• 한국가축번식학회지
• /
• 제24권4호
• /
• pp.321-333
• /
• 2000

High production of milk and its components are necessary to allow maximal growth of developing piglets. In this study, transgenic pigs were produced containing the $\alpha$ -lactalbumin gene, whose product is a potential limiting component in the production of milk. Two lines of transgenic pigs were produced to analyze the effects that overproduction of the milk protein $\alpha$ -lactalbumin may have on milk production and piglet growth. Transgenic pigs were produced through microinjection of the bovine $\alpha$ -lactalbumin gene. The gene construct contained 2.0 kb of 5'flanking region, the 2.0 kb coding region and 329 bp of 3'flanking region. Sows hemizygous for the trans gene produced as much as 0.9 g of bovine $\alpha$-lactalbumin per liter of pig milk. The production of the bovine protein caused approximately a 50% increase in the total $\alpha$ -lactalbumin concentration in pig milk throughout lactation. The concentration of bovine $\alpha$ -lactalbumin was highest on day 0 and 5 of lactation and decreased as lactation progressed. The ratio of bovine to porcine $\alpha$ -lactalbumin changed during the sow's lactation. This ratio was 4.3 to 1 on day 0 of lactation, but by day 20 of lactation the ratio was 0.43 to 1. This suggested that the bovine transgene and the endogenous porcine gene were under slightly different control mechanisms. The higher level of total $\alpha$-lactalbumin present on day 0 of lactation was correlated with higher lactose percentage on day 0 in transgenic sows (3.8%) as compared to controls (2.6%) (P＜0.01). Although there was also a trend for higher lactose percentage in transgenic sows on day 5 and 10 of lactation, no significant differences were observed. These data suggest that $\alpha$ -lactalbumin is limiting early in lactation of swine. Furthermore, higher concentrations of $\alpha$ -lactalbumin early in lactation may boost milk output.

• Asian-Australasian Journal of Animal Sciences
• /
• 제33권8호
• /
• pp.1360-1368
• /
• 2020

Objective: The aim of our study was to determine the associations of heifer reproductive performance with survival up to the first calving, first-lactation milk yield, and the probability of being culled within 50 days after first calving. Methods: Data from 33 large Holstein-Friesian commercial dairy herds were gathered from the official milk recording database in Hungary. The data of heifers first inseminated between January 1, 2011 and December 31, 2014 were analyzed retrospectively, using Cox proportional hazards models, competing risks models, multivariate linear and logistic mixed-effects models. Results: Heifers (n = 35,128) with younger age at conception were more likely to remain in the herd until calving, and each additional month in age at conception increased culling risk by 5.1%. Season of birth was related to first-lactation milk yield (MY1; n = 19,931), with cows born in autumn having the highest milk production (p<0.001). The highest MY1 was achieved by heifers that first calved between 22.00 and 25.99 months of age. Heifers that calved in autumn had the highest MY1, whereas calving in summer was related to the lowest milk production (p<0.001). The risk of culling within 50 days in milk in first lactation (n = 21,225) increased along with first calving age, e.g. heifers that first calved after 30 months of age were 5.52-times more likely to be culled compared to heifers that calved before 22 months of age (p<0.001). Calving difficulty was related to higher culling risk in early lactation (p<0.001). Heifers that required caesarean section were 24.01-times more likely to leave the herd within 50 days after first calving compared to heifers that needed no assistance (p<0.001). Conclusion: Reproductive performance of replacement heifers is closely linked to longevity and milk production in dairy herds.

• Animal Bioscience
• /
• 제34권8호
• /
• pp.1303-1308
• /
• 2021

Objective: The objective of this study was to define a new composite trait for Holstein dairy cows and evaluate the possibility of joint improvement in milk and fertility traits. Methods: A data set consisting 35,882 fertility related records (days open [DO], calving interval [CI], and number of services per conception [NSC], and total milk yield in each lactation [TMY]) was collected from 1998 to 2016 in Polish Holstein-Friesian breed herds. In this study TMY, DO, CI, and lactation length of each cow was used to obtain composite milk and fertility traits (CMF). Results: Moderate heritability (0.15) was estimated for composite trait that was higher than heritability of female fertility related traits: DO 0.047, CI 0.042, and NSC 0.014, and slightly lower than heritability of TMY 0.19. Favourable genetic correlations (-0.87) were estimated between CMF with TMY. Spearman rank correlation coefficients between breeding value of CMF with DO, CI, and TMY were high (>0.94) but with NSC were moderate (0.64). Selection on CMF caused favourable correlated genetic gains for DO, CI, and TMY. Different selection indices with different emphasis on fertility and milk production were constructed. The amount of correlated genetic gains obtained for DO and total milk production according to selection in CMF were higher than of genetic gains obtained for DO and TMY in selection indices with different emphasis on milk and fertility. Conclusion: The animal selection only based on a composite trait - CMF proposed in current study would simultaneously lead to favourable genetic gains for both milk and fertility related traits. In this situation CMF introduced in current study can be used to overcome to limitations of selection index and CMF could be useful for countries that have problems in recording traits, especially functional traits.

• Animal Bioscience
• /
• 제37권2호
• /
• pp.253-260
• /
• 2024

Objective: The objectives of the present study were to evaluate the effects of once-a-day milk feeding on growth performance and routine behavior of preweaning dairy calves. Methods: At 22nd day of age, twenty-four Holstein calves were randomly assigned to one of two treatment groups (n = 12/treatment) based on milk feeding frequency (MF): i) 3 L of milk feeding two times a day; ii) 6 L of milk feeding once a day. The milk feeding amount was reduced to half for all calves between 56 and 60 days of age and weaning was done at 60 days of age. To determine the increase in weight and structural measurements, each calf was weighed and measured at 3 weeks of age and then at weaning. The daily behavioral activity of each calf was assessed from the 22nd day of age till weaning (60th day of age) through Nederlandsche Apparatenfabriek (NEDAP) software providing real-time data through a logger fitted on the calf's foot. Results: There was no interaction (p≥0.17) between MF and sex of the calves for routine behavioral parameters, body weight and structural measurements. Similarly, there was no effect of MF on routine behavioral parameters, body weight and structural measurements. However, the sex of the calves affected body weight gain in calves. Male calves had 27% greater total body weight and average daily gain than female calves. There was no effect of the sex of the calves on behavioral measurements. Collectively, in the current study, no negative effects of a once-a-day milk feeding regimen were found on routine behavioral and growth parameters of preweaning calves in group housing. Conclusion: Once-a-day milk feeding can be safely adopted in preweaning calves from 22nd day of age.

• Asian-Australasian Journal of Animal Sciences
• /
• 제29권11호
• /
• pp.1530-1540
• /
• 2016

This study was conducted to estimate the genetic parameters of ${\beta}$-hydroxybutyrate (BHBA) and acetone concentration in milk by Fourier transform infrared spectroscopy along with test-day milk production traits including fat %, protein % and milk yield based on monthly samples of milk obtained as part of a routine milk recording program in Korea. Additionally, the feasibility of using such data in the official dairy cattle breeding system for selection of cows with low susceptibility of ketosis was evaluated. A total of 57,190 monthly test-day records for parities 1, 2, and 3 of 7,895 cows with pedigree information were collected from April 2012 to August 2014 from herds enrolled in the Korea Animal Improvement Association. Multi-trait random regression models were separately applied to estimate genetic parameters of test-day records for each parity. The model included fixed herd test-day effects, calving age and season effects, and random regressions for additive genetic and permanent environmental effects. Abundance of variation of acetone may provide a more sensitive indication of ketosis than many zero observations in concentration of milk BHBA. Heritabilities of milk BHBA levels ranged from 0.04 to 0.17 with a mean of 0.09 for the interval between 4 and 305 days in milk during three lactations. The average heritabilities for milk acetone concentration were 0.29, 0.29, and 0.22 for parities 1, 2, and 3, respectively. There was no clear genetic association of the concentration of two ketone bodies with three test-day milk production traits, even if some correlations among breeding values of the test-day records in this study were observed. These results suggest that genetic selection for low susceptibility of ketosis in early lactation is possible. Further, it is desirable for the breeding scheme of dairy cattle to include the records of milk acetone rather than the records of milk BHBA.

• Asian-Australasian Journal of Animal Sciences
• /
• 제24권10호
• /
• pp.1377-1385
• /
• 2011

This study was conducted to determine the nutritive value of live yeast culture (RumiSacc, Saccharomyces cerevisiae) and to investigate its effects on milk yield, milk composition and some blood parameters in lactating cows. Six multiparous Holstein cows were allocated to two groups of three cows and assigned randomly to one of two diets in a cross-over experiment. Daily 50 g RumiSacc was top dressed at the p.m. feeding for the treatment group. RumiSacc supplied a high protein and energy with high organic matter digestibility values (83.35%) determined by in vitro enzymatic analysis. Yeast culture supplementation significantly increased milk yield, tended to increase fat yield, protein yield and lactose yield of milk. Methylated fatty acid level of 18:3 (n-3) in milk fat was increased by yeast culture supplementation. The concentrations of methionine, phenyalanine, tyrosine, tryptophan and taurine were significantly increased with dietary inclusion of yeast culture. Live yeast culture supplementation did not affect other performance characteristics, milk quality characteristics and blood parameters. As a conclusion live yeast culture (RumiSacc, Saccharomyces cerevisiae) had high nutritive value and positive effects on milk production and some milk quality characteristics in lactating cows under field conditions.

• Asian-Australasian Journal of Animal Sciences
• /
• 제30권3호
• /
• pp.363-369
• /
• 2017

Objective: The current study compared the effects of dietary levels of two phase stoned olive cake (OC) in form of silage (OCS) on milk production and quality of Saanen goats. Methods: The OCS included in total mixed ration (TMR) at dry matter proportions of 0.0 (OC0), 0.10 (OC10), and 0.20 (OC20). The TMR were fed to a total of 18 goats in a completely randomized design for a period of 5 weeks. Results: Dietary treatments had no effect on the milk yield of Saanen goats, but the daily milk fat production was greater (p<0.05) at feeding OC20. The total phenolic (TP) compounds contents increased (p<0.01) in each increment of OCS in TMR and this was also reflected in the TP contents of milk. The C8:0, C10:0, C12:0, and C14:0 saturated fatty acids (FAs) in milk fat decreased (p<0.01) with increasing dietary level of OCS, but the decrease (p<0.001) in C16:0 and the increase (p<0.01) in C18:0 in milk fat occurred similarly at each inclusion level of OCS. Only OC20 reduced (p<0.05) the total saturated FA, yet the reduction (p<0.01) in n6/n3 ratio and atherogenicity index occurred in both OC10 and OC20. Conclusion: Two phase stoned OCS increases milk quality not only through modifying the milk FA composition, but also by increasing the milk TP content. These favorable changes in milk quality are closely associated with the dietary level of OCS.

• Asian-Australasian Journal of Animal Sciences
• /
• 제27권7호
• /
• pp.951-959
• /
• 2014

The objective of this study was to determine the effects of linseed oil or whole linseed supplementation on performance and milk fatty acid composition of lactating dairy cows. Thirty six Holstein Friesian crossbred lactating dairy cows were blocked by milking days first and then stratified random balanced for milk yields and body weight into three groups of 12 cows each. The treatments consisted of basal ration (53:47; forage:concentrate ratio, on a dry matter [DM] basis, respectively) supplemented with 300 g/d of palm oil as a positive control diet (PO), or supplemented with 300 g/d of linseed oil (LSO), or supplemented with 688 g/d of top-dressed whole linseed (WLS). All cows were received ad libitum grass silage and individually fed according to the treatments. The experiment lasted for 10 weeks including the first 2 weeks as the adjustment period, followed by 8 weeks of measurement period. The results showed that LSO and WLS supplementation had no effects on total dry matter intake, milk yield, milk composition, and live weight change; however, the animals fed WLS had higher crude protein (CP) intake than those fed PO and LSO (p<0.05). To compare with the control diet, dairy cow's diets supplemented with LSO and WLS significantly increased milk concentrations of cis-9,trans-11-conjugated linoleic acid (CLA) (p<0.05) and n-3 fatty acids (FA) (p<0.01), particularly, cis-9,12,15-C18:3, C20:5n-3 and C22:6n-3. Supplementing LSO and WLS induced a reduction of medium chain FA, especially, C12:0-C16:0 FA (p<0.05) while increasing the concentration of milk unsaturated fatty acids (UFA) (p<0.05). Milk FA proportions of n-3 FA remarkably increased whereas the ratio of n-6 to n-3 decreased in the cows supplemented with WLS as compared with those fed the control diet and LSO (p<0.01). In conclusion, supplementing dairy cows' diet based on grass silage with WLS had no effect on milk yield and milk composition; however, trans-9-C18:1, cis-9,trans-11-CLA, n-3 FA and UFA were increased while saturated FA were decreased by WLS supplementation. Therefore, it is recommended that the addition 300 g/d of oil from whole linseed should be used to lactating dairy cows' diets.

• 한국동물위생학회지
• /
• 제14권1호
• /
• pp.79-86
• /
• 1991

This report was undertaken to examine the correlationship between internal parasite infection and amount of milk production before and after vermicidal administration on F. hepatica and gastrointestinal nematoda infected cattle. The obtained results were as follows ; 1. Out of total number(358), the ratios of parasitic infected catle were 43.5%(156). Among them milking cattl. and Korean native cattle were 52.7% and 31.6%, respectively. 2. In this examination, 10 kinds of parasites were detected. Among them F. hepatica was encountered most frquently and also Buxtonella, Paramphistoma, Coccidim, Cestoda, and Trichur were encountered in order. 3. The average increased amount of milk production after vermicidal administration on F. hepatica and gastrointestinal nematoda infected cattle was 1.1Kg per day.

• Asian-Australasian Journal of Animal Sciences
• /
• 제8권5호
• /
• pp.523-527
• /
• 1995

Two on farm feeding trials were conducted at the Pabna milkshed area during July to October 1993, to evaluate the response of feeding urea molassesed straw (UMS) on milk production of Pabna milking cows and its economics. A feeding trial of 60 days with 50 Pabna milking cows showed that the cows fed UMS as a replacer of dry straw increased daily milk yield by 1.37 litre. Moreover, it reduced the daily requirement of concentrate by 1.0 kg/head. In the second trial, a herd of 52 animals including 14 milking cows were fed UMS in place of traditionally used dry straw. Introduction of UMS increased the milk production by 1.0 litre/cow/day and saved concentrate by 1.5 kg/cow daily. Urea molassesed straw can safely and economically be fed to lactating cows.