Prepartum mammogenesis, milk production, and optimal litter size

Oecologia ◽  
1998 ◽  
Vol 114 (2) ◽  
pp. 288-291 ◽  
Author(s):  
E. W. Jameson Jr.
Keyword(s):  
Milk Production ◽  
Litter Size ◽  
Optimal Litter Size

scholarly journals An Analysis of Culling Patterns during the Breeding Cycle and Lifetime Production from the Aspect of Culling Reasons for Gilts and Sows in Southwest China

Animals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 160 ◽  
Author(s):  
Chao Wang ◽  
Yinghui Wu ◽  
Dingming Shu ◽  
Hongkui Wei ◽  
Yuanfei Zhou ◽  
...  
Keyword(s):  
Milk Production ◽  
Litter Size ◽  
Reproductive System ◽  
Southwest China ◽  
Breeding Cycle ◽  
Common Disease ◽  
System Disease ◽  
Lactating Sows

To investigate culling patterns during the breeding cycle and lifetime production associated with culling reasons, 19,471 culling records were collected in southwest China. Lifetime pigs born alive (LPBA) and parity for culling reasons, and reason distribution at different parities and breeding cycle were analyzed. Sows culled for stress and death (SD), lameness (LA), common disease (CD), not being pregnant, return to estrus, and abortion (NP) had fewer than 20 LPBA (p < 0.05). Gilts were mainly culled for anestrus beyond nine months (AB9), CD, and LA, while weaned sows were culled for reproductive system disease (RS), CD, and anestrus beyond seven days (p < 0.0033). Gestating sows were mainly culled for NP, CD, and SD, while lactating sows were mainly culled for low or no milk production (NM), poor litter size, and CD (p < 0.0033). Moreover, sows were mainly culled at parity 0, 1, and 2 (p < 0.0024). Besides CD and RS, LA and NP were the primary reasons for parity 1 and 2 culls, respectively. In conclusion, SD, LA, CD, and NP sharply decrease sow lifetime production. AB9, RS, NP, and NM mainly occurred in gilts, weaned, gestating, and lactating sows, respectively. Low parity sows had a higher risk of CD, RS, LA, and NP.

scholarly journals Milk Production of Lacaune Sheep with Different Degrees of Crossing with Manchega Sheep in a Commercial Flock in Spain

Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 520
Author(s):  
Lizbeth E. Robles Jimenez ◽  
Juan C. Angeles Hernandez ◽  
Carlos Palacios ◽  
José A. Abecia ◽  
Anna Naranjo ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Milk Production ◽  
Litter Size ◽  
Milk Yield ◽  
Mixed Model ◽  
The Other ◽  
Commercial Flock ◽  
Parity Number ◽  
Available Information ◽  
Autumn And Winter

The objective of the present study was to evaluate the effect of the grade of crossbreeding (Lacaune x Manchega) and environmental factors on milk production in a commercial flock in Spain. A total of 5769 milk production records of sheep with different degrees of purity of the Lacaune breed crossed with Manchega were used as follows: 100% Lacaune (n = 2960), 7/8 Lacaune (n = 502), 13/16 Lacaune (n = 306), 3/4 (n = 1288), 5/8 Lacaune (n = 441) and 1/2 Lacaune: Manchega (n = 272). Additional available information included the number of parity (1 to 8), litter size (single or multiple), and the season of the year of lambing (spring, summer, autumn and winter). A mixed model was used to evaluate the level of crossbreeding and environmental factors on milk production. The 100% Lacaune sheep presented the highest milk production with respect to the F1 Lacaune x Manchega sheep (p < 0.01), showing that as the degree of gene absorption increases with the Manchega breed, it presents lower milk yield. The 100%, 13/16, and 3/4 Lacaune genotypes had the highest milk yields with respect to the 1/2 Lacaune/Manchega breed (p < 0.001). The Lacaune registered on average 181.1 L in a period adjusted to 160 days of lactation (1.13 L/ day). Likewise, the parity number, litter size, and season of lambing effects showed significant differences (p < 0.01). It was concluded that 13/16 and 3/4 Lacaune/Manchega ewes presented the highest milk yields with respect to the other crosses.

scholarly journals Hycole Doe Milk Properties and Kit Growth

Animals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 214
Author(s):  
Agnieszka Ludwiczak ◽  
Joanna Składanowska-Baryza ◽  
Beata Kuczyńska ◽  
Marek Stanisz
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Milk Production ◽  
Litter Size ◽  
Somatic Cell Count ◽  
Quality Traits ◽  
Litter Weight ◽  
Daily Milk Production ◽  
Rabbit Milk ◽  
Daily Milk

The level of production and the physiochemical traits of rabbit milk affect the growth and the mortality of bunnies during lactation. The goal of the study was to analyze the effect of litter size and day of lactation on the quality traits of rabbit milk, milk production, and associative traits. The study was conducted on 32 Hycole does and their litters. The rabbit milk pH ranged from 6.61 to 7.46. The colostrum was characterized by the highest content of total solids (31.54 and 31.80 g kg−1) and fat content (15.73 and 15.9 g kg−1). The milk from the beginning of the lactation was characterized by the highest level of somatic cell count (SCC) (523.67 and 536.57 103 mL−1), which gradually decreased to reach the lowest level on days 17 and 21 of lactation. The daily milk production was greater for does nursing 10 kits per litter compared to those nursing eight kits per litter (p < 0.001). The peak of milk production occurred on day 17 postpartum. To conclude, the litter size has a clear effect on milk production as well as litter weight and litter weight gains. It is also important to note that the day of lactation affected the physiochemical traits of rabbit milk.

Optimal litter size: Does it cost more to raise a large litter in Caluromys philander?

1992 ◽  
Vol 70 (8) ◽  
pp. 1511-1515 ◽  
Author(s):  
Martine Atramentowicz
Keyword(s):  
Food Intake ◽  
Reproductive Success ◽  
Litter Size ◽  
Body Length ◽  
Weaning Food ◽  
Daily Food Intake ◽  
Litter Mass ◽  
Large Litter ◽  
Daily Food ◽  
Optimal Litter Size

Food intake of lactating Caluromys philander, a didelphid marsupial, was recorded from parturition until weaning of the pouch young. Variation in the average caloric value of daily food intake throughout lactation, in relation to litter size, showed no significant differences, but females increased food intake during late lactation, prior to weaning. Food intake was positively correlated with total litter mass at weaning. Moreover, there were significant differences in body mass and body length of offspring at first pouch exit (3 months) and at weaning (4 months): young born in small litters (1–3) were bigger than those born in large litters (6–7). Reproductive success is discussed on the assumption that pouch-young survival depends on food resources.

scholarly journals Regulation of serum leptin and its role in the hyperphagia of lactation in the rat

2003 ◽  
Vol 176 (2) ◽  
pp. 193-203 ◽  
Author(s):  
RG Denis ◽  
G Williams ◽  
RG Vernon
Keyword(s):  
Energy Balance ◽  
Food Intake ◽  
Milk Production ◽  
Litter Size ◽  
High Energy ◽  
Negative Energy ◽  
Negative Energy Balance ◽  
Calorie Intake ◽  
Serum Leptin ◽  
Nocturnal Rise

The factors regulating serum leptin concentration and its relationship to the hyperphagia of lactation have been investigated in rats. Lactation results in hypoleptinaemia and loss, or at least marked attenuation, of the nocturnal rise in serum leptin. Litter removal resulted in a fall in food intake and restoration of the nocturnal rise in serum leptin. Returning the litter to the mother after a 48-h absence increased food intake and began to reinitiate milk production, but the nocturnal serum leptin levels were still increased at 48 h after litter restoration. Adjusting litter size to four, eight, ten or fourteen pups at parturition resulted in different rates of litter growth and food intake during the subsequent lactation, but had no effect on the degree of hypoleptinaemia. Reducing litter size from ten to four pups at mid-lactation resulted in a transient increase in both serum leptin and pup growth rate, while food intake fell to a level found in rats suckling four pups throughout lactation. Reducing milk production by injection of bromocriptine increased serum leptin, but did not restore the nocturnal rise in serum leptin; food intake decreased, but remained much higher than in non-lactating rats. Feeding a varied, high-energy diet resulted in a decrease in the weight of food ingested, but no change in calorie intake, and had no effect on the hypoleptinaemia. These studies suggested that the hypoleptinaemia of lactating rats is due to negative energy balance, but the loss of the nocturnal rise in serum leptin is due to the suckling stimulus. The negative energy balance of lactation does not appear to be caused by a physical constraint on food intake. While the hypoleptinaemia should facilitate the hyperphagia of lactation, other orexigenic signals must also be involved.

scholarly journals Breeding and exploitation of prolific breeds in Czechoslovakia

1988 ◽  
Vol 60 (6) ◽  
pp. 505-510
Author(s):  
V. Jakubec ◽  
J. Křižek
Keyword(s):  
Mortality Rate ◽  
Milk Production ◽  
Litter Size ◽  
Fibre Diameter ◽  
Carcass Weight ◽  
Meat Production ◽  
Wool Production ◽  
Production Increase ◽  
Daily Gain

In the years 1971—1979 many experiments were conducted in order to elucidate problems of meat production increase in sheep. Ewes of native breeds (Mutton Merino = M, Improved Wallachian = I) were mated to rams of prolific breeds (Finnsheep = F, Romanov = R), producing F1 crossbred females. The crossbred ewes were mated to rams of a third mutton breed (Texel, Dorset Down, M) to produce meat lambs. In experiments from 1980 to 1987on the basis of the I and the R and F crossbred combinations were produced to provide contemporary comparison of purebreds, F1, F2 and backcrosses, both to I and to F and R. The purebred and crossbred populations were analysed for the estimation of crossbreeding parameters necessary for the optimization of the formation of a synthetic dam breed. The reproduction characters which were analysed were fertility, prolificacy, mortality rate, litter size (born and weaned) and milk production. From the wool production characters the greasy wool production, clean wool production and mean fibre diameter were of interest. From the production characters the following were analysed: birth, weaning and slaughter weights, daily gain from birth to weaning or slaughter, carcass weight and other carcass value traits.

scholarly journals Polymorphism and association of progesterone receptor gene with milk production and reproductive traits of rabbits

2020 ◽  
Vol 65 (No. 9.) ◽  
pp. 346-353
Author(s):  
Lubomir Ondruska ◽  
Vladimir Parkanyi ◽  
Jan Rafay ◽  
Alica Navratilova
Keyword(s):  
Progesterone Receptor ◽  
Milk Production ◽  
Litter Size ◽  
Association Studies ◽  
Receptor Gene ◽  
Reproductive Traits ◽  
Genotype Frequencies ◽  
Progesterone Receptor Gene ◽  
Pcr Rflp ◽  
Genotype A

Using the PCR RFLP method polymorphism and three different genotypes (AA, AG and GG) were detected in the progesterone receptor gene (PGR) promoter in a local Slovak crossbred rabbit line. We have noted a slightly majority frequency of allele A (0.53) over allele G (0.47). Comparing the observed and expected genotype frequencies with the χ<sup>2</sup> test the results were statistically significant, which means the tested rabbit population was non-equilibrium. The best results and significantly highest milk production (P &lt; 0.001) were recorded in the does of GG genotype compared to AA genotype. Other association studies aimed at the effect of genotypes on litter size showed the highest litter size and number of weaned rabbits per litter in GG genotype. A significantly higher (P &lt; 0.05) average number of stillborn kits per litter was in the group of does with AA genotype (0.62) compared with GG genotype (0.34).

Optimal litter size is required for postnatal development studies

1985 ◽  
Vol 13 (4) ◽  
pp. 757-758
Author(s):  
FRANCESCO VITIELLO ◽  
JEAN CLOS ◽  
GUY VINCENDON ◽  
GIORGIO GOMBOS
Keyword(s):  
Postnatal Development ◽  
Litter Size ◽  
Development Studies ◽  
Optimal Litter Size
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