Effect of different feeding regimes on pre‐weaning growth rumen fermentation and its influence on post‐weaning performance of lambs

Influence of pre‐weaning live weight on post‐weaning growth performance was assessed on thirty‐nine 15‐day‐old Indian native lambs, randomly fed in three equal groups until 180 days of age. During pre‐weaning phase lambs were maintained under feeding regimen of grazing (C‐0; Control), grazing and ad lib creep mixture supplementation (C‐AL) or grazing, with ad lib creep mixture and milk replacer supplementation (C‐ALMR). Lambs were allowed to suckle respective dam in morning and evening till 90 days of age, and fed ad lib green leaves of Ailanthus excelsa after grazing. After weaning all lambs were maintained on grazing and ad lib finisher concentrates supplementation. Pre‐weaning performance of lambs in terms of weaning weight (17.2 kg), average daily gain (ADG; 154 g) and feed conversion ratio 3.73 was higher (p < 0.01) in C‐ALMR lambs but total gain and ADG were similar among three groups during post‐weaning phase. However, improved pre‐weaning plane of nutrition and growth rate increased (p < 0.01) finishing weight (FW) of lambs in C‐AL, 33 kg and C‐ALMR, 32 kg. Dry matter intake was significantly (p < 0.01) higher in C‐AL and C‐ALMR lambs due to combined effect of feeding. Rumen pH was lowest (p = 0.049) in C‐AL lambs. Rumen ciliate protozoa population (10⁴/ml) decreased in C‐ALMR lambs (4.3) but increased in C‐AL lambs (50.0) more so in C‐0 Lambs (19.8). Concentrate feeding of C‐AL lamb improved nutrient digestibility. Lambs of C‐0 group consumed more DM during post‐weaning phase that improved growth performance, while nutrient digestibility was not affected by pre‐weaning nutrition. Thus, pre‐weaning nutrition has significant influence on FW, however influence of milk replacer feeding on lamb growth need further studies.     

Effects of low feed intake and hot environment on plasma profiles of glucose, nonesterified fatty acids, insulin, glucagon, and IGF-I in lactating sows

This experiment was designed to compare the effects of high ambient temperature and of feed restriction on plasma hormones and metabolites in primiparous lactating sows. Females were exposed to a constant thermoneutral (20 degrees C) or hot environment (30 degrees C) during lactation. Sows housed at 30 degrees C were given free access to feed (30AL: n = 12), whereas those housed at 20 degrees C were either pair-fed with those at 30 degrees C (20RF: n = 6) or were fed ad libitum (20AL: n = 6). A jugular vein catheter was surgically inserted in all sows at 100 d of gestation. Absorption of nutrients during the meal induced significant increases in plasma glucose, insulin, and glucagon, and a decrease in nonesterified fatty acids on Day 19 of lactation and Day 1 postweaning (P < 0.05). On Day 19, feed restriction at 20 degrees C was associated with higher plasma glucagon before the meal, lower plasma insulin after the meal and a lower insulin-to-glucagon ratio (I/GA) before and after the meal (P < 0.05). On Day 19, mean plasma concentrations measured in 30AL females were between those measured in 20AL and 20RF sows for nonesterified fatty acids and glucagon before feeding, and for glucose, nonesterified fatty acids, insulin, and glucagon after feeding. None of the differences between the 30AL and the 20RF groups was significant (P < 0.1). On Day 19, the only significant differences between the 30AL and 20AL groups were observed after the meal for plasma insulin and I/GA. Plasma insulin-like growth factor-I increased after farrowing in 20AL and 30AL sows only (P < 0.05). It was higher in 20AL than in 20RF and 30AL sows on Days 4 and 19 of lactation (P < 0.05). Overall, underfeeding at 20 degrees C induced changes in plasma insulin, glucagon, I/GA, and insulin-like growth factor-I, which would favor gluconeogenesis and body-reserve mobilization during lactation. Differences in glucagon and I/GA before the meal between well-fed sows at 20 degrees C and heat-exposed sows were attenuated, which could have detrimental consequences on glucose availability to the mammary gland and hence on milk production at 30 degrees C.     

水貂膨化配合饲料筛选试验

采用对动、植物性饲料干、湿法膨化技术的加工工艺 ,配制成水貂膨化配合饲料 ,与新鲜鱼、肉搅碎后 ,再加入蒸、煮或炒熟的玉米、大豆 ,形成糊状饲料进行饲养水貂的不同饲料配方正交筛选试验。试验设计选用L4(2 3 )正交表 ,设置三因素 ,每因素二水平。试验动物选择纯种美洲标准貂 ,在生长前期、冬毛生长期分别进行了 89d与 5 9d的正交试验。试验结果表明 ,各因素极差值对影响日增重的主次关系估计为C >B >A ;B、C因素与A因素已达到显著水准 (P <0 0 5 ) ,B、C因素之间无显著差异。     

The Effect of Cage Environment and Ad Libitum Feeding on the Circadian Rhythm,Behaviour and Feed Intake of Farm Mink

Abstract

The effect of cage size and nest box environment on circadian rhythm and on stereotyped and non-stereotyped activities was measured for 66 farmed female mink fed ad libitum. The behaviour of the animals was recorded over 24 h on video in the months of September and October. Weight and feed consumption were measured for the 66 females and the 66 male mink placed with the females. The experiment included three cage sizes (0.10, 0.27 and 1.10 m²) and cages with and without nest boxes. In the cages with nest boxes the use of wire netting cylinders and shelves was evaluated.

Farm mink, fed ad libitum, had their primary activity period from 04:00 to 10:00 h. There was no food anticipatory activity, but the actual feeding at noon caused an interruption of the animals' resting period. Mink in cages without nest boxes performed more stereotyped behaviour than mink with nest boxes. There was no effect of cage size on the measured behavioural elements. Mink were passive for more than 70% of the day and night and preferred to rest together. Apart from resting in the nest box, mink preferred to rest on shelves above floor level. Lacking the possibility of using a nest box and performance of stereotyped behaviour increase the feed intake of farm mink. A large variation between animals, having a significant effect on all the measured behavioural elements, indicates different coping patterns and/or stress sensitivity.     

Effects of early and late feed restriction or feed withdrawal on growth performance,ascites and blood constituents of broiler chickens

A study was conducted with male broilers to determine the effects of early and late feed restriction or feed withdrawal. In the experiment five treatments were represented by three replicate floor pens, each containing 20 broilers. The experimental procedure was a completely randomized design. The treatments were ad libitum (AL), 25% (FR-25) and 50% (FR-50) feed-restricted or 8 h (FW-8) and 16 h (FW-16) feed withdrawal regimes, respectively. FW-16 regime significantly reduced weight gain to 21 days of age compared to AL or FR-25 regimes (P<0.05). However, the overall weight gains between 9 days and 42 days of age were not significantly affected by the treatments. FW-8 and FW-16 broilers consumed significantly less feed than either AL or FR broilers between 9 and 21 days (P<0.05), however FW-8 and FW-16 broilers had similar feed intake to AL or FR-25 and FR-50 broilers between 9 and 42 days of age. Feed: gain, abdominal fat pad and heart weights, mortality, death due to ascites, and the incidence of leg disorders were unchanged by feeding regimes, although the incidence of ascites in FW-16 was significantly (P<0.05) lower than AL fed broilers. Blood constituents, such as albumin, total cholesterol, ketone bodies, glucose, chlorine, lactate dehydrogenase, alanine aminotransferase and creatine were also significantly affected by feeding regimes (P<0.05).     

Effects of Different Fat Supplements on Growth and Hepatic Lipids and Fatty Acids in Male Mink

Male mink kits (n=10 for each group) were fed diets supplemented with different fats for 12 weeks (September-November). The levels of digestible fat (8%) and energy content (7 MJ kg-1) of the diets were equal. The supplements used were beef pork fat, mink fat, broiler offal, rainbow trout offal, capelin oil, soybean oil and linseed oil. The growth and hepatic lipids (analysed by a thin-layer chromatography- flame ionization detection analyser) and fatty acid composition (analysed by gas-liquid chromatography) were studied. The pattern of weight gain of the mink fed the beef pork diet differed from that of the other mink. These kits reached high but delayed weight maxima compared with the other mink but then during November they lost weight rapidly. In liver, both the capelin oil- and linseed oil-fed mink had large concentrations of total lipids and triacylglycerols. The mink fed capelin oil were significantly heavier. The fatty acid analyses of hepatic total lipids and phospholipids revealed that the f -linolenic acid (18:3 n-3) of linseed oil was not efficiently metabolized to longer chain and more unsaturated fatty acids important for cellular membranes. It is discussed that 18:3 n-3 may not be as valuable for growing mink kits as the polyunsaturated fatty acids of the fish oils.     

Multiphasic Growth Curves in Mink (Mustela vison) Selected for Feed Efficiency

Growth of mink from 1 to 28 weeks of age was modelled, using weekly body weights, and effects on model parameters of selection lines for high and low feed efficiency, sex and interaction were tested. From results on average growth curves, individual growth curves were modelled using a multiphasic logistic growth function with three phases. Individual growth curve parameters were tested for effects of selection line, sex, and interaction by analysis of variance.

Selection for feed efficiency affected the growth curve of mink. Selection lines differed for time of maximum increase (center) for each phase; the high feed efficiency line was centered later than the low line, the growth curve being shifted to the right. Males gained more weight in phases 2 and 3 than females; phase 2 was centered later for males than for females; males had a shorter duration for phase 3 than females. There was no line–sex interaction.     

The influence of level of feeding on growth and serum insulin-like growth factor I and insulin-like growth factor-binding proteins in growing beef cattle supplemented with somatotropin

The objective of this study was to determine the effects of level of feeding on growth, feed efficiency (gain:feed; G:F), body composition (BC), and serum concentrations of somatotropin (ST), IGF-I, and IGF-binding proteins (BP) in growing beef cattle supplemented with bovine (b) ST. In each of two consecutive years, 40 growing beef cattle were blocked by weight (average BW: yr 1 = 316 kg, yr 2 = 305 kg) and used in a 2 x 2 factorial arrangement with main effects of bST (0 or 33 microg x kg BW(-1) x d(-1)) and level of feed intake (ad libitum [AL] or 0.75 AL). Relative to uninjected cattle, treatment with bST increased ADG 9.6% (1.14 vs 1.25 kg/d; P < 0.05) and increased G:F 8.1% (12.3 vs 13.3 gain [g]:feed [kg]; P < 0.05), whereas ADG in AL animals was 39% greater than that in 0.75 AL animals (1.39 vs 1.00 kg/d; P < 0.05). There was a tendency (P = 0.10) for a bST x level of feeding interaction, such that the increase in ADG with bST was greater in AL cattle than in 0.75 AL cattle (10.6 vs 7.8%; P = 0.10). Serum concentrations of ST were greater in 0.75 AL cattle than in AL cattle (13.0 vs 8.6 ng/mL; P < 0.05) and in bST-treated cattle than in uninjected cattle (16.3 vs 5.2 ng/mL; P < 0.05). Due to a bST x level of feeding interaction (P < 0.01), the magnitude of the increase in serum ST to exogenous bST was greater (P < 0.01) in 0.75 AL cattle than in AL cattle. Relative to uninjected cattle, treatment with bST increased (P < 0.05) serum concentrations of IGF-I and IGFBP-3 and reduced (P < 0.05) concentrations of IGFBP-2. Similarly, AL cattle had greater (P < 0.05) serum concentrations of IGF-I and IGFBP-3 and reduced (P < 0.05) IGFBP-2 compared with 0.75 AL cattle. In summary, treatment with bST increased growth rate and G:F and stimulated serum IGF-I and IGFBP-3 while reducing IGFBP-2. Feeding at 0.75 ad libitum intake reduced the magnitude of response for each of these variables. Thus, limit-feeding may reduce the effect of exogenous bST on growth rate by blunting bST-induced increases in IGF-I and IGFBP-3 and bST-induced decreases in IGFBP-2.     

Influence of postpartum feeding method on performance of the lactating sow

Data on the effect of postpartum feeding methods on sow and litter performance and the incidence of lactation failure in the sow are presented. One hundred and sixteen sows were allowed either ad libitum consumption within 16 h postpartum (AL) or restricted to a gradual increase in feed, starting with 0.45 kg on Day 0 and increasing to 0.91 kg each day reaching ad libitum by Day 6 of lactation (R). The AL sows consumed more feed from Day 0 to Day 6 (P<0.01) and during total lactation period (P<0.10) than R sows. Litter performance was not affected by treatment. Loss of sow body weight and condition during lactation and the weaning-to-estrous interval were not affected by treatment. Lactation failure was minimal and not affected by treatment. Rectal temperatures of AL sows were generally higher than R sows, but were not related to incidence of lactation failure. Fecal consistency scores revealed more normal defecations from the AL sows. Neither AL nor R could be identified as the preferred feeding method.     

Impact of energy intake and pregnancy status on rate and efficiency of gain and backfat changes of sows postweaning

A collaborative study was conducted to evaluate factors related to determining optimal feeding and management programs for increasing net returns from marketing cull sows. A total of 269 multiparous sows averaging 192 kg of body weight were weaned, moved to individual gestation crates, and assigned to one of eight treatment combinations in a 2 x 2 x 2 factorial arrangement for a 42-d postweaning feeding experiment. Factors included limited (L) (1.8 kg/sow/d) or ad libitum (AL) access to feed during wk 1 postweaning, a corn-soybean meal (corn) or barley-sunflower meal (barley) diet, and pregnant or nonpregnant status. All sows were provided ad libitum access to feed from wk 2 to 6 postweaning. Gain and feed intake (FI) data were collected weekly for each sow and used to calculate gain:feed (G/F). Ultrasonic backfat (BF) data were collected on d 0, 21, and 42 postweaning. Sows on the AL treatment had greater FI (P < 0.05) but similar gain (P = 0.80) for the 42-d postweaning period compared to sows on the L treatment. Most of this response was due to lower sow body weight loss during wk 1 postweaning (P < 0.01) when sows were provided AL (-7.2 kg) vs L (-13.2 kg) access to feed. Sows fed the corn diet had higher gain (P < 0.01), improved G/F (P < 0.01), and increased BF (P < 0.01) over the 42-d feeding period than sows fed barley. The corn diet resulted in less sow BW loss (P < 0.01) during wk 1 (-8.8 kg) than the barley diet (-11.6 kg). Pregnant sows had higher gain, FI, G/ F, and BF (P < 0.01) than nonpregnant sows over the 42-d feeding period. Most of this advantage occurred during wk 4 postweaning when FI and gain of nonpregnant sows was lower (P < 0.01) than for pregnant sows. An economic analysis indicated that, when cull sow prices are relatively high and feed prices are moderate to low, maintaining and managing cull sows for an additional 6 wk postweaning may be economically advantageous compared to 0 or 3 wk. Pregnant sows fed the corn diet produced the greatest economic return. These results suggest that mating sows as they return to estrus postweaning and providing ad libitum access to a corn-soybean meal diet improves growth performance and feed efficiency, and may thereby provide increased returns when marketing cull sows.     

The effects of feed restriction on physical activity, body weight, physiology, haematology and immunology in female mink

The aim of the present study was to investigate if adult mink females characterised as having a high or low residual feed intake (RFI) differed in their response to feed restriction with regard to activity, body weight loss and physiological parameters. For RFI-High, the activity was higher prior to the expected feeding time both in the cases of restrictive and ad libitum feeding indicating a changed RFI-High feeding motivation and a higher risk of developing stereotypic activity. The body weight gain and the feed consumption were higher for RFI-High than for RFI-Low when feeding ad libitum indicating that RFI-High has a higher growth potential and/or a higher energy requirement than RFI-Low. Signs of immunosuppression were shown in connection with restrictive feeding compared to ad libitum feeding, and RFI-High females seemed to be more susceptible to immunosuppression than RFI-Low females. Based on the present results, mink characterised as RFI-Low would be preferable as breeders because they involve lower feed costs and seem to be less susceptible to immunosuppression. They also seem to have less risk of developing stereotypic activity, which is beneficial for the welfare.     

Comparative Nutrient Digestibility in Blue Foxes (Alopex lagopus) and Mink (Mustela vison) Fed Diets with Diverging Fat: Carbohydrate Ratios

Abstract

Nutrient digestibilities were evaluated in comparative experiments with blue foxes and mink by using six diets differing in fat:carbohydrate (F:C) ratios. In mink, apparent digestibilities of N and amino acids decreased with decreasing F:C ratio. N digestibility, and most amino acid digestibilities, were higher in blue foxes than in mink (P < 0.01). Fat digestibility in mink, but not in blue foxes, declined as the F:C ratio decreased (P < 0.05). Fat digestibility was higher in blue foxes than in mink (P < 0.05). Carbohydrate digestibility was not affected by the F:C ratio, but high levels of carbohydrates were digested more completely by foxes than by mink. The use of mink digestibility values in feed evaluations for blue foxes will consequently underestimate digestibility. Thus, to evaluate feed correctly, separate digestibility determinations should be made for mink and foxes.     

Effects of Feed Intake Restriction on Performance and Carcass Characteristics of Finishing Beef Steers,

Crossbred steers (n = 264, 311 ± 1.6 kg initial BW) were blocked by BW, randomly assigned to one of four treatments (28 pens, 7 pens per treatment), and fed a common 90% concentrate diet to determine the effects of the severity of caloric restriction on animal performance and carcass characteristics. Treatments were 1) ad libitum access to feed for 151 d (AL100); 2) 75% of DMI by AL100 for 65 d, 95% of DMI by AL100 for 65 d, and ad libitum access to feed for 21 d (AL85); 3) 80% of DMI by AL100 for 65 d, 100% of DMI by AL100 for 65 d, and ad libitum access to feed for 21 d (AL90); and 4) 85% of DMI by AL100 for 65 d, 105% of DMI by AL100 for 65 d, and ad libitum access to feed for 21 d (AL95). Feed was offered for AL85, AL90, and AL95 based on DMI by AL100 the previous week. All steers were fed a similar quantity of DM for 4 d prior to initial, interim, and final BW determinations to minimize gastrointestinal fill differences. Overall DMI was greater (P<0.01) for AL100 than for the average of the remaining treatments and decreased linearly (P<0.01) among AL95, AL90, and AL85. Overall ADG (carcass-adjusted) was less (P<0.01) for AL85, AL90, and AL95 than for AL100, whereas overall ADG:DMI (carcass-adjusted) did not differ (P>0.10) between AL100 and the average of the remaining treatments. Overall ADG and ADG:DMI (carcass-adjusted) responded quadratically (P<0.05) with increasing DMI restriction. Hot carcass weight, longissimus area, and kidney, pelvic, and heart fat percentage were greater (P<0.05) for AL100 than for the remaining treatments and responded quadratically (P<0.10) among AL85, AL90, and AL95. Marbling score was greater (P<0.10) for AL100 than for the average of the remaining treatments, and the number of carcasses grading Prime + Choice tended to be higher (P<0.15) for AL100 and AL95. Restricting feed intake of finishing yearling steers to an average of 85 to 95% of ad libitum for 130 d of a 151-d feeding period generally resulted in slower ADG, lesser marbling scores, and carcasses that were lighter and leaner compared with yearling steers allowed ad libitum to feed and harvested after an equal number of days on feed.     

Influence of birth weight and nutrient supply before and after weaning on the performance of rabbit does to age of the first mating

The objective of the study was to determine the effect of birth weight and the influence of nutrient supply during nursing and after weaning on the performance of suckling and growing rabbits (n = 182). The experiment was set-up using a 3 × 2 × 2 factorial arrangement. Newborn female rabbits were divided on the basis of their birth weight in 3 classes: low /L/ = 35–45 g, medium /M/ = 53–58 g and high /H/ = 65–70 g. Half of the litters were nursed by one (O) doe and the other half by two does (T). Kits were weaned at 3 weeks of age. From the age of 4 weeks half of the rabbits were fed ad libitum (AL), while the other half were reared on a restricted feeding regime (R) corresponding to 80–85% of the ad libitum feed intake level.Birth weight had a significant effect on the body weight up to the end of the experiment (18 weeks of age). H kits attained higher body weight at all ages (3772 g at 18 weeks of age compared to 3565 g and 3373 g for L and M rabbits, respectively). Significant differences were found in feed intake between 3 and 15 weeks of age, in feed conversion between 9 and 12 weeks of age and in weight gain between 3 and 4 and 12 and 15 weeks of age, in the majority of cases in favour of the H rabbits.Nursing by one or two does exerted the most pronounced effect on the body weight. T kits had significantly higher body weight than O kits up to 15 weeks of age (3306 vs. 3108 g). Differences in feed intake, feed conversion and body weight were only periodically demonstrable between the groups O and T.The feeding regime exerted a significant influence on the feed intake, weight gain and body weight of kits. Significant differences in the feed conversion were found, however, only between 15 and 18 weeks of age. Although AL rabbits achieved better feed conversion at all ages except the period between 9 and 12 weeks of age.It seems that the three factors (birth weight, number of nursing does and feeding regime), especially the feed restriction, could influence the production of does.     

The nutritional effect of <Emphasis Type="Italic">Moringa oleifera</Emphasis> fresh leaves as feed supplement on Rhode Island Red hen egg production and quality

This study aimed to evaluate the potential of Moringa oleifera fresh leaves (MOL) as feed supplement on the performance and egg quality of Rhode Island Red (RIR) hens under the tropical conditions of Yucatan, Mexico. Forty-eight RIR hens were allocated in 12 floor pen replicates each with four birds. Thereafter, the replicates were divided into three groups which were corresponded to ad libitum feed (control), ad libitum feed supplemented with MOL T1 (AL + MOL) and restricted feed amount (20% lower than control) with MOL T2 (RCD + MOL), respectively. T1 (AL + MOL) had higher egg laying rate (71.4% versus 66.6%), higher daily egg mass production (45.4 versus 41.9 g/day), lower feed intake (121.3 versus 127.5 g/day) and better feed conversion ratio (2.8 versus 3.2 g feed:g egg) versus control. T2 / (RCD + MOL) had lower values of body weight, egg laying rate, egg weight and egg mass, and recorded better feed conversion ratio than the control group. The control group recorded a higher percentage of pecked eggs versus T1 and T2 (6.5% versus 1.2% and 2.0 %). Similar intake of MOL (3.1 and 3.4 g DM/day) was recorded in T1 (AL + MOL) and T2 (RCD + MOL). Yolk color was improved significantly in T1 (AL + MOL) than both control and T2 (RCD + MOL), while T2 (RCD + MOL) had eggs with lower yolk and higher albumen percentages than the other two ad libitum groups. The results suggest that MOL could be used successfully as sustainable tropical feed resource for RIR hens.     

Effects of programmed growth rate and days fed on performance and carcass characteristics of feedlot steers.

Two experiments were conducted to investigate a feeding regimen in which a programmed amount of feed was offered daily to control growth rate of steers. In Exp. 1, steers (n = 107, 309 +/- 3 kg) were used to determine effects of offering ad libitum access to feed (AL) vs a programmed intake feeding regimen (PI) and the number of days steers were fed (168 vs 203) on performance and carcass characteristics. Steers in the programmed intake feeding regimen were fed to achieve a predicted gain of 1.13 kg/d for the first 78 kg of gain, 1.36 kg/d for the next 124 kg of gain, and were given ad libitum access to feed for the final 54 or 103 kg of gain before slaughter (for steers fed for 168 d or 203 d, respectively). Feed efficiency was greater (P < 0.02) for steers in the PI than for those in the AL feeding regimen (0.193 vs 0.183 kg gain/kg feed, respectively). From d 169 to 203, steers in the PI feeding regimen had greater (P < 0.06) ADG (1.60 vs 1.38 kg/d) and similar (P = 0.38) feed efficiency than steers in the AL regimen. In Exp. 2, steers (n = 96; 308 +/- 3 kg BW) were offered feed ad libitum throughout the experiment (AL) or were programmed to gain at a high (PI-H) or low (PI-L) growth rate. For the first 78 kg of gain, intake was restricted to achieve predicted gains of 1.13 kg/d (PI-L) or 1.25 kg/d (PI-H). For the next 124 kg of gain, intake was restricted to achieve predicted gains of 1.36 kg/d (PI-L) or 1.47 kg/d (PI-H). Feed was offered ad libitum for the final 58 kg of gain. Overall ADG was similar (P > 0.37) among feeding regimens despite lower DMI for the steers in the PI-L and PI-H feeding regimens than for those in the AL regimen. Feeding regimen did not affect (P < 0.22) carcass characteristics. Programmed intake feeding regimens sustained growth rate and feed efficiency for an extended period of time without detrimental effects on carcass characteristics.     

Effects of continual fluctuation in feed intake on growth performance response and carcass fat-to-lean ratio in grower-finisher pigs

An experiment was conducted to examine the effect of continual fluctuations in feed intake on grower-finisher pig growth performance and carcass fat-to-lean ratio (F:L). Sixty individually housed female pigs (Landrace x Large White) with initial BW of 29.8 +/- 0.4 kg were randomly allocated to 1 of 4 feeding regimens (n = 15): 1) ad libitum throughout (AL); 2) 85% of the mean intake of the AL group during the previous week (R); 3) 70% of the mean intake on 1 d, and on the following day, 100% of the amount consumed by the AL group during the preceding week, with this pattern repeated every 2 d throughout (D); and 4) 70% of the mean intake for 3 consecutive days, and 100% of the amount consumed by the AL group for the next 3 d, with this pattern repeated throughout the experiment (3-D). Pigs receiving each treatment were fed the same diets during the weaner (10 to 20 kg), grower (20 to 50 kg), finisher 1 (50 to 70 kg), and finisher 2 (70 kg to slaughter at approximately 104 kg) growth phases. Pigs receiving fluctuated feed intake either by the D or 3-D feeding regimen showed a pattern of growth similar to that of pigs on the R feeding regimen. Pigs on the R and 3-D regimens were lighter at 28 d (P < 0.05) and pigs on the R, D, and 3-D regimens were lighter at 63 d (P < 0.05) than pigs on the AL regimen. Pigs on the R, D, or 3-D feeding regimens had a greater G:F between 15 to 42 d of the experiment than pigs fed AL throughout (P < 0.05). The R, D, and 3-D feeding regimens seemed to have some effect on carcass weight and dressing percentage, and pigs had a decreased P2 (located 65 mm from the midline of the carcass at the last thoracic rib) backfat depth (P < 0.05) compared with pigs fed AL. Pigs on the AL and 3-D feeding regimens had thicker subcutaneous fat at the last lumbar vertebrae on the dorsal edge of the loin than pigs on the R feeding regimen (P < 0.05). Carcass and visceral fat content and the F:L in the carcass and primal cuts, as measured by dual energy x-ray absorptiometry, were not different among treatments. However, pigs on the AL and 3-D feeding regimens had decreased estimated bone content in the carcass compared with pigs on the R and D feeding regimens (P < 0.05). The results indicated that continual fluctuation in feed intake either every other day or every 3 d had minimal effects on growth and carcass F:L compared with pigs fed the same restricted amount throughout the experiment.     

Effects of phytogenic feed additives,probiotic and mannan-oligosaccharides on performance,blood metabolites,meat quality,intestinal morphology,and microbial population of Japanese quail

ABSTRACT

1. The aim of this experiment was to investigate the effects of ajwain (Trachyspermum ammi) and dill (Anethum graveolens) essential oils (AEO and DEO, respectively), probiotic (PRO) and mannan-oligosaccharides (MOS) on the growth performance, serum metabolites, meat quality, intestinal morphology and microbial populations of Japanese quail.

2. A total of 375 one-day-old Japanese quail were randomly allocated into five treatment groups with five replicates of 15 birds each for a 42 d feeding experiment. The dietary treatments were a basal diet (control) or the same diet supplemented with PRO (0.15 g/kg feed), MOS (2 g/kg feed), AEO (0.25 g/kg feed) or DEO (0.25 g/kg feed).

3. AEO, MOS, and PRO supplementation increased weight gain, while diets supplemented with AEO decreased feed intake (FI), and improved feed conversion ratio from d 1 to 21 (P < 0.05). The relative weight of the gizzard was higher in birds supplemented with AEO compared to control group, while the birds fed MOS diet had the longest intestine (P < 0.05). Ceca length was greater in control, MOS and PRO groups (P < 0.05). Both essential oils decreased malondialdehyde (MDA) concentration of breast meat and percentage of cooking loss in quail (P < 0.05). The villus length (VL) was greater in birds fed diet supplemented with MOS, AEO, and DEO (P < 0.05).The population of E.coli decreased in Japanese quail fed MOS, while Lactobacilli spp. count was increased in the MOS group (P < 0.05).

4. In conclusion, AEO, MOS, and PRO supplementation exhibited a positive effect on growth performance, while lipid peroxidation of the meat decreased in birds fed AEO and DEO diets. The intestinal morphometric indices increased in quail fed the AEO, MOS, and DEO diets. Supplementation with MOS modulated intestinal microbial populations of the Japanese quail.     

Molecular evolutionary analysis reveals Arctic-like rabies viruses evolved and dispersed independently in North and South Asia

BackgroundArctic-like (AL) lineages of rabies viruses (RABVs) remains endemic in some Arctic and Asia countries. However, their evolutionary dynamics are largely unappreciated.ObjectivesWe attempted to estimate the evolutionary history, geographic origin and spread of the Arctic-related RABVs.MethodsFull length or partial sequences of the N and G genes were used to infer the evolutionary aspects of AL RABVs by Bayesian evolutionary analysis.ResultsThe most recent common ancestor (tMRCA) of the current Arctic and AL RABVs emerged in the 1830s and evolved independently after diversification. Population demographic analysis indicated that the viruses experienced gradual growth followed by a sudden decrease in its population size from the mid-1980s to approximately 2000. Genetic flow patterns among the regions reveal a high geographic correlation in AL RABVs transmission. Discrete phylogeography suggests that the geographic origin of the AL RABVs was in east Russia in approximately the 1830s. The ancestral AL RABV then diversified and immigrated to the countries in Northeast Asia, while the viruses in South Asia were dispersed to the neighboring regions from India. The N and G genes of RABVs in both clades sustained high levels of purifying selection, and the positive selection sites were mainly found on the C-terminus of the G gene.ConclusionsThe current AL RABVs circulating in South and North Asia evolved and dispersed independently.     

Influence of feeding intensity on the growth, body composition and sexual maturity of male New Zealand White rabbits

An experiment was carried out with young male New Zealand White (NZW) rabbits to establish live body weight changes, body measurements, body composition and sexual maturity as a function of feeding intensity. Animals in Group 1 ('AL', n = 10) were fed ad libitum, while those in Group 2 ('RS', n = 10) received restricted feeding corresponding to 70% of the ad libitum level. The starting liveweights were practically the same (0.907 +/- 0.146 and 0.911 +/- 0.147 kg in Group AL and Group RS, respectively). The feeding trial lasted from 6 to 22 weeks of age. The average body weight was significantly higher in Group AL from 7 to 22 weeks of age. At 22 weeks of age the body weight of RS rabbits was 85.64% of the weight of AL animals (3.22 +/- 0.52 kg and 3.76 +/- 0.33 kg, respectively). Average body weights of RS males at 8, 9, 11, 19 and 21 weeks of age were similar to those of ad libitum fed (AL) animals at 7, 8, 10, 15 and 16 weeks of age, respectively. The growth of bucks fed restricted tended to be allometric. The most significant difference was found at 16 and 18 weeks of age, while the lowest difference occurred at 6, 12, 15 and 19 weeks of age. It can be stated that low-intensity feeding up to slaughtering weight causes backwardness in rear cannon length and this backwardness remains also after the 15th week, which is well over the optimal slaughtering age. Based on the present data, the 70% restricted feeding cannot be recommended either for the future breeding bucks or for broiler males reared for slaughter. To determine the major chemical components of the body, rabbits were euthanised. Original dry matter and crude fat content of the body significantly (P < 0.05) decreased under restricted feeding (41.42%; 32.48% and 16.73%; 7.35%) while the percentage of protein within the dry matter increased (49.6%; 65.0%) and fat decreased (40.17%; 22.1%) significantly. Libido unambiguously decreases as a consequence of feed deprivation. The most conspicuous difference was found in the level of blood testosterone. Although a few RS bucks produced semen but only much later than the rabbits fed ad libitum. On the other hand, there was no difference in the motility of spermatozoa and ejaculate volume in comparison with AL animals. There was no relationship between the body fat content and the reproductive status of bucks in the present trial.