STUDIES ON THE HORMONAL INDUCTION OF MAMMARY GROWTH AND LACTATION IN THE GOAT

1955 ◽  
Vol 13 (1) ◽  
pp. 46-NP ◽  
Author(s):  
G. K. BENSON ◽  
A. T. COWIE ◽  
C. P. COX ◽  
D. S. FLUX ◽  
S. J. FOLLEY

SUMMARY 1. Treatment of spayed virgin goats with oestrogen ('triggering'), following administration of oestrogen and progesterone for 150 days to cause udder development, had no significant effect on the milk yield or on the structure of their udders. 2. Daily injections of 0·5 mg hexoestrol plus 70 mg progesterone for 150 days with or without the final oestrogen 'triggering' treatment induced udders which were virtually free from histological abnormalities and in which the alveolar tissue was homogeneous and compact. The milk yields were reasonably uniform between goats, and the incidence and degree of asymmetry in milk yield between two halves of the udder were no greater than in normally lactating goats. 3. Treatment for 20 weeks with oestrogen alone at daily doses ranging from 0·025 to 0·25 mg grew glands characterized by histological abnormalities previously found in glands developed with higher doses of oestrogen, namely cystic alveoli, papillomatous outgrowths from the epithelium and immature lobules. There was no graded relationship between dose of oestrogen and milk yield, and asymmetry of yield between the two halves of an udder was marked and widespread, particularly in the goats receiving the lowest dose. 4. Total alveolar surface areas of half-udders removed at the peak of lactation were estimated by three related methods, all of which gave high correlations with the milk yields of these udder halves. With only one of these methods, however, was there an appreciable partial correlation between porosity index (surface area/unit volume) and milk yield.

2021 ◽  
Vol 105 (S1) ◽  
pp. 26-33
Author(s):  
Nadia Musco ◽  
Valeria Maria Morittu ◽  
Vincenzo Mastellone ◽  
Anna Antonella Spina ◽  
Giuseppe Vassalotti ◽  
...  

2018 ◽  
pp. 317-329 ◽  
Author(s):  
L. LI ◽  
M. L. HE ◽  
Y. LIU ◽  
Y. S. ZHANG

Dairy goats are often fed a high-concentrate (HC) diet to meet their lactation demands; however, long-term concentrate feeding is unhealthy and leads to milk yield and lactose content decreases. Therefore, we tested whether a buffering agent is able to increase the output of glucose in the liver and influence lactose synthesis. Eight lactating goats were randomly assigned to two groups: one group received a HC diet (Concentrate : Forage = 6:4, HG) and the other group received the same diet with a buffering agent added (0.2 % NaHCO3, 0.1 % MgO, BG) over a 19-week experimental period. The total volatile fatty acids and lipopolysaccharide (LPS) declined in the rumen, which led the rumen pH to become stabile in the BG goats. The milk yield and lactose content increased. The alanine aminotransferase, aspartate transaminase, alkaline phosphatase, pro-inflammatory cytokines, LPS and lactate contents in the plasma significantly decreased, whereas the prolactin and growth hormone levels increased. The hepatic vein glucose content increased. In addition, pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6PC) expression in the liver was significantly up-regulated. In the mammary glands, the levels of glucose transporter type 1, 8, 12 as well as of sodium-glucose cotransporter 1 increased. Cumulative buffering agent treatment increased the blood concentrations of glucose via gluconeogenesis and promoted its synthesis in the liver. This treatment may contribute to the increase of the milk yield and lactose synthesis of lactating goats.


1959 ◽  
Vol 31 (1) ◽  
pp. 1-10
Author(s):  
Pellervo Saarinen

The following results have been obtained from a statistical investigation carried out on experimental results from 27 feeding trials in which the effect of cholesterogenic dietary factors, observed in an earlier investigation (5), on the relative levels of milk and milk fat yields are compared. An execessive intake of energy either has no statistically clear effect on the level of yield, or the effect is negative. In this respect the results obtained are uniform with experimental results obtained in Norway and Denmark using other methods (1, 6). In the negative cases the effect appears more clearly in the level of milk and milk fat yields than in the plasma cholesterol content. An excessive intake of protein shows a negative effect only in well-conditioned obese cows. An increase of the proportion of digestible crude fibre in the food ration appears in most cases to have an increasing effect on the milk yield. This effect, however, seems to be slighter than the effect on the blood plasma cholesterol content. The level of milk and milk fat yields has proved to be statistically in positive partial correlation to the digestible crude fat intake in g/kg live weight ,and in negative partial correlation to the relative fat intake compared with the nutritional requirements of the animal. This indicates that the favourable level of fat intake varies according to the level of milk yield, being larger in stages of higher yields than in stages of small yields.


2021 ◽  
Author(s):  
Abd El-Kader Mahmoud Kholif ◽  
Gamal Eldeen Aboulfotouh ◽  
Ola Gamal Ahmed Hassan ◽  
Abdelalim Mohamed Abd El-Mola

Abstract The industries of Pomegranate juice processing generate enormous waste in peel’s form which are suggested and evaluated as a supplement in animal feed but pomegranate peel have high percent of tannins, So the aim of this paper is to assess the impact of mixing pomegranate peel (PP), detanninated pomegranate peel (DPP) and pomegranate peel with polyethylene glycol (PEG) on the digestibility of nutrients, the yield of goats milk and its composition, feed conversion and some parameters of blood. Moreover, simple economic assessment of the examined rations are considered. Sixteen lactating Zaraibi goats of about 3-4 years old (in their 2nd to 4th of lactation seasons with an average body weight of about 25 + 0.5 kg are used in the present study. After 14 days of parturition was randomly assigned into four groups, four animals per each tested ration (R) for 90days, R1: Control : 50% CFM + 25% Egyptian clover and 25% wheat straw, R2: Control ration+1% PP, R3: Control ration+1% PP + 20 g (PEG) and R4:Control ration+1% DPP. The results revealed that the PP contained 90.85% DM, 4.84% CP, 15.53% CF, 87.21%OM, 4.69% EE, 62.15% NFE and 15.28% tannins. No significant differences were found between the tested rations regarding nutrients digestibility except EE digestibility. Nutritive values of R2 and R3 were slightly higher than R4 and R1, respectively. Ration three (R3) was the best ration for daily milk yield and total milk yield, where R4 showed the worst one. Also, there are no significant differences for dry matter, SV and TDN intake. While, values of DCP intake were higher significantly (P<0.05), for R3 and R2 followed by R4 then R1. Regarding feed conversion, R4 was superior to other tested rations followed by R1 then R3 followed by R2. All blood serum parameters were in the normal rang which support that the healthy effect of tested additives in goats rations. It seems that R2 and R3 could be used successfully for lactating goats, but R3 is very expensive from economical point of view, where R3 was negatively economical effect, and not recommended.


1988 ◽  
Vol 55 (4) ◽  
pp. 487-493 ◽  
Author(s):  
Christopher H. Knight ◽  
Colin J. Wilde

SummaryFive lactating goats which had kidded normally in March were mated during seasonal anoestrus in May, at the time of peak milk production, after ovulation had been induced using gonadotrophin-releasing hormone (Knight et al. 1988). Milk yield was unaffected by the hormone treatment, and decreased at the same rate as that of control (non-pregnant) goats for the first 8 weeks of the pregnancy. Thereafter yield declined more quickly in the test goats and just before parturition (in October) was 57% of the control value. Following parturition in the test animals, yield rose rapidly as the second lactation was established. None became ‘dry’ at any stage. Yield continued to decline with advancing lactation in the controls, which were mated normally in October or November and dried-off in December. During their second (‘extra’) lactation in the winter the test animals produced 12% less than in a normal second lactation in summertime; during the year the extra lactation meant that the test animals produced 73% more milk than the controls. In some, a second concurrent pregnancy was established during the extra lactation, with the resuit that three lactations were obtained in the time normally taken for two. Mammary cell number and proliferation rate were both higher in the pregnant animals than in the controls in week 23 of the first lactation.


Animals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 299
Author(s):  
Luca Rapetti ◽  
Gianluca Galassi ◽  
Andrea Rota Graziosi ◽  
Gianni Matteo Crovetto ◽  
Stefania Colombini

In view of better environmental sustainability, livestock diets must not exceed protein requirements, as often happens with lactating goats reared in semi-intensive systems. The aim of this experiment was to verify in real-breeding conditions the influence of two diets with different protein contents (% crude protein (CP) on dry matter (DM)): 16.0 (high-protein diet; HP) vs 12.2 (low-protein diet; LP) on milk production in dairy goats. The diets differed only in the replacement—in the LP diet—of 250 g soybean meal with 250 g maize grain meal. Twenty-three Alpine goats were divided into two groups and used in a cross-over feeding trial for 2 months. Animals were weighed at the beginning of each month of the trial, and feed intake and milk yield and composition were recorded weekly. HP and LP did not differ statistically for milk yield and composition (3.32 vs 3.42 kg milk/d, 3.21% vs 3.27% fat, 3.31% vs 3.27% protein for HP and LP, respectively), but the HP diet determined a higher milk urea content (51.2 vs 36.6 mg/dL, p < 0.001) and a worse efficiency of nitrogen utilization (28.0% vs 37.2%). In conclusion, the LP diet resulted in a reduction of urinary nitrogen excretion by 28% and of the feed cost by about 10%.


2006 ◽  
Vol 82 (5) ◽  
pp. 717-722 ◽  
Author(s):  
A. Di Trana ◽  
P. Celi ◽  
S. Claps ◽  
V. Fedele ◽  
R. Rubino

AbstractThe aim of this study was to evaluate the effects of the hot season and nutrition on the oxidative status and metabolic profile of lactating goats during mid lactation. Twenty-four Red Syrian goats were allocated into three groups that were offered the following diets: natural pasture (P), pasture+500 g/h per day of concentrate (PC) and hay plus 500 g/h per day of concentrate (HC). Blood samples were taken in spring (85±7 days in milk (DIM)) and summer (120±7 DIM) and assayed for reactive oxygen metabolites (ROMs), α-tocopherol, glucose, triglycerides, cholesterol, non-esterified fatty acids, total protein, albumin and globulin concentrations and glutathione peroxidase (GHS-Px) and superoxide dismutase (SOD) activities. Milk yield and milk composition were also measured. SOD, GSH-Px and ROMs levels increased during summer when temperature humidity index values were high. The increase in ROMs in the PC and HC groups could be ascribed to the improved nutritional regime and to their higher production level. The markers of the oxidative status and of the metabolic profile measured in this study indicate that goats may have experienced moderate oxidative stress. It seems that, seasonal rather than nutritional factors have a more pronounced effect on oxidative status markers. Concentrate supplementation sustained milk yield and may represent a useful means to extend the lactation period in dairy goats during late spring and summer.


1994 ◽  
Vol 61 (4) ◽  
pp. 441-449 ◽  
Author(s):  
Christopher H. Knight ◽  
Richard J. Dewhurst

SummaryThe proportions of milk stored in the gland cistern (cisternal) and within secretory alveolar tissue (alveolar) were determined for a group of ten cows in mid lactation, yielding ∼ 20 kg milk/d. As a proportion of total milk, cisternal milk, measured at 8 h after milking, ranged from 0·09 to 0·53. Milking frequency was then reduced from twice daily to once daily on two occasions, first for 1 week and then, 2 weeks later, for 2 weeks. Milk yield was reduced during once daily milking in all cows, by an average of 22·8% during the first week (P < 0·001). The amount of decrease varied among cows in a way that was unrelated to pretreatment yield, but the immediate decrease was significantly and inversely correlated with cisternal milk proportion (r = 0·81, P < 0·01). When milking reverted to twice daily, yield recovered to a value not significantly different from pretreatment, and the degree of recovery was inversely related to cisternal milk proportion (r = 0·74, P < 0·01). With the exception of one cow, yield decreases correlated well between the two periods of once daily milking. When treatment weeks were disregarded, lactation persistency (the rate of decline in yield with time) was unaffected by once daily milking. The results show that the ability of individual cows to tolerate once daily milking is related to their cisternal storage characteristics; yield is reduced less in cows that store a greater proportion of their total milk production within the cistern. Once daily milking for up to 2 weeks had no lasting effect on milk yield or lactation persistency, suggesting that there had been no detrimental effect on udder development.


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