Spinosad application is a useful addition to a tick-control program, say researchers at USDA-ARS Knipling-Bushland U.S. Livestock Insects Research Laboratory in Kerrville, TX.

A study was conducted to evaluate the effect of repeated treatments of the insecticide, spinosad, applied as a whole-body spray at three-week intervals to cattle infested with Boophilus annulatus. The purpose was to determine if eradication of a field population of ticks could be achieved.

Using two different spinosad concentrations (0.05 and 0.08% active ingredient), results show that at one week following a given treatment, control remained relatively good, and treated cattle had significantly fewer ticks than untreated cattle on 76.9% of counting intervals.

Level of control declined substantially by two weeks following a given treatment. At three weeks, treated cattle had significantly fewer ticks than untreated cattle on only 61.2% of the counting intervals. Though some females reached repletion, the activity of spinosad was still high enough to at least protect treated cattle from being heavily re-infested.

While neither concentration resulted in total eradication, the high spinosad concentration was most effective.

Tick counts obtained from sentinel cattle placed with untreated and treated cattle at various intervals throughout the study showed the tick population in the pasture where cattle were treated declined through time. Meanwhile, tick counts obtained from sentinel cattle held with untreated cattle increased through time.

Researchers concluded that a spinosad-treatment regime wouldn't be suitable in an eradication program, but might be useful in a control program.
R.B. Davey et al, Southwestern Entomologist 2005, 30(4): 245-255

Whole cottonseed, or cottonseed-derived products, can replace feedstuffs commonly used in cattle-finishing diets without adversely affecting performance or carcass characteristics, Oklahoma State University (OSU) researchers say.

Feeding management of finishing cattle is efficiency driven, and cost of gain is the primary target. One of confinement feeding's biggest costs is purchasing and handling roughage, an expensive energy source compared with cereal grains.

Whole cottonseed and associated cottonseed products provide fiber, fat and protein in one package. One potential problem with feeding cottonseed is gossypol toxicity, but ruminants are able to detoxify large amounts of gossypol within the rumen.

Diets containing up to 25% (dry matter basis) whole cottonseed have been reported safe for consumption. But little research has been done regarding the effects of feeding processed cottonseed products on finishing performance and carcass characteristics of beef cattle.

OSU researchers conducted three experiments:

  • In experiment 1, a total of 120 beef steers were fed steamed-flaked, corn-based finishing diets with 10% basal roughage and whole cottonseed or individual cottonseed components (hull, meal and oil). Over the feeding period, average daily gain (ADG) didn't differ, but dry matter intake (DMI) increased and gain-to-feed ratio (G:F) decreased for steers fed cottonseed diet compared to the control diet. The control diet consisted of a conventional 90% concentrate steam-flaked corn-based finishing diet.

    Dressing percentage and marbling scores of steers fed the cottonseed diets were less than for steers fed the control diet.

  • In the second experiment, 150 beef steers were used to determine the effects of whole or pelleted cottonseed on performance and carcass characteristics.

    Cattle were fed steamed-flaked corn-based finishing diets in which whole or pelleted cottonseed replaced all dietary roughage, supplemental fat and supplemental natural protein of the control diet. During the feeding period, steers fed cottonseed diets had a lower DMI and greater G:F than steers fed the control. Carcass characteristics did not differ.

  • In experiment 3, 150 beef heifers were used to determine the effects of pelleted cottonseed or delinted whole cottonseed on performance and reproduction. Heifers were fed rolled, corn-based finishing diets, with cottonseed replacing dietary roughage, supplemental fat and part of the supplemental natural protein of the control diet.

Over the entire feeding period, ADG, DMI and G:F of heifers fed the control diet didn't differ from heifers on cottonseed diets, nor did carcass characteristics.
J.J. Cranston et al, Journal of Animal Science 2006, 84:2186-2199