Prolactin (PRL) is a polypeptide hormones produced by cells of the anterior pituitary. The bovine PRL gene consists of 4 introns and 5 exons, located on chromosome 23. Different biological functions of PRL were subdivided into five broad categories: reproduction, osmoregulation, growth, integument, and synergism with steroids. Also, It has been shown to be important for control of mammary growth, lactogenesis and lactation (Skinkyte et al., 2005). Chung et al, (1996) showed that PRL-RsaI locus had a significant effect on milk fat percent in dairy cattle. Therefore the PRL gene was chosen as a candidate gene for milk traits in dairy cattle. The objective of this study was to evaluate the association of genetic differences in bovine PRL gene and milk fat content in Iranian Sarabi cows.

Silkworm hybrids are produced in efforts to improve the yield of silkworm rearing, whereas these genetic characteristics greatly differ among groups of hybrids (Raju and Krishnamurthy, 1995). So, the identification and evaluation of the performance of hybrids in different seasons are very important for silkworm breeding and sericulture. In this research, we evaluated the performance of 15 new silkworm hybrids, which evolved in the Iran Silkworm Research Center from pure lines in order to select the most-production hybrids for commercial application.

Environmental pollutants, like pesticides, have been destructive on different aspects of life. Silkworm, as a beneficial insect, is no exception to this matter. Due to this, many problems have appeared in sericulture because of pesticide applications to cultivations, especially when mulberry trees grow next to cultivated plants. Many studies that have focused on the effect of insecticides on B. mori deal with toxicity, retardation of development and growth, fecundity, mortality, food utilization and economic parameters (Vassarmidaki et al., 2000). However, between these studies a few documents focused on the effect of fungicide residue on silkworm growth and performances (Dutta et al., 2003). Sik et al (1976) reported that more than 1.4% of yield reduction in sericulture is due to side effect of pesticide application. 49.4% was due to the application of different pesticides in rice filed, 21.2% in fruit garden and 12.3% in olericulture. Therefore, the present investigation deals effects of long term application of systemic insecticide, Oxydemeton-methyl(metasystox R) on some biological performance of silkworm. Because metasystox has just recently used to against of mulberry thrips in sericulture and it is necessary to study different side effects of this insecticide on silkworm.

Several experiments have been conducted on the value of rapeseed meal (RSM) for dairy cows (Laarveld et al., 1976). The crude protein (CP) content of RSM is almost high (360-420 g kg-1 of DM) with a good amino acid balance. The in situ degradability of RSM was extensively studied (Kendall et al., 1991). The aim of the present study was to determine the chemical composition, in situ degradable coefficients, and ruminal and post-ruminal dry matter (DM) and CP disappearances of an Iranian variety of rapeseed meal (SLM sp.).

Pistachio hulls are pistachio processing by-products produced during de-hulling of pistachio nuts soon after harvesting. Total pistachio by-products in Iran have been increased at an average rate of about 300000 Tons per year. Chemical composition of Pistachio hulls contained 12%CP, 5%EE, 34% NDF, 21% ADF, and 9% ash (DM basis). The dry matter content of fresh Pistachio hulls is about 28%. Reducing the moisture content of this by-product with dryer systems is a cost effective process and can not be applied by most of the producers. Finding other alternative methods for preserving and using this by-product is highly required. The objective of the present study was to assess changes in Pistachio hulls silage (PHS) quality associated with the inclusion of different levels of urea (U) and molasses (M), and to compare in situ DM and protein degradability of PHS with dried pistachio hulls (DPH).

Whole soybean (SB) is used as a high energy-protein supplement for dairy cows, but the protein is highly degradable by rumen microbes. Various chemical and physical processing has been suggested to decrease ruminal protein degradability, that heat processing is the most commonly used physical method. Modern systems for protein evaluations in ruminants are moving in the direction of predicting absorption of amino acids from the small intestine, so the determination of intestinal digestibility of amino acids is of special importance particularly in heat-treated feedstuffs. The objective of this research was to elucidate the effects of roasting and steep-roasting on ruminal and post-ruminal disappearance of essential and non-essential amino acids (EAA and NEAA) of Iranian SB.

Dairy producers use soyhulls, a byproduct of soybean processing, to replace either grain or forage in diets of lactating dairy cows. In view of the nutritional and economical value of soyhulls it is anticipated that this practice will continue to increase in popularity among nutritionists and producers of ruminant animals. According to the NRC (2001), SH contain 60.3% NDF and 44.6% ADF on a DM basis. Also The CP content of SH averaged 11.8%, which is within the range of 13.9± 4.6%. The objectives of this paper are to evaluate the in vitro DM and OM digestibility and in situ degradability of DM, CP and NDF contents of soybean hulls.

Available information on the effect of ruminal pH on degradation of crude protein of various feeds is scarce. It has been reported that in a high concentrate diets, protein degradation is usually reduced (Molero et al., 2004). This reduction has been attributed to lower ruminal pH, which causes the changes in protein solubility (Loerch et al., 1983) and reduces fibrolytic activity of rumen microflora. There is also limited information concerning the requirements for rumen degradable N (RDN) when high-grain diets are given to steers, and most of that information has been obtained using urea as the source of RDN. The aim of the present experiment was to evaluate the effect of different concentrate to lucerne hay ratios (60:40, 70:30, 80:20 or 90:10) on ruminal crude protein degradation kinetic of lucerne hay, barley grain, soybean meal and fish meal.

Safflower meal proteins are extensively degraded in the rumen. Attempts to decrease the degradability of feedstuffs proteins have involved treatment with heat, formaldehyde, tannic acid, acetic acid, xylose, and microwave (Sadeghi et al., 2006). To our knowledge, no information is available concerning effects of gamma irradiation on ruminal protein degradation and type of safflower meal proteins that leave the rumen undegraded. The objectives of this study were to investigate effects of gamma irradiation on ruminal degradability and intestinal digestibility of safflower meal crude protein, and to monitor fate of true proteins of safflower meal in the rumen by using SDS-PAGE methodology.

The use of by-product in animal nutrition is necessary since it may increase the availability of feed for animal and avoid accumulation that contributes to environmental problems. Sunflower meal is a source of supplemental protein for livestock feeding. The amount of hull or fibre in sunflower meal is the major source of variation in nutrient content of this feed. Methionin concentration in sunflower meal is high compared with other protein sources such as cottonseed meal. Sunflower meal without hulls has high degradability than sunflower meal with hull. This study was conducted to evaluate the chemical composition and in situ dry matter (DM)and crude protein (CP) degradability of three different sources of sunflower meal (high, medium and low fat).

Soybean meal (SBM) is commonly used as protein supplement in the ration of high producing dairy cattle. It has a good palatability and acceptable amino acid balance. However, SBM has relatively low protein efficiency because of the extensive ruminal degradation. Recently, tannins have become a matter of interest in ruminant nutrition because of their potentially beneficial effects on decreasing the ruminal degradation of dietary protein (Barry and McNab, 1999). Several methods (in vivo, in vitro, in situ and solubility methods) have been proposed to characterize the dietary protein. Cornell Net Carbohydrate and Protein System (CNCPS) have a submodel in which crude protein is partitioned into five fractions with different degradation rates. Hence, the objective of this study was to determine the protein fractions of soybean meal treated with tannin in grape pomace.

Welfare is often defined as the state of an individual to cope with the environment in which it finds itself (Fraser and Broom, 1997). This statement is further endorsed by the assertion that stress is triggered by environmental stimuli that cause a defence reaction or ‘stress response’ (Mostl and Palme, 2002). Stress can be measured by alterations in behaviour and through changes in physiological parameters. In a recent report, the Farm Animal Welfare Committee (2005) postulated that elevated levels of stress in semi feral ponies at auction maybe apparent in those ponies herded through auction sale rings by handlers displaying limited competence and knowledge of equine husbandry. Aversive handling and the consequent fear that animals feel towards humans can be a major source of stress and should be considered a welfare concern (Rushen et al., 1999). Research into aversive handling has a propensity to be more focused on intensively farmed production animals. However, it is apparent that the fast movement of pony stock through sale rings, and the often aggressive manner in which this can be carried out, may not be considered optimal for the welfare of these ponies. The aim of this study was to investigate the effects of prior handling experience on the stress response of semi feral foals at auction.

Stereotypic behaviour is generally attributed to a dysfunction of the basal ganglia, although confusion exists as to whether altered function stems from the dorsal (Caudatus and putamen) or ventral regions (nucleus accumbens). In rodents, imbalanced basal ganglia opioid physiology leads to enhanced efferent neural transmission from only the dorsal striatum to cortex. However, in horses performing oral stereotypy (crib-biting), neural alterations in dopamine receptor density have been recorded in both dorsal and ventral striatal regions (McBride and Hemmings, 2005) suggesting that both projections may be altered in the stereotypy phenotype. Indeed, if stereotypies are considered to stem from highly motivated appetitive behaviours, it seems probable that ventral elements of the basal ganglia ‘reward’ circuitry should also be involved If this is the case, then stereotypy performance has potentially rewarding consequences and could thus be employed as a coping strategy. To further address the issue of dorsal versus ventral striatum involvement in the equine oral stereotypy phenotype, comparisons of opioid receptor physiology between crib-biters and control horses were performed.

Studs are attached to horse shoes as anti slip devices for many performance horses (Dyson, 2000), with the aim of reducing the distance the hoof slides between impact and coming to rest. These anti slip devices are needed to prevent injury to the horse caused by over stretching of the joints and soft tissues during the slip or by loss of balance. Despite the practical benefits perceived by horse riders, it has been suggested that studs may have detrimental effects on the horse’s kinematics and musculoskeletal system, possibly increasing jarring (Wilson et al., 2001). The aim of this study was to measure the effects studs have on trot kinematics.

Respiratory disease poses a significant threat to the health and athletic performance of both horses and riders, necessitating the reduction of potential pollutants within equine environments (Deaton and Marlin, 2004). Enhanced management protocols for minimising respiratory irritants within equine housing have been developed, however knowledge of such pollutants in exercise areas remains ambiguous. The aim of this project was to investigate total dust levels and airborne surface dust dynamics during riding sessions on two different widely used arena surfaces.

Many domestic horses are kept in an environment very different from that of free-living horses, consuming a varied ad libitum forage based diet for up to 18 hours of the day (Harris, 1999). Cuddeford (1999) suggested that stabled horses may spend as little as 7 hours eating in a 24 hour period, with an increase in the time spent standing. Encouraging foraging behaviour, defined by Goodwin et al., (2002) to include sniffing, manipulating, biting, chewing or ingesting food, is thought to allow domesticated horses to spend more time eating, approaching the time spent on this activity in free-living horses. The diet of the free-living horse includes a selection of grasses and herbs (Putman et al., 1987) whereas most domestic horses are provided with a single forage diet (Goodwin et al., 2002). In a short term trial Goodwin et al., (2002) found that offering more than one source of forage to stabled horses resulted in them spending significantly more time foraging compared to a horse on a single forage diet. This effect was found to continue for longer periods by Thorne et al., (2005), however there appears to be no current literature on how many forages to feed within a multiple forage diet. The present study aimed to establish how many different forages to include in a multiple forage diet to maximise the time spent in foraging behaviour and minimise standing behaviour.

The production of young sport horses for British Eventing (BE) competition requires huge investment in terms of time, money and effort. To ensure that such resources are not wasted, it is necessary to select the individuals that display the most talent and potential for an illustrious competitive career. In order to facilitate such selection, the BE Breeding Championships were introduced in 2003. Sponsored by feed manufacturers PAVO, the series is formed by a number of national qualifiers run within a selection of BE one-day events each year. Successful horses qualify for the championship final at the end of the eventing season. The objective of the series is to provide a showcase of the most talented young event horses in the UK for breeders, owners, riders and prospective buyers. The aim of the study was to establish whether 4, 5 and 6 year old horses that qualified for the 2004 PAVO BE Breeding Championship final performed better in BE competition during the following year of competition compared to horses of the same age that did not qualify for the final.

The equine placenta being epitheliochorial, is a barrier to immunoglobulins, which means that the foal is unable to receive passive immunity (Davies Morel, 2003) other than a small quantity of IgM which is synthesised in utero. McClure (as cited in McKinnon and Voss, 1993) suggests that the most significant component of passive immunity passed to foals, is that obtained from colostral immunoglobulins. When the foal ingests the colostrum and absorbs the antibodies therein, a temporary protection is provided until autogenous production of immunoglobulins reaches protective levels (McClure as cited in McKinnon and Voss, 1993). It is highly important that the foal receives colostrum within the first 24 hours and preferably within the first 12 hours of life (Davies Morel, 2003). This enables immunoglobulins to be absorbed by enterocyte cells lining the small intestine which are controlled by cortisol, and over time are replaced by ones which are unable to absorb proteins. For foals where colostrum is not readily available (for example, if the foal is orphaned at birth), then stored colostrum could be used. However, it is postulated that IgG integrity could be compromised by freezing, and consequently, thawing of the colostrum. The aim of this experiment is to evaluate five thawing methods for their ability to preserve IgG content of stored colostrum.

Ca bioavailability has been of considerable interest. NRC (1989) expressed Ca requirement as total Ca but assumed an absorptive efficiency of 0.50. To improve the understanding of calcium absorption and excretion in horses, the present study analysed the quantitative calcium metabolism in animals fed different levels of calcium.

Laminitis is often recognised as one of the most common causes of lameness in horses. This painful condition has obvious far-reaching implications for the welfare of affected animals, yet, despite the prevalence and seriousness of laminitis, the exact aetiology of the disease has still to be unanimously identified. It is generally accepted that acidosis within the hind gut of the horse is a predisposing factor to the onset of laminitis (Bailey et al., 2003). Fast digestive transit times and low production rates of α-amylase, result in the horse being relatively inefficient at the breakdown of starch within the small intestine. Rapid fermentation of cereal starch in the caecum and dorsal colon will ultimately yield lactic acid and can culminate in changes to the caecal bacterial populations (Bailey et al, 2003). Rising lactic acid levels, coupled with a drop in pH will result in the development of acidosis. It is believed that a window of opportunity exists between the occurrence of acidosis and the development of the symptoms associated with laminitis (Al Jassim, 2005) in which changes to diet could be made, thus preventing the eventual onset of the disease. It has been established that faecal pH is intrinsically linked to caecal pH, and studies reporting diet-induced pH changes in both horses (McLean et al., 2000) and pigs (Cahn et al., 1998), have shown close correlation between faecal and caecal pH. It is therefore postulated that faecal pH may be an indication of acidotic conditions within the hindgut of the horse and a faecal test to indicate acidotic status would obviously be of benefit. The aim of this study was to investigate optimal collection times of faecal samples destined for pH analysis, and to establish whether time of feeding significantly altered faecal pH, thus enabling further work to be carried out on the development of a faecal test for acidosis.