In mammals the placenta is the vehicle for nutritional and gaseous exchange between the maternal and fetal circulations during pregnancy. The allantochorionic placenta of equids is classified as non–deciduate, non–invasive, epitheliochorial and diffuse and, as such, equine placentation demands fetomaternal interdigitation over the entire endometrial surface to optimise fetal development in utero. Any shortcomings are reflected by slower growth and delayed maturation of the fetus.This requirement for an unabbreviated area of placental attachment is emphasised by the inability of mares to carry twin conceptuses to term due to simple competition between the two placentae for the limited area of endometrium which results in progressive starvation of one or both fetuses (Jeffcott and Whitwell, 1973). In addition, age–related chronic degenerative changes in the mare's endometrium (endometrosis) may compromise the uterine environment during pregnancy and Bracher et al. (1996) showed a close relationship between the health of the endometrium, the normality of structure and the density of the microcotyledons on the surface of the allantochorion, and fetal weight.
SummarySugar cane and maize silage samples were evaluated by the semi automated in vitro gas production technique. The associations between gas production and dry matter degradation (DMD) were analysed and high coefficients of determination were obtained for all the substrates. The results showed that particles losses could be influencing the DMD, including errors mostly when obtained before 6 hours of incubation. The gas alone could better predict the lag phase than the DMD before 6 hours of incubation.
SummaryThe objective of this study was to compare five methods of forage preservation (ice, dry ice, liquid-N, drying in newspaper, and sundried) on the concentration of the n-alkane C31 in Medicago sativa cv Puebla 76 (lucerne/alfalfa), Trifolium repens latum (white clover), Lolium perenne (perennial ryegrass), Pennisetum clandestinum (kikuyu grass) and Dactylis glomerata (orchardgrass/cocksfoot). The sampled forages in ice and dry ice were kept in hermetically sealed plastic bags in a plastic cooler. The deep frozen samples were put into small plastic bags and submerged in liquid-N. The samples dried in newspaper were placed between sheets of newspaper, and put into hermetically sealed plastic bags. All these samples were taken to the laboratory and freeze-dried approximately 24 h later. The sun-dried samples were taken to the laboratory in newspaper and sun-dried for 48 h. The forage samples were ground and worked on in triplicate, extracted by the Soxhlet method (C34 n-alkane was used as standard and n-heptane as solvent), saponified, separated, purified and injected into a gas chromatograph. The data were analysed for variance as a randomised factorial (n=74). The comparison between means was by the Boneferroni test (P<0.05). The interaction between forage and method of conservation was significant P<0.0001). There were no differences between methods of conservation for white clover (mean 26mg C31/kg DM) or orchardgrass/cocksfoot (mean 31 mgC31/ kgDM). In comparison with liquid-N, (261 mgC31/kgDM), the other methods reduced the concentration of n-alkane in kikuyu grass by 27-35%. Sun and newspaper dried samples increased the concentration of C31 in alfalfa/lucerne by 6 and 15% respectively in comparison with freezing with liquid-N (291 mgC31/kgDM), while that frozen on ice reduced C31 by about 8%. This method, however, increased the ryegrass n-alkane by 12% in relation to liquid-N (169 mgC31/kgDM), but sun drying reduced it by about 40%. It is concluded that drying in liquid-N is the most reliable method for the conservation of samples for n-alkane analysis.
SummaryAn in vitro gas production technique was used to evaluate a fat protection method (Ca-soap). The Ca-soaps were prepared by incorporation of oil into a slaked lime solution which had been prepared immediately before. The proportions employed were 10:1 (oil:slaked lime). A feed sample of 0.5g was incubated in a N-rich medium, using 6 ml ruminal liquor and 54 ml medium. A factorial design 2x3 (2 inoculum sources from cows fed with and without Ca-soap x 3 diets) was employed. Diets were A) Control: 70% grass (Pennisetum purpureum var. Taiwan), 30% sorghum grain; B) Soybean lecithin: 70% grass, 20% sorghum, 10% Lecithin; and, C) Ca-soap: 70% grass, 20% sorghum 10% Ca-soap (made from lecithin). Total gas production, DM and OM in vitro digestibility were measured. A 10% reduction (approximately) (P<0.05) on IVDMD and IVOMD with the oil diet was found, but no differences were found (P>0.05) between Control and Ca-soap diets. No effect was found due to inoculum source (P>0.05). Compared with the Control diet, the total gas production was reduced (P<0.05) in the oil diet and was intermediate in Ca-soap diet (P>0.05). It was concluded that Ca-soap diets are a source of rumen inert fat for both the in vitro incubation and the animals fed with this supplement. Ca-soap had no effect on IVDMD and IVOMD. In vitro gas production techniques can be useful tools to evaluate dietary fats at ruminal level.
SummaryTo test the applicability of faecal NIRS to real conditions, an experimental approach was undertaken across several representative dairy farms (N = 30) located ‘La Réunion’ island. From an ongoing survey, this approach consists to characterize the nutritional value of all feeds (grazed fresh forage, hay, silages and supplementary feeds) offered to the lactating herds, and to predict ingested diet from faecal NIRS models previously developed on a large experimental sheep faeces reference data-base.The methodological objective was to evaluate if such a spectral database could be a useful reference to estimate dairy cow total dry matter intake and diet quality, and so predict the grazed grass intake with reasonable accuracy. According to preliminary results, the NIRS estimated total intake varied between 13.7 and 19 kg DM/day and in vivo organic matter digestibility ranged from 51.7 to 74.8 % with an averaged value of 66 %. The estimated grass intake varied between 0 to nearly 10 kg DM/d. On a spectral basis, dairy cows faeces were quite different from the sheep faeces reference database, with an averaged standardised distance (H) upper of 3.0 (H = 9.1; Hmin = 2.08 – Hmax = 19.22) but predicted intake appeared valid. Indeed, according to the feeding value of diets and lactating cow requirements, the NIRS predicted total intakes were well correlated to the level of milk production. Moreover, for four particular situations, the fresh grass was cut, distributed at the trough and total intake really measured. The correlation between predicted and measured values was high with R2 = 0.94 and standard error of regression = 0.469 kg DM/d. These initial results appear quite encouraging, although the methodology is still exploratory and needs to be validated across a larger set of data. As a low cost and rapid prediction technique, NIRS appears to be a potential methodology that could find many useful developments in the improvement of the knowledge of forage use in tropical conditions.
Summary The microbial fermentation of the tropical leguminous browses Acacia cornigera (ACA), Albisia lebbekoides (ALB), Enterolobium cyclocarpum (ENT) and Leucaena leucocephala (LEU) was estimated in vitro as the final production of gas. ACA gave the greatest final (asymptotic) gas volume (D; 179 ml/g DM) and fractional rate constant (0.070). Although ENT showed the greatest rate constant (0.87), reaching half its maximum gas production in 7.8 h, it produced less gas than ACA by 9 h incubation, and did not differ from LEU by 24 h ALB gave the lowest gas production. In another trial the negative effect of tannins was estimated over 48 h as ameliorated by the addition of PEG. The effect was variable between species, the greatest being with ALB (Restriction of 0.60-0.68 of the potential gas volume due to the presence of tannins) and increasing slowly, reaching its’ maximum at 12 or 24 h with ACA (0.33) or LEU (0.16). There was no response to the addition of PEG with ENT indicating that other secondary compounds distinct from the condensed tannins were affecting microbial utilisation.
SummaryThe in vitro gas production technique was used to observe the fermentation characteristics of three feedstuffs (barley, dried alfalfa meal, and dried beet pulp). Inocculum was provided from the caecal contents of suckling rabbits (23, 26, 31 and 35d old) which had access to their dams’ food. Mean OM degradation increased progressively with the age of the rabbits (P<0.01) from 67.4 to 70.8% with inocculum from 23 and 35d kits, and gas production from 302 to 357 ml/g OM incubated (P<0.01). It was confirmed that the in vitro gas production technique is a valid tool for the study the development of caecal microbial activity in rabbits.
SummaryAn experiment was carried out to evaluate the use of alkanes for estimating diet composition of goats and sheep offered three different dietary treatments. Twelve animals as two groups of 4 crossbred goats (G1, 24 kg live weight; G2, 22 kg) and 4 crossbred sheep (S, 26 kg live weight), were housed in metabolism pens. Animals were offered daily a total of 1 kg DM/100 kg live weight. G1 received 70% ryegrass (Lolium perenne) and 30% gorse (Ulex gallii), G2 received 70% ryegrass and 30% heather (Erica sp.) and S group ate 100% ryegrass. Diet composition was estimated from the alkane concentrations (using all alkanes from C23 to C36 or only odd-chain alkanes C27, C29, C31 and C33) in diet and faeces (with or without correction for incomplete faecal recoveries) using least-squares procedures.Dietary treatment and animal species significantly affected alkane faecal recoveries, except for C24 and C36. When applying the faecal recovery corrections, there were no significant differences between measured proportions of dietary components and those estimated using all alkanes or odd-chain alkanes. In contrast, the proportions calculated without faecal recovery correction differed significantly (P<0.05) from the actual proportions and over-estimated the amount in the diet of those plant components with higher concentrations of long-chain alkanes (Erica sp. and Lolium perenne). The results indicate that alkanes are useful markers to estimate diet composition, however, it was observed that animal species and diet composition influenced the faecal recovery of alkanes. This suggests that the use of the alkane methodology for estimating the diet selection of grazing animals should be preceded by a calculation of the actual alkane faecal recoveries for each experimental condition.
SummaryThe in situ technique (NB) was compared to the in vitro gas production technique (Gas) in terms of ability to estimate the dry matter degradation (DMD) using high soluble substrates (maize grains) and low soluble substrates (four tropical forages). The experiments (in situ and in vitro) were carried out at the same time using the same cow for both techniques and DMD was estimated at 6, 12, 24, 48 & 96 h. The results showed that DMD from Gas were lower than NB DMD and the correlation for the maize group were lower than those of the grass group which indicated that Gas technique, closed system, has potential to analyse highly soluble substrates, probably, overcoming the particle losses effect demonstrated by the in situ technique.
SummaryThe three most important factors describing the nutritive value of ruminant feeds are: feed intake, rumen fermentation, and enzymatic digestion. Animal experiments are usually expensive and time-consuming, so many in vitro techniques have been developed which are supposed to assist in the prediction of nutritive value, usually of rumen fermentation. One of these is the measurement of gas production from the substrate when incubated with a specific inoculum. The cumulative gas production technique measures gas at regular intervals in time, as an indicator of the kinetics of fermentation. The resultant cumulative gas profiles, fitted to specific equations, and in combination with other end-products (i.e. VFA and NH3) can indicate both the rate and extent of fermentability of the test substrates. This information can be used to compare substrates with each other. However, the fact that the technique has not yet been standardized, and that inoculum varies according to time and place, means that comparison both between runs and locations, can be very difficult. Also, there are a number of aspects of the technique which will always mean that its resemblance to the in vivo situation must be limited. Some of these limitations and other important considerations of the technique are described in this review.
Summary The objective was to highlight the role of supplementary feeding on resilience and resistance of browsing small ruminants against natural gastrointestinal nematode (GIN) infections. GIN infections have a negative impact on productivity of browsing Criollo kids especially during the wet season of Yucátan. Epidemiological studies have demonstrated the threat of GIN infectivity in the native vegetation available for browsing goats. Control of GIN in browsing ruminants is threatened by the emergence of anthelmintic resistant nematodes strains in the local flocks. Browsing trials with kids and lambs have shown that supplementary feeding (100–108g/day) improved resilience and resistance of Criollo kids against GIN. Supplements used successfully include sorghum:soybean meal (74:26 respectively), maize:soybean meal (74:26) and maize only (108g/day). The later result showed that animals might benefit from supplementation with rumen fermentable energy that could improve utilization of available browsing legumes by the goats. Wet season trials showed that, in spite of supplementation, infected animals have lower productivity compared to non-infected animals. However, the combined use of supplementation and copper oxide wire particles or tactic anthelmintic treatment, can improve growth rate of infected kids to maximum production levels. Short-term supplementation strategies have shown to be less effective than long-term strategies in achieving better resilience against GIN in kids. Lambs are more resistant but less resilient against GIN infections than kids. Improved resistance of lambs seemed to require more nutrients than in goats. In conclusion, supplementary feeding can play an important role in improving both resilience and resistance of growing small ruminants in the tropics but it can be further improved through the complementary use of other strategies leading to a more sustainable integrated parasite control strategy.
SummaryThe experiment was carried out in the east of Yucatán, in pastures ofB. brizantha. It was of three months duration during the end of the rainy season. Four rumen cannulated cows with an average weight of 442 kg were used at all of three stocking rates: Low (2LU/ha), Medium (4LU/ha) and High (6LU/ha), to evaluate the effect of an empty rumen on the rate of biting, which was measured as the time taken to take 20 uninterrupted bites on ten occasions. The measurements were made on two sequential days at 09.00 h, the first under normal conditions, the second with an empty rumen. There was no effect (P<0.050 of rumen emptying on the rate of biting which was 24 bites per minute when the animals were normal, and 25 bites a minute when the rumen was empty. On the other hand, there was a reduction of 8% in the rate of biting for the animals at the high stocking rate compared with the low and medium stocking rates. The finding that bite rate was not affected by an empty the rumen is evidence which gives confidence in the use of cannulated animals as collectors of representative samples of forage under grazing conditions.
SummaryExisting feed evaluation systems for ruminants assess the feed value in a rather empirical way, with a limited ability to integrate metabolism in a meaningful framework. For the quantitative description of the mechanisms, appropriate biological data can be obtained using in vitro methods. The aim of this paper is to examine the use of modelling and in vitro data to predict digestion processes in vivo. Suitable mathematical methods are required to describe and interpret substrate disappearance profiles or gas production profiles. The derivation of such models is important since this allows a clear definition of the underlying assumptions made. Such assumptions are related to the change in fractional rate of degradation (kd) during incubation that will determine the shape of the profile. Furthermore, the value of the fractional passage rate (kp) is of crucial importance in the prediction of extent of degradation in the rumen. The development and application of models, based on classic microbial growth equations, clearly shows that observed variation in microbial efficiency in batch cultures (including the gas production technique) is not necessarily related to that in vivo. Rather, kp is again a major factor contributing to explanation of variation in microbial efficiency. Similarly, the end products of fermentation (VFA) and the VFA molar proportions can be estimated in vitro, but its direct applicability to the in vivo situation is limited. It is concluded that some potential uses of in vitro techniques are ultimately misleading. Mechanistic models indicate that mechanisms governing microbial efficiency and VFA molar proportions in vitro are not necessarily valid for the in vivo situation. Therefore, the in vitro data cannot be used directly for a uniform system of feed evaluation to predict animal responses. Rather, the in vitro data obtained for substrate degradation may be used in whole rumen models as a basal input value to indicate the degradation potential.
SummaryThe diet of cattle grazing in the Sanyati communal area, Zimbabwe was determined using plant particle identification from faeces from intact animals, and faeces and oesophageal extrusa from fistulated animals. A total of 130 plant genus, species and types were identified. The twenty most frequently occurring species in the samples comprised between 76 and 90% of the identifiable diet. The most frequent grass species were more than half of the identified diet in the dry season while they were half or less of the identified diet in the wet season. There were more plant species identified in the wet season than in the dry season. Significant differences were found when comparing the plant species identified in faeces to those in oesophageal extrusa from fistulated animals. This may be due to incomplete recovery of ingesta in the bags, or to the loss of identifiable particles in the faeces when compared to oesophageal extrusa because of digestibility. More research is needed to validate the use of oesophageal extrusa for diet botanical determination.
SummaryIn this paper the diversity of the Leguminosae family in the Yucatán Peninsula is presented, explaining it by subfamilies, genus and species and in each of the three states of the Peninsula, as well as the distribution of the family in the different vegetation types and associations and in the secondary vegetation derived from both of them. The forage species that can be used combined with graminae to feed cattle like goats and sheep are also presented.
Physical treatments have been found to be effective in treating musculoskeletal problems in the human field (UK BEAM trial, 2004). Osteopathy is one such beneficial treatment, (Williams, Wilkinson, Russell , Edwards, Linck, Hibbs, 2003) which has been applied to musculoskeletal dysfunction in horses. (Colles, Pusey, 2003).Osteopathy as a medical philosophy was developed in the 1880s by Andrew Taylor Still, a doctor from the American mid–west. Dr Still was disillusioned with medical practice at that time when treatments such as bleeding, purgatives and emetics were common practice. Instead, his anatomical studies led him to envisage a system of the healing art, which placed chief emphasis on the structural integrity of the body as being most important in the well being of the organism. In other words, if the structure is normal, then the body can function at optimum levels (Still, 1902). This still forms the basis of the osteopathic philosophy, though the ground breaking new discoveries over the succeeding 125 years have brought a deeper understanding of the mechanisms underpinning this form of treatment (Kuchera, Kuchera, 1992).
Most mature horses and ponies in the UK are given restricted amounts of concentrate and forage diets in order to avoid excessive nutrient intake and obesity, usually in a number of small meals per day. One practical question often asked by horse owners relates to the timing of concentrate feeding relative to the timing of forage provision. The objective of this study was to examine the effects of feeding concentrate meals either before, with or after forage when either oat straw or grass haylage was offered as the basal forage. Actual dry matter intakes and diet digestibility values from this study have been published previously (Hyslop, 2004). This summary details the effects of offering concentrates either 2 hours before, along with or 2 hours after forage provision on digesta passage rates and mean retention times in mature ponies.6 mature Welsh-cross pony geldings (mean LW 298 kg: s.e. 16.2) were individually housed and used in an eight treatment, 6 x 4 partially balanced incomplete block design experiment consisting of four 21 day periods.
As a result of long-term work by Polish breeders the special type called ‘Polish type’ of Arabian horses has been created. Polish Arabians differ from their ancestors who were bred by Bedouins in the deserts of Arabia. The main differences are slightly more height, better stature and correct conformation. The process of Arabian improvement is on going and must be adapted to modern trends and conditions which is reflected in changes of biometric parameters (Budzynski et al., 1976). Height at withers HW (cm), girth circumference GC (cm) and cannon bone circumference CC (cm) are basic measurements that make it possible to compare horses born at different times and in different studs. The objective of this study was to evaluate the changes in biometric parameters of Arabian horses bred in Poland after the World War II until now.This study used data concerning basic measurements (HW, GC and CC) of 1218 Arabian horses (1076 mares and 142 stallions measured at 5 years of life) used in Polish state breeding after the World War II.
The term laminitis literally means ‘inflammation of the laminae’ and is a potentially crippling disease of the equine foot. The laminae are interlocking projections which connect the hoof wall to the pedal bone within the foot, effectively suspending the weight of the animal within the hoof capsule. During a laminitic attack, the laminae become damaged to varying degrees, and their ability to connect the pedal bone to the hoof wall may be compromised; the degree to which this occurs depending upon the severity of the attack. In severe cases, the bond between hoof wall and pedal bone may be so weakened, that the pedal bone rotates downwards and may penetrate the sole of the foot. Some animals respond well to treatment, other less so and a proportion require euthanasia. Once horses have had a laminitic attack, even if successfully treated, they are likely to suffer from reoccurrence of the disease.
It is crucial to emphasise the importance of a sound scientific underpinning in the tackling of equine problems and regulation of those who treat equines. It is becoming increasingly common for two types of ‘practitioner’ to be consulted by owners of horses experiencing some kind of behavioural problem, namely Horse Whisperers (HWs) and Horse Behaviour Advisors (HBAs).Throughout this paper HWs are considered to be those who can ‘communicate with an equine, in a para–normal, gifted manner’, whilst HBAs are considered to be those who ‘advise on horse behaviour, especially problem behaviour’. The commonly used term ‘Horse Behaviourist’ has deliberately not been used as it is technically incorrect. Anyone with a rudimentary knowledge of psychology and learning theory will know that behaviourists are proponents of ‘behaviourism’ – a particular way of explaining learning. It is not a generic term referring to the study of animal behaviour – that is ‘ethology’. Worryingly today the term ‘ethology’ is being employed as a marketing tool.
