Characterization of immune responses against gastrointestinal nematodes in weaned lambs grazing willow fodder blocks

A 131-day rotational grazing experiment was conducted in the summer autumn of 2007/2008 to compare effects of feeding condensed tannin (CT)-containing willow (Salix spp.) fodder blocks (i.e., silvopastoral system) or perennial ryegrass (Lolium perenne)/white clover (Trifolium repens) control pasture upon the immune response to gastrointestinal nematode parasite infection in Romney weaned lambs. Groups of lambs (n = 40) were allocated to either willow fodder blocks or control pasture; half of each group (n = 20) were regularly-drenched with anthelmintic at approximately 21 day intervals, whilst the remaining 20 weaned lambs were not drenched unless pre-determined faecal nematode egg counts (FEC) were reached, when all weaned lambs in that group were drenched with anthelmintic (i.e., trigger-drenching). Metabolizable energy and CT concentrations were higher in willow fodder versus pasture herbages. Weaned lambs grazing willow fodder blocks had lower live weight gain (92 g/day) and carcass weight (14.4 kg) than those grazing control pasture (134 g; 15.3 kg), with no effect of anthelmintic drenching. Regular anthelmintic treatment maintained similar and low FEC up to day 82, which then increased, whilst trigger-drenched lambs grazing willow fodder blocks had higher FEC than lambs grazing control pasture on three out of eight occasions. As judged by faecal larval cultures, grazing willow fodder blocks reduced the relative proportions of abomasal-dwelling parasites (Haemonchus contortus and Teladorsagia spp.). Trigger-drenched willow fodder block-fed sheep had higher platelet, eosinophil, total white blood cell and lymphocyte counts, greater CD21⁺ and greater γδ (Gamma Delta) TCR⁺ (T cell receptor) lymphocyte subsets than control pasture-fed sheep, and higher plasma levels of Immunoglobulin A (IgA) specific for carbohydrate larval antigen (CarLa) on day 105 (P<0.001). None of these parameters were affected by grazing treatment in regularly-drenched lambs. Higher immunological measurements in trigger-drenched lambs grazing willow fodder blocks could be due to higher larval intake and/or to the effects of secondary compounds in willow fodder blocks priming the immune system. Further research is required to separate these effects.     

Escape protein supplementation of growing steers grazing stargrass

A grazing trial utilizing 35 individually supplemented growing steers (211±42 kg initial body weight (BW)) was conducted to study the effect of supplemental escape protein on the performance of steers grazing on stargrass (Cynodon plectostachyus) during the dry season. N in supplements was 100%, 50%, or 0% natural protein (bloodmeal, coconut meal, and soybean meal), and 0%, 50% or 100% urea. All steers received 2 kg of supplement dry matter (DM) (2.2% N) daily during the 90 days of the experiment. Steers fed the urea supplement had the lowest ADG (0.97 kg day⁻¹). There was a linear (P<0.05) response in ADG to the natural protein level (50 and 100%) in supplements containing bloodmeal (1.11 and 1.21 kg day⁻¹) and coconut meal (1.05 and 1.21 kg day⁻¹), but no response was observed with soybean meal (1.01 and 1.0 kg day⁻¹). Forage intake was not affected by supplementation. As a result of the growth response observed for supplements containing bloodmeal and coconut meal above the urea-based and soybean meal supplements, it was concluded that growing ruminants grazing stargrass in the dry season were deficient in escape protein. ©1997 Elsevier Science B.V.     

Winter grazing of reindeer in woodland lichen pasture: Effect of lichen availability on the condition of reindeer

Winter grazing of semi-domesticated reindeer (Rangifer t. tarandus) was investigated at the woodland lichen pasture (lichen approximately 550 kg DM ha⁻¹) in Kaamanen, northern Finland during the winter 1996–1997. Nine female reindeer mainly dug their food in the snow for 122 days (3 December–4 April) in a fenced area of 36.3 ha. Over half of the fenced area was lichen dominated dry pine forest. The amount of lichens in lichen forest inside the fence was estimated before and after grazing. Area of grazed and condition of reindeer as well as snow conditions were monitored. Reindeer grazed over the whole area of lichen forest in early winter but from mid-winter they tended to graze on the areas with the greatest lichen abundancy. The amount of lichens measured decreased in the latter areas by 40% and in the other part of the lichen pasture by 17%, respectively. In both of these areas the residual amounts of lichens left after grazing were similar. Of the dominant lichens, the amount of C. stellaris decreased the most and the amount of Cl. uncialis the least. During the study, the estimated average daily area grazed varied from 4 to 87 m² per reindeer. It was calculated that individual reindeer obtained 2.6 kg of lichen DM per day during the most intensive digging period when the body condition score and weight of reindeer increased. Otherwise, the body condition score and weight decreased. Reindeer finished foraging for ground lichens and started to search for arboreal lichens in mid-March when the snow layer was 70–80 cm thick and contained some hard snow layers which lifted reindeer. Both the amount of lichens in the pasture and the snow conditions essentially affect the nutritional status of reindeer in the woodland region during winter. Assuming that a reindeer is able to graze around 30 m² per day in the snow during mid and late winter, there should be, on the basis of energy demand and grazing behaviour of reindeer as well as the nutritive value of lichen, an estimated 1000 kg lichen DM ha⁻¹ available in a good condition woodland lichen pasture.     

The effect of heather supplementation on gastrointestinal nematode infections and performance in Cashmere and local Celtiberic goats on pasture

A study was performed on 48 adult dry goats (16 local Celtiberic and 32 Cashmere does) at pasture and naturally infected with gastrointestinal nematodes to investigate the effects of heather supplementation on faecal egg count(s) (FEC) and live weight changes. The experiment was carried out in a mountain area in the north-west of Spain from June to November in 2003. Two plots of 10,550 and 9,050 m² with perennial ryegrass/white clover (Lolium perenne/Trifolium repens) pastures were established and a total of 24 goats (8 local Celtiberic does and 16 Cashmere does) were randomly allocated to each plot. The trial consisted of comparing live weight changes and FECs in goats fed heather supplement (treated group) or not (control group). A supplement of freshly cut heather was offered ad libitum to the treated group every 3 days in the morning. Cashmere does showed a significantly (P < 0.001) lower live weight decrease than the Celtiberic goats. The goats supplemented with heather showed a lower FEC than compared controls and this effect was significant (P < 0.05) in August and in the following controls (September, October and November). Two goats died before November in the control group. In conclusion, it seems that the availability of heather reduces the FEC in goats grazing ryegrass/white clover pastures and tends to improve their live weights.     

Landscape-scale crop diversity interacts with local management to determine ground beetle diversity

Crop diversification and maintenance of semi-natural habitats (grasslands and field boundaries) are suggested to enhance farmland biodiversity, but the relative importance of these factors remains poorly known. We evaluated how crop diversity and availability of semi-natural grasslands at a landscape-scale interacted with local farming management (three management types from low to high intensity: ley < winter wheat < sugar beet) in their effect on ground beetle assemblages in southern Sweden. Ground beetle diversity increased with crop diversity either independently of local management (Simpson species diversity), or only in the less intensively managed habitats (rarefied species richness). While ground beetle diversity in leys tended to increase with field boundary length, no such relationship was observed in winter wheat or sugar beet fields. In contrast, the landscape proportions of leys and semi-natural grasslands did not affect ground beetle species richness and diversity. We conclude that (a) semi-natural grasslands and leys may not function as source habitats at a landscape-scale if they comprise a low proportion of the total land-use, while (b) increasing crop diversity is correlated to ground beetle richness and diversity in agricultural landscapes dominated by arable land. The beneficial effect of landscape-scale crop diversification on farmland biodiversity may depend on the general level of agricultural intensity of a region.     

Milk fatty acid composition of dairy cows grazing at two pasture allowances and supplemented with different levels and sources of concentrate

Milk fatty acid (FA) composition of dairy cows from two grazing studies was examined. In the first study, effects of concentrate supplementation and pasture allowance were evaluated using 20 multiparous Holstein cows in five 4 × 4 Latin squares. The four treatments resulted from the combination of two pasture allowances (i.e., low, 25 versus high, 40 kg dry matter/cow/day) and two concentrate supplementation levels (i.e., 0 versus 1 kg concentrate/4 kg milk). No interactions occurred between concentrate supplementation and pasture allowance for milk FA composition. Concentrate supplementation increased short-chain FA content, and reduced the content of long-chain FA, trans11 C18:1, and cis9, trans11 conjugated linoleic acid (CLA) (1.36 versus 1.18 g/100 g). Concentrate supplementation increased saturated FA (58.6 versus 54.0 g/100 g) and reduced unsaturated FA content (39.9 versus 43.8 g/100 g). Grazing at high pasture allowance increased short-, medium-, and long-chain FA content, without affecting cis9, trans11 CLA content. Saturated FA content was higher (57.1 versus 55.6 g/100 g), and unsaturated FA content was lower (41.3 versus 42.5 g/100 g), when cows grazed at high pasture allowance. Concentrate supplementation reduced unsaturated FA and cis9, trans11 CLA in milk of dairy cows grazing at two pasture allowances. In the second study, two experiments evaluated effects of different energy supplements in grazing dairy cows. In Experiment 1, 25 multiparous Holstein cows were assigned to a cracked corn (CC) or a steam flaked corn (SFC) supplement containing 667 g/kg of corn grain plus a pelleted protein/mineral supplement. In Experiment 2, 22 multiparous Holstein cows were assigned to a ground corn grain (GC) or a non-forage fiber (NFF) supplement. The GC supplement contained 850 g/kg of corn grain, and the NFF supplement contained 440 g/kg of non-forage fiber sources (i.e., beet pulp, soyhulls, wheat middlings) that partially replaced corn grain. Milk FA composition was not affected by corn processing or carbohydrate source. The content of short-, medium-, long-chain FA, and cis9, trans11 CLA (2.5 g/100 g in Experiment 1; 2.1 g/100 g in Experiment 2) was similar between supplements in both experiments. The type of supplement did not affect the content of saturated (62.6 g/100 g in Experiment 1; 65.4 g/100 g in Experiment 2) and unsaturated FA (37.5 g/100 g in Experiment 1; 34.6 g/100 g in Experiment 2). Supplementation with supplements differing in the rate and extent of ruminal carbohydrate digestion did not affect the milk FA composition of grazing dairy cows.     

Effect of willow supplementation upon plasma amino acid concentration in ewes grazing drought pastures of low nutritive value

Effects of supplementing willow stem cuttings to ewes grazing drought pastures upon plasma amino acid (AA) concentrations was studied on Massey University's Riverside Farm, near Masteron, on the East Coast of New Zealand. Ewes of similar age and weight (i.e., 59.0 ± 2.22 kg) were assigned to two groups of 7 each, either with (supplemented) or without (control) supplementation of willow, and experimental grazing was carried for 10 weeks from early February until mid April of 2005. Live weight (LW) was recorded fortnightly and body condition score (BCS) was monthly. Blood samples for quantification of plasma amino acids were collected at week 5 and 10. Both groups had a similar pre-grazing pasture mass (i.e., 2000 kg of dry matter/ha) and dead matter content (0.80) with the diet selected by the ewes containing a metabolisable energy (ME) of 8.3 MJ/kg DM, which is typical of drought conditions. The willow was readily eaten, with intake averaging 0.26 kg DM/ewe/d. Willow was of higher ME content than short drought pasture (i.e., 10.1 versus 8.4 MJ/kg DM) and contained condensed tannins at 40.8 ± 1.97 g/kg DM. Both groups of ewes lost live weight at about 50 g/d. Plasma concentration of 3-methyl histidine (88 versus 127 μmol/L) at week 5 and non-essential amino acids (1082 versus 1417 μmol/L) at week 5 and (1155 versus 1324 μmol/L) at week 10, were substantially lower (P<0.05) in willow supplemented versus control ewes, indicating that willow supplementation reduced catabolism of body proteins in ewes under drought feeding conditions.     

Grazing of cover crops in integrated crop-livestock systems

Conventional agriculture is specializing rapidly into the management of few monoculture crops, threatening crop diversity and questioning the sustainability of extensive cropping systems. The grazing of cover crops in integrated crop-livestock systems could be a feasible biologically based technology to restore crop diversity and mitigate ecological issues in cropping systems. However, there is limited evidence on plausible synergies or trade-offs for the practice, and about how grazing plans could affect the herbage production and services from cover crops. This work assessed the effects of cattle grazing on the primary and secondary production of annual ryegrass (Lolium multiflorum) in an integrated ryegrass–soybean rotation system. Specifically, the prediction for synergistic effects of cattle grazing on the ryegrass herbage production, residual crop cover and animal performance were tested in a 2-year (2014 and 2015) study comprising a randomized complete block design of four grazing intensity treatments, replicated three times. A no-cattle grazing treatment (NG), used as control, or continuous grazing with Holstein heifers (~ 220 kg live weight) at targeted sward heights of 5, 10, 15 and 20 cm (hereafter referred as G₅, G₁₀, G₁₅ and G₂₀, respectively) was applied to ryegrass plots. The herbage production and residual herbage cover of ryegrass, and the average daily gain (ADG, kg/day) and live weight gain per hectare (LWG, kg/ha) of heifers were analyzed by ANOVA (P < 0.05) and compared by the Tukey_HSD test (P < 0.05). Regression models were used to estimate relationships between herbage production, animal performance and sward height. The herbage production was 60% higher (P < 0.01) for the grazing treatments compared to NG. The residual herbage for G₁₅ and G₂₀ was not different than that for NG and increased linearly as sward heights increased, reaching highest values for G₁₅ and G_20. Maximum ADG was 1.10 kg/day for ryegrass grazed at a 20.6 cm height, whereas maximum LWG was 427 kg/ha for ryegrass grazed to a 16.1 cm height. The results support the hypothesis for synergistic effects of using annual ryegrass as a dual forage and service cover crop. Moderate grazing intensity to sward height of 12–18 cm with continuous stocking led to optimized forage production and utilization by dairy heifers.     

The importance of grazing regime in the provision of breeding habitat for grassland birds: The case of the endangered little bustard (Tetrax tetrax)

In Mediterranean dry grasslands, grazing by domestic animals is an important agricultural activity on dry grasslands. Several bird species occur in these grazed habitats and are now experiencing a near continuous decline. We investigated the impact of livestock grazing on the threatened little bustard (Tetrax tetrax L.). The study was conducted at the NATURA 2000 Site/Important Bird Area of Cabrela, Portugal. Our main goals were to investigate responses of little bustard territorial males and breeding females to different livestock management practices, namely pasture types, stocking rates and sward structure. Bird distribution was surveyed using car and foot surveys. Data on grazing was supplied by land managers every 10 days from February to June through field interviews. Generalised additive models and model averaging were used to compute predictive models. Results indicate that higher probabilities of occurrence were found in long-term pastures and under light-moderate grazing conditions (stocking rates around 0.4 LU/ha). Conversely, lower probabilities of occurrence were found in ungrazed or heavy grazed fields. Males occurred mostly in large fields, but this variable seemed to be less important for females. On the other hand, green plant cover and the vegetation height were good predictors for the occurrence of females but not for males. Females used mostly pastures with vegetation height around 20–25 cm. Our results suggest that grazing management plans that aim to conserve little bustard populations should consider (1) the maintenance of the larger long-term pastures and (2) the use of light-moderate stocking rates (0.2–0.6 LU/ha).     

Behaviour and welfare of veal calves fed different amounts of solid feed supplemented to a milk replacer ration adjusted for similar growth

Veal calves in Europe are typically fed large quantities of milk replacer and small amounts of solid feed, a diet known to lead to the development of abnormal oral behaviours in these animals. These abnormal oral behaviours are thought to be an indication of frustration, chronic stress, and hence poor welfare. The present study investigated how different feeding strategies, differing in solid feed and milk replacer provision, affected the behaviour and welfare of veal calves across time. Four treatment groups (A–D) comprising of 12 Holstein–Friesian bull calves each (7.6 ± 0.1 weeks old and 54.7 ± 0.3 kg at arrival), penned in groups of three, were fed one of four amounts of a solid feed mixture, i.e. 50% concentrates, 25% fresh maize silage, and 25% wheat straw (on dry matter [DM] basis): A = 0, B = 9, C = 18, and D = 27 g DM/kg^0.75/d. Provision of milk replacer was adjusted to achieve similar average daily gain across treatments. Behaviour was recorded around feeding (10 min continuous focal observations of individual calves) and throughout the day (7 sessions of 30 min scan sampling at 5 min interval every 2 h from 06:30 h) every week for four months. In an attempt to find an easy practical method to measure behavioural response to feeding strategy, two 3-min behavioural tests were carried out: (1) in months 1 and 3, calves were presented with a ball and latency to make oral contact with it was recorded; and (2) in month 1, calves were presented with an overall and time spent orally manipulating (i.e. chewing or licking) it was recorded using scan sampling every 10 s. Calves in treatment D displayed less abnormal oral behaviours around feeding, less tongue playing throughout the day, and more chewing in the first two months, compared to treatment A. Treatment B only led to lower tongue playing levels compared to A and treatment C had no benefit in terms of reducing abnormal oral behaviours. Although a solid feed dose–response was expected on the display of abnormal behaviours in veal calves, treatment C did not fit within this expectation. These findings point to a more complex relationship between solid feed and abnormal oral behaviour frequency in veal calves. The two behavioural tests distinguished the different treatments as expected, and thus showed a solid feed dose–response. Because of an increase in chewing and ruminating efficiency over time, amounts of solid feed should be increased with age to maintain high levels of chewing and ruminating. Moreover, high levels of chewing and ruminating may have to be maintained long enough at the beginning of the fattening period to lead to a reduction in abnormal oral behaviours.     

A study on feeding ammoniated and processed barley to feedlot steers

A total of 120 commercial crossbred steer calves (284±1.9 kg) were allocated in a 2×2 arrangement to two barley processing methods; whole (W) or rolled (R) barley and two ammoniation treatments; ammoniated (A) or non-ammoniated (N) barley. Steers were randomly allocated to twelve pens with 10 steers per pen and 3 pens (replications) per diet. The study was divided into two stages, growing (0–84 day) and finishing (85–196 day). Average daily gain (ADG) for the overall 196 day period was affected by processing (p<0.01) averaging 1.10 and 1.20 kg day⁻¹ for steers on W and R barley, respectively. Steers on the R barley gained 19.6% more than those on W barley during the growing stage and 0.8% more during the finishing stage. There was a trend towards an improvement (p=0.06) in overall ADG by ammoniation. The ADG of steers was significantly higher (p<0.01) during the finishing (1.22 kg day⁻¹) than during the growing (1.06 kg day⁻¹) stage. Feed efficiency was better with R than with W barley (6.8 vs. 7.7; p=0.02). Processing and ammoniation had no effect (p>0.05) on carcass traits or grades.     

A brief report on effects of transfer from outdoor grazing to indoor tethering and back on urinary cortisol and behaviour in dairy cattle

The present study was performed to investigate the effects of transferring cattle (n = 7) from pasture to indoor confinement and their return to pasture on their physiological and behavioural responses. On the day after the cows were moved to indoor tethering, urinary cortisol increased approximately 3.4-fold in comparison with the levels before. The cortisol levels remained elevated for the first week, then declined, and the basal levels were maintained during the last 3 weeks. The urinary cortisol levels did not change after the cows were returned to pasture. The ratio of lying down while ruminating tended to decrease and remained low after the cattle were transferred from pasture to indoor tethering. This ratio recovered to pre-tethering levels after the cattle were returned to pasture. This study suggests that indoor tethering, in comparison with pasture grazing, is stressful for cattle.     

Effect of different level of roughage availability and contrast levels of concentrate supplementation on flavour of goat milk

Rancid and tart flavours are the most common off-flavours in Norwegian goat milk. In a feeding trial, we examined the effects of different levels of concentrate and of supplementary hay feeding on the occurrence of these off-flavours. Forty-eight experimental goats grazed cultivated pasture in the lowland during spring and autumn, and mountain pasture in summer. Twenty-four of the goats were fed 0.2 kg/day of concentrate (low concentrate, LC) and the remaining 24 goats 0.7 kg/day (high concentrate, HC). Twelve animals in LC and HC groups grazed freely, while the remaining goats in the two groups were given feeding challenges (limited periods of roughage restriction and ad libitum hay feeding). This was done to examine the effect of differing roughage availability on milk flavour. The animals fed low level of concentrate and with free grazing represented the control group. During the challenge periods, the goats were kept indoors and fed 0.2 kg hay/day for 2 days (roughage restriction) or hay according to appetite for 2 days (ad libitum feeding). At least 10 days of uninterrupted grazing were allowed between the challenges. Milk samples for sensory and chemical analysis were taken at the end of the challenge periods.The level of concentrate feeding did not influence the flavour of the milk when the goats were on lush spring pasture. However, the low level of concentrate feeding (LC) increased the frequency of off-flavour during the mountain and autumn experimental periods (P < 0.05).In the end of the mountain experimental period when the frequency of rancid/tart flavour increased in all groups, the sensory quality of milk produced by goats fed hay ad libitum (S1) had better taste ratings (P < 0.001) than milk from goats that were grazing. When the goats were given restricted amounts of hay, they adapted to the treatment by reducing their milk yield. In the spring and mountain experimental periods, restricted roughage feeding resulted in higher fat content and better taste ratings, especially in the group fed low level of concentrate (LC/S1). However, this connection was not clear in the autumn.Probably, the goats are able to handle a negative energy balance as long as mobilizable body reserves exist, but start to produce milk with lower dry matter content and higher frequencies of rancid/tart flavour when the body reserves are empty and the energy deficit is still pronounced.It is concluded that increasing the level of concentrate and feeding hay supplements will reduce the frequency of flavour defects at times when grazing is suboptimal or the pasture is of medium or low quality.     

The economic effects of an estrus synchronization protocol using prostaglandin in beef heifers

We estimated the effect of estrus synchronization on reproduction, production and economic outcomes in 272 beef heifers randomly allocated to a synchronized Test group or an unsynchronized Control group. The Test group received AI upon estrus detection for 6 days followed by PGF2 treatment of heifers that had not shown estrus by day 6 (PGF/6). In both groups AI was continued for 50 days, followed by a 42-day bull breeding period. Heifers were followed through their second breeding season and until they had weaned their first calves. Synchronization resulted in a reduction in median days to first insemination (8 vs. 11 in the Test and Control groups, respectively, P < 0.01) and median days to calving of calves born to AI (14 vs. 20, P = 0.04). There was no significant difference in pregnancy rate to the AI period (60.0% vs. 51.8%, P = 0.18), final pregnancy rate (82.2% vs. 83.2%, P = 0.87) or pregnancy rate to the subsequent breeding season (96.0% vs. 95.0%, P = 1.00). Although mean calf weaning mass was not significantly different (207.0 kg vs. 201.4 kg, P = 0.32), the total mass of calves weaned in this study was 14,843 kg vs. 13,060 kg and the benefit: cost ratio for synchronization was 2.8. It was therefore concluded that a PGF/6 protocol may affect the total mass of calves weaned by changing days to calving, weaning rate, the ratio of male: female calves born and/or the birth mass of calves.     

Effects of feeding system on carcass and non-carcass composition of Churra Tensina light lambs

Thirty-eight single male lambs (3.6 ± 0.08 kg live weight at birth) were used to study the influence of feeding system on carcass and non-carcass composition of Churra Tensina light lambs. Treatments: indoor (IND), lambs housed indoors consuming concentrate ad libitum until weaning at 53 days of age, and ewes grazing 8 h a day without their offspring and receiving a supplement of barley meal after grazing; grazing (GR), ewes and lambs grazed continuously without concentrate and lambs were unweaned. When lambs reached 22–24 kg live weight they were slaughtered. Carcass and non-carcass composition was recorded. GR lambs displayed higher carcass shrink (P < 0.05) and lower dressing percentage (P < 0.01) than concentrate-fed lambs. IND lambs had more body fat mainly due to the heavier kidney (P < 0.001) and subcutaneous (P < 0.001) fat depots. Total non-carcass weight was not affected by treatment (P > 0.05), but red organ (heart, lung and trachea, thymus, liver, spleen, kidney, diaphragm, pancreas, gall bladder, bladder, and testicles and penis), digestive tract (stomach, small intestine and large intestine) and head, skin, and feet (HSF) weights differed between treatments (P < 0.05). IND lambs had heavier red organs and HSF (P < 0.05) although this difference disappeared when expressed as a percentage of empty body weight. Small intestine weight in grazing lambs was heavier (P < 0.001) and, consequently, the total digestive tract differed similarly (P < 0.01). Treatment influenced the weights (P < 0.05) of all joints except leg (P > 0.05), showing heavier joints for IND carcasses. The feeding system had a greater effect on subcutaneous fat (P < 0.001) than on intermuscular fat (P < 0.05) in most of the standardized joints. IND carcasses produced a greater proportion of muscle/bone in all joints, except neck, whereas GR produced a greater proportion of muscle/total fat due to the lower amount of fat recorded in this treatment. The percentage of fatty acids was not affected by treatment (P > 0.05) although the percentage of C18:3 was greater and the ratio of C18:2/C18:3 was lower in grazing-fed lambs. The absence of any effect of treatment on the fatty acid percentages may be influenced by the short raising period and by the similar amount of intramuscular fat in both treatments. It is concluded that light lambs reared under grazing conditions can produce carcasses of acceptable quality, due to the lower percentage of subcutaneous fat, but with a similar intramuscular fat content.     

Improvement of biosustainability of a goat feeding system with key supplementation

A one-year study was conducted to measure the effects of balanced supplementation to improve biosustainability of a 110 head goat herd in Mexico in terms of economic feasibility on limited pasturing range land complemented with an alfalfa hay forage bank and grazing corn stubble. Average weight of adult females was 52.410±5 kg, yearlings 40.0±3 kg at first kidding. Average total lactation milk production was 455±21 kg in 210 days. Feeding strategy included balanced concentrate (BC) from December to May, gradually changing the supplementation when grazing started by offering a multinutritional block (MB) and complex catalytic granulate feed (CCF), which was used at the beginning of range pasture and continued, when goats were fed on corn stubble starting October. The initial BC was composed of corn, barley, wheat bran, soybean oil meal, but the latter was withdrawn from the mixture in May (3 Mcal ME and 12% CP; 10% from May on), offered twice a day. Animals on pasture from May until November were supplied ad libitum with MB prepared from molasses, urea, salt, cottonseed meal, limestone, cement kiln dust, corn stubble, and a mineral mixture, composed of triple superphosphate and a commercial mineral mix for ruminants and salt. Beginning in August, 200 g of CCF was added from a mixture of molasses, urea, salt, limestone, cottonseed meal, rice polishing, corn, poultry litter, commercial mineral salts, ammonium sulfate, cement kiln dust, and animal lard. Late pasture on corn stubble was from October to December. CCF was kept with the diet. Average voluntary feed intake (VFI) was 1.880 kg DM/d with an annual total of 828 kg; of which 248 kg DM was provided by alfalfa hay from a forage bank corresponding to 30% of the total feed intake; 182 kg or 22% of the diet was concentrate (BC, MB, CCF), and 398 kg or 48% was from range land (grasses, shrubs and tree leaves) or corn stubble pasturing. Balancing concentrate diminished the protein intake from 2.10 times requirements to 1.19. Changes in supplementation according to forage availability permitted nutritional optimization of the system. It was possible to improve biosustainability (forages produced on the farm) from 33% before to 48%, while increasing milk production from 400 to 455 kg/year and diminishing production cost from 20 to 17 US cents per liter of milk.     

The effect of inclusion of lupins/triticale whole crop silage in the diet of winter finishing beef cattle on their performance and meat quality at two levels of concentrates

This study investigated the performance and instrumental meat quality of finishing beef steers offered grass silage (GS), grass silage:maize silage (GS:MS) and grass silage:lupins/triticale silage (GS:LT). The lupins/triticale silage was grown as either two separate crops in the same field and harvested together (LT1) or grown and harvested as a mixture (LT2). The silages were offered to eighty continental cross beef steers, initial live weight 530 ± 47.7 kg and 18 ± 1.6 months of age and were supplemented with 3 or 6 kg concentrates fresh/head/d. Silage was fed ad libitum with the mixtures offered at a ratio of 60 GS:40 maize silage (MS), LT1 or LT2 on a dry matter (DM) basis and concentrates were offered once (3 kg) or twice (6 kg) daily on top of the silage. Animals were slaughtered in three batches after 100, 117 and 124 d on experiment. The LT1 and LT2 produced yields of 8.7 and 7.5 kg DM/ha and the silages were poorly fermented as demonstrated by high ammonia-N concentration (182 and 173 g/kg total N), low lactic acid (9 g/kg DM) and high pH (5.0 and 4.7). Silage type had no significant effect on slaughter live weight, liveweight gain, carcass gain, forage DM intake (DMI), total DMI or feed efficiency expressed as kg DMI/kg liveweight gain or kg DMI/kg carcass gain. Silage type had no effect on carcass characteristics or instrumental meat quality. The results of this study demonstrate that offering lupins/triticale silage in combination with high quality grass silage (D-value greater than 700) at a ratio of 60 grass silage:40 LT1 or LT2 on a DM basis had no effect on animal performance, carcass characteristics or meat quality parameters relative to high quality grass silage offered alone or in combination with maize silage.     

The significance of habitat continuity and current management on the compositional and functional diversity of grasslands in the uplands of Lower Saxony,Germany

There is a growing concern that land use intensification is having negative effects on semi-natural grasslands and that it leads to a general loss of biodiversity among all types of formerly extensively managed grasslands of poor to medium nutrient richness. Since the 1950s, many Central European uplands have been subject to an increase in grassland cover as a result of changes in land use practices. Using such a landscape in Lower Saxony, Germany, as a model region, we assessed environmental factors that control grassland diversity, including plant community composition, species richness and pollination trait composition. In 2007, 189 vegetation sampling sites were randomly distributed among grasslands covering some 394 ha within a 2500 ha study area. Plant communities were classified using TWINSPAN and the effects of environmental factors (soil, topography, current management and habitat continuity) were analysed by canonical correspondence analysis and regression analysis reducing for the effects of spatial autocorrelation by using principal coordinates of neighbour matrices.We found a wide range of six species-poor (<15 plant spp.) to extremely species-rich (>27 spp.) grassland types under mesic to dry site conditions, including sown, Cynosurion, Arrhenatherion and semi-natural grasslands. Grassland community composition was best explained by soil factors and species richness and pollination type composition by combined effects of current management and habitat continuity. During the 1950/60s, the extent of grassland area within the studied landscape rapidly increased to more than double its previous extent, and in 2007, grasslands comprised 16%. Natura 2000 grassland types comprised 1% of the surveyed site and medium-rich, high-nature-value grasslands a further 5%. While the number of wind-pollinated plant species was equal among all grassland types, there was a parallel decline in insect-pollinated plants and overall median species richness in the grassland communities along a gradient of increasing land use intensity (mowing, nutrient supply). Moreover, insect-pollinated plants occurring in intensively managed grasslands were found to additionally have the ability for self-pollination. Species-rich grasslands – including semi-natural grasslands and a semi-improved, species-rich Arrhenatherion community – occurred exclusively on old sites (with >100 years of habitat continuity) that had been used for traditional sheep grazing (environmental contracting). Medium-rich Arrhenatherion grasslands were established primarily on less productive, formerly arable fields (<30 years). We conclude that conservation efforts should focus on extant species-rich grassland types and should aim to implement traditional land use practices such as sheep grazing. Additional restoration efforts should focus on establishing new grasslands on less productive sites in the proximate surroundings of species-rich grasslands to facilitate seed dispersal, but nitrogen deposition should be buffered where appropriate. These measures would enhance the interaction between nature reserves and agricultural grasslands and thus improve the ecological quality of grasslands at the landscape scale.     

Influence of gradual adaptation of cattle to Leucaena leucocephala leaf meal on biodegradation of mimosine and 3- hydroxy-4(1H)-pyridone (3,4 DHP) in rumen,their levels in blood,fate and influence of absorbed DHP on thyroid hormones and liver enzymes

Three rumen fistulated Karan Fries crossbred (Holstein X Tharparkar) calves were fed increasing dry matter (DM) levels of 25%, 50%, 75% and 100% through leucaena leaf meal (LLM) starting at week 1, 2, 3 and 4, respectively. The mimosine, 3,4 DHP and 2,3 DHP levels were determined in strained rumen liquor (SRL) and serum at 0, 1, 2, 4, 8, 12 and 24 h postfeeding on days 1, 8, 15, 22, 29 and 42. LLM was incubated for 24 h with SRL in vitro on days 0, 7, 14, 21, 28 and 41 to study mimosine and dihydroxypyridone (DHP) biodegradation. On day 43, 1–1.5 l of rumen liquor was transferred to another set of three unadapted calves which were fed 50% LLM after transfer of inoculum. DM intake was 1.78%, 2.13%, 2.27%, 1.66%, 1.54% and 1.35% of live weight during the 1st through 5th week, respectively. Both in vitro and in vivo studies showed extensive degradation of mimosine to 3,4 DHP and 2,3 DHP from first day of LLM feeding. The overall in vitro DHP degradation was nil, 28.6%, 43.3% and 40.1% on day upto 15, 21, 28 and 42 of LLM feeding. No mimosine was found in serum on any day of sampling. The 3,4 DHP detected (56.94±31.65 μg ml⁻¹ serum) one hour post feeding on day 1 exhibited a decline from day 22 onwards. The serum also contained 2,3 DHP on days 8, 15, 22, 42. The faecal and urinary excretion of 3,4 DHP and 2,3 DHP as percent of mimosine intake declined from first week (76.3±2.8) to 4th week (42.1±4.1). The feeding of LLM resulted in reduced level of T₃ and T₄ within a week of LLM feeding. The level of T₃ improved to normal by 6th week while that of T₄ remained low. The SGOT and SGPT activities were within normal range. The gradual adaptation to LLM feeding caused Karan Fries calves to acquire DHP degrading ability to nontoxic compounds and this ability was transferred through transfer of rumen liquor from such calves to other unadapted calves at as early as 9th day of LLM feeding. The results revealed the possibility of two types of microbes degrading mimosine and 3,4 DHP to 2,3 DHP. One type of 2,3 DHP degrading microbes may be inhibited in the presence of 3,4 DHP whereas the other type may be active.