. High soluble dietary fiber concentration in S. latissima can be of interest as a fermentable substrate for probiotic bacteria. The easily digestible nutrients including, crude protein and fat were low in the seaweeds. However, the protein, fat, ash and dietary fiber fractions of the studied seaweeds were characterized by high concentrations of EAA, EFA, essential microminerals and interesting monomers of functional polysaccharides, respectively; which indicate possibilities for future use of seaweed-extracts in feed rations. [ABSTRACT FROM AUTHOR]

The aim of the present experiment was to test the hypothesis that a barley-based concentrate would induce an acidic ruminal environment in young calves and that increased milk allowance would alleviate this condition. Eight Holstein calves ruminally cannulated at d 7 ± 1 of age were used to study the effect of variation in barley-based starter concentrate intake induced by 4 different milk allowances (3.10, 4.84, 6.60, and 8.34 kg of milk replacer/d; 123 g of dry matter/kg of milk) on the ruminal environment, blood variables, and fore-stomach development from wk 2 to 5 of age. Twelve ruminal fluid samples were collected during a weekly 24-h sampling in 4 consecutive weeks. Blood samples were collected by venipuncture between 1200 and 1300 h on ruminal sampling days. Rumen papillae development and visceral organ mass were recorded at slaughter. A linear treatment x week effect was observed for concentrate intake, with the calves fed the lowest milk allowance having the fastest increase in concentrate intake whereby these calves reached the same ME intake in wk 5 compared with calves with the highest milk allowance. Effects on ruminal variables were dominated by week of sampling, with minor differences among treatments. Ruminal pH was below 5.5 for 5 to 13 h/d and all calves with concentrate intake above 20 g of dry matter/d were observed to have a daily ruminal pH minimum at pH 5.5 or lower. The ruminal concentration of total volatile fatty acids (VFA) increased from 71 to 133 ± 9 mmol/L in wk 2 to 5 and was characterized by a relatively high molar proportion of propionate, increasing from 34 to 40 mol/100 mol of VFA in wk 2 to 5. In addition, the presence of ethanol and propanol as well as numerous VFA esters points to a ruminal environment with a relatively high hydrogen pressure. Plasma glucose and insulin responded to the highest milk allowance in wk 2 to 4. Plasma VFA and ketone bodies increased with the lowest milk allowance in wk 4 to 5. At slaughter, empty wet weights of the rumen + reticulum and omasum as well as mass of digesta in these compartments were found to decrease linearly and perirenal fat was found to increase linearly with milk allowance, indicating that the milk allowance changed the body composition of the calves. Lengths of ruminal papillae in the atrium and ventral ruminal sac were not affected by treatment. We concluded that the ruminal environment of young calves fed a barley-based starter concentrate was characterized by a low ruminal pH and high VFA concentration regardless of the milk allowance. [ABSTRACT FROM AUTHOR]

Eight Holstein calves (44 ± 1 kg BW at birth) implanted with ruminal cannulaes (20 mm ID) at d 7 ± 1 after birth were used to investigate the effects of milk allowance on concentrate intake and ruminal fermentation patterns. Calves were allocated to one of four treatments (3.0, 4.7, 6.4 or 8.1 L skim-milk-based milk-replacer/d; 130 g solids/L milk). All calves had free access to a barley-based starter concentrate (319 g starch/kg), artificially-dried hay, and water. Ruminal samples were collected every 2 h for 24 h at wk 2, 3, 4, and 5. Ruminal pH was measured immediately and ruminal fluid was stabilized with metaphosphoric acid for later analysis. Concentrate intake was affected by a treatment times wk interaction (P < 0.01). The smallest concentrate intake was found with 6.4 L milk/d (17 g/d in wk 2 increasing to 389 g/d in wk 5) and the greatest concentrate intake was found with 3.0 L milk/d (310 g/d in wk 2 increasing to 1,601 g/d in wk 5 [SEM = 150]). Daily gain from wk 2 to 5 (714 ± 35 g/d) was not affected (P = 0.49) by treatment. The average (5.8 ± 0.1) and the minimum (5.4 ± 0.1) ruminal pH within a sampling period were not affected (P > 0.24) by treatment or wk. Hours/d with ruminal pH below 6.2 (18 ± 2 h/d), 5.8 (14 ± 2 h/d), and 5.4 (6 ± h/d) were not affected (P > 0.18) by treatment or wk. The total VFA concentration was affected by week (P < 0.01) and increased from 71 ± 9 mmol/L in wk 2 to 133 ± 9 mmol/L in wk 5. All data for calves with concentrate intakes above 25 g/d showed no relationship between concentrate intake level and severity of ruminal environment. The implication is that starch-based concentrates in general might be harmful to the juvenile rumen of milk-fed calves and more attention should be paid to formulating rumen-friendly starter concentrates. [ABSTRACT FROM AUTHOR]