Hormonal, behavioural and performance characteristics of Meishan sows during pregnancy and lactation

2003 ◽  
Vol 83 (1) ◽  
pp. 1-12 ◽  
Author(s):  
C. Farmer and S. Robert
Keyword(s):  
Reproductive Potential ◽  
Milk Composition ◽  
Mammary Development ◽  
Published Data ◽  
Endocrine Status ◽  
Pregnancy And Lactation ◽  
Management Schemes ◽  
Endocrine Factors ◽  
And Performance ◽  
Biological Differences

Meishan sows are known for their high prolificity and great lactational performances. Specific breed characteristics in terms of their embryonic, foetal and placental developments as well as their differences in mammary development at the end of gestation are covered. The various known metabolic, physiological and endocrine factors related to the decreased embryonic mortality and increased placental vascularity, which are largely responsible for the greater litter size of Meishans, are discussed. An overview of published data on the endocrine status of the sow and foetuses throughout pregnancy is also presented. The superiority of Meishan sows during lactation is described in terms of its various components (i.e., piglet growth and development, sow and litter behaviour, milk composition) and the breed differences pertaining to sow metabolism and endocrinology during lactation are covered in order to provide an insight as to the possible mechanisms responsible for these superior performances. This review illustrates how a better understanding of the biological differences between Meishan sows and sows from European breeds could benefit the development of new management schemes to further improve reproductive potential of sows from traditional breeds. Key words: Meishan, gestation, lactation, hormones, behaviour, performance

Surgical Drilling: Design and Performance of an Improved Drill

1982 ◽  
Vol 104 (3) ◽  
pp. 245-252 ◽  
Author(s):  
S. Saha ◽  
S. Pal ◽  
J. A. Albright
Keyword(s):  
Compact Bone ◽  
Helix Angle ◽  
Rake Angle ◽  
Peak Temperature ◽  
Published Data ◽  
Drill Bit ◽  
Effective Removal ◽  
Split Point ◽  
And Performance ◽  
Twist Drills

The majority of twist drills used in orthopaedics are very similar to chisel pointed metal drilling bits. Modifications usually observed are reduction of the point angle to 90 deg and sometimes grinding of the entire cutting lip at 0 deg rake angle, which appeared to have been made arbitrarily without any advantage. We have attempted to design a surgical drill bit with the objective of minimization of the drilling thrust and temperature and effective removal of bone chips. Our results showed that the presence of the chisel edge was mainly responsible for increasing the thrust force and the temperature developed. The effects of a constant feed rate and thrust on the peak temperature were also examined. The combined effect of the helix and the point angles on the rake angle which in turn determines the cutting efficiency was analyzed for various types of surgical bits. Based on our results and previously published data from the literature an optimized drill bit was designed with a split point, a point angle of 118 deg, a parabolic flute, and a helix angle of 36 deg and its performance was compared with other existing surgical drill bits. For drilling in compact bone, the new design decreased the thrust load by 45 percent and the peak temperature rise by 41 percent. Simlar improvements were also recorded for drilling bone cement. The time of drilling a bone cortex was also significantly reduced and “walking” on the curved bone surface was eliminated and dimensional tolerance on hole sizes was improved. The new design is likely to reduce the time of surgery and also minimize the tissue damage.

scholarly journals Maternal Lipid Intake During Pregnancy and Lactation Alters Milk Composition and Production and Litter Growth in Rats

1997 ◽  
Vol 127 (3) ◽  
pp. 458-462 ◽  
Author(s):  
Martha Del Prado ◽  
Guadalupe Delgado ◽  
Salvador Villalpando
Keyword(s):  
Milk Composition ◽  
Pregnancy And Lactation

The effect of feeding salmon oil to sows throughout pregnancy on pre-weaning mortality of piglets

2001 ◽  
Vol 73 (3) ◽  
pp. 489-500 ◽  
Author(s):  
J.A. Rooke ◽  
A.G. Sinclair ◽  
S.A. Edwards ◽  
R. Cordoba ◽  
S. Pkiyach ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Birth Weight ◽  
Polyunsaturated Fatty Acids ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Gestation Length ◽  
Nutritional Study ◽  
Pregnancy And Lactation ◽  
And Performance ◽  
Long Chain

AbstractSalmon oil (16·5 kg /t), a source of long-chain polyunsaturated n-3 fatty acids, was included in diets offered to multiparous sows during pregnancy and lactation to measure responses in pre-weaning mortality and performance of piglets in two studies. The first study, carried out under commercial conditions, included 196 sows which were offered salmon oil and control diets from immediately post service until weaning. The same diets were also offered to 10 sows per treatment from day 58 of pregnancy in a controlled nutritional study which measured the effects of salmon oil on piglet tissue fatty acid composition. Offering salmon oil to the sow significantly increased gestation length and decreased individual piglet birth weight but had no effect on litter size at birth. Overall, salmon oil reduced pre-weaning mortality from 11·7% to 10·2% mainly by reducing the incidence of deaths from crushing by the sow. More detailed analysis of mortality using a general linear mixed model and 2294 piglet records, demonstrated that the incidence of pre-weaning mortality was significantly decreased with increasing individual piglet birth weight and by inclusion of salmon oil in the diet; the incidence of mortality increased with average piglet birth weight in a litter. Salmon oil inclusion had no effect on weight of litter weaned, sow lactation food intake or subsequent reproductive performance. In both studies, dietary salmon oil increased the proportions of long-chain n-3 polyunsaturated fatty acids in colostrum to a similar extent. In the nutritional study, inclusion of salmon oil reduced the proportions of 20: 4 n-6 in piglet liver and brain at birth and increased the proportions of long-chain n-3 polyunsaturated fatty acids. Therefore, despite reducing piglet birth weight, offering sows salmon oil reduced pre-weaning mortality of piglets. The nutritional study showed that the amount and type of marine oil used may not have been optimal.

scholarly journals WINTER-SPRING NUTRITION AND MANAGEMENT EFFECTS ON EWE AND LAMB PERFORMANCE

1984 ◽  
pp. 190-198
Author(s):  
D.C. Smeaton ◽  
P.V. Rattray
Keyword(s):  
Live Weight ◽  
Grazing Management ◽  
Lactation Period ◽  
Restricted Feeding ◽  
Rotational Grazing ◽  
Short Rotation ◽  
Pregnancy And Lactation ◽  
And Performance ◽  
Carry Over ◽  
Management Effects

Aspects of the above theme were investigated in 5 trials. Trial 1 compared the effects of high and low nutrition during pregnancy and lactation on ewe and iamb production. Ewe live weight was substantially affected by nutrition treatment during pregnancy but carry-over effects on live weight at weaning were small. Nutrition during lactation strongly affected both lamb and ewe weaning weights. Ewe and lamb losses were not affected by nutrition at any stage. The results implied that ewes can be quite severely restricted on pasture during pregnancy in order to save feed for the much more important lactation period. Trials 2 and 3 investigated the management of ewes fed at maintenance levels in mid-pregnancy. The treatments consisted of various grazing durations where the ewes were shifted from one pasture break to another after a specific grazing duration, as defined by their treatment. These treatments consisted of grazing durations ranging from 3 to 56 days. Liveweight differences occurred during the 56-dav trial period but at the end there was only 2.5kg difference between extreme treatments. This suggests that where ewes are on restricted feeding during pregnancy to conserve pasture reserves, grazing duration has little consistent impact on final ewe live weight and performance. However, for several reasons, a shorter duration (3-7 days) is preferred. Trials 4 and 5 compared several winter-spring management treatments. Ewes on a 35day (short) rotation during pregnancy versus those on a 70day (long) rotation had less pasture on their farmlet at lambing (930 V. 1030 kg/ha). As a consequence the short rotation ewes were 1.5 kg lighter at weaning. Their lambs ware 2.3 kg lighter. In another comparison, set-stocking ewes 4 weeks before lambing compared with at lambing disadvantaged the ewes and lambs by 2-3 kg at weaning. The ewes set-stocked 4 weeks before lambing had consumed most of their winter reserves by lambing. In Trial 5, rotational grazing after lambing until weaning versus set-stocking, disadvantaged the ewes and iambs by 4 and 3 kg respectively at weaning. This was probably because the rotation length of 21 days in the rotational group was too long. Management implications from these results are discussed. Keywords: winter, spring, nutrition, grazing management, ewes, lambs, pregnancy, lactation, grazing duration, rotational grazing, set stocking.

scholarly journals Effects of Spondias mombin l. On milk composition of lactating West African Dwarf (WAD) ewes

2020 ◽  
Vol 36 (2) ◽  
pp. 335-343
Author(s):  
M. A. Oguike ◽  
M. E. Udeh
Keyword(s):  
Milk Protein ◽  
Post Partum ◽  
Milk Composition ◽  
West African ◽  
Trial Group ◽  
Total Solids ◽  
Treatment Groups ◽  
West African Dwarf ◽  
Spondias Mombin ◽  
And Performance

A study was conducted to investigate the effects of Spondias mombin on milk composition using milk from twelve lactating West African dwarf (WAD) ewes. The lactating ewes were assigned to two treatment groups of six ewes per group, designated T1 and T2 representing control and trial group, respectively The ewes in T2, the trial group were fed Spondias mombin L. post partum while those in T1 the control were not fed Spondias mombin. Colostrum samples were collected from each ewe the first four days following parturition while normal milk was sampled for analysis after two weeks of lambing through 12 weeks of lactation. The constituents studied were lactose, milk protein, butterfat, ash, total solids and solid non-fat. Results showed that the colostrums of ewes fed S. mombin had significantly higher (P<0.05) total solids, and solids not fat contents of 18.34 and 11.31% respectively, than those of the control ewes which were 17.32 and 10.35%, respectively. The other constituents of colostrums of the different groups were not significantly different (P>0.05). At week 2 of lactation, lactose (3.98%) and ash (0.98%) concentrations of normal milk of treated ewes were significantly higher (P<0.05) than those of the control ewes for lactose (3.74%) and ash (0.65%). Also by the 12th week of lactation, ash contents of the two treatments were significantly different (P<0.05) with T2 having higher value. There were no significant differences (P>0.05) in the normal milk compositions of both groups in weeks 4, 6, 8 and 10. These results suggest that feeding S. mombin to lactating ewes could be useful in improving on the milk composition of WAD ewes and has no adverse effects on their general health and performance.

Non-nutritional (novel) techniques for manipulation of milk composition

2000 ◽  
Vol 25 ◽  
pp. 223-239 ◽  
Author(s):  
C.H. Knight ◽  
A. Sorensen ◽  
D.D. Muir
Keyword(s):  
Protein Secretion ◽  
Milk Composition ◽  
Feedback Inhibitor ◽  
Milking Frequency ◽  
Endocrine Factors ◽  
Robotic Milking ◽  
New Research ◽  
Processing Properties ◽  
Extended Lactation ◽  
The Impact

AbstractThis review considers the control of milk composition by endocrine factors and local mechanisms operating within the udder, and the impact of management systems and the environment on these control systems. Much less is known about control of milk composition than yield, although one can propose that prolactin is more concerned with control of lactose and protein secretion whilst growth hormone has a bigger role to play in fat secretion. Molecular biological approaches have the potential to increase understanding and, in the distant but foreseeable future, to manipulate milk composition on a commercial scale. The feedback inhibitor of lactation (FIL), which is responsible for local control of milk yield, has equal effects on lactose, fat and protein secretion, so changes in milking frequency do not alter gross milk composition. During the course of lactation the processing properties of milk gradually deteriorate as a consequence of proteolytic degradation of caseins, but new research shows that this can largely be prevented by milking thrice–daily. This has significant implications for future milking strategies such as robotic milking and extended lactation.

Lycopene improves maternal reproductive performance by modulating milk composition and placental antioxidative and immune status

2021 ◽  
Author(s):  
Shishuai Sun ◽  
Qingwei Meng ◽  
Yongsong Bai ◽  
Chunyu Cao ◽  
Jibo Li ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Reproductive Performance ◽  
Immune Status ◽  
Milk Composition ◽  
Milk Quality ◽  
Pregnancy And Lactation ◽  
Anti Inflammation

Placental health and milk quality are important for maternal reproductive performance during pregnancy and lactation. Lycopene plays an important role in antioxidation, anti-inflammation and regulating lipid metabolism. The goal of...

Effects of B vitamins and methyl group donors on milk production, milk composition and blood biochemistry in dairy cows

2002 ◽  
Vol 2002 ◽  
pp. 196-196
Author(s):  
S.E Richards ◽  
S Hicklin ◽  
T Lord ◽  
A Nickson ◽  
J Long ◽  
...  
Keyword(s):  
Milk Yield ◽  
Milk Composition ◽  
Metabolic Fate ◽  
Dry Period ◽  
Very Low Density Lipoproteins ◽  
Methyl Group ◽  
Fat Reserves ◽  
Esterified Fatty Acids ◽  
Pregnancy And Lactation ◽  
Tag Accumulation

Recent reviews highlight the importance of the liver in the coordination of nutrient fluxes in support of pregnancy and lactation (e.g. Drackley et al., 2001). Mobilisation of body fat reserves in the late dry period and early lactation leads to an increase in uptake of non-esterified fatty acids (NEFA) by the liver. Their metabolic fate is either oxidation or esterification into triacylglycerides (TAG) that are either exported in very low density lipoproteins (VLDL) or accumulated within liver cells. Recent evidence indicates that TAG accumulation impairs ureagenic and gluconeogenic capacity of the liver, with consequent reductions in feed intake and milk yield, increased incidence of disease and decreased reproductive performance (Overton and Piepenbrink, 1999).LiFTTM (NuTec Ltd.) is a proprietary mixture of B-group vitamins and methyl group donors (rumen protected choline, niacin, vitamin B12, biotin, folic acid and thiamine) designed to reduce the accumulation of TAG in the liver and accelerate VLDL export. The objective of this experiment was to evaluate the effect of LiFT on milk yield and composition and concentrations of metabolites in blood.

Effects of bacterial inoculation of unwilted and wilted grass silages. 2. Intake, performance and eating behaviour by dairy cattle

1998 ◽  
Vol 131 (1) ◽  
pp. 113-119 ◽  
Author(s):  
D. C. PATTERSON ◽  
T. YAN ◽  
F. J. GORDON ◽  
D. J. KILPATRICK
Keyword(s):  
Milk Yield ◽  
Eating Behaviour ◽  
Milk Composition ◽  
Period Change ◽  
Eating Rate ◽  
Bacterial Inoculation ◽  
Lactating Dairy Cows ◽  
Soyabean Meal ◽  
The Mean ◽  
And Performance

Four grass silages, namely unwilted and wilted silages each with and without bacterial inoculation, were prepared on each of eight harvesting occasions during the 1994 growing season (Yan et al. 1998). The four silages, made at each harvest, were offered ad libitum to 48 lactating dairy cows in a 2 (control v. additive)×2 (unwilted v. wilted)×8 (harvest (period)) change-over design experiment with 3-week experimental periods. The animals also received 6·9 kg dry matter (DM) of a concentrate supplement daily during the first period and then the allowance of the supplement was reduced by 0·43 kg DM at the start of each subsequent period. The supplement was based on barley, molasses and soyabean meal. The data presented are the mean results obtained across the eight harvests.No significant interactions were found between inoculation and wilting for silage intake, performance and silage eating behaviour. Inoculation significantly increased milk yield (2·4%, P<0·05) and lactose output in milk (2·3%, P<0·05) across the unwilted and wilted silages. These increases following inoculation in general arose equally from both the unwilted and wilted silages. However, inoculation of either the unwilted or wilted silages had no significant effects on silage DM intake, milk composition, or silage eating behaviour. Wilting significantly increased silage DM intake (20·1%, P<0·001), milk yield (2·8%, P<0·05) and the concentrations (P<0·001) and yields (P<0·01) of both fat and protein across the untreated and inoculant-treated silages. The increases following wilting derived equally from both the untreated and inoculant-treated silages. Wilting also significantly influenced silage eating behaviour with a significant decrease following wilting in number of meals per day (6·5%, P<0·05) and an increase in eating rate (kg DM per eating hour) (29·7%, P<0·001) across the untreated and inoculant-treated silages. These results indicate that inoculation of the unwilted and wilted silages produced similar increases in milk production. Large positive responses in silage DM intake and performance were recorded following wilting with both the untreated and inoculant-treated silages.

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