Factors influencing placental and fetal development in the mare: important considerations for the selection of embryo recipients

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.

The use of alkanes as markers for estimating diet composition in sheep and goats

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.

Effect of method of conservation on the n-alkane C31 concentration of two legumes and three temperate grasses

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.

Diet determination of cattle grazing in the Sanyati communal areas in Zimbabwe

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.

The relationship between facial whorl direction and sidedness in ridden horses

The influence of Natural Selection on the evolution of the horse (Equus callabus) is minimal due to its close association with humans. Instead Artificial Selection is commonly imposed through selection for features such as a ‘breed standard’ or competitive ability. It has long been considered to be useful if indicators of characteristics such as physical ability could be identified. Kidd (1902) suggested that the hair coverings of animals were closely related to their lifestyle, whether they were active or passive. In 1973 Smith and Gong concluded that hair whorl (trichloglyph) pattern and human behaviour is linked since hair patterning is determined at the same time as the brain develops in the foetus. More recently Grandin et al. (1995), Randle (1998) and Lanier et al. (2001) linked features of facial hair whorls to behaviour and production in cattle. Hair whorl features have also been related to temperament in equines (Randle et al., 2003).

Positive and negative trends in biometrical changes among Arabian horses bred in Poland

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 use of branding within the equine related charity sector and the implications of brand orientation

The Charity Commission website lists in excess of 100 equine charities (Charity Commission, 2003) and this figure does not include those whose annual income is under £1,000. The size and nature of equine related charities varies enormously. In 2002 the top 6 equine charities (listed below) had a combined income of £40m and were responsible for rescuing approximately 600 horses, ponies and donkeys (Peplow, 2003).Blue CrossInternational League for the Protection of HorsesHome of Rest for HorsesThe Donkey SanctuaryRedwingsHorse and Pony Protection AssociationWhilst these larger charities have grown organically over the years, many smaller charities are failing to survive and are in some situations having to be ‘rescued’ themselves by their larger counterparts. The public, consisting of present and potential donors, are offered a vast choice of charities to support. Philanthropic behaviour has at best stagnated in recent years (Sargeant & Lee, 2002).