• Asian-Australasian Journal of Animal Sciences
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• v.22 no.9
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• pp.1328-1333
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• 2009

To evaluate different housing systems, 80 gilts were randomly allocated at puberty to four treatments: i) sow stall in gestation followed by farrowing crate (SC), ii) group housing with individual feeding in gestation followed by farrowing crate (GC), iii) ESF (Electronic Sow Feeding) system in gestation followed by farrowing crate (EC), and iv) ESF system followed by group farrowing pen (EG). The results showed that stalled sows had a longer interval between puberty and second estrus (p<0.001). The sows kept in the ESF system gained more body weight (p<0.01) and backfat (p<0.05) prior to service, and more backfat during gestation (p<0.05), but also had greater backfat losses in the subsequent lactation (p<0.01). Sows changing from loose housing to confinement at farrowing had longer gestation length (p<0.001). Total litter size did not differ significantly between gestation treatments, but the number of stillborn piglets was significantly higher in the SC treatment (p<0.01). After weaning, SC sows had the longest interval for rebreeding (p<0.001). Some EG sows came into heat before weaning, giving this treatment the shortest interval. These results indicate that gestation confinement in sow stalls had several detrimental effects on sow performance relative to group housing.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.5
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• pp.503-508
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• 1996

The data analysed consisted of records on lactation length (LL), total lactation yield (TLY), estimated 305-day yield (305 DY), days dry (DDRY), age at frist calving (AFC) and calving interval (CI) of 448 Friesian $\times$ Bunaji halfbreds that calved over a twenty-three year period (1967-1989) at the National Animal Production Research Institute, Shika, Nigeria. Least squares means of LL, TLY, 305DY, DDRY, AFC and CI were 250 days, 1,988 kg, 2,420 kg, 102 days, 35 months and 390 days, respectively. Parity, season and year of calving significantly affected LL, TLY (p < 0.01) and 350DY (p < 0.05), but not CI. DDRY was affected by season of calving only (p < 0.05). It was therefore concluded that the Shika Friesian $\times$ Bunaji crossbreeding programme was successful and beneficial in that the $F_1$ crosses calved at a younger age, produced twice as much milk, had longer lactations and slightly shorter calving intervals than the indigenous Bunaji.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.2
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• pp.171-174
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• 1994

The milk production of Anglo-Nubian, Barbari and Barbari $\times$ Black Bengal goats were compared. The respective average lactation yield of those genotypes were $171.27\;{\pm}\;16.90$, $88.22\;{\pm}\;8.67$ and $52.31\;{\pm}\;13.51$ kg; mean annual milk yield $208.41\;{\pm}\;24.57$, $117.13\;{\pm}\;12.44$ and $84.19\;{\pm}\;23.45$ kg; per day milk yield $0.82\;{\pm}\;0.07$, $0.61\;{\pm}\;0.05$ and $0.43\;{\pm}\;0.06$ kg and lactation length $207.67\;{\pm}\;7.36$, $143.89\;{\pm}\;6.67$ and $116.75\;{\pm}\;13.86$ days. All traits recorded were influenced significantly (p<0.01) by the genetic group. Introduction of Barbari genes to Black Bengal goats had a positive effect in improving milk yield.

• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.143-150
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• 2004

This study was conducted to analyze the relationship between the occurrence of mastitis and the conformation of udders, teats, and teat tips of Holstein cows raised in Korea. Udders, teats, and teat tips were categorized by their conformation and the teat length, teat diameter and the distance from the tip of teat to the ground of 259 cows were measured. The most common shapes of udder, teats and teat tip were milking machine udder (27.4%), U-shaped teats (53.9%) and disk teat tip (53.8%), respectively. Mean teat length and diameters were 4.78 cm and 3.11 cm, respectively. The length and the diameter of front teats were significantly longer and wider than those of rear teats. However, the distance of the tip of teats to the ground was similar between front teats $(50.5{\pm}7.51cm)$ and rear teats $(50.7{\pm}8.83cm)$. The average daily milk yield was 26.4 kg/day, and the highest milk yield was observed from cows with large udder shape and above 4th lactation.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.1
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• pp.1-5
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• 2008

To analyze genetic effects on milk production traits, 164 unrelated Italian Jersey cows reared in 15 farms located in Southern Italy were characterized at the growth hormone locus. Using a Polymerase Chain Reaction-Restriction Fragment Length Polymorphism protocol all three possible genotypes for the Leucine/Valine polymorphism were identified even if in the considered population the number of homozygous animals (Leucine/Leucine = 36; Valine/Valine = 28) was smaller than Leucine/Valine (n = 100) cows; the Hardy-Weinberg equilibrium was verified. Statistical analysis showed that daily milk yield in the Leucine/Leucine genotype was higher (p<0.01) than in Leucine/Valine (22.76 kg vs. 16.96 kg ); cows with Leucine/Valine genotype differed significantly from Leucine/Leucine and Valine/Valine genotypes particularly in fat (4.95% vs. 4.13% and 4.82%, respectively) and protein content (4.00% vs. 3.47% and 3.79%, respectively). No significant effect on lactation length was observed.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.8
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• pp.1088-1096
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• 2008

Data from milk performance testing were used to analyze genetic and environmental trends for purebred Tsigai, Improved Valachian and Lacaune sheep. 103,715 (Tsigai), 212,962 (Improved Valachian) and 2,196 (Lacaune) test-day records gathered by the State Breeding Institute of the Slovak Republic entered the analyses. The respective pedigree data comprised 23,724 (Tsigai), 51,401 (Improved Valachian) and 438 (Lacaune) records. The multiple-trait, mixed model methodology was used to predict the breeding values for daily milk yield, fat and protein content and to estimate the fixed and remaining random effects assumed to affect the above mentioned traits, separately for each breed. The breeding values for daily milk yield were adjusted for 150-day standardized lactation length by multiplying with the constant 150, as the breeding goal of the selection scheme in Slovakian sheep is to increase 150-day milk production and constant heritability throughout the whole lactation is assumed. The genetic trends were expressed as changes in averages of breeding values across birth years of animals. For Tsigai and Lacaune breeds, cumulative genetic changes over the analyzed period were 3.8 and 5.1 kg for 150-day milk, 0 and -0.16% for fat content and 0 and -0.12% for protein content. For Improved Valachian breed, either a low (1.6 kg for 150-day milk yield) or zero (fat and protein content) cumulative genetic change was found. The environmental trends were calculated as averages of solutions for flock-test day effect across years and months in which measurements were taken. A distinctive cyclical pattern which reflected short-time variation in milk production traits was found. Possible explanations for this phenomenon are given and discussed.

• Journal of Embryo Transfer
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• v.30 no.4
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• pp.265-270
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• 2015

Growth rate during rearing, which varies depending on provided nutrition, has been related with age at $1^{st}$ calving (AFC). This study investigated the effect of upgrowth parameters during the rearing period on the reproduction of nulliparous Holstein heifers. The study comprised 77 successively born heifers from the same herd. Growth rate and fertility traits were measured during rearing and fertility parameters were recorded in lactations 1. Growth parameters (body weight, height, heart girth and body length) were measured at the approximate birth time, 270 and 450 d of age. Reproduction data collected included age at $1^{st}$ breeding, number of services per conception (S/C), pregnancy rate to $1^{st}$ artificial insemination, AFC. Animals were subsequently divided into 4 AFC groups for analysis: <23 mo, 23~25 mo, 26~30 mo and >30 mo. The AFC reflected both upgrowth rate and heifer reproduction, with later calving heifers smaller. Increased skeletal growth (at 270 and 450 d) was related with a reduced AFC (p<0.05). Early calving animals (<23 mo) had the best reproduction as nulliparous heifers, with most conceiving at first service (87.5%). Fertility in the first lactation was the worst in the oldest AFC group (>30 mo). In the 1st lactation period, a number of services per conception ($3.1{\pm}0.3$) increased with increasing AFC (>30 mo). Sub-optimal upgrowth related with an increased AFC could be mitigated by improved monitoring of replacement heifers during the rearing period.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.5
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• pp.627-631
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• 2006

The objective of this study was to evaluate the association of genetic differences in the bovine leptin gene and milk yield, reproduction, body condition score (BCS), and plasma glucose level in Iranian Holstein cows. In total, two hundred and thirty eight cows were used and genotyped for a restricted fragment length polymorphism at the leptin gene locus. Two genotypes, AA and AB, have been distinguished which have the frequencies of 0.89 and 0.11, respectively. The genotypes were distributed according to the Hardy - Weinberg equilibrium ($x^2$ = 0.733). During the first 12 wk of lactation, milk yield and composition, live weight, BCS and plasma glucose were measured in 50 cows. Data were analyzed based on a repeated measures ANOVA. During this period, milk yield and composition, live weight, BCS and plasma glucose level were similar among the genotypes. The first cumulative 60-d milk yield, 305-d milk yield, days to first breeding, days open and days from first breeding to conception using previous lactation records were also analyzed using Standard Least Square within mixed models. Fixed effects were year, season, parity and age at calving, and sire. For the reproductive traits the cumulative first 60-d milk yield was also added to the model. Animal was fitted as a random effect. A significant association was detected between the RFLP-AB genotype and 305-d milk yield (p<0.05). The first 60-d cumulative milk yield was similar for the two genotypes (p = 0.21) and tended to be higher in the heterozygous cows. The heterozygous genotypes at the above mentioned locus had a trend to better reproductive performance than the homozygous. The results demonstrate that the RFLP B-allele can yield a higher 305-d milk production with a trend to better reproductive performance.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.3
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• pp.336-340
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• 1999

Age at maturity was studied in 661 Nili Ravi buffaloes maintained at six dairy farms in Pakistan. The mean age at maturity in the overall data from the six farms was $976.49{\pm}9.2$ days. Significantly lower mean age at maturity $(957.93{\pm}10.68\;days)$ was observed at Military Dairy Farm, Khyber Okara, Military Daiiy Farm, Punjnad and Livestock Research Station, National Agricultural Research Centre, Islamabad (Group I) compared to $(1015.26{\pm}17.39\;days)$ other three Military Dairy Farms, Peshawar, Nowshera and Rawalpindi (Group II). The advantages associated to early age at maturity were as following. Male and female calves were heavier $(38.35{\pm}0.17\;and\;31.84{\pm}15kg,\;respectively)$ in Group I as compared to $(29.27{\pm}0.26\;and\;26.27{\pm}0.26kg)$ in Group II. Milk yield per lactation was significantly higher in Group I $(1912{\pm}12\;lit.)$ as compared to $(1833.36{\pm}16.56\;lit.)$ in Group II. Lactation length was significantly longer $(284.41{\pm}1.23\;days)$ in Group I as compared to $(277.77{\pm}2.02\;days)$ in Group II. Dry period and service period were significantly shorter $(241.59{\pm}4.18\;and\;217.05{\pm}4.95\;days,\;respectively)$ in Group I as compared to $(306.39{\pm}78\;and\;280.95{\pm}9.32\;days)$ in Group II. The mean age at first calving and sex ratio were low ($1282.75{\pm}10.14$ days and 100 ♀ ♀:130.7 ♂ ♂) in Group I as compared to ($1308.7{\pm}16.44$ days and 100 ♀ ♀:152.15 ♂ ♂) in Group II but the differences were non significant.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.5
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• pp.661-668
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• 2007

Data on 1,037 Nili-Ravi buffaloes from four institutional herds were used to study lifetime milk yield, herd life, productive life and breeding efficiency. A general linear model was used to study the environmental effects while an animal model having herd, year of birth and age at first calving (as covariate) along with random animal effect was used to estimate breeding values. The lifetime milk yield, herd life, productive life and breeding efficiency averaged $7,723{\pm}164$ kg, $3,990{\pm}41$ days, $1,061{\pm}19$ days and 64 percent, respectively. All the traits were significantly (p<0.01) affected by the year of birth and herd of calving, while the herd life was also affected (p<0.01) by the age at first calving. The heritabilities for lifetime milk yield, herd life, productive life and breeding efficiency were $0.093{\pm}0.056$, $0.001{\pm}0.055$, $0.144{\pm}0.079$ and 0.001, respectively. The definition for productive life, where each lactation gets credit upto 10 months had slightly better heritability and may be preferred over the definition where no limit is placed on lactation length. The genetic correlation between productive life and lifetime milk yield was low but high between productive life and herd life. The selection for productive life will increase herd life while lifetime milk yield will also improve. The overall phenotypic trend during the period under the study was negative for lifetime milk yield (-280 kg/year), herd life (-93 days), productive life (-42 days/year) and breeding efficiency (-0.36 percent/year), whereas the genetic trend was positive for lifetime milk yield (+15 kg/year) and productive life (+4 days/year).