Nutrition of beef breeder cows in the dry tropics. 2. Effects of time of weaning and diet quality on breeder performance

2011 ◽  
Vol 51 (6) ◽  
pp. 529 ◽  
Author(s):  
R. M. Dixon ◽  
C. Playford ◽  
D. B. Coates
Keyword(s):  
Diet Quality ◽  
Body Condition Score ◽  
Dry Season ◽  
Near Infrared Reflectance ◽  
Lactating Cows ◽  
Dry Tropics ◽  
Body Reserves ◽  
Wide Range ◽  
Native Pasture ◽  
The Difference

In the seasonally dry tropics the effects of three times of weaning and three nutritional regimes on the changes in liveweight (LW) and body condition score (BCS) of grazing Bos indicus × Bos taurus breeder cows (n = 210) and their calves were examined through an annual cycle, commencing in the early dry season in April 1998. Most of the cows (n = 180) were lactating initially, and were weaned in April (W1), July (W2) or September (W3) to represent the expected early, mid and late dry season. In addition, cows that had not lactated for 11 months before the experiment commenced (NOCALF treatment; n = 30) were examined. The seasonal break occurred in late August, 3.5 months earlier than average for the site. The nutritional regimes consisted of a native pasture (LOW), another native pasture augmented with Stylosanthes spp. legumes (MEDIUM), or this latter pasture supplemented during the dry season with molasses-urea (HIGH). These nutritional regimes were imposed from the commencement of the experiment in April 1998 until February 1999, except that for the HIGH treatment the supplement was fed only during the dry season. Near-infrared reflectance spectroscopy of faeces (F.NIRS) was used to estimate the contents of non-grass, crude protein (CP) and DM digestibility of the diet selected, and also DM intake and metabolisable energy (ME) intake. Diet quality was in accord with the expected seasonal cycle, and was consistently lower (P < 0.05) for the LOW than for the MEDIUM treatment. Concentrations of CP and CP/MJ ME in the diet, and of N in faeces, indicated that the cows grazing the LOW treatment were deficient in rumen degradable protein during the dry season. There was no interaction (P > 0.05) between the nutritional regime and the time of weaning on changes in conceptus-free liveweight (CF.LW) or BCS during the dry season. Weaning increased breeder CF.LW, relative to lactating breeders, by 0.42 kg/day in the early dry season (April–July; the difference between the W1 and W2 treatments), and 0.18 kg/day in the usual mid dry season (July–September; the difference between the W2 and W3 treatments). The NOCALF treatment cows were initially 79 kg heavier than lactating cows, and lost more LW during the dry season. Microbial CP synthesis was 21 and 29% greater (P < 0.05) in lactating than in non-lactating cows in the late dry season and shortly after the seasonal break (August and September), respectively. Calf growth was not affected (P > 0.05) by nutritional regime during the early dry season (April–July), but was lower for the LOW nutritional regime during the usual mid dry season (July–September); this indicated that the LOW nutritional regime cows mobilised sufficient additional body reserves to maintain milk production during the former, but not the latter, interval. All cows that were lactating at the commencement of the experiment gained CF.LW rapidly from September 1998 following the seasonal break. In conclusion, although nutrition affected LW change of both cows and calves, there was a much larger effect of weaning than of the nutrition treatments examined on conservation of body reserves in breeder cows during the dry season. The observation that the effects of weaning on conservation of cow body reserves were similar across a wide range of nutrition is important for management to achieve appropriate targets for breeder cow body reserves.

Nutrition of beef breeder cows in the dry tropics. 1. Effects of nitrogen supplementation and weaning on breeder performance

2011 ◽  
Vol 51 (6) ◽  
pp. 515 ◽  
Author(s):  
R. M. Dixon ◽  
C. Playford ◽  
D. B. Coates
Keyword(s):  
Near Infrared ◽  
Body Condition Score ◽  
Management Strategies ◽  
Bos Indicus ◽  
Dry Season ◽  
The Body ◽  
Wet Season ◽  
Lactating Cows ◽  
Dry Tropics ◽  
Body Reserves

The effects of two dry season management strategies consisting of timing of weaning and/or nitrogen (N) supplementation on the body reserves, nutritional status and reproductive performance were, commencing in the early dry season, examined in Bos indicus × Bos taurus breeder cows (n = 122) grazing native pasture in the seasonally dry tropics. Cows were early-weaned in April in the early dry season or late-weaned in September in the late dry season. The supplement consisted of loose mineral mix which provided on average 14 g N/day, principally as non-protein N. In the early dry season in April 1997 all of the cows had been lactating for 3–5 months, averaged 363 kg (s.d. = 28) conceptus-free liveweight (CF.LW) and 4.7 (s.d. = 0.6) body condition score (9-point scale), and 53% were pregnant. In addition, from April to June 1997 10/26 non-pregnant lactating cows, and 24/31 non-pregnant non-lactating (i.e. early-weaned) cows became pregnant so that 81% of cows were pregnant by June. Predictions of diet from near-infrared spectroscopy of faeces indicated that the forage diet selected during the dry season (April–November) by the cows contained on average 9% (s.d. = 2) non-grass dicotyledonous plants and 4.4% (s.d. = 0.38) crude protein (CP), while DM digestibility was 51.1% (s.d. = 1.3). The diet CP concentration, the ratio of CP to metabolisable energy (ME) in the diet (mean 5.7, s.d. = 0.53, g CP/MJ ME) and faecal N concentration (mean 1.05, s.d. = 0.097, % N) all indicated that unsupplemented cows were deficient in dietary N during the dry season. Microbial CP synthesis in unsupplemented non-lactating cows decreased from 360 to 107 g microbial CP/day, or from 6.5 to 2.4 g microbial CP/MJ ME intake, as the dry season progressed from May to September 1997. Net endogenous N transfer to the rumen of up to 2 g CP/MJ ME apparently occurred from May to August. Microbial CP synthesis was 25% higher (P < 0.001) in lactating than in non-lactating cows. From April to September cow CF.LW was improved by 0.35 kg/day (P < 0.001) by early weaning, and by 0.11 kg/day (P < 0.10) by N supplementation, but there was no interaction (P > 0.10) between these treatments. From April to June 1997 calf LW gain averaged 0.79 kg/day, but from June to September was only 0.10 kg/day in unsupplemented paddocks and 0.13 kg/day in N-supplemented paddocks. Pregnant cows calved from November 1997 to March 1998. During subsequent mating 96% of non-lactating cows, but only 17% of lactating cows became pregnant. During the 1997–98 wet season there was compensatory LW gain of lower CF.LW non-lactating cows but not of lactating cows. In conclusion, weaning early in the dry season had a much greater effect than a non-protein N-based supplement to conserve breeder cow body reserves, and the effects of the two management strategies were additive.

Effect of pasture type and supplementary feeding on the reproductive performance of cattle in the dry tropics of north Queensland

1977 ◽  
Vol 17 (85) ◽  
pp. 197 ◽  
Author(s):  
RG Holroyd ◽  
PJ Allan ◽  
PK O'Rourke
Keyword(s):  
Reproductive Performance ◽  
Dry Season ◽  
Conception Rate ◽  
Wet Season ◽  
Lactating Cows ◽  
Dry Tropics ◽  
Stylosanthes Humilis ◽  
Native Pasture ◽  
Conception Rates ◽  
Townsville Stylo

A study was made over a four year period ( 1970-1 973) on the reproductive performance of cows grazing either native pasture stocked at 1 breeder 4.9 ha-1 or native pasture oversown with Townsville stylo (Stylosanthes humilis) and fertilized with superphosphate, stocked at 1 breeder 2.4 ha-1. Animals were supplemented on each pasture type with combinations of molasses, urea and phosphorus at various times of the year. Mating from September 1 to January 31 resulted in animals lactating during the dry season. At double the stocking rate, lactating cows on fertilized pastures had similar conception rates to those on native pasture. During a prolonged dry season, lactating cows on fertilized pasture had twice the conception rate and fewer required survival feeding. Urea compared with non-urea based supplements produced significant increases in conception rates of cows grazing native pasture especially during a dry year. Calves were born earlier, had shorter intercalving intervals and fewer cows had to be fed a survival ration when urea was available. On fertilized pasture, urea based supplements caused only a marginal increase in conception rate except in a dry year, when there was a significant increase. Over the four years, there was a diminishing response in the conception rate of lactating cows grazing native pasture and supplemented with phosphorus during the wet season compared with the control. On fertilized pasture, there was a variable but non-significant response. The addition of phosphorus either as a wet or dry season supplement to urea caused variable responses on each pasture type, but none differed significantly from that of urea.

Comparison of dry season urea supplements containing salt, sulfur or molasses for steers grazing native pasture in the dry tropics of northern Queensland

1981 ◽  
Vol 21 (112) ◽  
pp. 457 ◽  
Author(s):  
SR McLennan ◽  
PJ Dunster ◽  
PK O'Rourke ◽  
GM Murphy
Keyword(s):  
Compensatory Growth ◽  
Dry Season ◽  
Feeding Period ◽  
Post Feeding ◽  
Dry Tropics ◽  
Native Pasture ◽  
One Year ◽  
Better Than

The effects of feeding dry season supplements of salt and urea (NaU), salt, urea and sulfur (NaUS) and molasses and urea (MU) on the liveweight of steers grazing native pasture in northern Queensland were studied over four years. Liveweight during the feeding period was improved (P < 0.05) by each supplement in three years out of four, with a mean level of response of 49 g/d. The supplements gave similar results in two years while in one year NaU and MU were better than NaUS (P < 0.05) and in another NaUS was better than NaU (P < 0.05). Compensatory growth by unsupplemented animals after the feeding period eroded liveweight responses to supplements in most cases. Blood sulfate level was not affected by treatment, nor was it related to liveweight in either the feeding or post-feeding periods. Mean levels for unsupplemented animals were 15.8 and 21.2 �g/ml for the feeding and post-feeding periods, respectively. Salivary Na:K ratios exceeded 18:1 throughout the year for unsupplemented and NaUS groups, indicating sodium sufficiency.

Liveweight of grazing steers supplemented with molasses, urea and sulfur in northern Queensland

1982 ◽  
Vol 22 (117) ◽  
pp. 252 ◽  
Author(s):  
L Winks ◽  
PK O'Rourke ◽  
SR McLennan
Keyword(s):  
Compensatory Growth ◽  
Cattle Grazing ◽  
Dry Season ◽  
Feeding Period ◽  
Sulfate Sulfur ◽  
Native Pasture ◽  
Dry Seasons ◽  
The Difference ◽  
Native Pastures

Steers grazing native pasture were supplemented with 0, 0.8 or 2.4 g of sulfur/head.d in addition to a molasses (230 or 115 g/head.d) and urea (60 g/head.d) supplement over four dry seasons. The unsupplemented animals lost most or gained least weight during the feeding period in all four years but the difference was significant (P< 0.05) in only two years. Adding sulfur to the molasses and urea tended to give the best results but the effect was not significant (P> 0.05) over the results achieved with feeding only molasses and urea. There was a tendency for liveweight performance to be better with the higher level of molasses, but again differences were not significant. Blood sulfate-sulfur levels during the feeding period increased with the level of sulfur fed but levels were not significantly correlated with liveweight change. Compensatory growth by unsupplemented groups after the feeding period eliminated liveweight advantages of supplemented groups. The results suggest that the level of molasses in a molasses and urea supplement for yearling cattle grazing native pastures on solodic soils during the dry season in northern Queensland can be reduced to 115 g/head.d without adversely affecting liveweight. These results may not apply on sulfur deficient soils and in dry years.

Influence of pasture type and supplement on fertility and liveweight of cows, and progeny growth rate in the dry tropics of northern Queensland

1983 ◽  
Vol 23 (120) ◽  
pp. 4 ◽  
Author(s):  
RG Holroyd ◽  
PK O'Rourke ◽  
MR Clarke ◽  
ID Loxton
Keyword(s):  
Growth Rate ◽  
Reproductive Performance ◽  
Fold Increase ◽  
Dry Season ◽  
Wet Season ◽  
Calf Growth ◽  
Dry Tropics ◽  
Stylosanthes Humilis ◽  
Native Pasture ◽  
One Year

The reproductive performance of cows and growth rate of their calves to weaning was examined over a four-year period (1973-1977). Cows grazed either native pasture stocked at 1cowl4 ha, or native pasture oversown with Townsville stylo (Stylosanthes humilis) and fertilized with superphosphate stocked at 1 cow/2 ha. Animals were supplemented on each pasture type with urea-molasses in the dry season, phosphorus all year round plus urea-molasses in the dry season, or were unsupplemented. Mating was for three months from mid-January. Calving began towards the end of the dry season and cows lactated through the following wet season. Cows grazing fertilized legume pasture had significantly higher conception rates and earlier calving dates in one year only. In all years, foetal and calf losses between pregnancy diagnosis and weaning were lower on native pasture than on fertilized legume pasture. Cows grazing fertilized legume pasture were generally in better body condition and heavier throughout and their calves grew faster to weaning than on native pasture. Fertilized legume pasture produced a 2.4 fold increase over that of native pasture in cow and calf liveweight per unit area (382.7 kg/ha vs 159.8 kg/ha) over the four years. Supplementation did not influence liveweight or reproductive performance of cows or calf growth rate except during the final dry season when non-supplemented cows lost significantly more weight than those supplemented with phosphorus and urea.

The effect of a phosphorus supplement on the performance of steers grazing Townsville stylo-based pasture in north Queensland

1977 ◽  
Vol 17 (86) ◽  
pp. 357 ◽  
Author(s):  
L Winks ◽  
FC Lamberth ◽  
PK O'Rourke
Keyword(s):  
Dry Season ◽  
Wet Season ◽  
Dry Tropics ◽  
Stylosanthes Humilis ◽  
Native Pasture ◽  
Weight Gains ◽  
Annual Grasses ◽  
Townsville Stylo

The effect of phosphorus supplementation on the performance of steeres grazing unfertilized native pasture and Townsville stylo (Stylosanthes humilis) with andwithout superphosphate fertilizer on the subcoastal spear grass region of the dry tropics of north Queensland was studied over a period of 40 months. Liveweight gains in the absence of supplementation on fertilized Townsville stylo pastures were greater than on unfertilized Townsville stylo, where performance was similar to that recorded on untreated native pasture. Phosphorus supplementation increased weight gains during the wet season on both unfertilized Townsville stylo and native pasture but had no significant effect on dry season performance or performance on fertilized Townsville stylo. Fertilized areas became dominated by annual grasses, Digitaria ciliaris and Brachiaria milliiformis, and legume yields were higher on unfertilized than on fertilized areas. Fertilizer improved the quality of available pastures.

The performance of Brahman-Shorthorn and Sahiwal-Shorthorn beef cattle in the dry tropics of northern Queensland. 2. Reproductive rates and liveweights of F2et seq. females

1990 ◽  
Vol 30 (6) ◽  
pp. 727 ◽  
Author(s):  
RG Holroyd ◽  
TA James ◽  
VJ Doogan ◽  
G Fordyce ◽  
R Tyler ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Beef Cattle ◽  
Pregnancy Rate ◽  
Growth Parameters ◽  
Bos Indicus ◽  
Dry Season ◽  
Lactating Cows ◽  
Dry Tropics ◽  
Percentage Unit ◽  
Reproductive Rates

The female reproductive rates and liveweight performance of F2 et seq. generations of 1/2 Brahman (1/2 B), 1/2 Sahiwal (1/2 Sah), 3/4 Brahman (3/4 B) and 3/4 Sahiwal (3/4 Sah) were evaluated in the dry tropics of northern Queensland from 1978 to 1986. The balance of the breed composition was predominantly Shorthorn. A preliminary comparative analysis of F2 and F3 data showed no differences between the filial generations and data were subsequently pooled. Crossbreed differences between groups had a small effect on pregnancy rate and were not a major determinant of fertility compared with age and year effects. Any crossbreed differences were counteracted by inconsistent cross x year effects. For mature cows, 3/4 Sah had significantly (P<0.05) lower weaning rates than other crosses. The percentage unit difference between pregnancy rate and weaning rate was higher in Sahiwal cross than Brahman cross cows (19 v. 9%). In lactating cows, calving dates were an average 10 days later in 3/4 than 1/2 Bos indicus cows. Generally Brahman crosses were heavier than Sahiwal crosses. In the dry season, Brahman crosses were 16, 30, 36 and 43 kg heavier than Sahiwal crosses for 2-year-old heifers and 3-, 4- and 5-9-year-old cows, respectively. There was little difference between 1/2 and 3/4 B. indicus, except in mature cows, where 1/2 Sah were 27 kg heavier (P<0.05) than 3/4 Sah at start of mating. There were pronounced year effects on all of the reproductive and growth parameters of both heifers and lactating cows. Pregnancy rate and mating liveweight were negatively correlated with date of seasonal break of the dry season (r = -0.71 to -0.88, r = -0.84 to -0.98, respectively). Cross x year interactions for pregnancy rate, calving date and mating liveweight were attributed to factors other than the type of year.

Faecal near infrared reflectance spectroscopy estimates of diet quality and responses to nitrogen supplements by cattle grazing Bothriochloa pertusa pastures

2008 ◽  
Vol 48 (7) ◽  
pp. 829 ◽  
Author(s):  
D. B. Coates ◽  
R. M. Dixon
Keyword(s):  
Diet Quality ◽  
Near Infrared ◽  
Reflectance Spectroscopy ◽  
Dry Season ◽  
Infrared Reflectance ◽  
Wet Season ◽  
Near Infrared Reflectance Spectroscopy ◽  
Near Infrared Reflectance ◽  
Infrared Reflectance Spectroscopy ◽  
Grazing Cattle

A grazing experiment in the seasonally dry tropics of north Queensland examined the diet selected and the growth responses of Bos indicus steers to urea supplement over two dry seasons and one wet season, from August 2001 to January 2003. There were two groups of 10 steers (control and urea-supplemented) and each group comprised two age cohorts, A and B, of five steers each with an age difference of ~1 year. In June 2002, cohort A steers were replaced with steers 2 years younger (cohort C). The steers grazed Bothriochloa pertusa pastures on a low fertility Red Chromosol soil. The groups were switched between two adjoining paddocks at fortnightly intervals when they were weighed and faecal samples were collected for faecal near infrared reflectance spectroscopy (F.NIRS) estimates of diet quality and growth rate. Rainfall and diet quality followed the expected seasonal pattern, but the 2001–02 wet season was very short (November–January) with only 65% of the long-term average rainfall. There was no rain during the 2001 dry season (DS-1) from August to mid November, and no effective rain (17 mm) between February and December 2002. Non-grass (i.e. herbaceous dicot plants) made only a small contribution to the diet, averaging 13%. In DS-1 and in the dry season of 2002 (DS-2) diet crude protein (CP) averaged 2.5% and 2.9%, and DMD/CP (ratio of dry matter digestibility to CP) averaged 18.6 and 17.1, respectively. Liveweight (LW) loss in control steers during DS-1 averaged 32 kg. Urea supplement reduced LW loss by 18 kg (P < 0.001), but most of the benefit was lost during the following growing season. During the extended dry period in 2002, average LW losses of control steers were 85 and 47 kg in the older and younger cohorts, respectively, and supplementation with urea reduced weight losses by 53 and 31 kg, respectively (P < 0.001). F.NIRS predicted the cumulative LW of the unsupplemented steers in cohorts A and B with acceptable accuracy, the difference between the observed and predicted final LW being 6 kg for cohort A after 10 months, 12 kg for cohort B after 17 months, and 27 kg for cohort C after 7 months. The results demonstrated that F.NIRS can be effectively used to monitor dietary CP and DMD levels in grazing cattle, to help develop an understanding of cattle responses to urea supplement relative to the quality of the basal forage diet, and to provide useful decision support information for the nutritional management of grazing cattle.

The performance of Brahman-Shorthorn and Sahiwal-Shorthorn beef cattle in the dry tropics of northern Queensland. 1. Reproductive rates and liveweights of F1 and backcross females

1990 ◽  
Vol 30 (6) ◽  
pp. 717 ◽  
Author(s):  
RG Holroyd ◽  
TA James ◽  
VJ Doogan ◽  
G Fordyce ◽  
PK O'Rourke
Keyword(s):  
Beef Cattle ◽  
Bos Indicus ◽  
Research Station ◽  
Data Sets ◽  
Lactating Cows ◽  
Dry Tropics ◽  
Filial Generation ◽  
Sahiwal Cows ◽  
The Difference ◽  
Reproductive Rates

A breeding program was established at Swan's Lagoon Beef Cattle Research Station in the dry tropics of northern Queensland to evaluate the productivity of cattle which were genotypically at least one-half Bos indicus. Brahman or Sahiwal bulls were initially mated to B. taurus cows (predominantly Shorthorn) to produce the first filial generation (F1 1/2 Brahman and F1 1/2 Sahiwal). First backcross 314 Brahman and first backcross 314 Sahiwal were derived from crossing F1 1/2 Brahman or F1 1/2 Sahiwal cows to their respective sire breeds. This paper reports on the female reproductive rates and liveweight performance in 2 data sets: 1972-79, F1 1/2 Brahman v. F1 1/2 Sahiwal; 1975-83, first backcross 3/4 Brahman v. first backcross 3/4 Sahiwal. In both data sets, significant differences in fertility (pregnancy rate and calving date) between F1 or first backcross groups were infrequent, and where differences did occur, they were often inconsistent due to cross x year interactions. The difference between weaning rates and pregnancy rates (representing foetal and calf wastage) was 5 percentage units higher in Sahiwal crosses than Brahman crosses for lactating cows Year effects significantly (P<0.05) influencd both fertility and liveweight, demonstrating the extent of seasonal influences on cattle production in the dry tropics. Generally Brahman-cross cows were heavier throughout than their Sahiwal counterparts. Among lactating cows, F1 1/2 Brahman were 21 kg heavier at start of mating than F1 1/2 Sahiwal, while first backcross 3/4 Brahman were 29 kg heavier than first backcross 3/4 Sahiwal.

Intake of lick block supplements by cattle grazing native monsoonal tallgrass pastures in the Northern Territory.

1990 ◽  
Vol 12 (1) ◽  
pp. 7 ◽  
Author(s):  
AR Eggington ◽  
TH McCosker ◽  
CA Graham
Keyword(s):  
Northern Territory ◽  
Dry Season ◽  
Wet Season ◽  
Mineral Supplement ◽  
Protein Nitrogen ◽  
Lactating Cows ◽  
Native Pasture ◽  
Pure Salt ◽  
Dry Seasons ◽  
True Protein

Four supplementation treatments to investigate wet seasons responses were imposed on eight Brahman/Shorthom cross herds totalling 870 animals of all classes (cows and calves, bulls, heifers and steers). They grazed 12,300 ha of native pasture in the Darwin district of the Northern Territory. The treatments were: (i) control (no wet season supplement), (ii) Mineral (Ultraphos - supplementation with 13 minerals during the wet season), (iii) +Protein (Ultrapro-50 - the same 13 minerals plus non-protein nitrogen (WN) and true protein over the wet season), and (iv) Strategic (strategic use of salt, mineral and hTN supplements over the early wet, mid wet and late wet seasons respectively). All treatments received an hTN plus mineral supplement (Uramol) during the dry season. Supplement intakes by the herds were measured monthly for three years. Intake of Salt, Ultraphos and Ultrapro-50 supplements averaged 43, 124 and 149 g/animal/day respectively during the three wet seasons. Losses of the molasses-based block formulations due to rain were small (7%) during the wet season. However, up to one third of each pure salt block was eroded. Intake of Uramol during the three dry seasons averaged 182 g/animal/day across all herds. No urea toxicity problems were noticed over the three years of the supplement programme, despite high intakes during the dry season. All animals consumed some supplement. However, levels of supplement intake: (i) increased with the seasonal decrease in native pasture quality, (ii) decreased with an increase in proportion of paddock burnt, (iii) varied between animal classes, with lactating cows consuming 64% more supplement than non-lactating cows in two of the three years, and (iv) varied between individuals within classes. Individual intake varied widely (from 10 to 835 glanirnallday for lactating cows) with no significant correlation between individual intake and the pregnancy rate or average daily liveweight gain.

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