scholarly journals Milk yield and composition in first-cross and backcross beef cows

1994 ◽  
Vol 74 (2) ◽  
pp. 209-216
Author(s):  
R. M. McKay ◽  
G. W. Rahnefeld ◽  
G. M. Weiss ◽  
H. T. Fredeen ◽  
J. A. Newman ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Key Words ◽  
Milk Yield ◽  
Beef Cows ◽  
Milk Composition ◽  
Weight Changes ◽  
Pasture Management ◽  
Semi Arid

Milk yield and composition from three distinct milkings (spring, August, and fall) were evaluated on first-cross and backcross cows maintained under two contrasting environments. The dam crosses at Brandon (semi-intensive cultivated pasture management) were HA, SN, CN, ACA, CCA, ASA, SSA, HCH, CCH, HSH, SSH, NCN, CCN, NSN, and SSN with H = Hereford, A = Angus, N = Shorthorn, C = Charolais, S = Simmental and a SSA cross was 3/4 Simmental-1/4 Angus. At Manyberries (semi-arid and short grass rangeland) the dam crosses were HA, SN, ASA, SSA, HSH SSH, NSN, and SSN. All cows were bred to Limousin bulls and milkings took place from 1981 to 1985, inclusive. Definitive differences among the backcrosses and between the backcrosses and the F1 crosses were not present. Possible genotupe × environment interactins were observed for milk yield and composition. Milk yield and composition were affected by age of cow and influenced cow and calf weight changes. Key words: Beef cattle, crossbreeding, backcrosses, milk yield, milk composition

scholarly journals 29 The effect of fleshing ability on cow and calf performance

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 22-22
Author(s):  
Amanda Holder ◽  
Aksel Wiseman ◽  
Adam McGee ◽  
David Lalman ◽  
Claire Andresen
Keyword(s):  
Body Weight ◽  
Milk Yield ◽  
Body Condition ◽  
Body Condition Score ◽  
Beef Cows ◽  
Milk Composition ◽  
Weight Changes ◽  
Beef Cow ◽  
Randomized Design ◽  
Condition Score

Abstract Several factors influence the overall maintenance requirements of a mature beef cow including age, gain, lactation, pregnancy, and fleshing ability. However, limited research is available to distinguish what sets a hard-fleshing cow apart from an easy-fleshing cow. Cows that are hard-fleshing maintain a lower body condition score (BCS) throughout the year compared to easy-fleshing counterparts. The objectives of this experiment are to determine the differences in characteristics and production between cows classified as easy- vs. hard- fleshing. Characteristics of interest include feed intake, milk yield, milk composition, body weight changes, BCS changes, and other body composition measurements, as well as calf weaning weight. In this study, 24 spring-calving, mature Angus beef cows were classified as either hard-fleshing or easy-fleshing based on BCS and ultrasound measurements for back fat and rump fat. The intake study took place during the second trimester, cows were assigned to an easy- or hard-fleshing pen based on treatment where they remained for the entirety of the 45-day intake study. Each treatment was replicated three times in a completely randomized design. Milk data collection began one month after calving with monthly milkings from May-August. There were no differences (P = 0.9) in DMI, although hard-fleshing cows had greater DMI calculated on a metabolic body weight basis (P = 0.05). There was a trend (P = 0.12) for hard-fleshing cows to wean heavier calves, although there was no difference in mean milk yield (P = 0.44). Body condition score was positively correlated with protein and carbohydrate content of milk with easy-fleshing cows having greater contents of both (P = 0.02 and P < 0.01, respectively). Overall, an increase in BCS without an increase in DMI may be beneficial from a reproductive standpoint, though more research in this area is needed.

scholarly journals 178 The Effect of Fleshing Ability on Cow and Calf Performance

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 62-62
Author(s):  
Amanda Holder ◽  
Aksel Wiseman ◽  
Adam McGee ◽  
David Lalman ◽  
Claire Andresen
Keyword(s):  
Body Weight ◽  
Milk Yield ◽  
Body Condition ◽  
Body Condition Score ◽  
Beef Cows ◽  
Milk Composition ◽  
Weight Changes ◽  
Beef Cow ◽  
Randomized Design ◽  
Condition Score

Abstract Several factors influence the overall maintenance requirements of a mature beef cow including age, gain, lactation, pregnancy, and fleshing ability. However, limited research is available to distinguish what sets a hard-fleshing cow apart from an easy-fleshing cow. Cows that are hard-fleshing maintain a lower body condition score (BCS) throughout the year compared to easy-fleshing counterparts. The objectives of this experiment are to determine the differences in characteristics and production between cows classified as easy- vs. hard- fleshing. Characteristics of interest include feed intake, milk yield, milk composition, body weight changes, BCS changes, and other body composition measurements, as well as calf weaning weight. In this study, 24 spring-calving, mature Angus beef cows were classified as either hard-fleshing or easy-fleshing based on BCS and ultrasound measurements for back fat and rump fat. The intake study took place during the second trimester, cows were assigned to an easy- or hard-fleshing pen based on treatment where they remained for the entirety of the 45-day intake study. Each treatment was replicated three times in a completely randomized design. Milk data collection began one month after calving with monthly milkings from May—August. There were no differences (P = 0.9) in DMI, although hard-fleshing cows had greater DMI calculated on a metabolic body weight basis (P = 0.05). There was a trend (P = 0.12) for hard-fleshing cows to wean heavier calves, although there was no difference in mean milk yield (P = 0.44). Body condition score was positively correlated with protein and carbohydrate content of milk with easy-fleshing cows having greater contents of both (P = 0.02 and P < 0.01, respectively). Overall, an increase in BCS without an increase in DMI may be beneficial from a reproductive standpoint, though more research in this area is needed.

scholarly journals 127 Predicting Dry Matter Intake of Gestating and Lactating Beef Cows

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 58-58
Author(s):  
Megan A Gross ◽  
Claire Andresen ◽  
Amanda Holder ◽  
Alexi Moehlenpah ◽  
Carla Goad ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Milk Yield ◽  
Feed Intake ◽  
Beef Cows ◽  
Multiple Regression Equation ◽  
Validation Data ◽  
Data Set ◽  
Lactating Cows ◽  
Downward Bias ◽  
Protein Supply

Abstract In 1996, the NASEM beef cattle committee developed and published an equation to estimate cow feed intake using results from studies conducted or published between 1979 and 1993 (Nutrient Requirements of Beef Cattle). The same equation was recommended for use in the most recent version of this publication (2016). The equation is sensitive to cow weight, diet digestibility and milk yield. Our objective was to validate the accuracy of this equation using more recent published and unpublished data. Criteria for inclusion in the validation data set included projects conducted or published within the last ten years, direct measurement of forage intake, adequate protein supply, and pen feeding (no tie stall or metabolism crate data). The validation data set included 29 treatment means for gestating cows and 26 treatment means for lactating cows. Means for the gestating cow data set was 11.4 ± 1.9 kg DMI, 599 ± 77 kg BW, 1.24 ± 0.14 Mcal/kg NEm per kg of feed and lactating cow data set was 14.5 ± 2.0 kg DMI, 532 ± 116.3 kg BW, and 1.26 ± 0.24 Mcal NEm per kg feed, respectively. Non intercept models were used to determine equation accuracy in predicting validation data set DMI. The slope for linear bias in the NASEM gestation equation did not differ from 1 (P = 0.07) with a 3.5% positive bias. However, when the NASEM equation was used to predict DMI in lactating cows, the slope for linear bias significantly differed from 1 (P &lt; 0.001) with a downward bias of 13.7%. Therefore, a new multiple regression equation was developed from the validation data set: DMI= (-4.336 + (0.086427 (BW^.75) + 0.3 (Milk yield)+6.005785(NEm)), (R-squared=0.84). The NASEM equation for gestating beef cows was reasonably accurate while the lactation equation underestimated feed intake.

scholarly journals Endocrine control of energy metabolism in the cow: the effect on milk yield and levels of some blood constituents of injecting growth hormone and growth hormone fragments

1980 ◽  
Vol 43 (1) ◽  
pp. 179-188 ◽  
Author(s):  
J. A. Bines ◽  
I. C. Hart ◽  
S. V. Morant
Keyword(s):  
Growth Hormone ◽  
Mammary Gland ◽  
Energy Metabolism ◽  
Dairy Cows ◽  
Milk Yield ◽  
Beef Cows ◽  
Milk Composition ◽  
Endocrine Control ◽  
N Retention ◽  
Blood Constituents

1. Circulating concentrations of some hormones and metabolites and nitrogen balance were measured in lactating beef and dairy cows given daily injections of growth hormone (GH) and were compared to values before injection. Changes in milk yield and composition were recorded in these cows and in additional cows injected with GH fragments.2. GH, but not GH fragments, raised milk yield while milk composition did not change. GH injection caused a large, rapid increase in the level of the hormone in blood and slower, smaller increases in the concentrations of insulin, prolactin and thyroxine. Blood metabolite levels were unaltered except for a rise in glucose concentration in beef cows during GH injection and a fall in 3-hydroxybutyrate concentration in the same cows after the injections ceased. An increase in N output in milk was partly balanced by a reduction in urinary N so that N retention did not change significantly.3. GH caused a reduction in food intake in the beef cows.4. The results are discussed in relation to control of partition of nutrients in the lactating cow, where GH is considered to play an important role. It was concluded that this role may be in increasing the supply of energy metabolites for milk synthesis, rather than a direct effect on the activity of the mammary gland.

scholarly journals The effects of gonadotrophin releasing hormone in prostaglandin F2α-based timed insemination programs for beef cattle

2001 ◽  
Vol 81 (3) ◽  
pp. 335-343 ◽  
Author(s):  
J. A. Small ◽  
J. D. Ambrose ◽  
W. P. McCaughey ◽  
D. R. Ward ◽  
W. D. Sutherland ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Key Words ◽  
Prostaglandin F2α ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Progesterone Concentration ◽  
Gender Ratio ◽  
Plasma Progesterone ◽  
Estrous Synchronization ◽  
Gonadotrophin Releasing Hormone

Trials were conducted in the spring (May; n = 324) and fall (October; n = 132) with crossbred continental-type beef cows assigned on the basis of parity and postpartum interval to one of three timed-AI treatments and one of two post-AI treatments. The timed-AI treatments were: (DPG) double (14 d apart) PGF2α (Lutalyse®) and AI (day = 0) 72 h after the second PGF2α (day –3); (OVS) Ovsynch® with the second GnRH (Factrel®) at 48 h and AI at 66 h; and (BRC) the same as OVS except that the second GnRH was given at the time of AI. Half of the cows within each treatment were given GnRH on day 14. Plasma progesterone concentrations were determined for the day of the first injection and on days –3, 0, 14, and 21. Timed-AI pregnancy was diagnosed by ultrasonography at day 42 and confirmed at calving. For DPG, OVS and BRC, PGF2α responder rates were 75.9, 51.4 and 71.3%, respectively, in spring (P < 0.05) and 70.4, 70.4 and 59.1% in fall (P > 0.05), and AI pregnancy rates were 28.7, 44.9 and 44.4% in spring (P< 0.05) and 25.0, 40.9 and 43.2% in fall (P > 0.05). Post-AI GnRH had no significant effect on pregnancy or conception rates or day 21 progesterone. The use of GnRH in the PGF2α based timed-AI program improved pregnancy rates and the BRC treatment was as effective as OVS. Neither postpartum interval nor initial progesterone concentration influenced (P >0.05) the effect of GnRH on AI pregnancy rate, and GnRH had no effect (P > 0.05) on twinning rate or gender ratio. Key words: Beef cows, estrous synchronization, pregnancy, timed-AI, progesterone

Slaughter and carcass traits of calves from first-cross and reciprocal back-cross beef cows

1994 ◽  
Vol 74 (4) ◽  
pp. 621-632 ◽  
Author(s):  
J. A. Newman ◽  
A. K. W. Tong ◽  
S. D. M. Jones ◽  
G. W. Rahnefeld ◽  
D. R. C. Bailey ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Key Words ◽  
Carcass Traits ◽  
Beef Cows ◽  
Carcass Composition ◽  
Carcass Weight ◽  
Back Cross ◽  
Breed Type ◽  
Bone Content

Breed-of-dam and sex-of-calf effects are reported based on observation of 2007 heifer and steer carcasses. The carcasses were derived from Limousin-sired calves born to dams representing 15 F1 and backcross genotypes reared at two locations over a period of 5 yr. The calves represented Hereford × Angus, Charolais × Shorthorn, Simmental × Shorthorn and all backcross combinations involving Charolais or Simmental with Hereford, Angus or Shorthorn. Carcass traits were analyzed on an unadjusted, a constant hot-carcass weight, and a constant rib-fat depth basis. The slaughter criteria dictated that steers were heavier at slaughter than heifers. They also exhibited higher dressing yield, greater longissimus thoracis area, and lower fat depth. Charolais and Simmental breeding was associated with less rib fat depth, greater longissimus thoracis area, a higher proportion of preferred cuts, less dissectible fat, more bone and more lean in the preferred cuts than British beef breeding. Within the European (Charolais and Simmental) and British beef (Hereford, Angus and Shorthorn) breed groups, breed effects were smaller, but for carcass composition traits they were frequently significant. When compared with Simmental, Charolais breeding tended to be associated with less marbling, less rib fat depth, less dissectible fat and more lean in the preferred cuts. Among the British beef breeds, Hereford was associated with the highest proportion of preferred cuts, Shorthorn with the lowest rib fat depth — but the highest dissectible fat — and Angus with the most marbling, the greatest longissimus thoracis area and the lowest bone content. This research has demonstrated that breed effects for carcass composition traits tend to be additive and that a significant effect may be associated with substitution of as little as one-eighth of the breed composition. Key words: Beef cattle, slaughter traits, carcass traits, breed type, crossbred dam, backcross dam

Response of autumn calving suckler cows to the feed additive Avotan

1994 ◽  
Vol 1994 ◽  
pp. 96-96
Author(s):  
B G Lowman ◽  
N A Scott ◽  
A J Mudd
Keyword(s):  
Beef Cattle ◽  
Dairy Cows ◽  
Feed Efficiency ◽  
Beef Cows ◽  
Milk Composition ◽  
Feed Additive ◽  
Glycopeptide Antibiotic ◽  
Gram Positive Bacteria ◽  
Cattle Systems ◽  
Product Licence

Avotan is a feed additive commonly used in finishing and growing beef cattle systems to improve feed efficiency - producing higher liveweight gains on similar feed intakes. The active ingredient is a glycopeptide antibiotic (Avoparcin, Cyanamid UK) active against Gram - positive bacteria. In 1991 Avotan received an EEC product licence for use in dairy cows. Extensive trials showed that on average Avotan gave a 5% response in milk yield on the same level of feed intake with no effect on milk composition. No information was however available on the use of Avotan in beef cows. This trial reports on the response of autumn calving suckler cows to Avotan in terms of both cow and calf liveweight change and cow fertility.

scholarly journals Management strategies to improve cow-calf productivity on meadow bromegrass pastures

2004 ◽  
Vol 84 (3) ◽  
pp. 529-535 ◽  
Author(s):  
J. C. Kopp ◽  
K. M. Wittenberg ◽  
W. P. McCaughey
Keyword(s):  
Milk Yield ◽  
Average Daily Gain ◽  
Management Strategies ◽  
Beef Cows ◽  
Fertilizer Application ◽  
Milk Composition ◽  
Low Protein ◽  
Cow Calf ◽  
Meadow Bromegrass ◽  
The Cost

A 4-yr experiment was conducted to determine the effects of fertilization, incorporation of a legume and use of the Rumensin®-controlled release capsules (CRC) on productivity of cow-calf pairs grazing meadow bromegrass (Bromus biebersteinii Roem & Schult.). Four pasture treatments (T), alfalfa-grass fertilized (AF), alfalfa-grass unfertilized (AU), grass-only fertilized (GF) and grass-only unfertilized (GU), each replicated twice were compared. The eight 3.7-ha pastures were split into five equally sized paddocks and rotationally stocked with first-calf cows in 1995 and 1998, and with mature cows in 1996 and 1997. Half of the cows on each pasture received a Rumensin® CRC 1 wk prior to the start of the pasture season. Cow DMI was not influenced by fertilization or incorporation of a legume. However, cows treated with monensin consumed less (2.3% BW) compared to the control cows (2.5% BW, P < 0.05). Incorporation of alfalfa and fertilization improved pasture quality and resulted in higher CP and lower NDF content in forage selected by the animals. Monensin improved (P < 0.05) cow average daily gain (ADG, kg d-1) when grazing unfertilized grass and alfalfa-grass pastures, but did not influence gains of cows on fertilized pastures. Fertilizer application, legume incorporation and monensin administration did not affect milk yield or milk composition. Despite differences in diet quality, calf ADG for AU, AF, and GF were similar. However, calf ADG was lower for GU pastures (P < 0.05), probably as a result of the high fibre and low protein content of this pasture treatment. Both incorporation of alfalfa and fertilization increased total calf gain (kg ha-1); the greatest improvement was associated with fertilization. There were, however, economic advantages to legume incorporation, as the cost of the additional gain for GF and AF pastures averaged $1.08 and $0.79 kg-1 ha-1, and no extra costs were incurred for AU. Key words: Beef cows, calves, milk yield, pasture productivity, alfalfa, meadow bromegrass

The composition of body-weight changes in underfed lactating beef cows

1981 ◽  
Vol 32 (1) ◽  
pp. 95-103 ◽  
Author(s):  
P. R. N. Chigaru ◽  
J. H. Topps
Keyword(s):  
Body Weight ◽  
Milk Production ◽  
Milk Yield ◽  
Deuterium Oxide ◽  
Tritiated Water ◽  
Body Weight Loss ◽  
Beef Cows ◽  
Weight Changes ◽  
Weight Losses ◽  
Unit Body Weight

ABSTRACTThe effects of reducing the feed intake of 12 winter-calving (Hereford male × British Friesian female) cows to the maintenance level for 6 weeks from week 10 of lactation were investigated during two consecutive lactation periods. Initially, six cows were in their first and six in their third lactation. In each year the period of ‘underfeeding’ was preceded by a period of ‘adequate feeding’ (maintenance plus milk production requirements) and succeeded by a period of ‘refeeding’ (2 × maintenance). Changes in body water, estimated by the dilution of tritiated water and deuterium oxide at the end of each feeding period, were used to calculate changes in body tissue. Milk yield during the period of ‘adequate feeding’ indicated that individual cows differed markedly in milk production potential. During ‘underfeeding’ milk yield was related to lactation potential. Cows of higher potential tended to maintain higher yields than those of lower potential but in doing so they incurred higher body-weight losses. The ‘refeeding’ period did not result in significant increases in milk yield. The weight losses during ‘underfeeding’ consisted mainly of fat but some cows apparently mobilized relatively large amounts of protein. More fat per unit body weight loss was mobilized by the heifers than by the cows, which, on the other hand appeared to mobilize relatively more protein. On ‘refeeding’, only a few cows were able to achieve complete tissue repletion.

scholarly journals FACTORS INFLUENCING MILK YIELD OF BEEF CATTLE

1971 ◽  
Vol 51 (3) ◽  
pp. 551-560 ◽  
Author(s):  
H. B. JEFFERY ◽  
R. T. BERG ◽  
R. T. HARDIN
Keyword(s):  
Weight Loss ◽  
Weight Gain ◽  
Birth Weight ◽  
Beef Cattle ◽  
Milk Yield ◽  
Average Daily Gain ◽  
Negative Relationship ◽  
Beef Cows ◽  
Positive Influence ◽  
Hybrid Breeding

The joint and separate effects of several cow-calf variables on milk yield were studied with 176 and 201 beef cows from the University of Alberta beef breeding herd for 1966 and 1967, respectively. The dams consisted of Hereford, Aberdeen Angus, Galloway and hybrid breeding. Independent variables considered were: breed, post-calving weight, winter weight loss, summer weight gain and age of dam, and weaning age, sex and birth weight of calf. Total variance of milk yield explained by all variables together was only 40 and 52% for 1966 and 1967, respectively. Breed and age differences of dam accounted for 82 and 87% of explained variance in milk yield respectively for 1966 and 1967. Holding cow age constant, post-calving weight of cow explained 0.0 and 8.5% additional variance in milk yield for 1966 and 1967, respectively. Summer weight gain of cow was negatively associated with milk yield. Winter weight loss of cow had little influence on milk yield. There appeared to be a negative relationship between early parturition and milk yield. The effect of calf sex on milk yield of dam was inconsistent; cows suckling male calves vs. female calves yielded more milk in 1966 but less in 1967. Birth weight of calf had a small positive influence on milk yield of dam. Association between milk yield of dam and preweaning performance of progeny was high. It appeared that the quickest way to improve milk yield in beef cattle would be the introduction of breeds noted for high milk yield and by indirect selection, through selection of dams with progeny that have high average daily gain to weaning.

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