A quantitative analysis of mammary glands of dairy heifers reared at different rates of live weight gain

1983 ◽  
Vol 50 (4) ◽  
pp. 405-412 ◽  
Author(s):  
Roger D. Harrison ◽  
Ian P. Reynolds ◽  
William Little
Keyword(s):  
Weight Gain ◽  
Live Weight ◽  
Mammary Glands ◽  
Mammary Development ◽  
First Year ◽  
Live Weight Gain ◽  
Dairy Heifers ◽  
Gland Weight ◽  
Secretory Tissue ◽  
First Year Of Life

SUMMARYThe mammary glands of conventionally reared cows, never exceeding a live weight gain (LWG) of 0·74 kg/d, weighed 39% more and contained 68% more secretory tissue than glands of rapidly reared animals grown at 1·1 kg/d. In 11-month-old heifers reared at 3 rates of LWG (L, 0·57; M, 0·76 and H, 1·18 kg/d) gland weight was related to LWG, but dissected mammary parenchyma was heavier in animals on treatment L than on treatment H and followed a quadratic relationship. Parenchymal composition on treatment H was correlated to both age and body weight at puberty. No similar trend was observed in treatments L and M although group L animals had more ductal tissue and less fat than those of group M. Heifers from treatment L were reared during pregnancy at either 0·68 or 0·84 kg/d LWG (treatments LL and LH respectively) and heifers from treatment H at 0·58 kg/d (treatment HL). Total gland weight was unaffected by treatment, but the percentage by weight of secretory tissue in the gland in treatment HL was less than for treatments LL and LH. These experiments confirm that mammary development is permanently impaired by high rates of LWG in the first year of life. There was no impairment of mammary development in heifers reared moderately in the first year and more rapidly during pregnancy.

Thyroid hormones and daily gain in cattle. Relationships between plasma total thyroxine, free thyroxine, triiodothyronine and average daily gain during the first year of life in Belgian blue and Friesian cattle

1983 ◽  
Vol 36 (3) ◽  
pp. 355-361 ◽  
Author(s):  
J. Fabry
Keyword(s):  
Weight Gain ◽  
Thyroid Hormones ◽  
Performance Test ◽  
Average Daily Gain ◽  
Live Weight ◽  
Free Thyroxine ◽  
First Year ◽  
Live Weight Gain ◽  
First Year Of Life ◽  
Daily Gain

ABSTRACTCorrelation between circulating thyroid hormones and live-weight gain during the first year of life were observed in four trials on cattle of the two main Belgian breeds: Belgian Blue and Friesian. Thyroid hormones assayed and considered as potential predictors of growth rate were: thyroxine (T4), triiodothyronine (T3) and free thyroxine (FT4). Triiodothyronine uptake (T,U), thyroid stimulating hormone (TSH) and free thyroxine index (FTI) were also estimated.No significant correlation was found between live-weight gain and T4 or T3 in 13 Belgian Blue heifers (trial 1). In 49 bulls submitted to a performance test, T4 and FTI increased from 3 to 12 months whilst T3U decreased (trial 2). Significant correlations between live-weight gain and T4 and between live-weight gain and FTI were obtained from samples taken between 66 and 95 days. Live-weight gain was correlated with T3U when animals were between 96 and 125 days, and 126 to 155 days of age. It is possible that the interaction between total T4 and T3U is important in controlling growth. In 13 young calves, beef merit, expressed as live-weight gain in 1 year, was highly correlated with T4 concentration at 8 to 10 days of age (trial 3). T3 and FT4 did not seem to be directly associated with the growth processes. In trial 4, live-weight gains of 42 young animals housed on a commercial farm were negatively correlated with T4 and with FTI. The conflicting results encountered may perhaps be explained by the lack of information on the use of anabolic preparations in field conditions. T4 concentration and FTI may be considered as potential parameters for the estimation of beef merit but the results are insufficient to draw definite conclusions.

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.

Association between resting behaviour and live weight gain in dairy heifers housed in pens with different space allowance and floor type

1997 ◽  
Vol 55 (1-2) ◽  
pp. 11-19 ◽  
Author(s):  
Lisbeth Mogensen ◽  
Christian C. Krohn ◽  
Jan Tind Sørensen ◽  
Jens Hindhede ◽  
Lone Harder Nielsen
Keyword(s):  
Weight Gain ◽  
Live Weight ◽  
Live Weight Gain ◽  
Dairy Heifers ◽  
Resting Behaviour

Effect of rationing grass on the growth rate of dairy heifers and on output per acre, with a note on its significance in experimental design

1963 ◽  
Vol 60 (3) ◽  
pp. 371-380 ◽  
Author(s):  
W. H. Broster ◽  
Valerie J. Tuck ◽  
C. C. Balch
Keyword(s):  
Growth Rate ◽  
Weight Gain ◽  
Dry Matter ◽  
Live Weight ◽  
Maximum Output ◽  
Flowering Stage ◽  
Live Weight Gain ◽  
Dairy Heifers ◽  
Low Levels ◽  
Point Level

1. A series of three experiments were performed to examine grass as a food for dairy heifers.2. Indoor feeding resulted in lower intakes of herbage and slower growth but gave greater outputs per acre of animal days and live-weight gain than grazing.3. The maximum consumption and growth rate, obtained on young grass, were 2·84 lb. herbage dry matter per 100 lb. live weight per day and 2·2 lb. live-weight gain per day for grazing stock. The corresponding figures for indoor feeding were 2·49 lb. herbage dry matter per 100 lb. per day and 1·34 lb. live weight gain per day.4. Live-weight gain per day was linearly related to herbage dry matter intake from 1·48 to 2·48 lb./ 100 lb. live weight/day.5. Intake of herbage and growth rate only fell after the herbage came into full flower.6. Increased stocking rate had small effects on growth rate because the animals grazed the paddocks more heavily.7. 2·6–3·0 lb. grass dry matter offered per 100 lb. live weight per day was judged an adequate ration for yearling heifers. This gave growth rates of 1·60 lb./day on herbage up to the flowering stage and a consumption of 88% of the available herbage.8. As an experimental technique zero grazing was found inadequate to replace grazing since it fails to reproduce similar intakes and rates of production. It permitted the reduction of intake to sufficiently low levels that live-weight gain per animal and per acre were reduced.9. The greatest output per acre was found to occur between limits of intake per day of 1·8–2·4 lb. herbage dry matter per 100 lb. live weight. Above the point of maximum output per acre level of feeding had little effect on production per animal and rate of stocking controlled output per acre. Below this point level of feeding controlled production per animal. The case is advanced that these latter levels of feeding are necessary in grassland experiments.

Evaluation of the performance of in-calf dairy heifers either housed or out-wintered on forage brassicas (stubble turnips)

2009 ◽  
Vol 2009 ◽  
pp. 9-9 ◽  
Author(s):  
S P Marsh ◽  
P Billington ◽  
C Brizuela ◽  
S Kirby
Keyword(s):  
Weight Gain ◽  
New Zealand ◽  
Dairy Cows ◽  
Live Weight ◽  
Herd Size ◽  
Comprehensive Review ◽  
Live Weight Gain ◽  
Capital Costs ◽  
Dairy Heifers ◽  
Waste Storage

There is increased interest in out-wintering systems which have the potential to reduce costs and hence increase farm profitability. Out-wintering also offers the potential to increase herd size, within the constraints of Nitrate Vulnerable Zone (NVZ) restrictions without the substantial capital costs associated with waste storage. The majority of out-wintering research has focused on kale and its utilisation by dry dairy and suckler cows where relatively modest performance levels are required. In a comprehensive review on forage brassica for out-wintering stock (MDC 2007) it was stated that “despite the developments in New Zealand in the use of brassica based out-wintering systems for dry dairy cows, there seems to be no detailed studies on the use of these systems for growing (0.7-0.85kg daily live weight gain [DLWG]) dairy heifers”. The objective of this experiment was therefore to evaluate the performance of replacement dairy heifers either housed or out-wintered on forage brassicas (stubble turnips).

Experiments on the nutrition of the dairy heifer: I. Protein requirements of yearling stock

1957 ◽  
Vol 49 (4) ◽  
pp. 435-445 ◽  
Author(s):  
G. L. Bailey ◽  
W. H. Broster
Keyword(s):  
Weight Gain ◽  
Crude Protein ◽  
Live Weight ◽  
Rapid Decline ◽  
Published Data ◽  
Short Term ◽  
Protein Supplements ◽  
Live Weight Gain ◽  
Protein Requirements ◽  
Dairy Heifers

The literature on the protein requirements of young dairy heifers has been discussed and the wide variations noted, both in quantities estimated for particular live-weight ranges and in the suggested trends of requirements with live weight.Short-term trials have been conducted in which the effect of variation in protein intake on rate of live-weight gain of dairy heifers of various ages was studied.The response to increments of protein in the ration was found to be curvilinear with a rapid decline in response above critical levels of intake. This level varied with the live weight of the animal, being 0·8 lb. crude protein at 300 lb. live weight and 1·0 lb. at 400 and 500 lb. when rations based on hay, decorticated ground-nut meal and flaked maize were fed.These levels are somewhat lower than estimates of protein requirements quoted in the literature, though the trend indicated in them agrees with some of the published data.No marked difference was observed between the values of decorticated ground-nut meal and white fish meal as protein supplements. Urea was inferior to decorticated ground-nut meal.The overall depressant effect of straw on rate of live-weight gain is demonstrated and discussed.

A note on the feeding of fodder beet to dairy youngstock

1988 ◽  
Vol 46 (2) ◽  
pp. 297-299 ◽  
Author(s):  
D. J. Roberts ◽  
J. A. Bax
Keyword(s):  
Weight Gain ◽  
Forage Quality ◽  
Live Weight ◽  
Supplementary Food ◽  
Fodder Beet ◽  
Live Weight Gain ◽  
Dairy Heifers ◽  
Agricultural College

Friesian/Holstein dairy heifers require an average daily live-weight gain of about 0·68 kg/day from birth to calving if they are o t reach a target live weight of 540 kg before first calving at 2 years of age. For autumn- born cattle the diet during their second winter is usually based on silage, hay or straw and the level of supplementation depends on the forage quality. When supplementation is necessary the aim should be to feed a least-cost diet. One possible supplementary food is fodder beet which, if grown without the use of purchased fertilizer (West of Scotland Agricultural College, 1984), can be a relatively cheap source of energy and compares favourably with other crops in yield per ha. In the two experiments reported here fodder beet was used for feeding dairy youngstock. The objective of experiment 1 was to evaluate the substitution of barley by fodder beet in straw-based diets. In experiment 2, fodder beet was fed as a partial substitute for silage.

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