Litters Research Articles

Yield and Nutrition of Moth Bean-Mustard Rotation in Soils Amended with Tree Leaf Litters in the Arid Region of Rajasthan

Background: The incorporation of leaf litters in agroforestry systems can meet a significant share of nutrients demand and improve crop yield. The Citrus aurontifolia, Aegle marmelos and Cordia myxa (among fruit trees) and Colophospermum mopane, Acacia senegal, Acacia tortilis, Dalbergia sissoo (among trees) are well-adapted species to the arid environment. Unfortunately, little work has been done in the past to study the influence of leaf litters of these species on yield and nutrition of crops grown in arid region. Therefore, the present experiment was planned to study the influence of leaf litters of Colophospermum mopane, Acacia senegal, Acacia tortilis, Dalbergia sissoo, Citrus aurontifolia, Aegle marmelos and Cordia myxa on yield and uptake of nutrients in moth bean and Indian mustard in arid region. Methods: Field experiment was conducted at ICAR-Central Arid Zone Research Institute, Regional Research Station, Bikaner in moth bean-mustard rotation during 2010-11 and 2011-12 by incorporating leaf litters of seven tree species i.e. Mopane (Colophospermum mopane), Gum acacia (Acacia Senegal), Umbrella tree (Acacia tortilis), Indian rosewood (Dalbergia sissoo), Sour lime (Citrus aurantifolia), Assyrian plum (Cordia myxa) and Bengal quince (Aegle marmelos) in randomized block design with three replications. Grain and straw yield was recorded and analysed for N, P and K content. Result: The maximum grain yield of moth bean and its residual effect on mustard was observed in the soils amended with leaf litters of Citrus aurontifolia followed by Aegle marmelos and Dalbergia sissoo. The total uptake of N, P and K was significantly higher in the treatments of Citrus aurontifolia and Aegle marmelos, which was due to the higher dry matter production of crops, faster rate of litter decomposition and higher release of nutrients.

Effects of different litters on ammonia emissions from chicken manure

Experiments were conducted to investigate the influences of type of litter, initial moisture content (IMC) of litter, and dry weight ratio of manure to litter (DWRML) on ammonia emissions from chicken manure and the effects of pH values of tea leaves and the mixtures of tea leaves and other litter on the ammonia emissions from chicken manure. For the experiments, four kinds of litter, Northeast pine sawdust (sawdust), rice husk, tea leaves, and wheat straw, were selected. The IMCs of the litter were (20±2)%, (30±2)%, and (40±2)%; and the DWRML values were 1:4, 1:6 and 1:8, respectively. The different litters adjusted at different moisture contents were mixed with chicken manure in different DWRML and then placed in different static test chambers, which were real-time monitored the ammonia concentrations. Pure chicken manure without any litter was used as a control group. The four kinds of litter had obvious inhibitory effects on the ammonia emissions from chicken manure under various conditions. There were significant differences among four kinds of litter (p 0.05). The DWRML had no significant effects on ammonia emission inhibition for tea leaves (p > 0.05), but had a significant effects on the ammonia emission inhibition for the other three kinds of litter (p 0.05). The mixed litter made of tea leaves and sawdust, rice husk, or straw were significantly better than the tea leaves and other single litter (p < 0.01). It indicated that adding appropriate amount of tea leaves in the litter can effectively inhibit ammonia emissions from chicken manure. Keywords: litter, moisture content, dry weight ratio of manure to litter, chicken manure, inhibitory effect, ammonia emission DOI: 10.25165/j.ijabe.20191204.5011 Citation: Tan H Q, Li M, Jie D F, Zhou Y F, Li X A. Effects of different litters on ammonia emissions from chicken manure. Int J Agric & Biol Eng, 2019; 12(4): 27–33.

Reproductive Indices and Oxidative Stress Biomarkers of Male Wistar Rats Prenatally Exposed to Cigarette Smoke.

The negative influence of cigarette smoking on developing fetus is well documented but reports of prenatal cigarette smoking on male reproductive hormones are controversial. However, shortened anogenital distance (AGD) has been established to be an indicator of potential male infertility. We therefore investigated the effects of prenatal exposure to passive cigarette smoke on AGD, reproductive hormones and oxidative stress biomarkers of Wistar rats. Female rats were randomly divided into two groups (n=5) and cohabited with male. Group 1 was exposed to smoke from an idling cigarette from day 1 of gestation till parturition, while Group 2 served as control (no-exposure). Morphometric variables of the litters were recorded on postnatal day 1 (PND1) and at 6th week postnatal life. The male offspring were then sacrificed by cervical dislocation. Testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) were analysed using ELISA. Serum levels of Catalase, sodium dismutase (SOD), malondialdehyde (MDA), lipid profile and liver function biomarkers were examined spectrophotometrically. On PND1, crown rump length and total body length of rats prenatally exposed to cigarette smoke were significantly shorter. Significantly shorter AGD and crown rump length were also observed at 6th week. Testosterone, LH and FSH were not significantly affected. Cigarette smoke exposure significantly decreased Catalase and SOD while MDA increased. Liver function biomarkers, HDL and LDL were not affected but serum levels of total cholesterol and triglyceride significantly increased. The observed decline in AGD and precipitation of oxidative stress by intrauterine cigarette smoke exposure may predispose to male infertility at adulthood.

Suínos dos Balcãs de Leste – uma raça suína autóctone Búlgara

The East Balkan Swine (EBS) is the last remained aboriginal pig breed in Bulgaria. It is a lard-type swine similar by phenotype to the wild boar with excellent adaptability to extensive conditions. Nowadays (2016) the population size of the breed is 1114 sows and 48 boars and for that reason the East Balkan swine is categorized as endangered maintained. The breed inhabits forest parts of the country on the East slopes of Stara Planina Mt. (the Balkan) and Strandzha Mt. Similarly to the wild pig the local pig of the East Balkan breed is characterized by a late onset of maturity - the age at first farrowing is over 500 days. Throughout their reproductive this local breed produce in average 5.2 litters. The prolificacy varies from 6 to 8 live-born piglets and 5-6 piglets at weaning. EBS reaches live body weight of 100 kg for about 14 months. Average values characterizing carcass quality at 100 kg body weight are as follows: - carcass - 56.7 kg (determined after removal of the skin, head, legs to the hock and elbow, all the viscera), total meat with bones - 41.8 kg, (73.4% of carcass) and fat - 15.08 kg (26.6% of carcass).

THE AGE AT PUBERTY OF THE NIGERIAN LOCAL DOGS IN IBADAN. SOUTHWEST, NIGERIA -

The age at puberty of the Nigeria Local Dogs (NLD) in Ibadan was studied by monitoring the changes in their weekly live body weight, semen parameters, testicular, epididymal biometry and testosterone profile. The puppies were selected randomly from different healthy litters at different regions of Ibadan metropolis. These dogs were divided into four age groups consisting of 3 animals in each group, namely, group-A (12 weeks), group-B (16 weeks), group-C (20 weeks) and group-D (24 weeks). Weekly live body weights of the puppies were obtained from 7 weeks to 24 weeks of age. Blood samples were collected at 12, 16, 20 and 24 weeks into EDTA bottles and the plasma decanted were assayed for testosterone. The puppies were castrated at 12, 16, 20 and 24 weeks. Semen was collected from the caudal epididymis and evaluated. The result showed a positive linear relationship (P < 0.05) between the age and body weight of the dogs with R (correlation coefficient) = 0.980. The right testes had higher values of the testicular and epididymal parameters compared to the left testes. There was a linear relationship among weight of dog, testicular weight and corresponding percentage. There were fluctuations in the levels of testosterone during this study and a significant difference in the results of testosterone before and after castration (P < 0.05). It was therefore concluded that Nigerian local dogs do not have spermatozoa present in their semen and have very low serum testosterone level before 24 weeks of age, therefore puberty in the Nigerian local dog does not occur before 24 weeks of age and results of this study can be used as a baseline data in the further study of the classification and characterization of the NLD.

ASSESSMENT OF WASTEWATER FOR DISPOSAL IN ACCORDANCE WITH NEQS CRITERIA AND ITS REUSE FOR IRRIGATION WITH DILUTION

According to Section 11 of Pakistan Environmental Protection Act (PEPA) 1997, “No person shall discharge or emit or allow the discharge of any effluent or waste in an amount, concentration or level which is more than the National Environmental Quality Standards(NEQS)”. Even in the presence of this act there are many housing societies and Industrial zones, which are continuously disposing off their untreated wastewater to the natural water bodies. In this study Laboratory investigations on 5 composite samples were carried out. Total of 19 parameters were analyzed including Total Dissolve Solid (TDS), Total Suspended Solids (TSS), Bio-Chemical Oxygen Demand (BOD), Chemical Oxygen demand (COD), Sulfide, Fluoride, Lead, Nickel, Boron, Copper, Iron, Zinc, Manganese, Chlorine Total and Chromium hexavalent with average value of 502.6, 665.6, 267.4, 453.8, 3.1,5.3 0.6, 0.4, 1.4, 0.5, 0.5, 2.15, 0.6 and 0.5 mg/L respectively. TSS, BOD, COD and Mn exceeded the limits of NEQS for all samples.The same wastewater can be used for irrigation purpose if it fulfills FAO irrigation water criteria. For this purpose, important properties like SAR, Sodium ratio, Salt Index, Residual Sodium Carbonate, Permeability Index, Magnesium Adsorption Ratio, Sulfate ion and Boron were analyzed having result of 9.36 √(meq/L), 5.64, 75 ppm, 4.66 meq/L, 110.46, 0.42, 6.07 meq/L, 1.386 mg/L mean concentrations respectively, violating the standards. A dilution factor of 1.09 litters is computed per liter of sewage to minimize, the concentrations of exceeded parameters by mixing with normal water, into a range that can be used safely for irrigation.

Regulatory effect of vitamin D on the expression of occludin in the intestinal epithelial cells of neonatal rats with necrotizing enterocolitis

Objective To investigate the expression of occludin in the intestinal epithelial cells of neonatal rats with necrotizing enterocolitis (NEC). The influence of vitamin D on NEC and the expression of occludin was also explored. Methods Sixty neonatal Wistar rats from different litters were divided into four groups 48 hours after birth: 10 in the breast-fed+ control group, 10 in the breast-fed + vitamin D group, 20 in the NEC+ control group and 20 in the NEC+ vitamin D group.In groups with NEC, neonatal rats were separated from their mothers and treated with rat milk substitute+ hypoxia+ hypothermia.In groups with vitamin D treatment, paricalcitol was given through intraperitoneal injection 30 minutes before, one day and two days after the induction of NEC.The tissue was harvested from the ileum of the rats 72 hours after induction of NEC.Microscopically, the tissue was assessed according to the Nadler scoring system.The expression and location of occludin was observed after immunofluorescence staining.Western blotting was performed and quantified to compare the expression of occludin among groups. Results In NEC rats, the intestinal structure was destructed.Separation of the submucosal or muscular layer, discharge or disappearance of the villa was accompanied by necrosis of the intestinal cells.Vitamin D treatment could significantly alleviate those changes, with the Nadler score 1.70±0.21 compared to 2.90±0.23 without vitamin D treatment(P<0.01). The expression of occludin was decreased in NEC rats and vitamin D could partly rescue this decrease(P<0.01). The distribution of occludin was sparse and discontinuous in NEC rats while after vitamin D treatment, the distribution was maintained even and continuous. Conclusion The expression of occludin in intestinal epithelial cells is significantly reduced in NEC rat.Vitamin D treatment may inhibit the development of NEC by maintaining the expression of occludin. Key words: Occludin; Intestinal epithelial cells; Vitamin D; Necrotizing enterocolitis

Seasonal Reproduction in Neotropical Rainforest Mammals.

Gérard Dubost, and Olivier Henry (2017) Seasonal changes in tropical forests have been documented in dry and semi-deciduous forests, but not in evergreen ones. Owing to its high level of annual rainfall, French Guiana is considered to be a rainy region, despite a pronounced dry season. French Guiana is therefore appropriate for studying the impact of the dry season on the phenology of rainforest animals. For this purpose, the reproductive characteristics of six terrestrial mammals of the French Guiana rainforest were studied during the four main seasons of the year. Reproduction was more or less continuous in both sexes of all species. Seasonality was not very pronounced and the species were not synchronised, except in terms of births. In all species, the minimum number of litters occurred between August and October. Furthermore, the seasonal birth percentages appeared to be linked to environmental factors such as rainfall and fruiting trees, and to diet as well: the more the diet of one species was composed of fruits, the more seasonal its litters were. Thus, like in many other regions worldwide, most births occur during the most favourable seasons for raising young in this rainforest. This signi es that even in this seemingly aseasonal region, the reproduction of mammals is mainly regulated by environmental factors at the time of birth.

Design, Fabrication and Performance Test of Ethanol Extractor From Cassava

ABSTRACT The ethanol extractor was design, fabricated and its performance was evaluated. It comprises of two plastic containers (fermentation and separating tanks) each of which is 41.2 litters in capacity and a steam boiler of 10.6 liters in capacity which was mounted on an electric heater and the temperature was controlled by a thermostat. Aluminum pipe was used to connect the steam boiler by the top side in which gaseous ethanol flows to the water jacket of 15.3 liters in capacity to condense the ethanol to liquid which is collected at the bottom side of the water jacket. Thermometer was mounted on the steam boiler to read the temperature of the mixture inside the steam boiler. Continuous flow of water is ensured in the water jacket to enhance the rate of condensation. The performance test was carried out using four different feed rates of cassava starch at two different durations of extraction which include 500g, 1000g, 1500g and 2000g at 180minutes and 200minutes. Each one was replicated five times. The results showed that the quantity of alcoholic extracted depends on quantity of starch used. The high the quantity of cassava starch will lead to high durations of extraction that produced high volume of ethanol. The Analysis of Variance (ANOVA) for the effect of feed rates and time on the efficiency of the machine confirms that these factors are important parameters that significantly affect the performance and the volume of ethanol extracted by the machine.

Captive Breeding of the Shark Bay Mouse Pseudomys fieldi to Facilitate Species Recovery in the Wild

Shark Bay Mice ( P. fieldi ) were bred at Perth Zoo to provide animals for release to the wild as part of recovery actions for the species. Three-hundred and thirty-five young were produced from 93 litters, with an average litter size of 3.6 (range 1 – 6). Sexual maturity for both sexes was reached at 65 days of age, and breeding was observed all year round. The oldest female to give birth was 625 days of age and the oldest male to sire young was 531 days of age. Following a planned interruption to the program and the separation of breeding pairs, there was some difficulty in later re-establishing reproduction. A strategy to stimulate a return to breeding, along with detailed husbandry methods, is described.

Optimal timing of antenatal taurine supplementation for improvement of neuron and neural stem cell proliferation in fetal rats with intrauterine growth restriction

Objective To determine the optimal timing of antenatal taurine supplementation to improve neuron and neural stem cell proliferation in fetal rats with intrauterine growth restriction. Methods Twenty-five pregnant SD rats were randomly divided into five groups (five rats in each group): group A was the control group, group B to E were the fetal growth restriction (FGR) model groups with low-protein diet during the experiment, group C, D, and E were supplemented with taurine [300 mg/(kg·d)] at day 9, 11 and 15, respectively. The birth weight of newborn rats was measured after natural delivery. The rats with body weight two standard deviations lower than the average weight in group A were diagnosed as FGR. There were five litters of newborn rats in each group, and two were randomly selected from each litter, resulting in ten newborn rats in each group. Proliferating cell nuclear antigen (PCNA) and fatty acid binding protein 7 (FABP7) positive cell expression in newborn rat brain tissues were detected by immunohistochemistry. Single factor analysis of variance, LSD tests were used for statistical analysis. Results The average birth weight of newborn rats in group A, B, C, D and E were (6.61±0.45), (4.65±0.23), (5.37±0.17), (5.74±0.21), and (5.00±0.24) g, respectively. Average birth weight was lower in group B than in group A (t=2.447), higher in group D and E than in group B (t=2.306 and 2.306), higher in group D than in group C and E (t=2.306 and 2.306), and the differences were statistically significant (all P 0.05). The IOD in group D was higher than that in group E, and the difference was statistically significant (t=4.182, P<0.05). Conclusions Antenatal taurine supplementation can promote neuron and neural stem cell proliferation in rats with FGR. The effect is most obvious on the 11th day of pregnancy, and may lead to the promotion of brain development. Key words: Fetal growth retardation; Taurine; Neurons; Neural stem cells; Cell proliferation; Proliferating cell nuclear antigen; Nerve tissue proteins; Fatty acid-binding proteins; Disease models, animal

Effects of early postnatal nutrition on adult-onset insulin resistance in Sprague-Dawley rats

Objective To explore the effects of early postnatal nutrition on adult-onset insulin resistance by an artificial nutrition intervention during the critical period. Methods On postnatal day 2, Sprague-Dawley rats were assigned randomly to overnutrition (SL), normonutrition (NL) and undernutrition (LL) via artificially adjusting the number of pups nursed per dam. Litter size was adjusted to 3 pups/dam, 10 pups/dam and 20 pups/dam for the SL, NL and LL groups, respectively. There were eight litters for each group. All the pups were nursed by their natural dams and fed with a standard rodent laboratory chow. The pups were weaned on postnatal day 21 and three male pups from each litter were separated. After that, all male rats were housed three per cage and fed standard chow until 16 weeks old. At 3 and 16 weeks, rats were killed after overnight fasting and blood was collected. Liver, gastrocnemius muscle and perirenal and epididymal fat pads were dissected and weighed to calculate relative mass after normalization for body weight. Physiological parameters, biochemical values and insulin resistance status, including serum insulin level, homeostasis model assessment for insulin resistance (HOMA-IR) index and intraperitoneal glucose tolerance test (IPGTT), were dynamically monitored. Analysis of variance was used for statistical analysis. Results (1) Before weaning, the body weights of SL rats were significantly heavier than NL rats after postnatal day 10, and weights of LL rats were significantly lower than NL rats after postnatal day 7. After weaning, body weights of SL rats still remained heavier and weights of LL rats continued to be lower than NL rats (P<0.05). (2) At 3 weeks, the weights of liver and perirenal and epididymal fat pads in SL rats were significantly heavier than NL rats, whereas LL rats were lower than NL rats (P<0.05). At 16 weeks, the weights of liver, epididymal fat pads and gastrocnemius muscle in SL rats were significantly heavier than NL rats. Meanwhile, the weights of all detected tissues in LL rats were lower than the NL group. The weights of epididymal fat pads after normalization for body weight in the SL group were heavier than the NL group (P<0.05). (3) At 3 weeks, the fasting serum glucose level of the SL group was significantly higher than the NL and LL groups [(7.77±1.10) vs (6.33±1.20) and (5.80±1.51) mmol/L, respectively, F=13.217, P<0.01]. At 16 weeks of age, the serum insulin level in SL rats significantly increased compared to NL and LL rats [(0.31±0.11) vs (0.16±0.08) and (0.14±0.11) ng/ml, respectively, F=5.369, P=0.017]. For HOMA-IR evaluation, the index was significantly lower in LL rats compared to NL and LL rats at 3 weeks of age [(0.09±0.01) vs (0.25±0.01) and (0.31±0.05), respectively, F=25.923, P=0.005]. At 16 weeks, the index was significantly elevated in SL rats compared to NL and LL rats [(1.77±0.53) vs (0.84±0.44) and (0.83±0.67), respectively, F=5.765, P=0.015]. Furthermore, IPGTT was performed in all groups at 14 weeks of age. SL rats had significantly higher serum glucose levels at 60 min and a significantly increased area under the curve when compared to NL and LL rats (all P<0.05). (4) Serum from 16 week old SL rats was found to contain significantly higher levels of albumin, triglycerides and free fatty acids compared to NL rats (all P<0.05). Conclusions Early postnatal overnutrition induces persistent overweight and visceral white adipose accumulation in rats, while early postnatal undernutrition show the opposite effects. Early postnatal overnutrition may lead to adult-onset insulin resistance in rats. Avoiding overnutrition during the early postnatal period, a critical window for growth and development, may prevent or decrease later metabolic risks. Key words: Nutritional status; Insulin resistance; Overnutrition; Rats, Sprague-Dawley

Carcass characteristics and meat quality of rabbit litters from rabbit does restricted during pregnancy

Carcass characteristics and meat quality of rabbit litters from rabbit does restricted during pregnancy

THE NATURE AND CHALLENGES OF STREET SWEEPING IN ADO-EKITI

This study examined the nature of street sweeping, the composition of litters, the socio-economic and health status of street sweepers and the public perception of the benefits and challenges of street sweeping in Ado-Ekiti. Primary data were obtained through direct personal observation, questionnaire administration and in-depth interview while secondary data were sourced from published and unpublished documents. Purposive and random sampling methods were adopted in the selection of respondents for questionnaire administration. Four types of structured questionnaire were designed and administered separately to: 103 (20%) of the street sweepers along the 21 swept streets; 193 (5%) buildings along the 21 streets; 14 officials of the Ekiti State Waste Management Authority involved in the street sweeping programme, and 42 pedestrians (female and male) along the 21 swept streets. Descriptive statistics were used to analyse the data collected. Findings revealed that all the street sweepers were females and casual workers. Sediments/broken blocks/sand/gravel (18.8%), plastics (16.6%), nylon/polythene (16.6%), leaves/wood/grass (15.0%), food wastes (12.6%), paper (9.9%), aluminum cans/metals/glass (5.3%), and miscellaneous (5.2%) constituted the street litters. The sweepers suffered from joint pain (96.1%), catarrh (91.3%), cough (83.5%) eye infection (70.8%) asthma (46.6%) and malaria (31.1%). Inadequate personnel, insufficient tools and equipment, poor remuneration, stigmatisation, exposure to accidents and harassment were the challenges faced by the sweepers. The benefits created by the street sweeping programme are: city beautification and aesthetics (74.6%); employment opportunity (16.6%); improved urban environmental health (6.2%), and attractiveness of the streets (2.6%).The study concluded that the street sweeping programme has made the streets sanitary and aesthetically pleasing, provided employment and raised public perception of Ado-Ekiti as a clean and healthy city. Employment of more sweepers, provision of adequate equipment, public sensitisation and attitudinal change, enforcement of environmental sanitation laws, and improved remuneration will make street sweeping a sustainable waste management strategy in Ado-Ekiti.

Effect of neonatal overfeeding on associated enzymes of lipid metabolism in rat liver

Objective To investigate the effect of neonatal overfeeding on the expression of lipid metabolic associated enzymes and molecular mechanisms in the livers of rats. Methods Male Sprague-Dawley rats were randomly assigned to litter sizes of three group (small litters, SL group) or ten (normal litters, NL group) on postnatal day 3.Body weight, milk intake, liver and fat pad (epididymal and retroperitonea) weight, and hepatic histological analysis were recorded in week 2 and week 3, respectively.The levels of lipids were detected by the automatic biochemical analyzer.The mRNA expressions of acetyl-CoA carboxylase (ACC), lipoprotein lipase (LPL), liver-type fatty acid-binding protein (L-FABP), carnitine palmitoyltransferase 1(CPT1), microsomal triglyceride transfer protein (MTP), sterol regulatory element-binding protein-1c (SREBP-1c) and peroxisome proliferator activated receptor α (PPARα)in liver were determined by real time PCR; the protein expressions of SREBP-1c and PPARα were determined by Western lot. Results As early as week 2, the body weight of rats in SL group began to elevate (t=-5.997, P<0.001) and food intake (t=-3.462, P=0.002) compared with the rats in NL group, and persistent to weaning (body weight: t=-17.019, P<0.001; food intake: t=-2.276, P=0.031). By the time of 3 weeks old, SL rats increased visceral fat pad [retroperitonea (t=-7.643, P<0.001), epididymal (t=5.997, P=0.001)], liver weight (t=-7.812, P<0.001), hepatosomatic index (t=-3.829, P=0.003) and serum triglyceride (TG) level (t=-2.703, P=0.022) compared with those of NL rats, as well as the level of hepatic ACC mRNA (t=-3.751, P=0.007), LPL (t=-2.721, P=0.017) and L-FABP mRNA (t=-2.521, P=0.026) .While CPT1 mRNA (t=-1.531, P=0.155) and MTP mRNA (t=-1.741, P=0.098) levels remained unchanged in both groups.Hepatic SREBP-1c mRNA expression increased in SL rats after 2 to 3 weeks (t=-2.836, P=0.016), paralleled with ACC and LPL mRNA expression; while the mRNA and protein expression of PPARα remained unchanged (t=-0.854, P=0.411). Conclusions Postnatal overfeeding can promote higher liver pad and dyslipidemia at the time of weaning.The process may be regulated by up-regulated expression of ACC, LPL and L-FABP.SREBP-1c may be participated in the regulation of ACC, a rate-limiting enzyme involved in lipogenesis. Key words: Nutritional programming; Liver; Lipid metabolism; Rat

Reproductive trends of captive polar bears in North American zoos: a historical analysis

Despite the fact that nearly all captive polar bears ( Ursus maritimus ) are recommended for breeding, very few cubs are born each year and the rate of neonatal mortality is high. Animal caretakers tend to rely on anecdotal reports regarding reproductive events, such as timing of parturition, litter size and cub survival. To objectively document trends in polar bear reproduction during their tenure in North American zoos, this analysis utilised 99 years of records in the Polar Bear Studbook to characterise patterns in reproduction and cub survival. Factors evaluated included latitude, year of birth, parental demographics (age, origin (captive-born or wild-caught) and litter size), sex, survival, litter size and litter order. Between 1912 and 2010, 697 individuals (456 litters) were born at latitudes ranging from 25.90 to 52.94 oN. The average number of litters produced per year was 4.60 ± 0.51 with a range of zero to 18. The polar bear birth season lasted 106 days with mean and median birth dates of 29 November. Litter size was unaffected by any of the variables analysed: 52.7% of litters were singletons, 44.9% were twins and 2.4% were triplets. Older sires produced a higher proportion of male offspring than younger sires (P < 0.05). More than half of all individuals died prior to 30 days of age and 30.4% reached adulthood (four years). Cubs of captive-born parents lived longer than those of wild-caught parents (P < 0.05). Individuals born in litters of multiples were more likely to die as neonates than those born as singletons (P < 0.01) and individuals born to multiparous dams lived longer than those born to primiparous dams (P < 0.02). This study represents the largest analysis of captive polar bear reproduction conducted to date and may serve as a reference for individuals involved in the management and care of captive polar bears.

Growth performance of genetically modified tilapia (Oreochromis niloticus) cultured in concrete pond

Reproductive data from 24 does (Chinchilla X New Zealand White) of twenty weeks, were analyzed to determine the effect of generation, housing systems and season on the reproductive performance of rabbits raised in the humid tropics. The experiment was carried out during four seasons namely: early dry season (EDS-September to November), late dry season (LDS- December to February), early rainy season (ERS-March to May) and late rainy season (LRS June to August). The study was repeated in the second generation and the data obtained were subjected to analysis of variance in a 2x2x4 factorial arrangement. Factors considered were generations, housing systems, and seasons respectively. Highest breeding efficiency of 83.33% was obtained in the first generation and maximum litter size at birth (35) and weaning (28) were observed in caged-does that kindled in EDS of first and second generations respectively, while does housed on deep litter system produced the smallest litter size at birth (24) and weaning (18) in the ERS of the second generation. Highest (12) and least (4) pre-weaning losses were recorded in caged-does that kindled in ERS of the first and second generation respectively, whereas highest average birth weight (120.58g) was observed in litters of deep litter-does that kindled in EDS of the second generation. These results indicated that the production of rabbits for breeding purposes is better achieved during early dry season (September-November) and also revealed that deep litter system allows satisfactory performance and has comparative advantage over wooden cage system considering the reduction in housing cost and can be used to improve the nutritional status of the family and also to obtain some supplementary income. Keywords: Season, Breeding efficiency, Litter size, Cage, Deep litter

A survey on bacterial involvement in neonatal mortality in dogs.

Bacterial infections represent the second cause of neonatal morbidity and mortality in dogs, so the present study aimed to investigate the bacterial involvement in canine neonatal mortality and to evaluate the antibiotic susceptibility of the isolated bacteria. Fifty-one newborn purebred puppies, born dead or dead within 28 days of age, belonging to 36 different litters, were enrolled and the following procedures were performed on their fresh dead bodies: necropsy, collection of swabs by liver, kidney, lung, small bowel, and possible thoracic and/ or abdominal effusion, for both bacteriological examination and antimicrobial susceptibility testing, and collection of samples by the same organs for histology. About 47% of total swabs were positive at bacteriology (pure bacterial culture or bacterial association). In 65% of the newborn puppies the mortality could be attributed to a bacterial infection. Although the high multidrug resistance, the most effective antimicrobials were third generation cephalosporins and fluorquinolones. In case of neonatal mortality, bacterial culture and antimicrobial susceptibility testing become essential for a targeted therapy in surviving littermates and for the management of following pregnancies in bitches with recurrent neonatal loss.

Lactation litter size differentially affects satiety hormone concentrations and gut adaptations in Wistar rat dams

Introduction: Peptide-YY (PYY) is a satiety hormone secreted by the colon. We have previously shown that PYY significantly increases in early lactation in rats, despite hyperphagia. Increased PYY may be associated with significantly increased gut growth by late lactation in dams with average-sized litters. Our aim was to determine whether feeding different litter sizes influences postpartum changes occurring during the maternal adaptation to lactation. Materials and Methods: Wistar rats had litter sizes adjusted to 4, 8 (standard) or 12 pups by 1 day postpartum and were sacrificed at day 25 of lactation. Colonic PYY was quantified using radioimmunoassay. Gut tissue measurements were standardised by free-floating gut for length measurements and using nicardipine for circumference measurements. Results and Discussion: Dams feeding 4 pups had significantly shorter and lighter small and large intestines and lighter caecums compared with dams feeding 8 pups and we hypothesise that this is due to reduced suckling demand. Significantly increased descending colon PYY in dams with 8 pups was associated with increased gut size in these dams. Despite no increase in gut length or wet weight, dams feeding 12 pups had significantly increased gut circumferences, which may represent an adaptation to lactation that requires less energy. Energy insufficiency for structural modifications may be why dams feeding 12 pups showed different adaptations to dams feeding 8 pups. This study is the first time such differential adaptations have been shown in dams due to litter size; further work is being carried out to establish if pups from different sized litters have altered endocrine profiles or gut structure that influence feeding.

Sex differences in gut satiety hormones peptide-YY and glucagon-like peptide-1 in pups raised in larger lactation litter sizes

Introduction: Previous studies have established that the size of litters during lactation influences body size and adiposity in male rat pups. Levels of gut hormones such as appetite-stimulating ghrelin and appetite-reducing peptide-YY (PYY) and glucagon-like peptide-1 (GLP-1) have not been examined in this model despite an increased susceptibility to obesity into adulthood. This study aimed to establish whether changes in gut appetite hormones, resulting from lactation litter size, could contribute to the increased risk of adulthood obesity. Methods: Male and female littermates from small (n=4), control (n=8) and large (n=12) litter sizes were studied at weaning age (25 days), with litter sizes adjusted prior to 1 day postpartum; pups remained with the dams throughout the study. Stomach ghrelin and colonic PYY and GLP-1 were quantified using radioimmunoassay. Stomachs were emptied, blotted dry and weighed. Body length was taken from between the front paws to the anus. Results and Discussion: No differences were found in stomach ghrelin levels between the pups, but levels of the gut satiety hormones PYY and GLP-1 were found to be altered in colon tissue. In descending colon, PYY and GLP-1 concentrations were significantly lower in male, but not female, pups from the large litters. Physically, both the male and female pups fed in the large litters were significantly shorter and lighter and had significantly lighter stomach tissue. We suggest that the significantly smaller male pups may have had reduced satiety as a mechanism to achieve ‘catch-up growth’ into adulthood. It is unclear whether females may show similar adaptations at a later stage. This study further demonstrated differences between young males and females, with differences evident even before sexual maturation. This work highlights the importance of standardising litter size as early as possible, especially in studies of appetite control.