scholarly journals Effects of sodium intake on lactation and Na levels in body fluids of Blackface ewes

1986 ◽  
Vol 56 (1) ◽  
pp. 193-198 ◽  
Author(s):  
Isobel C. Vincent ◽  
H. Ll. Williams ◽  
R. Hill
Keyword(s):  
Weight Gain ◽  
Sodium Chloride ◽  
Milk Production ◽  
Sodium Intake ◽  
Live Weight ◽  
Body Fluids ◽  
Live Weight Gain ◽  
Low Sodium Diet ◽  
Low Sodium ◽  
K Concentration

1. A low-sodium diet was given to Blackface ewes over two reproductive seasons; the diet provided 3–7 mmol Na daily, except for the period of lactation, when Na intake was increased to around 11 mmol/d. The diet of the control ewes was supplemented with sodium chloride to provide the recommended allowance of about ten times the level in the experimental low-Na diet.2. Milk production was assessed during the first 2 months of lactation from incremental changes in the live weight of lambs during controlled sucking periods. Na and potassium were determined in milk and also in plasma, saliva and urine.3. Neither yield nor concentration of Na and K in milk was affected by the level of Na in the diet. These results were supported by the similarity in live-weight gain of lambs in both years regardless of diet.4. Plasma Na and K concentrations were not affected by the level of dietary Na. Na concentration in saliva and urine was significantly lower in the treated than in the control ewes, and K concentration in saliva was significantly higher.

The effects of plane of nutrition and diet type on metabolic hormone concentrations, growth and milk production in high genetic merit dairy herd replacements

2000 ◽  
Vol 70 (2) ◽  
pp. 349-362 ◽  
Author(s):  
A.F. Carson ◽  
A.R.G. Wylie ◽  
J.D.G. McEvoy ◽  
M. McCoy ◽  
L.E.R. Dawson
Keyword(s):  
Weight Gain ◽  
Milk Production ◽  
Live Weight ◽  
Live Weight Gain ◽  
Genetic Merit ◽  
Grass Silage ◽  
Nutrition And Diet ◽  
Condition Score ◽  
Metabolic Hormone ◽  
Diet Type

AbstractSeventy high genetic merit Holstein heifers were used in two experiments to investigate (1) the effects of plane of nutrition and diet type during the pre-pubertal period and (2) the effects of plane of nutrition during the post-pubertal period on metabolic hormone concentrations, growth and milk production. In experiment 1, treatment 1 and 2 heifers were given food to achieve a live-weight gain of 0·70 and 0·95 kg/day from 3 to 10 months of age on a grass silage based diet, while treatment 3 heifers were given food to achieve 0·95 kg/day on a barley straw/concentrate diet. During the pre-pubertal period, heifers reared on treatment 1 had significantly higher growth hormone(GH) concentrations (ng/ml per 1 h) than heifers reared on treatment 2 (P < 0·01) and had significantly lower insulin concentrations than heifers reared on treatment 3 (P < 0·01). Heifers reared on treatment 1 had significantly lower insulin-like growth factor 1 (IGF-1) concentrations than those reared on treatment 3 (P < 0·01). At 10 months of age heifers reared on treatment 1 were of lower condition score (P < 0·01) than those on treatment 2 and had a smaller heart girth diameter (P < 0·01) than those on treatments 2 and 3. During the first lactation, milk yield and composition produced by the heifers was not significantly affected by treatment. In experiment 2, treatment A heifers were given, from 14 to 24 months of age, a low plane of nutrition to allow a live-weight gain of 0·65 kg/day on a grass silage and grass based diet during the winter and summer periods respectively. Treatment B heifers were kept on a high plane of nutrition to allow a live-weight gain of 0·90 kg/day on the same forage along with concentrate supplementation. During the rearing period, GH and IGF-1 concentrations were not significantly affected by treatment. Treatment A heifers weighed less before calving (P < 0·05), had a lower condition score (P < 0·01), and had a smaller heart girth diameter (P < 0·01) than those on treatment B. During the first 10 weeks of lactation, heifers on treatment A had a higher silage dry matter intake and lost less weight (P < 0·05) than those on treatment B, however, by 20 weeks of lactation these effects had disappeared. Milk yield and composition during the first lactation were not significantly affected by treatment. Overall, the findings of experiments 1 and 2 did not show any beneficial effects of higher weights at first calving in high genetic merit Holsteins and therefore indicate that accelerated growth in the pre- or post-pubertal period may not be required.

A herb and legume sward mix increased ewe milk production and ewe and lamb live weight gain to weaning compared to a ryegrass dominant sward

2011 ◽  
Vol 164 (1-2) ◽  
pp. 1-7 ◽  
Author(s):  
P.G. Hutton ◽  
P.R. Kenyon ◽  
M.K. Bedi ◽  
P.D. Kemp ◽  
K.J. Stafford ◽  
...  
Keyword(s):  
Weight Gain ◽  
Milk Production ◽  
Live Weight ◽  
Live Weight Gain

The effect of year, suckling, dry season and type of dam (ewe or gimmer) on milk production in East African Blackheaded sheep as measured by lamb growth

1966 ◽  
Vol 66 (1) ◽  
pp. 93-95
Author(s):  
G. D. Sacker ◽  
J. C. M. Trail
Keyword(s):  
Weight Gain ◽  
Milk Production ◽  
Live Weight ◽  
Dry Season ◽  
East African ◽  
Live Weight Gain ◽  
Weight Gains ◽  
The Mean ◽  
Lamb Growth ◽  
Lower Production

1. The mean daily live weight gains of lambs were used to estimate the milk production of ewes and gimmers during the first 8 weeks of lactation. Records of 1178 lambings of East African Blackheaded sheep between the years 1952 and 1962 were available.2. Gimmers had significantly lower production than second and subsequent lamb ewes. Ewes rearing twins had a significantly higher yield than ewes rearing singles. There appeared to be no difference in yield between ewes producing twins but rearing singles, and ewes rearing natural singles.3. A long dry season with resultant lowered plane of nutrition significantly reduced the live-weight gain of lambs.

scholarly journals Sulphur as a nutrient for Merino sheep

1973 ◽  
Vol 30 (3) ◽  
pp. 537-543 ◽  
Author(s):  
J. P. Langlands ◽  
H. A. M. Sutherland ◽  
M. J. Playne
Keyword(s):  
Regression Analysis ◽  
Weight Gain ◽  
Milk Production ◽  
Live Weight ◽  
Weighted Regression ◽  
Live Weight Gain ◽  
Merino Sheep ◽  
Foetal Membranes ◽  
Weighted Regression Analysis ◽  
The Mean

1. Estimates of sulphur retention by Merino sheep during growth, pregnancy and wool production, and of S excretion during lactation were obtained to derive estimates of the S requirements of Merino sheep.2. The S content of fifty Merino sheep was related by weighted regression analysis to age, live weight and (age × live weight). The quantity of S stored was calculated for varying rates of live-weight gain in sheep differing in age and live weight.3. The S contents of twenty-five samples of foetus, foetal membranes and uteruses were determined. Relationships between S content and days from mating were calculated, and differentiated to give daily net changes in S content during pregnancy.4. Milk production of twenty-seven Merino ewes was estimated on eight to ten occasions at approximately weekly intervals to the 84th day of lactation. The average S content was 472 mg/l; it increased on average by 1·0 mg/l per d of lactation. The mean S content of ninety-seven samples of wool averaged 34 g S/kg clean dry wool.5. It was concluded that wool represented the major demand for S by the Merino since approximately 70 g S were secreted in producing 2 kg clean wool, 50 g S in a lactation yielding 100 l milk and 8 g S in giving birth to a single lamb.

A simple model of lactation curves for milk yield, food requirement and body weight

1979 ◽  
Vol 28 (1) ◽  
pp. 55-63 ◽  
Author(s):  
P. D. P. Wood
Keyword(s):  
Weight Gain ◽  
Milk Production ◽  
Milk Yield ◽  
Live Weight ◽  
Energy Output ◽  
Algebraic Models ◽  
Live Weight Gain ◽  
Food Requirement ◽  
Potential Demand ◽  
Desk Calculator

ABSTRACTSimple algebraic models of milk yield, live-weight change and food requirement are developed for use in a programmable desk calculator. The unit of time used is a week and of energy a megajoule. An algebraic equation for milk production is used to define potential energy output. An expression using live-weight gain describes the demand for energy for the recovery of weight lost and the requirements of pregnancy. The use of appropriate conversion factors enables the necessary dietary input to be calculated. The model also takes account of restricted feeding by allocating dietary energy to milk production and live-weight gain in proportion to their potential demand. Ten decisions relating to milk yield, live-weight loss and live-weight gain are required by the model.

Experiments on the nutrition of the dairy heifer: VI. The effect on milk production of the level of feeding during the last six months of pregnancy and the first eight weeks of lactation

1967 ◽  
Vol 69 (3) ◽  
pp. 465-477 ◽  
Author(s):  
W. H. Broster ◽  
Valarie J. Tuck
Keyword(s):  
Weight Gain ◽  
Milk Production ◽  
Dry Matter ◽  
Live Weight ◽  
Experimental Period ◽  
Mean Difference ◽  
Weight Increase ◽  
Live Weight Gain ◽  
The Mean ◽  
Dairy Heifer

1. Forty-five Friesian first calf heifers were used in an experiment to study the effect on milk production of two levels of feeding in the last 6 months of pregnancy and two levels of feeding in the first 8 weeks of lactation.2. In each of two years herbage was rationed daily at different rates to two groups of pregnant heifers from late April until they calved in the autumn. The mean daily rations were 3·5 lb herbage dry matter and 2·4 lb herbage dry matter per 100 lb live weight for the two groups. The mean daily amounts consumed were 2·1 and 1·8 lb herbage dry matter per 100 lb live weight respectively.3. The rates of gross live-weight gain during the period April to August were 2·2 and 1·7 lb/day for the two groups respectively. Estimated as the net gain of the dam alone, the rates of live-weight increase during the experimental period were 0·89 and 0·49 lb/day respectively, amounting to a mean difference in live weight after calving of 57 lb between the groups.

A Comparison of Natriuresis after Oral and Intravenous Sodium Loading in Sodium-Depleted Rabbits: Evidence for a Gastrointestinal or Portal Monitor of Sodium Intake

1975 ◽  
Vol 49 (5) ◽  
pp. 433-436 ◽  
Author(s):  
R. J. Lennane ◽  
W. S. Peart ◽  
R. M. Carey ◽  
J. Shaw
Keyword(s):  
Sodium Chloride ◽  
Sodium Intake ◽  
Portal Circulation ◽  
Sodium Diet ◽  
Low Sodium Diet ◽  
Low Sodium ◽  
Sodium Loading ◽  
Portal Monitor ◽  
Oral Doses ◽  
Intravenous Sodium

1. Rabbits in balance on a low sodium diet were given doses of sodium chloride either orally or intravenously. 2. Those receiving oral doses responded with a much greater natriuresis than those receiving intravenous ones. 3. This could be explained by the existence of a sodium input monitor somewhere in the gut or portal circulation.

The effect of genetic merit for milk production and concentrate feeding level on the reproductive performance of Holstein-Friesian cows in a grass-based system

2003 ◽  
Vol 76 (2) ◽  
pp. 297-308 ◽  
Author(s):  
J. Kennedy ◽  
J. Kennedy ◽  
P. Dillon ◽  
K. O’Sullivan ◽  
F. Buckley ◽  
...  
Keyword(s):  
Weight Gain ◽  
Pregnancy Rate ◽  
Milk Production ◽  
Reproductive Performance ◽  
Repeated Measures ◽  
Live Weight ◽  
Live Weight Gain ◽  
Genetic Merit ◽  
Feeding Level ◽  
Concentrate Supplementation

AbstractThe objective of the study was to evaluate the effect on reproductive performance of varying level of concentrate supplementation with both high and medium genetic merit cows in a spring calving grass-based system of milk production. The effect of year, cow genetic merit for milk production and concentrate feeding level on milk production, body condition score, live weight, blood metabolites and dry-matter (DM) intake were studied. A repeated measures model with a factorial arrangement of genetic merit and concentrate feeding level was used to do this. Associations between these variables and pregnancy to first service (PREG1), pregnancy to first and second service (PREG12) and overall pregnancy (PREG) rates were assessed using logistic regressions for year 2.Cows were grouped into high (HM) and medium (MM) genetic merit based on their pedigree indices for milk production (PD milk). The HM cows had a PD milk of + 276 (s.d. 100) kg, while the MM cows had mean PD milk of + 81 (s.d. 95) kg. Within genetic merit groupings, cows were assigned to one of three concentrate feeding levels; low (LC), 376 kg; medium (MC), 810 kg; and high (HC), 1540 kg of concentrate per cow per lactation. In year 1, all 78 cows were second lactation animals, while in year 2, 71 cows (previously in year 1) were third lactation and 12 second lactation. All cows calved between February and April, and were presented for rebreeding from late April until late July each year.When treatment means were compared, genotype and concentrate feeding levels had no significant effects on reproductive performance while year was significant for most parameters. Comparing year 2 to year 1 pregnancy rate to first service (P 0•001; 37 v. 64%), pregnancy rate to first and second service (P < 0•05; 64 v. 81%), overall pregnancy rate (P < 0•05; 78 v. 92%) were lower. Also in year 2, cows had significantly higher milk yields at first insemination (36•9 v. 32•3 kg per cow per day), greater live-weight losses from calving to first insemination (-86 v. –53 kg per cow), lower live-weight gain in the 90 days after their first insemination (+ 24•6 v. + 34•2 kg per cow), higher DM intake (20•6 v. 17•3 kg DM per cow per day) and lower plasma glucose concentrations (3•18 v. 3•61 mmol/l) than in year 1.In year 2, there were significant negative associations between the likelihood of PREG12 and both PD milk and live-weight gain in the 90 days after first insemination. The results of this study indicate that continued selection for increased milk production, resulting in greater partitioning of energy to milk production rather than body reserves will reduce reproductive performance and offering higher levels of concentrate supplementation may not alleviate this problem.

scholarly journals Reduction of body-weight gain enhances in vitro embryo production in overfed superovulated dairy heifers

Reproduction ◽  
2006 ◽  
Vol 131 (4) ◽  
pp. 783-794 ◽  
Author(s):  
S Freret ◽  
B Grimard ◽  
A A Ponter ◽  
C Joly ◽  
C Ponsart ◽  
...  
Keyword(s):  
Weight Gain ◽  
Dietary Intake ◽  
Live Weight ◽  
Reproductive Hormones ◽  
Embryo Production ◽  
Live Weight Gain ◽  
Dairy Heifers ◽  
Period 2 ◽  
Significant Difference

The aim of our study was to test whether a reduction in dietary intake could improve in vitro embryo production in superovulated overfed dairy heifers. Cumulus–oocyte complexes of 16 Prim’ Holstein heifers (14 ± 1 months old) were collected by ovum pick-up (OPU), every 2 weeks following superovulation treatment with 250 μg FSH, before being matured and fertilized in vitro. Embryos were cultured in Synthetic Oviduct Fluid medium for 7 days. Heifers were fed with hay, soybean meal, barley, minerals and vitamins. From OPU 1 to 4 (period 1), all heifers received individually for 8 weeks a diet formulated for a 1000 g/day live-weight gain. From OPU 5 to 8 (period 2), the heifers were allocated to one of two diets (1000 or 600 g/day) for 8 weeks. Heifers’ growth rates were monitored and plasma concentrations of metabolites, metabolic and reproductive hormones were measured each week. Mean live-weight gain observed during period 1 was 950 ± 80 g/day (n = 16). In period 2 it was 730 ± 70 (n = 8) and 1300 ± 70 g/day (n = 8) for restricted and overfed groups respectively. When comparing period 1 and period 2 within groups, significant differences were found. In the restricted group, a higher blastocyst rate, greater proportions of grade 1–3 and grade 1 embryos, associated with higher estradiol at OPU and lower glucose and β-hydroxybutyrate, were observed in period 2 compared with period 1. Moreover, after 6 weeks of dietary restriction (OPU 7), numbers of day 7 total embryos, blastocysts and grade 1–3 embryos had significantly increased. On the contrary, in the overfed group, we observed more <8 mm follicles 2 days before superovulation treatment, higher insulin and IGF-I and lower nonesterified fatty acids in period 2 compared with period 1 (no significant difference between periods for embryo production). After 6 weeks of 1300 g/day live-weight gain (OPU 7), embryo production began to decrease. Whatever the group, oocyte collection did not differ between period 1 and 2. These data suggest that following a period of overfeeding, a short-term dietary intake restriction (6 weeks in our study) may improve blastocyst production and embryo quality when they are low. However, nutritional recommendations aiming to optimize both follicular growth and embryonic development may be different.

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